This specification is provided under the RF
on Limited Terms Mode of the OASIS IPR Policy,
the mode chosen when the Technical Committee was established. For information
on whether any patents have been disclosed that may be essential to
implementing this specification, and any offers of patent licensing terms,
please refer to the Intellectual Property Rights section of the TC’s web page (https://www.oasis-open.org/committees/tosca/ipr.php).
The TOSCA Simple Profile in YAML specifies a rendering of
TOSCA which aims to provide a more accessible syntax as well as a more concise
and incremental expressiveness of the TOSCA DSL in order to minimize the
learning curve and speed the adoption of the use of TOSCA to portably describe
cloud applications.
This proposal describes a YAML rendering for TOSCA. YAML is
a human friendly data serialization standard (http://yaml.org/)
with a syntax much easier to read and edit than XML. As there are a number of
DSLs encoded in YAML, a YAML encoding of the TOSCA DSL makes TOSCA more
accessible by these communities.
This proposal prescribes an isomorphic rendering in YAML of
a subset of the TOSCA v1.0 XML specification ensuring that TOSCA semantics are
preserved and can be transformed from XML to YAML or from YAML to XML.
Additionally, in order to streamline the expression of TOSCA semantics, the
YAML rendering is sought to be more concise and compact through the use of the
YAML syntax.
The TOSCA metamodel uses the
concept of service templates that describe cloud workloads as a topology
template, which is a graph of node templates modeling the components a workload
is made up of and of relationship templates modeling the relations between
those components. TOSCA further provides a type system of node types to
describe the possible building blocks for constructing a service template, as
well as relationship types to describe possible kinds of relations. Both node
and relationship types may define lifecycle operations to implement the
behavior an orchestration engine can invoke when instantiating a service
template. For example, a node type for some software product might provide a
‘create’ operation to handle the creation of an instance of a component at
runtime, or a ‘start’ or ‘stop’ operation to handle a start or stop event
triggered by an orchestration engine. Those lifecycle operations are backed by
implementation artifacts such as scripts or Chef recipes that implement the
actual behavior.
An orchestration engine
processing a TOSCA service template uses the mentioned lifecycle operations to
instantiate single components at runtime, and it uses the relationship between
components to derive the order of component instantiation. For example, during
the instantiation of a two-tier application that includes a web application
that depends on a database, an orchestration engine would first invoke the
‘create’ operation on the database component to install and configure the
database, and it would then invoke the ‘create’ operation of the web
application to install and configure the application (which includes
configuration of the database connection).
The TOSCA simple profile
assumes a number of base types (node types and relationship types) to be
supported by each compliant environment such as a ‘Compute’ node type, a
‘Network’ node type or a generic ‘Database’ node type. Furthermore, it is
envisioned that a large number of additional types for use in service templates
will be defined by a community over time. Therefore, template authors in many
cases will not have to define types themselves but can simply start writing
service templates that use existing types. In addition, the simple profile will
provide means for easily customizing and extending existing types, for example
by providing a customized ‘create’ script for some software.
Different kinds of processors
and artifacts qualify as implementations of the TOSCA simple profile. Those
that this specification is explicitly mentioning or referring to fall into the
following categories:
·
TOSCA YAML service template (or “service template”): A YAML
document artifact containing a (TOSCA) topology template (see sections 3.9
“Service template definition”) that represents a Cloud application. (see
sections 3.8 “Topology template definition”)
·
TOSCA processor (or “processor”): An engine or tool that is
capable of parsing and interpreting a TOSCA service template for a particular
purpose. For example, the purpose could be validation, translation or visual
rendering.
·
TOSCA orchestrator (also called orchestration engine): A TOSCA processor
that interprets a TOSCA service template or a TOSCA CSAR in order to instantiate,
deploy, and manage the described application in a Cloud.
·
TOSCA generator: A tool that generates a TOSCA service template.
An example of generator is a modeling tool capable of generating or editing a
TOSCA service template (often such a tool would also be a TOSCA processor).
·
TOSCA archive (or TOSCA Cloud Service Archive, or “CSAR”): a package
artifact that contains a TOSCA service template and other artifacts usable by a
TOSCA orchestrator to deploy an application.
The above list is not
exclusive. The above definitions should be understood as referring to and
implementing the TOSCA simple profile as described in this document
(abbreviated here as “TOSCA” for simplicity).
The TOSCA language introduces a YAML grammar for describing service
templates by means of Topology Templates and towards enablement of interaction
with a TOSCA instance model perhaps by external APIs or plans. The primary focus
currently is on design time aspects, i.e. the description of services to ensure
their exchange between Cloud providers, TOSCA Orchestrators and tooling.
The language provides an extension mechanism that can be
used to extend the definitions with additional vendor-specific or
domain-specific information.
The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”,
“SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” in
this document are to be interpreted as described in [RFC2119].
·
Sections that are titled “Example” throughout this document are
considered non-normative.
·
A feature marked as deprecated
in a particular version will be removed in the subsequent version of the
specification.
|
Reference Tag
|
Description
|
|
[RFC2119]
|
S. Bradner, Key words for use in RFCs to Indicate Requirement
Levels, http://www.ietf.org/rfc/rfc2119.txt,
IETF RFC 2119, March 1997.
|
|
[TOSCA-1.0]
|
Topology and Orchestration Topology and Orchestration
Specification for Cloud Applications (TOSCA) Version 1.0, an OASIS Standard,
25 November 2013, http://docs.oasis-open.org/tosca/TOSCA/v1.0/os/TOSCA-v1.0-os.pdf
|
|
[YAML-1.2]
|
YAML, Version 1.2, 3rd Edition, Patched at 2009-10-01, Oren
Ben-Kiki, Clark Evans, Ingy döt Net http://www.yaml.org/spec/1.2/spec.html
|
|
[YAML-TS-1.1]
|
Timestamp Language-Independent Type for YAML Version 1.1,
Working Draft 2005-01-18, http://yaml.org/type/timestamp.html
|
|
Reference Tag
|
Description
|
|
[Apache]
|
Apache Server, https://httpd.apache.org/
|
|
[Chef]
|
Chef, https://wiki.opscode.com/display/chef/Home
|
|
[NodeJS]
|
Node.js, https://nodejs.org/
|
|
[Puppet]
|
Puppet, http://puppetlabs.com/
|
|
[WordPress]
|
WordPress, https://wordpress.org/
|
|
[Maven-Version]
|
https://cwiki.apache.org/confluence/display/MAVEN/Version+number+policy
|
|
[JSON-Spec]
|
|
|
[JSON-Schema]
|
|
|
[XMLSpec]
|
XML Specification, W3C Recommendation, February 1998,
http://www.w3.org/TR/1998/REC-xml-19980210
|
|
[XML
Schema Part 1]
|
XML Schema Part 1: Structures, W3C Recommendation, October 2004,
http://www.w3.org/TR/xmlschema-1/
|
|
[XML
Schema Part 2]
|
XML Schema Part 2: Datatypes, W3C Recommendation, October 2004,
http://www.w3.org/TR/xmlschema-2/
|
|
[IANA register for Hash Function Textual
Names]
|
https://www.iana.org/assignments/hash-function-text-names/hash-function-text-names.xhtml
|
|
[Jinja2]
|
Jinja2, jinja.pocoo.org/
|
|
[Twig]
|
Twig, https://twig.symfony.com
|
The following terms are used throughout this
specification and have the following definitions when used in context of this
document.
|
Term
|
Definition
|
|
Instance Model
|
A deployed service is a running instance of a Service
Template. More precisely, the instance is derived by instantiating the
Topology Template of its Service Template, most often by running a declarative
workflow that is automatically generated based on the node templates and
relationship templates defined in the Topology Template.
|
|
Node Template
|
A Node Template specifies the occurrence of a
component node as part of a Topology Template. Each Node Template refers to a
Node Type that defines the semantics of the node (e.g., properties,
attributes, requirements, capabilities, interfaces). Node Types are defined separately
for reuse purposes.
|
|
Relationship Template
|
A Relationship Template specifies the occurrence of
a relationship between nodes in a Topology Template. Each Relationship
Template refers to a Relationship Type that defines the semantics
relationship (e.g., properties, attributes, interfaces, etc.). Relationship
Types are defined separately for reuse purposes.
|
|
Service
Template
|
A Service Template is typically used to specify the
“topology” (or structure) and “orchestration” (or invocation of management behavior)
of IT services so that they can be provisioned and managed in accordance with
constraints and policies.
Specifically, TOSCA Service Templates optionally allow
definitions of a TOSCA Topology Template,
TOSCA types (e.g., Node, Relationship, Capability, Artifact, etc.),
groupings, policies and constraints along with any input or output
declarations.
|
|
Topology
Model
|
The term Topology Model is often used synonymously with
the term Topology Template with the use
of “model” being prevalent when considering a Service Template’s topology
definition as an abstract representation of an application or
service to facilitate understanding of its functional components and by
eliminating unnecessary details.
|
|
Topology
Template
|
A Topology Template defines the structure of a service in
the context of a Service Template. A Topology Template consists of a set of
Node Template and Relationship Template definitions that together define the
topology model of a service as a (not necessarily connected) directed
graph.The term Topology Template is often used synonymously with the term Topology Model. The distinction is that a
topology template can be used to instantiate and orchestrate the model as a reusable
pattern and includes all details necessary to accomplish it.
|
|
Abstract Node Template
|
An abstract node template is a node template that doesn’t
define any implementations for the TOSCA lifecycle management operations. Service
designers explicitly mark node templates as abstract using the substitute
directive. TOSCA orchestrators provide implementations for abstract node
templates by finding substituting templates for those node templates.
|
|
No-Op Node Template
|
A No-Op node template is a node template that does not
specify implementations for any of its operations, but is not marked as
abstract. No-op templates only act as placeholders for information to be used
by other node templates and do not need to be orchestrated.
|
This non-normative section contains several sections
that show how to model applications with TOSCA Simple Profile using YAML by
example starting with a “Hello World” template up through examples that show
complex composition modeling.
2.1 A “hello world” template for TOSCA Simple
Profile in YAML
As mentioned before, the TOSCA
simple profile assumes the existence of a small set of pre-defined, normative set
of node types (e.g., a ‘Compute’ node) along with other types, which will be introduced
through the course of this document, for creating TOSCA Service Templates. It
is envisioned that many additional node types for building service templates
will be created by communities. Some may be published as profiles that build
upon the TOSCA Simple Profile specification. Using the normative TOSCA Compute
node type, a very basic “Hello World” TOSCA template for deploying just a
single server would look as follows:
Example 1 - TOSCA Simple "Hello World"
|
tosca_definitions_version: tosca_simple_yaml_1_3tosca_simple_yaml_1_3
description: Template for deploying a single server with
predefined properties.
topology_template:
node_templates:
db_server:
type: tosca.nodes.Compute
capabilities:
# Host container properties
host:
properties:
num_cpus: 1
disk_size: 10 GB
mem_size: 4096 MB
# Guest Operating System properties
os:
properties:
# host Operating System image
properties
architecture: x86_64
type: linux
distribution: rhel
version: 6.5
|
The template above contains a very simple topology
template” with only a single ‘Compute’ node template named “db_server that declares some basic values for
properties within two of the several capabilities that are built into the
Compute node type definition. All TOSCA Orchestrators are expected to know how
to instantiate a Compute node since it is normative and expected to represent a
well-known function that is portable across TOSCA implementations. This
expectation is true for all normative TOSCA Node and Relationship types that
are defined in the Simple Profile specification. This means, with TOSCA’s approach,
that the application developer does not need to provide any deployment or
implementation artifacts that contain code or logic to orchestrate these common
software components. TOSCA orchestrators simply select or allocate the correct
node (resource) type that fulfills the application topologies requirements
using the properties declared in the node and its capabilities.
In the above example, the “host”
capability contains properties that allow application developers to optionally supply
the number of CPUs, memory size and disk size they believe they need when the
Compute node is instantiated in order to run their applications. Similarly, the
“os” capability is used to provide
values to indicate what host operating system the Compute node should have when
it is instantiated.
The logical diagram of the “hello world” Compute node would
look as follows:
As you can see, the Compute
node also has attributes and other built-in capabilities, such as Bindable and Endpoint, each with additional properties that
will be discussed in other examples later in this document. Although the
Compute node has no direct properties apart from those in its capabilities,
other TOSCA node type definitions may have properties that are part of the node
type itself in addition to having Capabilities. TOSCA orchestration engines
are expected to validate all property values provided in a node template
against the property definitions in their respective node type definitions referenced
in the service template. The tosca_definitions_version
keyname in the TOSCA service template identifies the versioned set of
normative TOSCA type definitions to use for validating those types defined in
the TOSCA Simple Profile including the Compute node type. Specifically, the
value tosca_simple_yaml_1_3 indicates
Simple Profile v1.3.0 definitions would be used for validation. Other type definitions
may be imported from other service templates using the import keyword discussed later.
Typically, one would want to
allow users to customize deployments by providing input parameters instead of
using hardcoded values inside a template. In addition, output values are
provided to pass information that perhaps describes the state of the deployed template
to the user who deployed it (such as the private IP address of the deployed
server). A refined service template with corresponding inputs and outputs
sections is shown below.
Example 2 - Template with
input and output parameter sections
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: Template for
deploying a single server with predefined properties.
topology_template:
inputs:
db_server_num_cpus:
type: integer
description: Number of CPUs
for the server.
constraints:
- valid_values: [ 1, 2, 4,
8 ]
node_templates:
db_server:
type: tosca.nodes.Compute
capabilities:
# Host container
properties
host:
properties:
#
Compute properties
num_cpus: { get_input:
db_server_num_cpus }
mem_size: 2048 MB
disk_size: 10 GB
mem_size: 4096 MB
# Guest Operating System
properties
os:
# omitted for brevity
outputs:
server_ip:
description: The private IP
address of the provisioned server.
value: { get_attribute: [ db_server,
private_address ] }
|
The inputs
and outputs sections are contained in
the topology_template element of the
TOSCA template, meaning that they are scoped to node templates within the
topology template. Input parameters defined in the inputs section can be
assigned to properties of node template within the containing topology
template; output parameters can be obtained from attributes of node templates
within the containing topology template.
Note that the inputs
section of a TOSCA template allows for defining optional constraints on each
input parameter to restrict possible user input. Further note that TOSCA
provides for a set of intrinsic functions like get_input, get_property
or get_attribute to reference elements
within the template or to retrieve runtime values.
2.2 TOSCA template for a simple software
installation
Software installations can be modeled in TOSCA as node
templates that get related to the node template for a server on which the
software would be installed. With a number of existing software node types
(e.g. either created by the TOSCA work group or a community) template authors
can just use those node types for writing service templates as shown below.
Example 3 - Simple (MySQL) software installation on a
TOSCA Compute node
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: Template for
deploying a single server with MySQL software on top.
topology_template:
inputs:
mysql_rootpw:
type: string
mysql_port:
type: integer
# rest omitted here for
brevity
node_templates:
db_server:
type: tosca.nodes.Compute
# rest omitted here for
brevity
mysql:
type: tosca.nodes.DBMS.MySQL
properties:
root_password: {
get_input: mysql_rootpw }
port: { get_input:
mysql_port }
requirements:
- host: db_server
outputs:
# omitted here for brevity
|
The example above makes use of a node type tosca.nodes.DBMS.MySQL for the mysql node template to install MySQL on a
server. This node type allows for setting a property root_password to adapt the password of the
MySQL root user at deployment. The set of properties and their schema has been
defined in the node type definition. By means of the get_input function, a value provided by the user at
deployment time is used as the value for the root_password
property. The same is true for the port
property.
The mysql node template is related to the db_server node template (of type tosca.nodes.Compute) via the requirements section to indicate where
MySQL is to be installed. In the TOSCA metamodel, nodes get related to each
other when one node has a requirement against some capability provided by
another node. What kinds of requirements exist is defined by the respective
node type. In case of MySQL, which is software that needs to be installed or
hosted on a compute resource, the underlying node type named tosca.nodes.SoftwareComponent has a predefined
requirement called host, which
needs to be fulfilled by pointing to a node template of type tosca.nodes.Compute.
The
logical relationship between the mysql
node and its host db_server node would
appear as follows:
Within the list of requirements, each list entry is a map that contains
a single key/value pair where the symbolic name of a requirement definition is the
key and the identifier of the fulfilling node is the value. The
value is essentially the symbolic name of the other node template;
specifically, or the example above, the host
requirement is fulfilled by referencing the db_server
node template. The underlying TOSCA DBMS
node type already has a complete requirement definition for the host requirement of type Compute and assures that a HostedOn TOSCA relationship will automatically
be created and will only allow a valid target host node is of type Compute. This approach allows the template
author to simply provide the name of a valid Compute
node (i.e., db_server) as the value for
the mysql node’s host requirement and not worry about defining
anything more complex if they do not want to.
Node types in TOSCA have
associated implementations that provide the automation (e.g. in the form of
scripts such as Bash, Chef or Python) for the normative lifecycle operations of
a node. For example, the node type implementation for a MySQL database would associate
scripts to TOSCA node operations like configure,
start, or stop to manage the state of MySQL at runtime.
Many node types may already
come with a set of operational scripts that contain basic commands that can
manage the state of that specific node. If it is desired, template authors can
provide a custom script for one or more of the operations defined by a node
type in their node template which will override the default implementation in
the type. The following example shows a mysql
node template where the template author provides their own configure script:
Example 4 - Node Template overriding its Node Type's
"configure" interface
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: Template for
deploying a single server with MySQL software on top.
topology_template:
inputs:
# omitted here for brevity
node_templates:
db_server:
type: tosca.nodes.Compute
# rest omitted here for
brevity
mysql:
type: tosca.nodes.DBMS.MySQL
properties:
root_password: {
get_input: mysql_rootpw }
port: { get_input:
mysql_port }
requirements:
- host: db_server
interfaces:
Standard:
configure: scripts/my_own_configure.sh
outputs:
# omitted here for brevity
|
In the example above, the my_own_configure.sh script is provided for
the configure operation of the MySQL
node type’s Standard lifecycle interface.
The path given in the example above (i.e., ‘scripts/’) is interpreted relative
to the template file, but it would also be possible to provide an absolute URI
to the location of the script.
In other words, operations
defined by node types can be thought of as “hooks” into which automation can be
injected. Typically, node type implementations provide the automation for those
“hooks”. However, within a template, custom automation can be injected to run
in a hook in the context of the one, specific node template (i.e. without
changing the node type).
In the Example 4, shown above, the
deployment of the MySQL middleware only, i.e. without actual database content
was shown. The following example shows how such a template can be extended to
also contain the definition of custom database content on-top of the MySQL DBMS
software.
Example 5 - Template for deploying database content
on-top of MySQL DBMS middleware
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: Template for
deploying a single server with predefined properties.
topology_template:
inputs:
wordpress_db_name:
type: string
wordpress_db_user:
type: string
wordpress_db_password:
type: string
# rest omitted here for
brevity
node_templates:
db_server:
type: tosca.nodes.Compute
# rest omitted here for
brevity
mysql:
type: tosca.nodes.DBMS.MySQL
# rest omitted here for
brevity
wordpress_db:
type: tosca.nodes.Database.MySQL
properties:
name: { get_input: wordpress_db_name
}
user: { get_input: wordpress_db_user
}
password: { get_input: wordpress_db_password
}
artifacts:
db_content:
file: files/wordpress_db_content.txt
type: tosca.artifacts.File
requirements:
- host: mysql
interfaces:
Standard:
create:
implementation: db_create.sh
inputs:
# Copy DB file
artifact to server’s staging area
db_data: { get_artifact: [
SELF, db_content ] }
outputs:
# omitted here for brevity
|
In the example above, the wordpress_db node template of type tosca.nodes.Database.MySQL represents an
actual MySQL database instance managed by a MySQL DBMS installation. The requirements section of the wordpress_db node template expresses that the
database it represents is to be hosted on a MySQL DBMS node template named mysql which is also declared in this
template.
In the artifacts section of the wordpress_db the node template, there is an
artifact definition named db_content
which represents a text file wordpress_db_content.txt
which in turn will be used to add content to the SQL database as part of the create operation.
As you can see above, a script is associated with the create
operation with the name db_create.sh.
The TOSCA Orchestrator sees that this is not a named artifact declared in the
node’s artifact section, but instead a filename for a normative TOSCA
implementation artifact script type (i.e., tosca.artifacts.Implementation.Bash).
Since this is an implementation type for TOSCA, the orchestrator will execute
the script automatically to create the node on db_server, but first it will prepare the
local environment with the declared inputs for the operation. In this case, the
orchestrator would see that the db_data
input is using the get_artifact
function to retrieve the file (wordpress_db_content.txt)
which is associated with the db_content
artifact name prior to executing the db_create.sh
script.
The logical diagram for this example would appear as
follows:
Note that while it would be possible
to define one node type and corresponding node templates that represent both
the DBMS middleware and actual database content as one entity, TOSCA normative
node types distinguish between middleware (container) and application
(containee) node types. This allows on one hand to have better re-use of
generic middleware node types without binding them to content running on top of
them, and on the other hand this allows for better substitutability of, for
example, middleware components like a DBMS during the deployment of TOSCA
models.
The definition of multi-tier
applications in TOSCA is quite similar to the example shown in section 2.2, with the only difference that multiple software node stacks (i.e., node
templates for middleware and application layer components), typically hosted on
different servers, are defined and related to each other. The example below
defines a web application stack hosted on the web_server
“compute” resource, and a database software stack similar to the one shown
earlier in section 6 hosted on the db_server
compute resource.
Example 6 - Basic two-tier application (web application
and database server tiers)
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: Template for
deploying a two-tier application servers on 2 servers.
topology_template:
inputs:
# Admin user name and password
to use with the WordPress application
wp_admin_username:
type: string
wp_admin_password:
type: string
mysql_root_password:
type: string
context_root:
type: string
# rest omitted here for
brevity
node_templates:
db_server:
type: tosca.nodes.Compute
# rest omitted here for
brevity
mysql:
type: tosca.nodes.DBMS.MySQL
# rest omitted here for
brevity
wordpress_db:
type:
tosca.nodes.Database.MySQL
# rest omitted here for
brevity
web_server:
type: tosca.nodes.Compute
# rest omitted here for
brevity
apache:
type:
tosca.nodes.WebServer.Apache
requirements:
- host: web_server
# rest omitted here for
brevity
wordpress:
type: tosca.nodes.WebApplication.WordPress
properties:
context_root: { get_input:
context_root }
admin_user: { get_input:
wp_admin_username }
admin_password: {
get_input: wp_admin_password }
db_host: { get_attribute:
[ db_server, private_address ] }
requirements:
- host: apache
- database_endpoint: wordpress_db
interfaces:
Standard:
inputs:
db_host: { get_attribute:
[ db_server, private_address ] }
db_port: {
get_property: [ mysql, port ] }
db_name: {
get_property: [ wordpress_db, name ] }
db_user: {
get_property: [ wordpress_db, user ] }
db_password: {
get_property: [ wordpress_db, password ] }
outputs:
# omitted here for brevity
|
The web application stack
consists of the wordpress [WordPress],
the apache [Apache] and the web_server
node templates. The wordpress node template represents a custom web
application of type tosca.nodes.WebApplication.WordPress which is hosted
on an Apache web server represented by the apache node template. This
hosting relationship is expressed via the host entry in the requirements
section of the wordpress node template. The apache node template,
finally, is hosted on the web_server compute node.
The database stack consists of the wordpress_db, the mysql
and the db_server node templates. The wordpress_db node
represents a custom database of type tosca.nodes.Database.MySQL which is
hosted on a MySQL DBMS represented by the mysql node template. This
node, in turn, is hosted on the db_server compute node.
The wordpress node requires a connection to the
wordpress_db node, since the WordPress application needs a database to
store its data in. This relationship is established through the database_endpoint entry in the requirements
section of the wordpress node template’s declared node type. For
configuring the WordPress web application, information about the database to
connect to is required as input to the configure operation. Therefore,
the input parameters are defined and values for them are retrieved from the properties
and attributes of the wordpress_db node via the get_property and get_attribute functions. In the above
example, these inputs are defined at the interface-level and would be available
to all operations of the Standard
interface (i.e., the tosca.interfaces.node.lifecycle.Standard
interface) within the wordpress node
template and not just the configure
operation.
In previous examples, the
template author did not have to think about explicit relationship types to be
used to link a requirement of a node to another node of a model, nor did the
template author have to think about special logic to establish those links. For
example, the host requirement
in previous examples just pointed to another node template and based on
metadata in the corresponding node type definition the relationship type to be
established is implicitly given.
In some cases, it might be
necessary to provide special processing logic to be executed when establishing
relationships between nodes at runtime. For example, when connecting the
WordPress application from previous examples to the MySQL database, it might be
desired to apply custom configuration logic in addition to that already
implemented in the application node type. In such a case, it is possible for
the template author to provide a custom script as implementation for an
operation to be executed at runtime as shown in the following example.
Example 7 - Providing a custom relationship script to
establish a connection
|
tosca_definitions_version:
tosca_simple_yaml_1_3
description:
Template for deploying a two-tier application on two servers.
topology_template:
inputs:
#
omitted here for brevity
node_templates:
db_server:
type: tosca.nodes.Compute
# rest omitted here for brevity
mysql:
type: tosca.nodes.DBMS.MySQL
# rest omitted here for brevity
wordpress_db:
type: tosca.nodes.Database.MySQL
# rest omitted here for brevity
web_server:
type: tosca.nodes.Compute
# rest omitted here for brevity
apache:
type: tosca.nodes.WebServer.Apache
requirements:
- host: web_server
# rest omitted here for brevity
wordpress:
type:
tosca.nodes.WebApplication.WordPress
properties:
#
omitted here for brevity
requirements:
-
host: apache
-
database_endpoint:
node:
wordpress_db
relationship: wp_db_connection
# rest omitted here for brevity
wordpress_db:
type:
tosca.nodes.Database.MySQL
properties:
#
omitted here for the brevity
requirements:
-
host: mysql
relationship_templates:
wp_db_connection:
type: ConnectsTo
interfaces:
Configure:
pre_configure_source: scripts/wp_db_configure.sh
outputs:
#
omitted here for brevity
|
The node type definition for the wordpress node template is WordPress which declares the complete database_endpoint
requirement definition. This database_endpoint
declaration indicates it must be fulfilled by any node template that provides
an Endpoint.Database Capability Type
using a ConnectsTo relationship. The wordpress_db
node template’s underlying MySQL type
definition indeed provides the Endpoint.Database
Capability type. In this example however, no explicit relationship
template is declared; therefore, TOSCA orchestrators would automatically create
a ConnectsTo relationship to establish the link between the wordpress node and the wordpress_db node at runtime.
The ConnectsTo
relationship (see 5.7.4) also provides a default Configure interface with operations that optionally
get executed when the orchestrator establishes the relationship. In the above
example, the author has provided the custom script wp_db_configure.sh to be executed for the operation
called pre_configure_source. The script file is assumed
to be located relative to the referencing service template such as a relative
directory within the TOSCA Cloud Service Archive (CSAR) packaging format. This
approach allows for conveniently hooking in custom behavior without having to
define a completely new derived relationship type.
In the previous section it was
shown how custom behavior can be injected by specifying scripts inline in the
requirements section of node templates. When the same custom behavior is
required in many templates, it does make sense to define a new relationship
type that encapsulates the custom behavior in a re-usable way instead of
repeating the same reference to a script (or even references to multiple
scripts) in many places.
Such a custom relationship type
can then be used in templates as shown in the following example.
Example 8 - A web application Node Template requiring
a custom database connection type
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: Template for
deploying a two-tier application on two servers.
topology_template:
inputs:
# omitted here for brevity
node_templates:
wordpress:
type: tosca.nodes.WebApplication.WordPress
properties:
# omitted here for brevity
requirements:
- host: apache
- database_endpoint:
node: wordpress_db
relationship: my.types.WordpressDbConnection
wordpress_db:
type:
tosca.nodes.Database.MySQL
properties:
# omitted here for the
brevity
requirements:
- host: mysql
# other resources not shown
here ...
|
In the example above, a special relationship type my.types.WordpressDbConnection is specified
for establishing the link between the wordpress
node and the wordpress_db node
through the use of the relationship
keyword in the database
reference. It is assumed, that this special relationship type provides some
extra behavior (e.g., an operation with a script) in addition to what a generic
“connects to” relationship would provide. The definition of this custom
relationship type is shown in the following section.
The following YAML snippet shows the definition of
the custom relationship type used in the previous section. This type derives
from the base “ConnectsTo” and overrides one operation defined by that base
relationship type. For the pre_configure_source
operation defined in the Configure
interface of the ConnectsTo relationship type, a script implementation is
provided. It is again assumed that the custom configure script is located at a
location relative to the referencing service template, perhaps provided in some
application packaging format (e.g., the TOSCA Cloud Service Archive (CSAR)
format).
Example 9 - Defining a custom relationship type
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: Definition of custom
WordpressDbConnection relationship type
relationship_types:
my.types.WordpressDbConnection:
derived_from: tosca.relationships.ConnectsTo
interfaces:
Configure:
pre_configure_source:
scripts/wp_db_configure.sh
|
In some cases, it can be
necessary to define a generic dependency between two nodes in a template to
influence orchestration behavior, i.e. to first have one node processed before
another dependent node gets processed. This can be done by using the generic dependency requirement which is defined by
the TOSCA Root Node Type and thus gets
inherited by all other node types in TOSCA (see section 5.9.1).
Example 10 - Simple dependency relationship between
two nodes
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: Template with a
generic dependency between two nodes.
topology_template:
inputs:
# omitted here for brevity
node_templates:
my_app:
type: my.types.MyApplication
properties:
# omitted here for brevity
requirements:
- dependency: some_service
some_service:
type: some.nodetype.SomeService
properties:
# omitted here for brevity
|
As in previous examples, the relation that one node
depends on another node is expressed in the requirements
section using the built-in requirement named dependency
that exists for all node types in TOSCA. Even if the creator of the MyApplication node type did not define a
specific requirement for SomeService
(similar to the database requirement in
the example in section 2.6), the template author who knows that there is a
timing dependency and can use the generic dependency
requirement to express that constraint using the very same syntax as used for
all other references.
In TOSCA templates, nodes are either:
·
Concrete: meaning that they have a deployment and/or one
or more implementation artifacts that are declared on the “create” operation of
the node’s Standard lifecycle interface, or they are
·
Abstract: where the template describes only the node type
along with its required capabilities and properties that must be satisfied.
TOSCA Orchestrators, by default, when finding an abstract
node in TOSCA Service Template during deployment will attempt to “select” a
concrete implementation for the abstract node type that best matches and fulfills
the requirements and property constraints the template author provided for that
abstract node. The concrete implementation of the node could be provided by
another TOSCA Service Template (perhaps located in a catalog or repository
known to the TOSCA Orchestrator) or by an existing resource or service
available within the target Cloud Provider’s platform that the TOSCA
Orchestrator already has knowledge of.
TOSCA supports two methods for template authors to express requirements
for an abstract node within a TOSCA service template.
1. Using
a target node_filter: where a node template can describe a requirement
(relationship) for another node without including it in the topology. Instead,
the node provides a node_filter to describe the
target node type along with its capabilities and property constrains
2. Using
an abstract node template: that describes the abstract node’s type
along with its property constraints and any requirements and capabilities it
also exports. This first method you have already seen in examples from
previous chapters where the Compute node is abstract and selectable by the
TOSCA Orchestrator using the supplied Container and OperatingSystem capabilities property
constraints.
These approaches allow architects and developers to create
TOSCA service templates that are composable and can be reused by allowing
flexible matching of one template’s requirements to another’s capabilities. Examples
of both these approaches are shown below.
The following section describe how a user can define a
requirement for an orchestrator to select an implementation and replace a node.
For more details on how an orchestrator may perform matching and select a node
from it’s catalog(s) you may look at section 14 of the specification.
Using TOSCA, it is possible to
define only the software components of an application in a template and just
express constrained requirements against the hosting infrastructure. At
deployment time, the provider can then do a late binding and dynamically
allocate or assign the required hosting infrastructure and place software
components on top.
This example shows how a single software component (i.e.,
the mysql node template) can define its host
requirements that the TOSCA Orchestrator and provider will use to select or
allocate an appropriate host Compute
node by using matching criteria provided on a node_filter.
Example
11 - An abstract "host" requirement using a node filter
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: Template with
requirements against hosting infrastructure.
topology_template:
inputs:
# omitted here for brevity
node_templates:
mysql:
type: tosca.nodes.DBMS.MySQL
properties:
# omitted here for brevity
requirements:
- host:
node_filter:
capabilities:
# Constraints for
selecting “host” (Container Capability)
- host:
properties:
- num_cpus:
{ in_range: [ 1, 4 ] }
- mem_size:
{ greater_or_equal: 2 GB }
# Constraints for
selecting “os” (OperatingSystem Capability)
- os:
properties:
-
architecture: { equal: x86_64 }
- type:
linux
- distribution: ubuntu
|
In the example above, the mysql component contains a host requirement for a node of type Compute which it inherits from its
parent DBMS node type definition; however, there is no declaration or reference
to any node template of type Compute.
Instead, the mysql node template
augments the abstract “host”
requirement with a node_filter which contains
additional selection criteria (in the form of property constraints that the provider
must use when selecting or allocating a host Compute
node.
Some of the constraints shown above narrow down the
boundaries of allowed values for certain properties such as mem_size or num_cpus
for the “host” capability by means of
qualifier functions such as greater_or_equal.
Other constraints, express specific values such as for the architecture or distribution properties of the “os” capability which will require the
provider to find a precise match.
Note that when no qualifier
function is provided for a property (filter), such as for the distribution property, it is interpreted to
mean the equal operator as shown on the
architecture property.
2.9.2
Using an abstract node template to define infrastructure requirements for
software
This previous approach works well if no other
component (i.e., another node template) other than mysql node template wants to reference the
same Compute node the orchestrator
would instantiate. However, perhaps another component wants to also be deployed
on the same host, yet still allow the flexible matching achieved using a
node-filter. The alternative to the above approach is to create an abstract
node template that represents the Compute
node in the topology as follows:
Example
12 - An abstract Compute node template with a node filter
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: Template with
requirements against hosting infrastructure.
topology_template:
inputs:
# omitted here for brevity
node_templates:
mysql:
type: tosca.nodes.DBMS.MySQL
properties:
# omitted here for
brevity
requirements:
- host: mysql_compute
# Abstract node template
(placeholder) to be selected by provider
mysql_compute:
type: Compute
directives: [ select ]
node_filter:
capabilities:
- host:
properties:
num_cpus: {
equal: 2 }
mem_size: {
greater_or_equal: 2 GB }
- os:
properties:
architecture: {
equal: x86_64 }
type: linux
distribution:
ubuntu
|
In this node template, the msql_compute
node template is marked as abstract using the select
directive. As you can see the resulting mysql_compute
node template looks very much like the “hello world” template as shown in Chapter 2.1 but
this one also allows the TOSCA orchestrator more flexibility when “selecting” a
host Compute node by providing flexible
constraints for properties like mem_size.
As we proceed, you will see that TOSCA provides many
normative node types like Compute for
commonly found services (e.g., BlockStorage,
WebServer, Network, etc.). When these TOSCA normative
node types are used in your application’s topology they are always assumed to
be “implementable” by TOSCA Orchestrators which work with target infrastructure
providers to find or allocate the best match for them based upon your
application’s requirements and constraints.
In the same way requirements
can be defined on the hosting infrastructure (as shown above) for an
application, it is possible to express requirements against application or
middleware components such as a database that is not defined in the same
template. The provider may then allocate a database by any means, (e.g. using a
database-as-a-service solution).
Example
13 - An abstract database requirement using a node filter
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: Template with a TOSCA
Orchestrator selectable database requirement using a node_filter.
topology_template:
inputs:
# omitted here for brevity
node_templates:
my_app:
type: my.types.MyApplication
properties:
admin_user: { get_input:
admin_username }
admin_password: {
get_input: admin_password }
db_endpoint_url: { get_property:
[SELF, database_endpoint, url_path ] }
requirements:
- database_endpoint:
node: my.types.nodes.MyDatabase
node_filter:
properties:
- db_version: {
greater_or_equal: 5.5 }
|
In the example above, the application my_app requires a database node of type MyDatabase which has a db_version property value of greater_or_equal to the value 5.5.
This example also shows how the get_property intrinsic function can be used
to retrieve the url_path property from
the database node that will be selected by the provider and connected to my_app at runtime due to fulfillment of the database_endpoint requirement. To locate the
property, the get_property’s first argument is set to the keyword SELF which indicates the property is being
referenced from something in the node itself. The second parameter is the name
of the requirement named database_endpoint
which contains the property we are looking for. The last argument is
the name of the property itself (i.e., url_path)
which contains the value we want to retrieve and assign to db_endpoint_url.
The alternative representation,
which includes a node template in the topology for database that is still
selectable by the TOSCA orchestrator for the above example, is as follows:
Example
14 - An abstract database node template
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: Template with a TOSCA
Orchestrator selectable database using node template.
topology_template:
inputs:
# omitted here for brevity
node_templates:
my_app:
type: my.types.MyApplication
properties:
admin_user: { get_input:
admin_username }
admin_password: {
get_input: admin_password }
db_endpoint_url: {
get_property: [SELF, database_endpoint, url_path ] }
requirements:
- database_endpoint: my_abstract_database
my_abstract_database:
type:
my.types.nodes.MyDatabase
properties:
- db_version: {
greater_or_equal: 5.5 }
|
From an application perspective, it is often not necessary
or desired to dive into platform details, but the platform/runtime for an
application is abstracted. In such cases, the template for an application can
use generic representations of platform components. The details for such
platform components, such as the underlying hosting infrastructure and its
configuration, can then be defined in separate template files that can be used
for substituting the more abstract representations in the application level
template file. Service designers use the substitute
directive to declare node templates as abstract. At deployment time, TOSCA
orchestrators are expected to substitute
abstract node templates in a service template before service orchestration can
be performed.
When a topology template is instantiated by a TOSCA
Orchestrator, the orchestrator has to first look for abstract node templates in
the topology template. Abstract node templates are node templates that include
the substitute directive. These
abstract node templates must then be realized using substituting service templates that
are compatible with the node types specified for each abstract node template.
Such realizations can either be node types that include the appropriate
implementation artifacts and deployment artifacts that can be used by the
orchestrator to bring to life the real-world resource modeled by a node
template. Alternatively, separate topology templates may be annotated as being
suitable for realizing a node template in the top-level topology template.
In the latter case, a TOSCA Orchestrator will use additional
substitution mapping information provided as part of the substituting topology
templates to derive how the substituted part gets “wired” into the overall
deployment, for example, how capabilities of a node template in the top-level
topology template get bound to capabilities of node templates in the
substituting topology template.
Thus, in cases where no “normal” node type implementation is
available, or the node type corresponds to a whole subsystem that cannot be
implemented as a single node, additional topology templates can be used for
filling in more abstract placeholders in top level application templates.
The following sample defines a
web application web_app connected to a
database db. In this example, the
complete hosting stack for the application is defined within the same topology
template: the web application is hosted on a web server web_server, which in turn is installed
(hosted) on a compute node server.
The hosting stack for the
database db, in contrast, is not
defined within the same file but only the database is represented as a node
template of type tosca.nodes.Database.
The underlying hosting stack for the database is defined in a separate template
file, which is shown later in this section. Within the current template, only a
number of properties (user, password, name)
are assigned to the database using hardcoded values in this simple example.
Figure 1: Using template substitution to implement a
database tier
When a node template is to be substituted by another service
template, this has to be indicated to an orchestrator by marking he node template
as abstract using the substitute directive.
Orchestrators can only instantiate abstract node templates by substituting them
with a service template that consists entirely of concrete nodes. Note that
abstract node template substitution may need to happen recursively before a
service template is obtained that consists only of concrete nodes.
Note that in contrast to the use case described in section 2.9.2 (where a database was abstractly referred to in the requirements section of a node and the
database itself was not represented as a node template), the approach shown
here allows for some additional modeling capabilities in cases where this is
required.
For example, if multiple components need to use the same database (or any other
sub-system of the overall service), this can be expressed by means of normal
relations between node templates, whereas such modeling would not be possible
in requirements sections of disjoint
node templates.
Example
15 - Referencing an abstract database node template
|
tosca_definitions_version:
tosca_simple_yaml_1_3
topology_template:
description: Template of an application connecting to a database.
node_templates:
web_app:
type:
tosca.nodes.WebApplication.MyWebApp
requirements:
-
host: web_server
-
database_endpoint: db
web_server:
type: tosca.nodes.WebServer
requirements:
- host: server
server:
type: tosca.nodes.Compute
# details omitted for brevity
db:
# This node is abstract as specified by the substitute directive
# and must be substituted with a topology provided by another template
# that exports a Database type’s capabilities.
type:
tosca.nodes.Database
directives:
- substitute
properties:
user:
my_db_user
password:
secret
name:
my_db_name
|
The following sample defines a template for a
database including its complete hosting stack, i.e. the template includes a database node template, a template for the
database management system (dbms)
hosting the database, as well as a computer node server on which the DBMS is installed.
This service template can be used standalone for deploying
just a database and its hosting stack. In the context of the current use case,
though, this template can also substitute the database node template in the previous
snippet and thus fill in the details of how to deploy the database.
In order to enable such a substitution, an additional metadata
section substitution_mappings is added
to the topology template to tell a TOSCA Orchestrator how exactly the topology
template will fit into the context where it gets used. For example,
requirements or capabilities of the node that gets substituted by the topology
template have to be mapped to requirements or capabilities of internal node
templates for allow for a proper wiring of the resulting overall graph of node
templates.
In short, the substitution_mappings
section provides the following information:
1. It defines
what node templates, i.e. node templates of which type, can be substituted by
the topology template.
2. It defines
how capabilities of the substituted node (or the capabilities defined by the
node type of the substituted node template, respectively) are bound to
capabilities of node templates defined in the topology template.
3. It defines
how requirements of the substituted node (or the requirements defined by the
node type of the substituted node template, respectively) are bound to
requirements of node templates defined in the topology template.
Figure
2: Substitution mappings
The substitution_mappings
section in the sample below denotes that this topology template can be used for
substituting node templates of type tosca.nodes.Database.
It further denotes that the database_endpoint
capability of the substituted node gets fulfilled by the database_endpoint capability of the database node contained in the topology
template.
Example
16 - Using substitution mappings to export a database implementation
|
tosca_definitions_version:
tosca_simple_yaml_1_3
topology_template:
description: Template of a database including its hosting stack.
inputs:
db_user:
type: string
db_password:
type: string
#
other inputs omitted for brevity
substitution_mappings:
node_type: tosca.nodes.Database
capabilities:
database_endpoint: [ database, database_endpoint ]
node_templates:
database:
type:
tosca.nodes.Database
properties:
user: { get_input: db_user }
# other properties omitted for brevity
requirements:
- host: dbms
dbms:
type:
tosca.nodes.DBMS
# details omitted for brevity
server:
type:
tosca.nodes.Compute
#
details omitted for brevity
|
Note that the substitution_mappings
section does not define any mappings for requirements of the Database node
type, since all requirements are fulfilled by other nodes templates in the
current topology template. In cases where a requirement of a substituted node
is bound in the top-level service template as well as in the substituting
topology template, a TOSCA Orchestrator should raise a validation error.
Further note that no mappings for properties or attributes
of the substituted node are defined. Instead, the inputs and outputs defined by
the topology template are mapped to the appropriate properties and attributes
or the substituted node. If there are more inputs than the substituted node has
properties, default values must be defined for those inputs, since no values
can be assigned through properties in a substitution case.
A common use case when providing an end-to-end service is to
define a chain of several subsystems that together implement the overall
service. Those subsystems are typically defined as separate service templates to
(1) keep the complexity of the end-to-end service template at a manageable
level and to (2) allow for the re-use of the respective subsystem templates in
many different contexts. The type of subsystems may be specific to the targeted
workload, application domain, or custom use case. For example, a company or a
certain industry might define a subsystem type for company- or industry
specific data processing and then use that subsystem type for various end-user
services. In addition, there might be generic subsystem types like a database
subsystem that are applicable to a wide range of use cases.
Figure 3 shows the chaining of three subsystem types
– a message queuing subsystem, a transaction processing subsystem, and a
databank subsystem – that support, for example, an online booking application.
On the front end, this chain provides a capability of receiving messages for
handling in the message queuing subsystem. The message queuing subsystem in
turn requires a number of receivers, which in the current example are two
transaction processing subsystems. The two instances of the transaction
processing subsystem might be deployed on two different hosting infrastructures
or datacenters for high-availability reasons. The transaction processing
subsystems finally require a database subsystem for accessing and storing
application specific data. The database subsystem in the backend does not require
any further component and is therefore the end of the chain in this example.
Figure 3: Chaining of subsystems in a service template
All of the node templates in the service template shown
above are abstract and considered substitutable where each can be treated as
their own subsystem; therefore, when instantiating the overall service, the
orchestrator would realize each substitutable node template using other TOSCA
service templates. These service templates would include more nodes and
relationships that include the details for each subsystem. A simplified version
of a TOSCA service template for the overall service is given in the following
listing.
Example
17 - Declaring a transaction subsystem as a chain of substitutable node
templates
|
tosca_definitions_version:
tosca_simple_yaml_1_3
topology_template:
description: Template of online transaction processing service.
node_templates:
mq:
type: example.QueuingSubsystem
directives:
- substitute
properties:
# properties omitted for brevity
capabilities:
message_queue_endpoint:
# details omitted for brevity
requirements:
- receiver: trans1
- receiver: trans2
trans1:
type: example.TransactionSubsystem
directives:
- substitute
properties:
mq_service_ip: { get_attribute: [ mq, service_ip ] }
receiver_port: 8080
capabilities:
message_receiver:
# details omitted for brevity
requirements:
- database_endpoint: dbsys
trans2:
type: example.TransactionSubsystem
directives:
- substitute
properties:
mq_service_ip: { get_attribute: [ mq, service_ip ] }
receiver_port: 8080
capabilities:
message_receiver:
# details omitted for brevity
requirements:
- database_endpoint: dbsys
dbsys:
type: example.DatabaseSubsystem
directives:
- substitute
properties:
# properties omitted for brevity
capabilities:
database_endpoint:
# details omitted for brevity
|
As can be seen in the example above, the subsystems are
chained to each other by binding requirements of one subsystem node template to
other subsystem node templates that provide the respective capabilities. For
example, the receiver requirement of
the message queuing subsystem node template mq
is bound to transaction processing subsystem node templates trans1 and trans2.
Subsystems can be parameterized by providing
properties. In the listing above, for example, the IP address of the message
queuing server is provided as property mq_service_ip
to the transaction processing subsystems and the desired port for receiving
messages is specified by means of the receiver_port
property.
If attributes of the instantiated subsystems need to
be obtained, this would be possible by using the get_attribute intrinsic function on the
respective subsystem node templates.
The types of subsystems that are required for a
certain end-to-end service are defined as TOSCA node types as shown in the following
example. Node templates of those node types can then be used in the end-to-end
service template to define subsystems to be instantiated and chained for
establishing the end-to-end service.
The realization of the defined node type will be
given in the form of a whole separate service template as outlined in the
following section.
Example
18 - Defining a TransactionSubsystem node type
|
tosca_definitions_version:
tosca_simple_yaml_1_3
node_types:
example.TransactionSubsystem:
properties:
mq_service_ip:
type: string
receiver_port:
type: integer
attributes:
receiver_ip:
type: string
type: integer
message_receiver: tosca.capabilities.Endpoint
requirements:
-
database_endpoint: tosca.capabilities.Endpoint.Database
|
Configuration parameters that would be allowed for
customizing the instantiation of any subsystem are defined as properties of the
node type. In the current example, those are the properties mq_service_ip and receiver_port that had been used in the
end-to-end service template in section 2.11.1.
Observable attributes of the
resulting subsystem instances are defined as attributes of the node type. In
the current case, those are the IP address of the message receiver as well as
the actually allocated port of the message receiver endpoint.
The details of a subsystem, i.e. the software components and
their hosting infrastructure, are defined as node templates and relationships
in a service template. By means of substitution mappings that have been
introduced in section 2.10.2, the service template is annotated to indicate to
an orchestrator that it can be used as realization of a node template of a certain
type, as well as how characteristics of the node type are mapped to internal
elements of the service template.
Figure
4: Defining subsystem details in a service template
Figure 1 illustrates how a transaction processing subsystem
as outlined in the previous section could be defined in a service template. In
this example, it simply consists of a custom application app of type SomeApp
that is hosted on a web server websrv,
which in turn is running on a compute node.
The application named app provides a capability to receive
messages, which is bound to the message_receiver
capability of the substitutable node type. It further requires access to a
database, so the application’s database_endpoint
requirement is mapped to the database_endpoint
requirement of the TransactionSubsystem
node type.
Properties of the TransactionSubsystem node type are used to
customize the instantiation of a subsystem. Those properties can be mapped to
any node template for which the author of the subsystem service template wants
to expose configurability. In the current example, the application app and the
web server middleware websrv get
configured through properties of the TransactionSubsystem
node type. All properties of that node type are defined as inputs of the service template. The input
parameters in turn get mapped to node templates by means of get_input function calls in the respective
sections of the service template.
Similarly, attributes of the whole subsystem can be
obtained from attributes of particular node templates. In the current example,
attributes of the web server and the hosting compute node will be exposed as
subsystem attributes. All exposed attributes that are defined as attributes of
the substitutable TransactionSubsystem
node type are defined as outputs of the subsystem service template.
An outline of the subsystem service
template is shown in the listing below. Note that this service template could
be used for stand-alone deployment of a transaction processing system as well,
i.e. it is not restricted just for use in substitution scenarios. Only the
presence of the substitution_mappings
metadata section in the topology_template
enables the service template for substitution use cases.
Example
19 - Implementation of a TransactionSubsytem node type using substitution
mappings
|
tosca_definitions_version:
tosca_simple_yaml_1_3
topology_template:
description: Template of a database including its hosting stack.
inputs:
mq_service_ip:
type: string
description: IP address of the message queuing server to receive messages
from
receiver_port:
type: string
description: Port to be used for receiving messages
#
other inputs omitted for brevity
substitution_mappings:
node_type: example.TransactionSubsystem
capabilities:
message_receiver: [ app, message_receiver
]
requirements:
database_endpoint: [ app, database ]
node_templates:
app:
type: example.SomeApp
properties:
# properties omitted for brevity
capabilities:
message_receiver:
properties:
service_ip: { get_input: mq_service_ip }
# other properties omitted for brevity
requirements:
- database:
# details omitted for brevity
-
host: websrv
websrv:
type: tosca.nodes.WebServer
properties:
# properties omitted for brevity
capabilities:
data_endpoint:
properties:
port_name: { get_input: receiver_port }
# other properties omitted for brevity
requirements:
- host: server
server:
type: tosca.nodes.Compute
# details omitted for brevity
outputs:
receiver_ip:
description: private IP address of the message receiver application
value: { get_attribute: [ server, private_address ] }
receiver_port:
description: Port of the message receiver endpoint
value: { get_attribute: [ app, app_endpoint, port ] }
|
2.12
Using node template substitution to provide product choice
Some service templates might include abstract node templates
that model specific functionality without fully specifying the exact product or
technology that provides that functionality. The objective of such service
templates is to allow the end-user of the service to decide at service deployment time
which specific product component to use.
2.12.1 Defining a service template with vendor-independent component
For example, let’s assume an abstract security service that
includes a firewall component where the choice of firewall product is left to
the end-user at service deployment time. The following template shows an
example of such a service: it includes an abstract firewall node template that
has a vendor
property that represents the firewall vendor. The value of this property is
obtained from a topology input variable that allows end-users to specify the
desired firewall vendor at deployment time.
Defining a security service with a vendor-independent
firewall component
tosca_definitions_version: tosca_simple_yaml_1_3
description:
Service template for an abstract security service
topology_template:
inputs:
vendorInput:
type: string
rulesInput:
type: list
entry_schema: FirewallRules
node_templates:
firewall:
type: abstract.Firewall
directives:
- substitute
properties:
vendor: { get_input: vendorInput }
rules: { get_input: rulesInput }
|
The abstract firewall node type is defined in the
following code snippet. The abstract firewall node type defines a rules property to hold the configured firewall rules. In
addition, it also defines a property for capturing the name of the vendor of
the firewall.
Node type defining an abstract firewall component
tosca_definitions_version:
tosca_simple_yaml_1_3
description:
Template defining an abstract firewall component
node_types:
abstract.Firewall:
derived_from: tosca.nodes.Root
properties:
vendor:
type: string
rules:
type: list
entry_schema: FirewallRules
|
2.12.2 Defining vendor-specific component options
In the above example, the firewall node template is
abstract, which means that it needs to be substituted with a substituting
firewall template. Let’s assume we have two firewall vendors—ACME Firewalls and
Simple Firewalls—who each provide implementations for the abstract firewall
component. Their respective implementations are defined in vendor-specific
service templates. ACME Firewall’s service template might look as follows:
Service template for an ACME firewall
tosca_definitions_version: tosca_simple_yaml_1_3
description:
Service template for an ACME firewall
topology_template:
inputs:
rulesInput:
type: list
entry_schema: FirewallRules
substitution_mappings:
node_type: abstract.Firewall
properties:
rules: [ rulesInput ]
node_templates:
acme:
type: ACMEFirewall
properties:
rules: { get_input: rulesInput }
acmeConfig:
# any ACME-specific properties go here.
|
In this example the node type ACMEFirewall is an
ACME-specific node type that models the internals of the ACME firewall product.
The ACMEFirewall node type definition is omitted here for brevity since it is
not relevant for the example.
Similarly, Simple Firewall’s service template looks
as follows:
Service template for a Simple Firewall
tosca_definitions_version:
tosca_simple_yaml_1_3
description:
Service template for a Simple Corp. firewall
topology_template:
inputs:
rulesInput:
type: list
entry_schema: FirewallRules
substitution_mappings:
node_type: abstract.Firewall
properties:
rules: [ rulesInput ]
node_templates:
acme:
type: SimpleFirewall
properties:
rules: { get_input: rulesInput }
|
As the substitution mappings section in the service
templates show, either firewall service template can be used to implement the
abstract firewall component defined above.
2.12.3 Substitution matching using substitution filters
Since both the ACME Firewall and the Simple Firewall can
substitute for abstract node templates of type abstract.Firewall,
either firewall is a valid candidate to substitute the abstract firewall node
template. When multiple matching templates are available, the orchestrator must
provide mechanisms to allow the end-user to drive the decision about which
matching template must be selected.
TOSCA uses a substitution_filter
in the substitution mappings section of a service template to further constrain
the abstract nodes for which a service template can be a valid substitution.
Using substitution filters, a service template is a valid candidate to
substitute an abstract node template if the following two conditions are met:
1. The type advertised in the substitution_mappings section
of the service template matches the type of the abstract node template.
2. The
property values of the abstract node template satisfy the constraints defined
in the substitution_filtter of the substituting
service template.
In the security service example used in this
section, the value of the vendor property of the
abstract firewall node template is provide by the end-user using a topology
input parameter. Substituting templates use a substitution_filter to match the
appropriate vendor-specific service templates with the abstract firewall node
template based on the value of the vendor property.
The following code snippet shows an updated version of the ACME
Firewall service template. This version includes a substitution_filter that
specifies that this service template only matches abstract firewall nodes with
a vendor property equal to ‘ACME’.
Service template for an ACME firewall with a substitution
filter
tosca_definitions_version:
tosca_simple_yaml_1_3
description:
Service template for an ACME firewall
topology_template:
inputs:
rulesInput:
type: list
entry_schema: FirewallRules
substitution_mappings:
node_type: abstract.Firewall
substitution_filter:
properties:
-
vendor: { equal: ACME }
properties:
rules: [ rulesInput ]
node_templates:
acme:
type: ACMEFirewall
properties:
rules: { get_input: rulesInput }
acmeConfig: # any ACME-specific properties go here.
|
Similarly, an updated service template for Simple
Corp’s firewall looks as follows:
Service template for a Simple firewall with a substitution
filter
tosca_definitions_version:
tosca_simple_yaml_1_3
description:
Service template for a Simple Corp. firewall
topology_template:
inputs:
rulesInput:
type: list
entry_schema: FirewallRules
substitution_mappings:
node_type: abstract.Firewall
substitution_filter:
properties:
-
vendor: { equal: Simple }
properties:
rules: [ rulesInput ]
node_templates:
acme:
type: SimpleFirewall
properties:
rules: { get_input: rulesInput }
|
As specified in this example, only abstract firewall node
templates that have the vendor property set to ‘Simple’
can be substituted by this service template.
In designing applications composed of several interdependent
software components (or nodes) it is often desirable to manage these components
as a named group. This can provide an effective way of associating policies
(e.g., scaling, placement, security or other) that orchestration tools can
apply to all the components of group during deployment or during other
lifecycle stages.
In many realistic scenarios it is desirable to
include scaling capabilities into an application to be able to react on load
variations at runtime. The example below shows the definition of a scaling web
server stack, where a variable number of servers with apache installed on them
can exist, depending on the load on the servers.
Example
20 - Grouping Node Templates for possible policy application
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: Template for a
scaling web server.
topology_template:
inputs:
# omitted here for brevity
node_templates:
apache:
type: tosca.nodes.WebServer.Apache
properties:
# Details omitted for
brevity
requirements:
- host: server
server:
type: tosca.nodes.Compute
# details omitted for
brevity
groups:
webserver_group:
type: tosca.groups.Root
members: [ apache, server ]
|
The example first of all uses the concept of
grouping to express which components (node templates) need to be scaled as a
unit – i.e. the compute nodes and the software on-top of each compute node.
This is done by defining the webserver_group
in the groups section of the template
and by adding both the apache node
template and the server node
template as a member to the group.
Furthermore, a scaling policy
is defined for the group to express that the group as a whole (i.e. pairs of server node and the apache component installed on top)
should scale up or down under certain conditions.
In cases where no explicit
binding between software components and their hosting compute resources is
defined in a template, but only requirements are defined as has been shown in
section 2.9, a provider could decide to place software components on the same
host if their hosting requirements match, or to place them onto different
hosts.
It is often desired, though, to
influence placement at deployment time to make sure components get collocation
or anti-collocated. This can be expressed via grouping and policies as shown in
the example below.
Example
21 - Grouping nodes for anti-colocation policy application
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: Template hosting
requirements and placement policy.
topology_template:
inputs:
# omitted here for brevity
node_templates:
wordpress_server:
type: tosca.nodes.WebServer
properties:
# omitted here for brevity
requirements:
- host:
# Find a Compute node
that fulfills these additional filter reqs.
node_filter:
capabilities:
- host:
properties:
- mem_size:
{ greater_or_equal: 512 MB }
- disk_size:
{ greater_or_equal: 2 GB }
- os:
properties:
- architecture:
x86_64
- type: linux
mysql:
type: tosca.nodes.DBMS.MySQL
properties:
# omitted here for brevity
requirements:
- host:
node: tosca.nodes.Compute
node_filter:
capabilities:
- host:
properties:
- disk_size:
{ greater_or_equal: 1 GB }
- os:
properties:
- architecture:
x86_64
- type: linux
groups:
my_co_location_group:
type: tosca.groups.Root
members: [ wordpress_server,
mysql ]
policies:
- my_anti_collocation_policy:
type: my.policies.anticolocateion
targets: [ my_co_location_group
]
# For this example, specific
policy definitions are considered
# domain specific and are
not included here
|
In the example above, both software components wordpress_server and mysql have similar hosting
requirements. Therefore, a provider could decide to put both on the same server
as long as both their respective requirements can be fulfilled. By defining a
group of the two components and attaching an anti-collocation policy to the
group it can be made sure, though, that both components are put onto different
hosts at deployment time.
The YAML 1.2 specification allows for defining of aliases, which allow
for authoring a block of YAML (or node) once and indicating it is an “anchor”
and then referencing it elsewhere in the same document as an “alias”. Effectively,
YAML parsers treat this as a “macro” and copy the anchor block’s code to
wherever it is referenced. Use of this feature is especially helpful when
authoring TOSCA Service Templates where similar definitions and property
settings may be repeated multiple times when describing a multi-tier
application.
For example, an application that has a web server and
database (i.e., a two-tier application) may be described using two Compute nodes (one to host the web server and
another to host the database). The author may want both Compute nodes to be
instantiated with similar properties such as operating system, distribution,
version, etc.
To accomplish this, the author would describe the
reusable properties using a named anchor in the “dsl_definitions” section of the TOSCA Service
Template and reference the anchor name as an alias in any Compute node templates where these properties
may need to be reused. For example:
Example 22 - Using YAML anchors in TOSCA templates
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
TOSCA simple profile that just
defines a YAML macro for commonly reused Compute
properties.
dsl_definitions:
my_compute_node_props: &my_compute_node_props
disk_size: 10 GB
num_cpus: 1
mem_size: 2 GB
topology_template:
node_templates:
my_server:
type: Compute
capabilities:
host:
properties: *my_compute_node_props
my_database:
type: Compute
capabilities:
host:
properties: *my_compute_node_props
|
It is possible for type and template authors to declare
input variables within an inputs block
on interfaces to nodes or relationships in order to pass along information
needed by their operations (scripts). These declarations can be scoped such as
to make these variable values available to all operations on a node or
relationships interfaces or to individual operations. TOSCA orchestrators will
make these values available using the appropriate mechanisms depending on the
type of implementation artifact used for each operation. For example, when
using script artifacts, input values are passed as environment variables within
the execution environments in which the scripts associated with lifecycle
operations are run.
2.15.1 Example: declaring
input variables for all operations on a single interface
|
node_templates:
wordpress:
type:
tosca.nodes.WebApplication.WordPress
requirements:
...
- database_endpoint:
mysql_database
interfaces:
Standard:
inputs:
wp_db_port: {
get_property: [ SELF, database_endpoint, port ] }
|
|
node_templates:
wordpress:
type:
tosca.nodes.WebApplication.WordPress
requirements:
...
- database_endpoint:
mysql_database
interfaces:
Standard:
create:
wordpress_install.sh
configure:
implementation:
wordpress_configure.sh
inputs:
wp_db_port: {
get_property: [ SELF, database_endpoint, port ] }
|
In the case where an input variable name is defined
at more than one scope within the same interfaces section of a node or template
definition, the lowest (or innermost) scoped declaration would override those
declared at higher (or more outer) levels of the definition.
Service template designers have the ability to define
operation outputs that specify named output values that are expected to be
returned by interface operations as well as the attributes on nodes or
relationships into which these output values must be stored.
2.16.1 Example: setting output values to a node attribute
The service template below shows an example service template
that is used to create a compute node. The config operation of the Standard
lifecycle returns both the private and the public IP addresses of the config
node. The attribute mappings grammar is used to reflect these addresses
into the appropriate Compute node attributes:
|
tosca_definitions_version:
tosca_simple_yaml_1_3
description: Template for creating
compute node
topology_template:
node_templates:
node:
type: tosca.nodes.Compute
interfaces:
Standard:
configure:
outputs:
ip1: [ SELF,
private_address ]
ip2: [ SELF,
public_address ]
|
2.16.2 Example: setting output values to a capability attribute
Some operation outputs may need to be reflected into
attributes of capabilities of nodes, rather than in attributes of the nodes
themselves. The following example shows how an IP address returned by a config
operation is stored in the ip_address attribute of
the endpoint capability of a Compute
node:
tosca_definitions_version:
tosca_simple_yaml_1_2_0
description:
Template for creating compute node
topology_template:
node_templates:
compute:
type: tosca.nodes.Compute
interfaces:
Standard:
config:
outputs:
ip1: [ SELF, endpoint, ip_address ]
|
As shown in the previous section, TOSCA allows service template
designers to reflect the results of executing interface operations into node or
relationship artifacts using output mappings. However, there are many
situations where components modeled by a node can change independently as a
result of external events (e.g. load changes, failures, mode changes, etc.) rather
than as a result of executing lifecycle management operations. To support those
situations, TOSCA includes support for notifications that allow service
template designers to specify how to asynchronously receive external events and
how those events should result in node or relationship attribute changes.
Just like operations, notifications are specified as
part of interface definitions. The major difference between notifications and
operations is that the former are called from the outside world to on the
orchestrator, and not the other way around. As a result, notifications do not
have inputs defined (since they are called asynchronously from the outside). Information
carried in notifications is pushed to the orchestrator via notification outputs
(similar to operation outputs).
The following example shows how a health monitoring
interface is used to allow the orchestrator to monitor the health of a database
node by listening for heartbeats as well as by waiting for asynchronous failure
alerts:
|
tosca_definitions_version:
tosca_simple_yaml_1_3
description: Template showing a
health monitoring interface
topology_template:
node_templates:
db_1:
type: org.ego.nodes.Database
interfaces:
HealthMonitor:
notifications:
heartbeat:
outputs:
tick: [ SELF,
still_alive ]
failure_report:
outputs:
level: [SELF,
failure_level]
time: [SELF,
failure_time]
environment:
[SELF, failure_context]
|
A TOSCA service template contains a topology template,
which models the components of an application, their relationships and dependencies
(a.k.a., a topology model) that get interpreted and instantiated by TOSCA
Orchestrators. The actual node and relationship instances that are created represent
a set of resources distinct from the template itself, called a topology
instance (model). The direction of this specification is to provide access
to the instances of these resources for management and operational control by
external administrators. This model can also be accessed by an orchestration
engine during deployment – i.e. during the actual process of instantiating the
template in an incremental fashion, That is, the orchestrator can choose the
order of resources to instantiate (i.e., establishing a partial set of node and
relationship instances) and have the ability, as they are being created, to
access them in order to facilitate instantiating the remaining resources of the
complete topology template.
Most entity types in TOSCA (e.g., Node, Relationship,
Capability Types, etc.) have property
definitions, which allow template authors to set the values for as inputs
when these entities are instantiated by an orchestrator. These property values
are considered to reflect the desired state of the entity by the author. Once
instantiated, the actual values for these properties on the realized
(instantiated) entity are obtainable via attributes on the entity with the same
name as the corresponding property.
In other words, TOSCA orchestrators will
automatically reflect (i.e., make available) any property defined on an entity
as an attribute of the entity with the same name as the property.
Use of this feature is shown in the example below where a
source node named my_client, of type ClientNode, requires a connection to another
node named my_server of type ServerNode. As you can see, the ServerNode type defines a property named notification_port which defines a dedicated
port number which instances of my_client
may use to post asynchronous notifications to it during runtime. In this case,
the TOSCA Simple Profile assures that the notification_port
property is implicitly reflected as an attribute in the my_server node (also with the name notification_port) when its node template is
instantiated.
Example 23 - Properties reflected as attributes
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
TOSCA simple profile that shows
how the (notification_port) property is reflected as an attribute and can be
referenced elsewhere.
node_types:
ServerNode:
derived_from: SoftwareComponent
properties:
notification_port:
type: integer
capabilities:
# omitted here for brevity
ClientNode:
derived_from: SoftwareComponent
properties:
# omitted here for brevity
requirements:
- server:
capability: Endpoint
node: ServerNode
relationship:
ConnectsTo
topology_template:
node_templates:
my_server:
type:
ServerNode
properties:
notification_port:
8000
my_client:
type:
ClientNode
requirements:
-
server:
node: my_server
relationship:
my_connection
relationship_templates:
my_connection:
type: ConnectsTo
interfaces:
Configure:
inputs:
targ_notify_port: {
get_attribute: [ TARGET, notification_port ] }
# other operation
definitions omitted here for brevity
|
Specifically, the above example shows that the ClientNode type needs the notification_port value anytime a node of ServerType is connected to it using the ConnectsTo relationship in order to make it
available to its Configure operations
(scripts). It does this by using the get_attribute
function to retrieve the notification_port
attribute from the TARGET node of the ConnectsTo relationship (which is a node of
type ServerNode) and assigning it to an
environment variable named targ_notify_port.
It should be noted that the actual port value of the notification_port attribute may or may not be
the value 8000 as requested on the
property; therefore, any node that is dependent on knowing its actual “runtime”
value would use the get_attribute
function instead of the get_property
function.
TOSCA service templates specify a set of nodes that
need to be instantiated at service deployment time. Some service templates may
include multiple nodes that perform the same role. For example, a template that
models an SD-WAN service might contain multiple VPN Site nodes, one for each
location that accesses the SD-WAN. Rather than having to create a separate
service template for each possible number of VPN sites, it would be preferable
to have a single service template that allows the number of VPN sites to be
specified as an input to the template at deployment time. This section
introduces experimental TOSCA language extensions in support of
this functionality.It is expected that these extensions will be formally
standardized in a future version of this specifications.
The discussion in this section uses an example
SD-WAN deployment to three sites as shown in the following figure:
Example SD-WAN
Service Deployment
The following code snippet shows a TOSCA service template
from which this service could have been deployed:
Example
24 – TOSCA SD-WAN Service Template
|
tosca_definitions_version:
tosca_simple_yaml_1_3
description: Template for
deploying SD-WAN with three sites.
topology_template:
inputs:
location1:
type: Location
location2:
type: Location
location3:
type: Location
node_templates:
sdwan:
type: VPN
site1:
type: VPNSite
properties:
location: { get_input: location1 }
requirements:
- vpn: sdwan
site2:
type: VPNSite
properties:
location: { get_input: location2 }
requirements:
- vpn: sdwan
site3:
type: VPNSite
properties:
location: { get_input: location3 }
requirements:
- vpn: sdwan
|
Unfortunately, this template can only be used to deploy an
SD-WAN with three sites. To deploy a different number of sites, additional
service templates would have t be created, one for each number of possible
SD-WAN sites. This leads to template proliferation, which is undesirable. The
next section explores alternatives.
2.20.1 Specifying Number of Occurrences
To avoid the need for multiple service templates, TOSCA must
provide a mechanism that allows all VPN Site nodes to be created from the same
Site node template in the topology, and allow the number of sites to be
specified at deployment time. Specifically, this functionality must:
-
Allow service template designers to specify that multiple node
instances can be created from a single node template
-
Allow service template designers to constrain how many node
instances can be created from a single node template
-
Allow users to specify at deployment time the exact number of
instances that need to be created from the single node template.
To provide this functionality, the TOSCA node template
definition grammar is extended with an occurrences
keyword that specifies the minimum and maximum number of instances that can be
created from this node template. If occurrences is not specified, only one
single instance can be created. In addition, an instance_count
keyword is used to specify the requested number of runtime instances of this
node template. It is expected that the value of the instance_count is provided
as an input to the topology template. These extensions enable the creation of a
simplified SD-WAN service template that contains only one single VPN Site node
as shown in the following code snippet:
Example
25 – TOSCA SD-WAN Service Template
|
tosca_definitions_version:
tosca_simple_yaml_1_3
description:
Template for deploying SD-WAN with a variable number of sites.
topology_template:
inputs:
numberOfSites:
type: integer
node_templates:
sdwan:
type: VPN
site:
type: VPNSite
occurrences: [1, UNBOUNDED]
instance_count: { get_input: numberOfSites }
requirements:
- vpn: sdwan
|
2.20.2 Specifying Inputs
The service template in the previous section
conveniently ignores the location property of the Site node. As shown earlier,
the location property is expected to be provided as an input value. If Site
node templates can be instantiated multiple times, then it follows that
multiple input values are required to initialize the location property for each
of the Site node instances.
To allow specific input
values to be matched with specific node template instances, a new reserved
keyword called INDEX is introduced. A TOSCA orchestrator will interpret this
keyword as the runtime index in the list of node instances created from a
single node template.
The following service
template shows how the INDEX keyword is used to retrieve specific values from a
list of input values in a service template:
Example
26 – TOSCA SD-WAN Service Template
|
tosca_definitions_version:
tosca_simple_yaml_1_3
description:
Template for deploying SD-WAN with a variable number of sites.
topology_template:
inputs:
numberOfSites:
type: integer
locations:
type: list
entry_schema: Location
node_templates:
sdwan:
type: VPN
site:
type: VPNSite
occurrences: [1, UNBOUNDED]
instance_count: { get_input: numberOfSites }
properties:
location: { get_input: [ locations, INDEX ] }
requirements:
- vpn: sdwan
|
3
TOSCA Simple Profile definitions in YAML
Except for the examples, this section is normative
and describes all of the YAML grammar, definitions and block structure for all
keys and mappings that are defined for the TOSCA Version 1.3 Simple Profile
specification that are needed to describe a TOSCA Service Template (in YAML).
The following TOSCA Namespace URI alias and TOSCA
Namespace Alias are reserved values which SHALL be used when identifying the
TOSCA Simple Profile version 1.3 specification.
|
Namespace Alias
|
Namespace URI
|
Specification Description
|
|
tosca_simple_yaml_1_3
|
http://docs.oasis-open.org/tosca/ns/simple/yaml/1.3
|
The TOSCA Simple Profile v1.3 (YAML) target namespace and
namespace alias.
|
The following TOSCA Namespace prefix is a reserved
value and SHALL be used to reference the default TOSCA Namespace URI as
declared in TOSCA Service Templates.
|
Namespace Prefix
|
Specification Description
|
|
tosca
|
The reserved TOSCA Simple Profile Specification prefix
that can be associated with the default TOSCA Namespace URI
|
In the TOSCA Simple Profile, TOSCA Service Templates
MUST always have, as the first line of YAML, the keyword “tosca_definitions_version” with an associated
TOSCA Namespace Alias value. This single line accomplishes the following:
1. Establishes
the TOSCA Simple Profile Specification version whose grammar MUST be used to
parse and interpret the contents for the remainder of the TOSCA Service
Template.
2. Establishes
the default TOSCA Namespace URI and Namespace Prefix for all types found in the
document that are not explicitly namespaced.
3. Automatically
imports (without the use of an explicit import statement) the normative type
definitions (e.g., Node, Relationship, Capability, Artifact, etc.) that are
associated with the TOSCA Simple Profile Specification the TOSCA Namespace
Alias value identifies.
4. Associates
the TOSCA Namespace URI and Namespace Prefix to the automatically imported
TOSCA type definitions.
TOSCA Simple Profiles allows template authors to declare
their own types and templates and assign them simple names with no apparent
namespaces. Since TOSCA Service Templates can import other service templates to
introduce new types and topologies of templates that can be used to provide
concrete implementations (or substitute) for abstract nodes. Rules are needed
so that TOSCA Orchestrators know how to avoid collisions and apply their own
namespaces when import and nesting occur.
3.1.3.1 Additional Requirements
·
The URI value “http://docs.oasis-open.org/tosca”,
as well as all (path) extensions to it, SHALL be reserved for TOSCA approved
specifications and work. That means Service Templates that do not originate
from a TOSCA approved work product MUST NOT use it, in any form, when declaring
a (default) Namespace.
·
Since TOSCA Service Templates can import (or substitute in) other
Service Templates, TOSCA Orchestrators and tooling will encounter the “tosca_definitions_version” statement for each
imported template. In these cases, the following additional requirements
apply:
o
Imported type definitions with the same Namespace URI, local name
and version SHALL be equivalent.
o
If different values of the “tosca_definitions_version”
are encountered, their corresponding type definitions MUST be uniquely
identifiable using their corresponding Namespace URI using a different
Namespace prefix.
·
Duplicate local names (i.e., within the same Service Template SHALL
be considered an error. These include, but are not limited to duplicate names found
for the following definitions:
o
Repositories (repositories)
o
Data Types (data_types)
o
Node Types (node_types)
o
Relationship Types (relationship_types)
o
Capability Types (capability_types)
o
Artifact Types (artifact_types)
o
Interface Types (interface_types)
·
Duplicate Template names within a Service Template’s Topology
Template SHALL be considered an error. These include, but are not limited to
duplicate names found for the following template types:
o
Node Templates (node_templates)
o
Relationship Templates (relationship_templates)
o
Inputs (inputs)
o
Outputs (outputs)
·
Duplicate names for the following keynames within Types or
Templates SHALL be considered an error. These include, but are not limited to
duplicate names found for the following keynames:
o
Properties (properties)
o
Attributes (attributes)
o
Artifacts (artifacts)
o
Requirements (requirements)
o
Capabilities (capabilities)
o
Interfaces (interfaces)
o
Policies (policies)
o
Groups (groups)
3.2 Using Namespaces
As of TOSCA version 1.2, Service template authors may
declare a namespace within a Service Template that would be used as the default
namespace for any types (e.g., Node Type, Relationship Type, Data Type, etc.) defined
within the same Service template.
Specifically, a Service Template’s namespace declaration’s
URI would be used to form a unique, fully qualified Type name when combined
with the locally defined, unqualified name of any Type in the same Service
Template. The resulatant, fully qualified Type name would be used by TOSCA
Orchestrators, Processors and tooling when that Service Template was imported
into another Service Template to avoid Type name collision.
If a default namespace for the Service Template is declared,
then it should be declared immediately after the “tosca_definitions_version” declaration, to ensure
that the namespace is clearly visible.
3.2.1 Example – Importing a Service Template and Namespaces
For example, let say we have two Service Templates,
A and B, both of which define Types and a Namespace. Service Template B
contains a Node Type definition for “MyNode” and
declares its (default) Namespace to be “http://companyB.com/service/namespace/”:
Service Template B
|
tosca_definitions_version:
tosca_simple_yaml_1_2
description: Service Template B
namespace:
http://companyB.com/service/namespace/
node_types:
MyNode:
derived_from: SoftwareComponent
properties:
# omitted here for brevity
capabilities:
# omitted here for brevity
|
Service Template A has its own, completely different, Node
Type definition also named “MyNode“.
Service Template A
|
tosca_definitions_version:
tosca_simple_yaml_1_2
description: Service Template A
namespace:
http://companyA.com/product/ns/
imports:
- file: csar/templates/ServiceTemplateB.yaml
namespace_prefix: templateB
node_types:
MyNode:
derived_from: Root
properties:
# omitted here for brevity
capabilities:
# omitted here for brevity
|
As you can see, Service Template A also “imports“
Service Template B (i.e., “ServiceTemplateB.yaml“) bringing in its Type
defintions to the global namespace using the Namespace URI declared in Service
Template B to fully qualify all of its imported types.
In addition, the import includes a “namespace_prefix“ value
(i.e., “templateB“ ), that can be used to qualify and disambiguate any
Type reference from from Service Template B within Service Template A. This
prefix is effectively the local alias for the corresponding Namespace URI
declared within Service Template B (i.e., “http://companyB.com/service/namespace/“).
To illustrate conceptually what a TOSCA Orchestrator, for
example, would track for their global namespace upon processing Service
Template A (and by import Service Template B) would be a list of global
Namespace URIs and their associated Namespace prefixes, as well as a list of
fully qualified Type names that comprises the overall global namespace.
3.2.1.1 Conceptual Global Namespace URI and Namespace Prefix tracking
|
Entry#
|
Namespace URI
|
Namespace Prefix
|
Added by Key (Source
file)
|
|
1
|
http://open.org/tosca/ns/simple/yaml/1.3/
|
tosca
|
·
tosca_definitions_version:
- from
Service Template A
|
|
2
|
http://companyA.com/product/ns/
|
<None>
|
·
namespace:
- from Service
Template A
|
|
3
|
http://companyB.com/service/namespace/
|
templateB
|
·
namespace:
- from
Service Template B
·
namespace_prefix:
- from Service
Template A, during import
|
In the above table,
·
Entry 1: is an entry for the default TOSCA namespace,
which is required to exist for it to be a valid Service template. It is
established by the “tosca_definitions_version”
key’s value. By default, it also gets assigned the “tosca” Namespace prefix.
·
Entry 2: is the entry for the local default namespace for
Service Template A as declared by the “namespace”
key.
o
Note that no Namespace prefix is needed; any locally defined
types that are not qualified (i.e., not a full URI or using a Namespace Prefix)
will default to this namespace if not found first in the TOSCA namespace.
·
Entry 3: is the entry for default Namespace URI for any
type imported from Service Template B. The author of Service Template A has
assigned the local Namespace Prefix “templateB” that can be used to qualify
reference to any Type from Service Template B.
As per TOSCA specification, any Type, that is not qualified
with the ‘tosca’ prefix or full URI name, should be first resolved by its
unqualified name within the TOSCA namespace. If it not found there, then it
may be resolved within the local Service Template’s default namespace.
3.2.1.2 Conceptual Global Namespace and Type tracking
|
Entry#
|
Namespace URI
|
Unqualified Full Name
|
Unqualified Short Name
|
Type Classification
|
|
1
|
http://open.org/tosca/ns/simple/yaml/1.3/
|
tosca.nodes.Compute
|
Compute
|
node
|
|
2
|
http://open.org/tosca/ns/simple/yaml/1.3/
|
tosca.nodes.SoftwareComponent
|
SoftwareComponent
|
|
|
3
|
http://open.org/tosca/ns/simple/yaml/1.3/
|
tosca.relationships.ConnectsTo
|
ConnectsTo
|
relationship
|
|
...
|
...
|
|
|
|
|
100
|
http://companyA.com/product/ns/
|
N/A
|
MyNode
|
node
|
|
...
|
...
|
|
|
|
|
200
|
http://companyB.com/service/namespace/
|
N/A
|
MyNode
|
node
|
|
...
|
...
|
|
|
|
In the above table,
·
Entry 1: is an example of one of the TOSCA standard Node
Types (i.e., “Compute”) that is brought into the global namespace via the
“tosca_definitions_version” key.
o
It also has two forms, full and short that are unique to TOSCA
types for historical reasons. Reference to a TOSCA type by either its
unqualified short or full names is viewed as equivalent as a reference to the
same fully qualified Type name (i.e., its full URI).
o
In this example, use of either “tosca.nodes.Compute”
or “Compute” (i.e., an unqualified full and
short name Type) in a Service Template would be treated as its fully qualified
URI equivalent of:
§
“http://docs.oasis-open.org/tosca/ns/simple/yaml/1.3/tosca.nodes.Compute”.
·
Entry 2: is an example of a standard TOSCA Relationship
Type
·
Entry 100: contains the unique Type identifer for the Node
Type “MyNode” from Service Template A.
·
Entry 200: contains the unique Type identifer for the Node
Type “MyNode” from Service Template B.
As you can see,
although both templates defined a NodeType with an unqualified name of
“MyNode”, the TOSCA Orchestrator, processor or tool tracks them by their unique
fully qualified Type Name (URI).
The
classification column is included as an example on how to logically
differentiate a “Compute” Node Type and “Compute” capability type if the table
would be used to “search” for a match based upon context in a Service
Template.
For example, if the
short name “Compute” were used in a template on a Requirements clause, then the
matching type would not be the Compute Node Type, but instead the Compute
Capability Type based upon the Requirement clause being the context for Type
reference.
This clause describes the primitive types that are used for
declaring normative properties, parameters and grammar elements throughout this
specification.
Many of the types we use in this profile are
built-in types from the YAML
1.2 specification (i.e., those identified by the “tag:yaml.org,2002”
version tag) [YAML-1.2].
The following table declares the valid YAML type
URIs and aliases that SHALL be used when possible when defining parameters or
properties within TOSCA Service Templates using this specification:
3.3.1.1 Notes
·
The “string” type is the default type when not specified on a parameter
or property declaration.
·
While YAML supports further type aliases, such as “str” for
“string”, the TOSCA Simple Profile specification promotes the fully expressed
alias name for clarity.
TOSCA supports the concept of “reuse” of type
definitions, as well as template definitions which could be version and change
over time. It is important to provide a reliable, normative means to represent
a version string which enables the comparison and management of types and
templates over time. Therefore, the TOSCA TC intends to provide a normative
version type (string) for this purpose in future Working Drafts of this
specification.
|
Shorthand Name
|
version
|
|
Type Qualified Name
|
tosca:version
|
3.3.2.1 Grammar
TOSCA version strings have the following grammar:
|
<major_version>.<minor_version>[.<fix_version>[.<qualifier>[-<build_version]
] ]
|
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
major_version: is a
required integer value greater than or equal to 0 (zero)
·
minor_version: is a
required integer value greater than or equal to 0 (zero).
·
fix_version: is an optional
integer value greater than or equal to 0 (zero).
·
qualifier: is an optional
string that indicates a named, pre-release version of the associated code that
has been derived from the version of the code identified by the combination major_version, minor_version and fix_version numbers.
·
build_version: is an
optional integer value greater than or equal to 0 (zero) that can be used to
further qualify different build versions of the code that has the same qualifer_string.
3.3.2.2 Version Comparison
·
When comparing TOSCA versions, all component versions (i.e., major,
minor and fix) are compared in sequence from left to right.
·
TOSCA versions that include the optional qualifier are considered
older than those without a qualifier.
·
TOSCA versions with the same major, minor, and fix versions and have
the same qualifier string, but with different build versions can be compared
based upon the build version.
·
Qualifier strings are considered domain-specific. Therefore,
this specification makes no recommendation on how to compare TOSCA versions
with the same major, minor and fix versions, but with different qualifiers strings
and simply considers them different named branches derived from the same code.
3.3.2.3 Examples
Examples of valid TOSCA version strings:
|
# basic version strings
6.1
2.0.1
# version string with optional
qualifier
3.1.0.beta
# version string with optional
qualifier and build version
1.0.0.alpha-10
|
3.3.2.4 Notes
·
[Maven-Version] The TOSCA
version type is compatible with the Apache Maven versioning policy.
3.3.2.5 Additional Requirements
·
A version value of zero (i.e., ‘0’, ‘0.0’, or ‘0.0.0’) SHALL indicate
there no version provided.
·
A version value of zero used with any qualifiers SHALL NOT be
valid.
The range type can be used to define numeric ranges
with a lower and upper boundary. For example, this allows for specifying a
range of ports to be opened in a firewall.
|
Shorthand Name
|
range
|
|
Type Qualified Name
|
tosca:range
|
3.3.3.1 Grammar
TOSCA range values have the following grammar:
|
[<lower_bound>,
<upper_bound>]
|
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
lower_bound: is a
required integer value that denotes the lower boundary of the range.
·
upper_bound: is a
required integer value that denotes the upper boundary of the range. This value
MUST be greater than or equal to lower_bound.
3.3.3.2 Keywords
The following Keywords may be used in the TOSCA
range type:
|
Keyword
|
Applicable Types
|
Description
|
|
UNBOUNDED
|
scalar
|
Used to represent an unbounded upper bounds (positive)
value in a set for a scalar type.
|
3.3.3.3 Examples
Example of a node template property with a range
value:
|
# numeric range between 1 and 100
a_range_property: [ 1, 100 ]
# a property that has allows any
number 0 or greater
num_connections: [ 0, UNBOUNDED ]
|
The list type allows for specifying multiple values for a
parameter of property. For example, if an application allows for being
configured to listen on multiple ports, a list of ports could be configured
using the list data type.
Note that entries in a list for one property or
parameter must be of the same type. The type (for simple entries) or schema (for
complex entries) is defined by the entry_schema
attribute of the respective property
definition, attribute definitions,
or input or output parameter definitions.
|
Shorthand Name
|
list
|
|
Type Qualified Name
|
tosca:list
|
3.3.4.1 Grammar
TOSCA lists are essentially normal YAML lists with
the following grammars:
3.3.4.1.1 Square bracket notation
|
[ <list_entry_1>,
<list_entry_2>, ... ]
|
3.3.4.1.2 Bulleted list notation
|
- <list_entry_1>
- ...
- <list_entry_n>
|
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
<list_entry_*>:
represents one entry of the list.
3.3.4.2 Declaration Examples
3.3.4.2.1 List declaration using a simple type
The following example shows a list declaration with
an entry schema based upon a simple integer type (which has additional
constraints):
|
<some_entity>:
...
properties:
listen_ports:
type: list
entry_schema:
description: listen port
entry (simple integer type)
type: integer
constraints:
- max_length: 128
|
3.3.4.2.2 List declaration using a complex type
The following example shows a list declaration with
an entry schema based upon a complex type:
|
<some_entity>:
...
properties:
products:
type: list
entry_schema:
description: Product
information entry (complex type) defined elsewhere
type: ProductInfo
|
3.3.4.3 Definition Examples
These examples show two notation options for defining lists:
·
A single-line option which is useful for only short lists with
simple entries.
·
A multi-line option where each list entry is on a separate line;
this option is typically useful or more readable if there is a large number of
entries, or if the entries are complex.
3.3.4.3.1 Square bracket notation
|
listen_ports: [ 80, 8080 ]
|
3.3.4.3.2 Bulleted list notation
|
listen_ports:
- 80
- 8080
|
The map type allows for specifying multiple values for a
parameter of property as a map. In contrast to the list type, where each entry
can only be addressed by its index in the list, entries in a map are named
elements that can be addressed by their keys.
Note that entries in a map for one property or
parameter must be of the same type. The type (for simple entries) or schema
(for complex entries) is defined by the entry_schema
attribute of the respective property
definition, attribute definition,
or input or output parameter definition.
In addition, the keys that identify entries in a map must be of the same type as
well. The type of these keys is defined by the key_schema attribute of the
respective property_definition, attribute_definition, or input or output
parameter_definition. If the key_schema is not specified, keys are assumed to
be of type string.
|
Shorthand Name
|
map
|
|
Type Qualified Name
|
tosca:map
|
3.3.5.1 Grammar
TOSCA maps are normal YAML dictionaries with
following grammar:
3.3.5.1.1 Single-line grammar
|
{ <entry_key_1>:
<entry_value_1>, ..., <entry_key_n>: <entry_value_n> }
|
3.3.5.1.2 Multi-line grammar
|
<entry_key_1>:
<entry_value_1>
...
<entry_key_n>:
<entry_value_n>
|
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
entry_key_*: is the
required key for an entry in the map
·
entry_value_*: is the
value of the respective entry in the map
3.3.5.2 Declaration Examples
3.3.5.2.1 Map declaration using a simple type
The following example shows a map with an entry
schema definition based upon an existing string type (which has additional
constraints):
|
<some_entity>:
...
properties:
emails:
type: map
entry_schema:
description: basic email
address
type: string
constraints:
- max_length: 128
|
3.3.5.2.2 Map declaration using a complex type
The following example shows a map with an entry
schema definition for contact information:
|
<some_entity>:
...
properties:
contacts:
type: map
entry_schema:
description: simple
contact information
type: ContactInfo
|
3.3.5.3 Definition Examples
These examples show two notation options for defining
maps:
·
A single-line option which is useful for only short maps with
simple entries.
·
A multi-line option where each map entry is on a separate line;
this option is typically useful or more readable if there is a large number of
entries, or if the entries are complex.
3.3.5.3.1 Single-line notation
|
# notation option for shorter maps
user_name_to_id_map: { user1:
1001, user2: 1002 }
|
3.3.5.3.2 Multi-line notation
|
# notation for longer maps
user_name_to_id_map:
user1: 1001
user2: 1002
|
The scalar-unit type can be used to define scalar values
along with a unit from the list of recognized units provided below.
3.3.6.1 Grammar
TOSCA scalar-unit typed values have the following
grammar:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
scalar: is a required scalar
value.
·
unit: is a required unit
value. The unit value MUST be type-compatible with the scalar.
3.3.6.2 Additional requirements
·
Whitespace: any number of spaces (including zero or
none) SHALL be allowed between the scalar
value and the unit value.
·
It SHALL be considered an error if either the scalar or
unit portion is missing on a property or attribute declaration derived from any
scalar-unit type.
·
When performing constraint clause evaluation on values of the
scalar-unit type, both the scalar value portion and unit value portion SHALL
be compared together (i.e., both are treated as a single value). For example,
if we have a property called storage_size.
which is of type scalar-unit, a valid range constraint would appear as follows:
o
storage_size: in_range [ 4 GB, 20 GB ]
where storage_size’s range would be evaluated using
both the numeric and unit values (combined together), in this case ‘4 GB’ and
’20 GB’.
3.3.6.3 Concrete Types
|
Shorthand Names
|
scalar-unit.size, scalar-unit.time, scalar-unit.frequency,
scalar-unit.bitrate
|
|
Type Qualified Names
|
tosca:scalar-unit.size, tosca:scalar-unit.time
|
The scalar-unit type grammar is abstract and has four recognized
concrete types in TOSCA:
·
scalar-unit.size – used to define properties that have
scalar values measured in size units.
·
scalar-unit.time – used to define properties that have
scalar values measured in size units.
·
scalar-unit.frequency – used to define properties that
have scalar values measured in units per second.
·
scalar-unit.bitrate – used to define properties that have
scalar values measured in bits or bytes per second
These types and their allowed unit values are
defined below.
3.3.6.4.1 Recognized Units
|
Unit
|
Usage
|
Description
|
|
B
|
size
|
byte
|
|
kB
|
size
|
kilobyte (1000 bytes)
|
|
KiB
|
size
|
kibibytes (1024 bytes)
|
|
MB
|
size
|
megabyte (1000000 bytes)
|
|
MiB
|
size
|
mebibyte (1048576 bytes)
|
|
GB
|
size
|
gigabyte (1000000000 bytes)
|
|
GiB
|
size
|
gibibytes (1073741824 bytes)
|
|
TB
|
size
|
terabyte (1000000000000
bytes)
|
|
TiB
|
size
|
tebibyte (1099511627776
bytes)
|
3.3.6.4.2 Examples
|
# Storage size in Gigabytes
properties:
storage_size: 10 GB
|
3.3.6.4.3 Notes
·
The unit values recognized by TOSCA Simple Profile for size-type
units are based upon a subset of those defined by GNU at http://www.gnu.org/software/parted/manual/html_node/unit.html,
which is a non-normative reference to this specification.
·
TOSCA treats these unit values as case-insensitive (e.g., a value
of ‘kB’, ‘KB’ or ‘kb’ would be equivalent), but it is considered best practice
to use the case of these units as prescribed by GNU.
·
Some Cloud providers may not support byte-level granularity for
storage size allocations. In those cases, these values could be treated as
desired sizes and actual allocations would be based upon individual provider capabilities.
3.3.6.5
scalar-unit.time
3.3.6.5.1 Recognized Units
|
Unit
|
Usage
|
Description
|
|
d
|
time
|
days
|
|
h
|
time
|
hours
|
|
m
|
time
|
minutes
|
|
s
|
time
|
seconds
|
|
ms
|
time
|
milliseconds
|
|
us
|
time
|
microseconds
|
|
ns
|
time
|
nanoseconds
|
3.3.6.5.2 Examples
|
# Response time in milliseconds
properties:
respone_time: 10 ms
|
·
The unit values recognized by TOSCA Simple Profile for time-type
units are based upon a subset of those defined by International System of Units
whose recognized abbreviations are defined within the following reference:
o http://www.ewh.ieee.org/soc/ias/pub-dept/abbreviation.pdf
o
This document is a non-normative reference to this specification
and intended for publications or grammars enabled for Latin characters which
are not accessible in typical programming languages
3.3.6.6.1 Recognized Units
|
Unit
|
Usage
|
Description
|
|
Hz
|
frequency
|
Hertz, or Hz. equals one cycle per second.
|
|
kHz
|
frequency
|
Kilohertz, or kHz, equals to 1,000 Hertz
|
|
MHz
|
frequency
|
Megahertz, or MHz, equals to 1,000,000 Hertz or 1,000 kHz
|
|
GHz
|
frequency
|
Gigahertz, or GHz, equals to 1,000,000,000 Hertz, or
1,000,000 kHz, or 1,000 MHz.
|
3.3.6.6.2 Examples
|
# Processor raw clock rate
properties:
clock_rate: 2.4 GHz
|
3.3.6.6.3 Notes
·
The value for Hertz (Hz) is the International Standard
Unit (ISU) as described by the Bureau International des Poids et Mesures (BIPM)
in the “SI Brochure: The International System of Units (SI)
[8th edition, 2006; updated in 2014]”, http://www.bipm.org/en/publications/si-brochure/
3.3.6.7 scalar-unit.bitrate
3.3.6.7.1 Recognized Units
|
Unit
|
Usage
|
Description
|
|
bps
|
bitrate
|
bit per second
|
|
Kbps
|
bitrate
|
kilobit (1000 bits) per second
|
|
Kibps
|
bitrate
|
kibibits (1024 bits) per second
|
|
Mbps
|
bitrate
|
megabit (1000000 bits) per second
|
|
Mibps
|
bitrate
|
mebibit (1048576 bits) per second
|
|
Gbps
|
bitrate
|
gigabit (1000000000 bits) per second
|
|
Gibps
|
bitrate
|
gibibits (1073741824 bits) per second
|
|
Tbps
|
bitrate
|
terabit (1000000000000 bits) per second
|
|
Tibps
|
bitrate
|
tebibits (1099511627776 bits) per second
|
|
Bps
|
bitrate
|
byte per second
|
|
KBps
|
bitrate
|
kilobyte (1000 bytes) per second
|
|
KiBps
|
bitrate
|
kibibytes (1024 bytes) per second
|
|
MBps
|
bitrate
|
megabyte (1000000 bytes) per second
|
|
MiBps
|
bitrate
|
mebibyte (1048576 bytes) per second
|
|
GBps
|
bitrate
|
gigabyte (1000000000 bytes) per second
|
|
GiBps
|
bitrate
|
gibibytes (1073741824 bytes) per second
|
|
TBps
|
bitrate
|
terabytes (1000000000000 bits) per second
|
|
TiBps
|
bitrate
|
tebibytes (1099511627776 bits) per second
|
3.3.6.7.2 Examples
|
#### Somewhere in a node template
definition
requirements:
- link:
node_filter:
capabilities:
- myLinkable
properties:
bitrate:
-
greater_or_equal: 10 Kbps # 10 * 1000 bits per second at least
|
3.3.6.7.3 Notes
·
Unlike with the scalar-unit.size type, TOSCA treats scalar-unit.bitrate
values as case-sensitive (e.g., a value of ‘KBs’ means kilobyte per second,
whereas ‘Kb’ means kilobit per second).
·
For comparison purposes, 1 byte is the same as 8 bits.
As components (i.e., nodes) of TOSCA applications are
deployed, instantiated and orchestrated over their lifecycle using normative
lifecycle operations (see section 5.8 for normative lifecycle definitions) it
is important define normative values for communicating the states of these
components normatively between orchestration and workflow engines and any
managers of these applications.
The following table provides the list of recognized node
states for TOSCA Simple Profile that would be set by the orchestrator to
describe a node instance’s state:
|
Node State
|
|
Value
|
Transitional
|
Description
|
|
initial
|
no
|
Node is not yet created.
Node only exists as a template definition.
|
|
creating
|
yes
|
Node is transitioning from initial state
to created state.
|
|
created
|
no
|
Node software has been
installed.
|
|
configuring
|
yes
|
Node is transitioning from created state
to configured state.
|
|
configured
|
no
|
Node has been configured
prior to being started.
|
|
starting
|
yes
|
Node is transitioning from configured
state to started state.
|
|
started
|
no
|
Node is started.
|
|
stopping
|
yes
|
Node is transitioning from
its current state to a configured state.
|
|
deleting
|
yes
|
Node is transitioning from
its current state to one where it is deleted and its state is no longer
tracked by the instance model.
|
|
error
|
no
|
Node is in an error state.
|
Similar to the Node States described in the previous
section, Relationships have state relative to their (normative) lifecycle
operations.
The following table provides the list of recognized
relationship states for TOSCA Simple Profile that would be set by the
orchestrator to describe a node instance’s state:
|
Node State
|
|
Value
|
Transitional
|
Description
|
|
initial
|
no
|
Relationship is not yet
created. Relationship only exists as a template definition.
|
3.4.2.1 Notes
·
Additional states may be defined in future versions of the TOSCA
Simple Profile in YAML specification.
The following directive values are defined for this
version of the TOSCA Simple Profile:
|
Directive
|
Description
|
|
substitute
|
Marks a node template as
abstract and instructs the TOSCA Orchestrator to substitute this node
template with an appropriate substituting template.
|
|
substitutable
|
This deprecated
directive is synonymous to the substitute directive.
|
|
select
|
Marks a node template as
abstract and instructs the TOSCA Orchestrator to select a node of this type
from its inventory (based on constraints specified in the optional
node_filter in the node template)
|
|
selectable
|
This deprecated
directive is synonymous to the select directive.
|
The following are recognized values that may be used
as aliases to reference types of networks within an application model without
knowing their actual name (or identifier) which may be assigned by the
underlying Cloud platform at runtime.
|
Alias value
|
Description
|
|
PRIVATE
|
An alias used to reference
the first private network within a property or attribute of a Node or
Capability which would be assigned to them by the underlying platform at
runtime.
A private network contains
IP addresses and ports typically used to listen for incoming traffic to an
application or service from the Intranet and not accessible to the public
internet.
|
|
PUBLIC
|
An alias used to reference
the first public network within a property or attribute of a Node or
Capability which would be assigned to them by the underlying platform at
runtime.
A public network contains IP
addresses and ports typically used to listen for incoming traffic to an
application or service from the Internet.
|
3.4.4.1 Usage
These aliases would be used in the tosca.capabilities.Endpoint Capability type
(and types derived from it) within the network_name
field for template authors to use to indicate the type of network the Endpoint
is supposed to be assigned an IP address from.
This section defines all modelable entities that comprise
the TOSCA Version 1.0 Simple Profile specification along with their keynames,
grammar and requirements.
The TOSCA metamodel includes complex types (e.g., Node
Types, Relationship Types, Capability Types, Data Types, etc.) each of which include
their own list of reserved keynames that are sometimes marked as required.
These types may be used to derive other types. These derived types (e.g.,
child types) do not have to provide required keynames as long as they have been
specified in the type they have been derived from (i.e., their parent type).
This optional element provides a means include single or
multiline descriptions within a TOSCA Simple Profile template as a scalar
string value.
3.6.1.1 Keyname
The following keyname is used to provide a
description within the TOSCA Simple Profile specification:
3.6.1.2 Grammar
Description definitions have the following grammar:
3.6.1.3 Examples
Simple descriptions are treated as a single literal
that includes the entire contents of the line that immediately follows the description key:
|
description: This is an example of a single line description (no
folding).
|
The YAML “folded” style may also be used for
multi-line descriptions which “folds” line breaks as space characters.
|
description: >
This is an example of a
multi-line description using YAML. It permits for line
breaks for easier readability...
if needed. However, (multiple)
line breaks are folded into a single space
character when processed into a
single string value.
|
3.6.1.4 Notes
- Use of “folded” style is discouraged for the YAML string
type apart from when used with the description
keyname.
3.6.2 Metadata
This optional element provides a means to include optional
metadata as a map of strings.
3.6.2.1 Keyname
The following keyname is used to provide metadata
within the TOSCA Simple Profile specification:
3.6.2.2 Grammar
Metadata definitions have the following grammar:
3.6.2.3 Examples
|
metadata:
foo1: bar1
foo2: bar2
...
|
3.6.2.4 Notes
- Data provided within metadata, wherever it appears, MAY be
ignored by TOSCA Orchestrators and SHOULD NOT affect runtime behavior.
3.6.3 Constraint clause
A constraint clause defines an operation along with one or
more compatible values that can be used to define a constraint on a property or
parameter’s allowed values when it is defined in a TOSCA Service Template or
one of its entities.
The following is the list of recognized operators (keynames)
when defining constraint clauses:
|
Operator
|
Type
|
Value Type
|
Description
|
|
equal
|
scalar
|
any
|
Constrains a property or parameter to a value equal to
(‘=’) the value declared.
|
|
greater_than
|
scalar
|
comparable
|
Constrains a property or parameter to a value greater than
(‘>’) the value declared.
|
|
greater_or_equal
|
scalar
|
comparable
|
Constrains a property or parameter to a value greater than
or equal to (‘>=’) the value declared.
|
|
less_than
|
scalar
|
comparable
|
Constrains a property or parameter to a value less than
(‘<’) the value declared.
|
|
less_or_equal
|
scalar
|
comparable
|
Constrains a property or parameter to a value less than or
equal to (‘<=’) the value declared.
|
|
in_range
|
dual scalar
|
comparable, range
|
Constrains a property or parameter to a value in range of
(inclusive) the two values declared.
Note: subclasses or templates of types that declare a
property with the in_range constraint MAY only further restrict the range
specified by the parent type.
|
|
valid_values
|
list
|
any
|
Constrains a property or parameter to a value that is in
the list of declared values.
|
|
length
|
scalar
|
string, list, map
|
Constrains the property or parameter to a value of a given
length.
|
|
min_length
|
scalar
|
string, list, map
|
Constrains the property or parameter to a value to a
minimum length.
|
|
max_length
|
scalar
|
string, list, map
|
Constrains the property or parameter to a value to a
maximum length.
|
|
pattern
|
regex
|
string
|
Constrains the property or parameter to a value that is
allowed by the provided regular expression.
Note: Future drafts of this specification will detail the use of
regular expressions and reference an appropriate standardized grammar.
|
|
schema
|
string
|
string
|
Constrains the property or parameter to a value that is
allowed by the referenced schema.
|
In the Value Type column above, an entry of
“comparable” includes integer, float, timestamp,
string, version,
and scalar-unit types while an entry of “any”
refers to any type allowed in the TOSCA simple profile in YAML.
3.6.3.2 Schema Constraint purpose
TOSCA recognizes that there are external
data-interchange formats that are widely used within Cloud service APIs and
messaging (e.g., JSON, XML, etc.).
The ‘schema’ Constraint was added so that, when TOSCA types
utilize types from these externally defined data (interchange) formats on
Properties or Parameters, their corresponding Property definitions’ values can be
optionally validated by TOSCA Orchestrators using the schema string provided on
this operator.
3.6.3.3 Additional Requirements
·
If no operator is present for a simple scalar-value on a
constraint clause, it SHALL be interpreted as being equivalent to having
the “equal” operator provided; however,
the “equal” operator may be used for
clarity when expressing a constraint clause.
·
The “length” operator SHALL
be interpreted mean “size” for set types (i.e., list, map, etc.).
- Values provided by the operands (i.e., values and scalar
values) SHALL be type-compatible with their associated operations.
- Future drafts of this specification will detail the use of
regular expressions and reference an appropriate standardized grammar.
- The value for the keyname ‘schema’ SHOULD be a string that
contains a valid external schema definition that matches the corresponding
Property definitions type.
- When a valid ‘schema’ value is provided on a Property
definition, a TOSCA Orchestrator MAY choose use the contained schema
definition for validation.
3.6.3.4 Grammar
Constraint clauses have one of the following
grammars:
|
# Scalar grammar
<operator>:
<scalar_value>
# Dual scalar grammar
<operator>: [
<scalar_value_1>, <scalar_value_2> ]
# List grammar
<operator>: [
<value_1>, <value_2>, ..., <value_n> ]
# Regular expression (regex) grammar
pattern: <regular_expression_value>
# Schema grammar
schema: <schema_definition>
|
In the above grammar, the
pseudo values that appear in angle brackets have the following meaning:
·
operator: represents a
required operator from the specified list shown above (see section 3.5.2.1 “Operator keynames”).
·
scalar_value, scalar_value_*:
represents a required scalar (or atomic quantity) that can hold only one value
at a time. This will be a value of a primitive type, such as an integer or string
that is allowed by this specification.
·
value_*: represents a
required value of the operator that is not limited to scalars.
·
reqular_expression_value:
represents a regular expression (string) value.
·
schema_definition:
represents a schema definition as a string.
3.6.3.5 Examples
Constraint clauses used on parameter or property
definitions:
|
# equal
equal: 2
# greater_than
greater_than: 1
# greater_or_equal
greater_or_equal: 2
# less_than
less_than: 5
# less_or_equal
less_or_equal: 4
# in_range
in_range: [ 1, 4 ]
# valid_values
valid_values: [ 1, 2, 4 ]
# specific length (in characters)
length: 32
# min_length (in characters)
min_length: 8
# max_length (in characters)
max_length: 64
# schema
schema: <
{
# Some schema syntax that
matches corresponding property or parameter.
}
|
A property filter definition defines criteria, using
constraint clauses, for selection of a TOSCA entity based upon it property
values.
3.6.4.1 Grammar
Property filter definitions have one of the
following grammars:
3.6.4.1.1 Short notation:
The following single-line grammar may be used when
only a single constraint is needed on a property:
3.6.4.1.2 Extended notation:
The following multi-line grammar may be used when
multiple constraints are needed on a property:
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
property_name: represents
the name of property that would be used to select a property definition with
the same name (property_name) on a
TOSCA entity (e.g., a Node Type, Node Template, Capability Type, etc.).
·
property_constraint_clause_*:
represents constraint clause(s) that would be used to filter entities based
upon the named property’s value(s).
3.6.4.2 Additional Requirements
·
Property constraint clauses must be type compatible with the
property definitions (of the same name) as defined on the target TOSCA entity
that the clause would be applied against.
A node filter definition defines criteria for selection of a
TOSCA Node Template based upon the template’s property values, capabilities and
capability properties.
3.6.5.1 Keynames
The following is the list of recognized keynames for
a TOSCA node filter definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
properties
|
no
|
list of
property filter definition
|
An optional list of property
filters that would be used to select (filter) matching TOSCA entities (e.g.,
Node Template, Node Type, Capability Types, etc.) based upon their property
definitions’ values.
|
|
capabilities
|
no
|
list of capability names or capability type names
|
An optional list of capability
names or types that would be used to select (filter) matching TOSCA entities
based upon their existence.
|
3.6.5.2 Additional filtering on named Capability properties
Capabilities used as filters often have their own
sets of properties which also can be used to construct a filter.
|
Keyname
|
Required
|
Type
|
Description
|
|
<capability
name_or_type>
name>:
properties
|
no
|
list of
property filter definitions
|
An optional list of property
filters that would be used to select (filter) matching TOSCA entities (e.g.,
Node Template, Node Type, Capability Types, etc.) based upon their capabilities’
property definitions’ values.
|
3.6.5.3 Grammar
Node filter definitions have following grammar:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
property_filter_def_*: represents
a property filter definition that would be used to select (filter) matching
TOSCA entities (e.g., Node Template, Node Type, Capability Types, etc.) based
upon their property definitions’ values.
·
capability_name_or_type_*:
represents the type or name of a capability that would be used to select
(filter) matching TOSCA entities based upon their existence.
·
cap_*_property_def_*:
represents a property filter definition that would be used to select (filter)
matching TOSCA entities (e.g., Node Template, Node Type, Capability Types,
etc.) based upon their capabilities’ property definitions’ values.
3.6.5.4 Additional requirements
·
TOSCA orchestrators SHALL search for matching capabilities
listed on a target filter by assuming the capability name is first a symbolic
name and secondly it is a type name (in order to avoid namespace collisions).
3.6.5.5 Example
The following example is a filter that would be used to select
a TOSCA Compute node based upon the
values of its defined capabilities. Specifically, this filter would select Compute
nodes that supported a specific range of CPUs (i.e., num_cpus value between 1 and 4) and memory
size (i.e., mem_size of 2 or greater)
from its declared “host” capability.
|
my_node_template:
# other details omitted for
brevity
requirements:
- host:
node_filter:
capabilities:
# My “host” Compute
node needs these properties:
- host:
properties:
- num_cpus: {
in_range: [ 1, 4 ] }
- mem_size: {
greater_or_equal: 512 MB }
|
A repository definition defines a named external repository
which contains deployment and implementation artifacts that are referenced
within the TOSCA Service Template.
3.6.6.1 Keynames
The following is the list of recognized keynames for
a TOSCA repository definition:
|
Keyname
|
Required
|
Type
|
Constraints
|
Description
|
|
description
|
no
|
description
|
None
|
The optional description for the repository.
|
|
url
|
yes
|
string
|
None
|
The required URL or network address used to access the
repository.
|
|
credential
|
no
|
Credential
|
None
|
The optional Credential used to authorize access to the
repository.
|
3.6.6.2 Grammar
Repository definitions have one the following
grammars:
3.6.6.2.1 Single-line grammar (no credential):
3.6.6.2.2 Multi-line grammar
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
repository_name:
represents the required symbolic name of the repository as a string.
·
repository_description:
contains an optional description of the repository.
·
repository_address:
represents the required URL of the repository as a string.
·
authorization_credential:
represents the optional credentials (e.g., user ID and password) used to
authorize access to the repository.
3.6.6.3 Example
The following represents a repository definition:
|
repositories:
my_code_repo:
description: My project’s code
repository in GitHub
url:
https://github.com/my-project/
|
An artifact definition defines a named, typed file that can
be associated with Node Type or Node Template and used by orchestration engine
to facilitate deployment and implementation of interface operations.
3.6.7.1 Keynames
The following is the list of recognized keynames for
a TOSCA artifact definition when using the extended notation:
|
Keyname
|
Required
|
Type
|
Description
|
|
type
|
yes
|
string
|
The required artifact type for the artifact definition.
|
|
file
|
yes
|
string
|
The required URI string (relative or absolute) which can
be used to locate the artifact’s file.
|
|
repository
|
no
|
string
|
The optional name of the repository definition which
contains the location of the external repository that contains the artifact.
The artifact is expected to be referenceable by its file URI
within the repository.
|
|
description
|
no
|
description
|
The optional description for the artifact definition.
|
|
deploy_path
|
no
|
string
|
The file path the associated file would be deployed into
within the target node’s container.
|
|
artifact_version
|
no
|
string
|
The version of this artifact. One use of this artifact_version
is to declare the particular version of this artifact type, in addition to
its mime_type (that is declared in the artifact type definition). Together
with the mime_type it may be used to select a particular artifact processor
for this artifact. For example a python interpreter that can interpret python
version 2.7.0
|
|
checksum
|
no
|
string
|
The checksum used to validate the integrity of the
artifact.
|
|
checksum_algorithm
|
no
|
string
|
Algorithm used to calculate the artifact checksum (e.g.
MD5, SHA [Ref]). Shall be specified if checksum is
specified for an artifact.
|
|
properties
|
no
|
map of
property
assignments
|
The optional map of property assignments associated with
the artifact.
|
3.6.7.2 Grammar
Artifact definitions have one of the following
grammars:
3.6.7.2.1 Short notation
The following single-line grammar may be used when
the artifact’s type and mime type can be inferred from the file URI:
3.6.7.2.2 Extended notation:
The following multi-line grammar may be used when
the artifact’s definition’s type and mime type need to be explicitly declared:
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
artifact_name: represents
the required symbolic name of the artifact as a string.
·
artifact_description:
represents the optional description for
the artifact.
·
artifact_type_name:
represents the required artifact type
the artifact definition is based upon.
·
artifact_file_URI: represents the
required URI string (relative or absolute)
which can be used to locate the artifact’s file.
·
artifact_repository_name: represents the optional name of the repository definition to use to
retrieve the associated artifact (file) from.
·
file_deployement_path:
represents the optional path the artifact_file_URI
would be copied into within the target node’s container.
·
artifact_version:
represents the version of artifact
·
artifact_checksum:
represents the checksum of the Artifact
·
artifact_checksum_algorithm:represents
the algorithm for verifying the checksum. Shall be specified if checksum is
specified
·
properties:
represents an optional map of property assignments associated with the artifact
3.6.7.3 Examples
The following represents an artifact definition:
|
my_file_artifact:
../my_apps_files/operation_artifact.txt
|
The following example represents an artifact definition with
property assignments:
3.6.8 Import definition
An import definition is used within a TOSCA Service Template
to locate and uniquely name another TOSCA Service Template file which has type
and template definitions to be imported (included) and referenced within another
Service Template.
3.6.8.1 Keynames
The following is the list of recognized keynames for
a TOSCA import definition:
|
Keyname
|
Required
|
Type
|
Constraints
|
Description
|
|
file
|
yes
|
string
|
None
|
The required symbolic name for the imported file.
|
|
repository
|
no
|
string
|
None
|
The optional symbolic name of the repository definition
where the imported file can be found as a string.
|
|
namespace_prefix
|
no
|
string
|
None
|
The optional namespace prefix (alias) that will be used to
indicate the namespace_uri when forming a qualified name (i.e., qname)
when referencing type definitions from the imported file.
|
|
namespace_uri
|
no
|
string
|
Deprecated
|
The optional, deprecated namespace URI to that will be
applied to type definitions found within the imported file as a string.
|
3.6.8.2 Grammar
Import definitions have one the following grammars:
3.6.8.2.1 Single-line grammar:
|
imports:
- <URI_1>
- <URI_2>
|
3.6.8.2.2 Multi-line grammar
|
imports:
- file: <file_URI>
repository:
<repository_name>
namespace_uri: <definition_namespace_uri>
# deprecated
namespace_prefix: <definition_namespace_prefix>
|
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
file_uri: contains the
required name (i.e., URI) of the file to be imported as a string.
·
repository_name:
represents the optional symbolic name of the repository definition where the
imported file can be found as a string.
·
namespace_uri: represents
the optional namespace URI to that will be applied to type definitions found
within the imported file as a string.
·
namespace_prefix:
represents the optional namespace prefix (alias) that will be used to indicate
the default namespace as declared in the imported Service Template when forming
a qualified name (i.e., qname) when referencing type definitions from the
imported file as a string.
3.6.8.2.3 Requirements
·
The “file” keyname’s vlue MAY be an approved TOSCA Namespace
alias.
·
The namespace prefix “tosca” Is reserved and SHALL NOT be used to
as a value for “namespace_prefix” on import.
·
The imports key “namespace_uri” is now deprecated. It was
intended to be able to define a default namespace for any types that were
defined within the Service Template being imported; however, with version 1.2,
Service Templates MAY now declare their own default Namespace which SHALL be
used in place of this key’s value.
o
Please note that TOSCA Orchestrators and Processors MAY still use
the”namespace_uri” value if provided, if the imported Service Template has no
declared default Namespace value. Regardless it is up to the TOSCA
Orchestrator or Processor to resolve Namespace collisions caused by imports as
they see fit, for example, they may treat it as an error or dynamically
generate a unique namepspace themselves on import.
3.6.8.2.4 Import URI processing requirements
TOSCA Orchestrators, Processors and tooling SHOULD treat the
<file_URI> of an import as follows:
·
URI: If the <file_URI>
is a known namespace URI (identifier), such as a well-known URI defined by a
TOSCA specification, then it SHOULD cause the corresponding Type defintions to
be imported.
o
This implies that there may or may not be an actual Service
Template, perhaps it is a known set Types identified by the well-known URI.
o
This also implies that internet access is NOT needed to import.
·
Alias – If the <file_URI>
is a reserved TOSCA Namespace alias, then it SHOULD cause the corresponding
Type defintions to be imported, using the associated full, Namespace URI to
uniquely identify the imported types.
·
URL - If the <file_URI>
is a valid URL (i.e., network accessible as a remote resource) and the location
contains a valid TOSCA Service Template, then it SHOULD cause the remote
Service Template to be imported.
·
Relative path - If the <file_URI>
is a relative path URL, perhaps pointing to a Service Template located in the
same CSAR file, then it SHOULD cause the locally accessible Service Template to
be imported.
o
If the “repository” key is
supplied, this could also mean relative to the repository’s URL in a remote
file system;
o
If the importing file located in a CSAR file, it should be
treated as relative to the current document’s location within a CSAR file’s
directory structure.
·
Otherwise, the import SHOULD be considered a failure.
3.6.8.3 Example
The following represents how import definitions
would be used for the imports keyname within a TOSCA Service Template:
|
imports:
- path1/path2/some_defs.yaml
- file: path1/path2/file2.yaml
repository: my_service_catalog
namespace_uri:
http://mycompany.com/tosca/1.0/platform
namespace_prefix: mycompany
|
3.6.9 Schema
Definition
All entries in a map or list for one property or parameter
must be of the same type. Similarly, all keys for map entries for one property
or parameter must be of the same type as well. A TOSCA schema definition
specifies the type (for simple entries) or schema (for complex entries) for
keys and entries in TOSCA set types such as the TOSCA list or map.
3.6.9.1 Keynames
The following is the list of recognized keynames for
a TOSCA schema definition:
|
Keyname
|
Required
|
Type
|
Constraints
|
Description
|
|
type
|
yes
|
string
|
None
|
The required data type for the key or entry.
|
|
description
|
no
|
description
|
None
|
The optional description for the schema.
|
|
constraints
|
no
|
list of
constraint
clauses
|
None
|
The optional list of sequenced constraint clauses for the
property.
|
|
key_schema
|
no
|
schema_definition
|
None
|
When the schema itself is of type map, the optional schema
definition that is used to specify the type of they keys of that map’s
entries.
|
|
entry_schema
|
no
|
schema_definition
|
None
|
When the schema itself is of type map or list, the
optional schema definition that is used to specify the type of the entries in
that map or list
|
3.6.9.2 Grammar
Schema definitions have the following grammar:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
schema_description:
represents the optional description of the schema definition
·
schema_type: represents
the required type name for
entries of the specified schema.
·
schema_constraints:
represents the optional list of one or more constraint
clauses on on entries of the specified schema.
·
key_schema_definition: if
the schema_type is map, represents the optional schema definition for they keys
of that map’s entries.
·
entry_schema_definition: if
the schema_type is map or list, represents the optional schema definition for
the entries in that map or list.
3.6.10 Property definition
A property definition defines a named, typed value and
related data that can be associated with an entity defined in this
specification (e.g., Node Types, Relationship Types, Capability Types, etc.).
Properties are used by template authors to provide input values to TOSCA
entities which indicate their “desired state” when they are instantiated. The
value of a property can be retrieved using the get_property function within TOSCA Service
Templates.
3.6.10.1 Attribute and Property reflection
The actual state of the entity, at any point in its
lifecycle once instantiated, is reflected by Attribute definitions. TOSCA
orchestrators automatically create an attribute for every declared property
(with the same symbolic name) to allow introspection of both the desired state
(property) and actual state (attribute).
3.6.10.2 Keynames
The following is the list of recognized keynames for
a TOSCA property definition:
|
Keyname
|
Required
|
Type
|
Constraints
|
Description
|
|
type
|
yes
|
string
|
None
|
The required data type for the property.
|
|
description
|
no
|
description
|
None
|
The optional description for the property.
|
|
required
|
no
|
boolean
|
default: true
|
An optional key that declares a property as required (true) or not (false).
|
|
default
|
no
|
<any>
|
None
|
An optional key that may provide a value to be used as a
default if not provided by another means.
|
|
status
|
no
|
string
|
default: supported
|
The optional status of the property relative to the
specification or implementation. See table below for valid values.
|
|
constraints
|
no
|
list of
constraint
clauses
|
None
|
The optional list of sequenced constraint clauses for the
property.
|
|
key_schema
|
no
|
schema_definition
|
None
|
The optional schema definition for the keys used to
identify entries in properties of type TOSCA map.
|
|
entry_schema
|
no
|
schema_definition
|
None
|
The optional schema definition for the entries in
properties of TOSCA set types such as list or map.
|
|
external-schema
|
no
|
string
|
None
|
The optional key that contains a schema definition that
TOSCA Orchestrators MAY use for validation when the “type” key’s value
indicates an External schema (e.g., “json”)
See section “External schema” below for further
explanation and usage.
|
|
metadata
|
no
|
map of string
|
N/A
|
Defines a section used to declare additional metadata
information.
|
The following
property status values are supported:
|
Value
|
Description
|
|
supported
|
Indicates the property is supported. This is the default
value for all property definitions.
|
|
unsupported
|
Indicates the property is not supported.
|
|
experimental
|
Indicates the property is experimental and has no official
standing.
|
|
deprecated
|
Indicates the property has been deprecated by a new
specification version.
|
3.6.10.4 Grammar
Named property definitions have the following
grammar:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
property_name: represents
the required symbolic name of the property as a string.
·
property_description:
represents the optional description of
the property.
·
property_type: represents
the required data type of the property.
·
property_required:
represents an optional boolean value (true or
false) indicating whether or not the property is required. If this keyname is
not present on a property definition, then the property SHALL be considered required
(i.e., true) by default.
·
default_value: contains a
type-compatible value that may be used as a default if not provided by another
means.
·
status_value: a string that contains a keyword that indicates the
status of the property relative to the specification or implementation.
·
property_constraints:
represents the optional list of one or more sequenced constraint clauses on the property
definition.
·
key_schema_definition: if
the property_type is map, represents the optional schema definition for they
keys used to identify entries in that map.
·
entry_schema_definition: if
the property_type is map or list, represents the optional schema definition for
the entries in that map or list.
·
metadata_map: represents
the optional map of string.
3.6.10.5 Additional Requirements
·
Implementations of the TOSCA Simple Profile SHALL
automatically reflect (i.e., make available) any property defined on an entity
as an attribute of the entity with the same name as the property.
·
A property SHALL be considered required by default
(i.e., as if the required keyname on
the definition is set to true) unless
the definition’s required keyname is explicitly
set to false.
·
The value provided on a property definition’s default keyname SHALL be type compatible with
the type declared on the definition’s type
keyname.
·
Constraints of a property definition SHALL be
type-compatible with the type defined for that definition.
·
If a ‘schema’ keyname is provided, its value (string) MUST represent
a valid schema definition that matches the recognized external type provided as
the value for the ‘type’ keyname as described by
its correspondig schema specification.
·
TOSCA Orchestrators MAY choose to validate the value of the
‘schema’ keyname in accordance with the corresponding schema specifcation for
any recognized external types.
3.6.10.6 Refining Property Definitions
TOSCA allows derived types to refine properties defined in base
types. A property definition in a derived type is considered a refinement when
a property with the same name is already defined in one of the base types for
that type.
Property definition refinements use parameter definition
grammar rather than property
definition grammar. Specifically, this means the following:
·
The type keyname is optional. If
no type is specified, the property refinement reuses the type of the property
it refines. If a type is specified, the type must be the same as the type of
the refined property or it must derive from the type of the refined property.
·
Property definition refinements support the value keyname that specifies a fixed type-compatible
value to assign to the property. These value assignments are considered final,
meaning that it is not valid to change the property value later (e.g. using
further refinements)..
Property refinement definitions can refine properties
defined in one of base types by doing one or more of the following:
·
Assigning a new (compatible) type as per the rules outlined
above.
·
Assigning a (final) fixed value
·
Adding a default value
·
Changing a default value
·
Adding constraints.
·
Turning an optional property into a required property.
No other refinements are allowed.
3.6.10.7 Notes
·
This element directly maps to the PropertiesDefinition element defined as part
of the schema for most type and entities defined in the TOSCA
v1.0 specification.
- In the TOSCA v1.0 specification
constraints are expressed in the XML Schema definitions of Node Type
properties referenced in the PropertiesDefinition
element of NodeType definitions.
3.6.10.8 Examples
The following represents an example of a property
definition with constraints:
|
properties:
num_cpus:
type: integer
description: Number of CPUs
requested for a software node instance.
default: 1
required: true
constraints:
- valid_values: [ 1, 2, 4, 8
]
|
The following shows an example
of a property refinement. Consider the definition of an Endpoint capability
type:
tosca.capabilities.Endpoint:
derived_from: tosca.capabilities.Root
properties:
protocol:
type: string
required: true
default: tcp
port:
type: PortDef
required: false
secure:
type: boolean
required: false
default: false
# Other property definitions omitted for brevity
|
The Endpoint.Admin capability type refines the secure property of the Endpoint capability type from
which it derives by forcing its value to always be true:
tosca.capabilities.Endpoint.Admin:
derived_from: tosca.capabilities.Endpoint
#
Change Endpoint secure indicator to true from its default of false
properties:
secure: true
|
3.6.11 Property assignment
This section defines the grammar for assigning values to
named properties within TOSCA Node and Relationship templates that are defined
in their corresponding named types.
3.6.11.1 Keynames
The TOSCA property assignment has no keynames.
3.6.11.2 Grammar
Property assignments have the following grammar:
3.6.11.2.1 Short notation:
The following single-line grammar may be used when a
simple value assignment is needed:
|
<property_name>:
<property_value> | { <property_value_expression> }
|
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
property_name: represents
the name of a property that would be used to select a property definition with
the same name within on a TOSCA entity (e.g., Node Template, Relationship
Template, etc.,) which is declared in its declared type (e.g., a Node Type,
Node Template, Capability Type, etc.).
·
property_value, property_value_expression:
represent the type-compatible value to assign to the named property. Property
values may be provided as the result from the evaluation of an expression or a
function.
An attribute definition defines a named, typed value that
can be associated with an entity defined in this specification (e.g., a Node,
Relationship or Capability Type). Specifically, it is used to expose the
“actual state” of some property of a TOSCA entity after it has been deployed
and instantiated (as set by the TOSCA orchestrator). Attribute values can be
retrieved via the get_attribute
function from the instance model and used as values to other entities within
TOSCA Service Templates.
3.6.12.1 Attribute and Property reflection
TOSCA orchestrators automatically create Attribute definitions for any Property definitions declared on the
same TOSCA entity (e.g., nodes, node capabilities and relationships) in order
to make accessible the actual (i.e., the current state) value from the running
instance of the entity.
3.6.12.2 Keynames
The following is the list of recognized keynames for
a TOSCA attribute definition:
|
Keyname
|
Required
|
Type
|
Constraints
|
Description
|
|
type
|
yes
|
string
|
None
|
The required data type for the attribute.
|
|
description
|
no
|
description
|
None
|
The optional description for the attribute.
|
|
default
|
no
|
<any>
|
None
|
An optional key that may provide a value to be used as a
default if not provided by another means.
This value SHALL be type compatible with the type declared
by the property definition’s type keyname.
|
|
status
|
no
|
string
|
default: supported
|
The optional status of the attribute relative to the
specification or implementation. See supported status values defined under
the Property definition section.
|
|
key_schema
|
No
|
schema_definition
|
None
|
The optional schema definition for the keys used to
identify entries in attributes of type TOSCA map.
|
|
entry_schema
|
no
|
schema_definition
|
None
|
The optional schema definition for the entries in attributes
of TOSCA set types such as list or map.
|
3.6.12.3 Grammar
Attribute definitions have the following grammar:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
attribute_name:
represents the required symbolic name of the attribute as a string.
·
attribute_type:
represents the required data type of the attribute.
·
attribute_description:
represents the optional description of
the attribute.
·
default_value: contains a
type-compatible value that may be used as a default if not provided by another
means.
·
status_value: contains a
value indicating the attribute’s status relative to the specification version
(e.g., supported, deprecated, etc.). Supported status values for this keyname
are defined under Property definition.
·
key_schema_definition: if
the attribute_type is map, represents the optional schema definition for they
keys used to identify entries in that map.
·
entry_schema_definition: if
the attribute_type is map or list, represents the optional schema definition
for the entries in that map or list.
3.6.12.4 Additional Requirements
·
In addition to any explicitly defined attributes on a TOSCA
entity (e.g., Node Type, RelationshipType, etc.), implementations of the TOSCA
Simple Profile MUST automatically reflect (i.e., make available) any
property defined on an entity as an attribute of the entity with the same name
as the property.
·
Values for the default keyname MUST be derived or
calculated from other attribute or operation output values (that reflect the
actual state of the instance of the corresponding resource) and not hard-coded
or derived from a property settings or inputs (i.e., desired state).
3.6.12.5 Notes
·
Attribute definitions are very similar to Property definitions; however,
properties of entities reflect an input that carries the template author’s
requested or desired value (i.e., desired state) which the orchestrator
(attempts to) use when instantiating the entity whereas attributes reflect the
actual value (i.e., actual state) that provides the actual instantiated value.
o
For example, a property can be used to request the IP address of
a node using a property (setting); however, the actual IP address after the
node is instantiated may by different and made available by an attribute.
3.6.12.6 Example
The following represents a required attribute
definition:
|
actual_cpus:
type: integer
description: Actual number of
CPUs allocated to the node instance.
|
This section defines the grammar for assigning values to
named attributes within TOSCA Node and Relationship templates which are defined
in their corresponding named types.
3.6.13.1 Keynames
The TOSCA attribute assignment has no keynames.
3.6.13.2 Grammar
Attribute assignments have the following grammar:
3.6.13.2.1 Short notation:
The following single-line grammar may be used when a
simple value assignment is needed:
|
<attribute_name>:
<attribute_value> | { <attribute_value_expression> }
|
3.6.13.2.2 Extended notation:
The following multi-line grammar may be used when a
value assignment requires keys in addition to a simple value assignment:
|
<attribute_name>:
description: <attribute_description>
value: <attribute_value> |
{ <attribute_value_expression> }
|
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
attribute_name: represents
the name of an attribute that would be used to select an attribute definition
with the same name within on a TOSCA entity (e.g., Node Template, Relationship
Template, etc.) which is declared (or reflected from a Property definition) in
its declared type (e.g., a Node Type, Node Template, Capability Type, etc.).
·
attribute_value, attribute_value_expresssion:
represent the type-compatible value to assign to the named attribute.
Attribute values may be provided as the result from the evaluation of an
expression or a function.
·
attribute_description:
represents the optional description of
the attribute.
3.6.13.3 Additional requirements
·
Attribute values MAY be provided by the underlying
implementation at runtime when requested by the get_attribute function or it MAY
be provided through the evaluation of expressions and/or functions that derive
the values from other TOSCA attributes (also at runtime).
3.6.14 Parameter definition
A parameter definition is essentially a TOSCA property
definition; however, it also allows a value to be assigned to it (as for a
TOSCA property assignment). In addition, in the case of output parameters, it
can optionally inherit the data type of the value assigned to it rather than
have an explicit data type defined for it.
3.6.14.1 Keynames
The TOSCA parameter definition has all the keynames
of a TOSCA Property definition, but in addition includes the following
additional or changed keynames:
|
Keyname
|
Required
|
Type
|
Constraints
|
Description
|
|
type
|
no
|
string
|
None
|
The required data type for the parameter.
Note:
This keyname is required for a TOSCA Property definition, but is not for a
TOSCA Parameter definition.
|
|
value
|
no
|
<any>
|
N/A
|
The type-compatible value to assign to the named
parameter. Parameter values may be provided as the result from the
evaluation of an expression or a function.
|
3.6.14.2 Grammar
Named parameter definitions have the following
grammar:
In addition, the following single-line grammar is
supported when only a fixed value needs to be provided:
|
<parameter_name>:
<parameter_value> | { <parameter_value_expression> }
|
This single-line grammar is equivalent to the
following:
|
<parameter_name>:
value : <parameter_value>
| { <parameter_value_expression> }
|
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
parameter_name:
represents the required symbolic name of the parameter as a string.
·
parameter_description:
represents the optional description of
the parameter.
·
parameter_type:
represents the optional data type of the parameter. Note, this keyname is
required for a TOSCA Property definition, but is not for a TOSCA Parameter
definition.
·
parameter_value, parameter_value_expresssion:
represent the type-compatible value to assign to the named parameter.
Parameter values may be provided as the result from the evaluation of an
expression or a function.
·
parameter_required:
represents an optional boolean value (true or
false) indicating whether or not the parameter is required. If this keyname is
not present on a parameter definition, then the property SHALL be considered required
(i.e., true) by default.
·
default_value: contains a
type-compatible value that may be used as a default if not provided by another
means.
·
status_value: a string that contains a keyword that indicates the
status of the parameter relative to the specification or implementation.
·
parameter_constraints:
represents the optional list of one or more sequenced constraint clauses on the parameter
definition.
·
key_schema_definition: if
the parameter_type is map, represents the optional schema definition for they
keys used to identify entries in that map.
·
entry_schema_definition: if
the parameter_type is map or list, represents the optional schema definition
for the entries in that map or list.
3.6.14.3 Additional Requirements
·
A parameter SHALL be considered required by default
(i.e., as if the required keyname on
the definition is set to true) unless
the definition’s required keyname is
explicitly set to false.
·
The value provided on a parameter definition’s default keyname SHALL be type
compatible with the type declared on the definition’s type keyname.
- Constraints of a parameter definition SHALL be
type-compatible with the type defined for that definition.
3.6.14.4 Example
The following represents an example of an input
parameter definition with constraints:
|
inputs:
cpus:
type: integer
description: Number of CPUs
for the server.
constraints:
- valid_values: [ 1, 2, 4, 8
]
|
The following represents an example of an (untyped)
output parameter definition:
|
outputs:
server_ip:
description: The private IP
address of the provisioned server.
value: { get_attribute: [
my_server, private_address ] }
|
3.6.15 Attribute Mapping definition
An attribute mapping defines a named output value that is expected
to be returned by an operation implementations and a mapping that specifies the
node or relationship attribute into which the returned output value must be
stored.
3.6.15.1 Grammar
Attribute mappings have the following grammar :
|
output_name: [ <SELF | SOURCE |
TARGET >, <optional_capability_name>, <attribute_name>,
<nested_attribute_name_or_index_1>, ...,
<nested_attribute_name_or_index_or_key_n> ]
|
The various entities in this grammar are defined as follows:
|
Parameter
|
Required
|
Type
|
Description
|
|
SELF | SOURCE | TARGET
|
yes
|
string
|
For operation outputs in interfaces on node templates, the
only allowed keyname is SELF: output values must always be stored into
attributes that belong to the node template that has the interface for which
the output values are returned.
For operation outputs in interfaces on relationship
templates, allowable keynames are SELF, SOURCE, or TARGET.
|
|
<optional_capability_name>
|
no
|
string
|
The optional name of the capability within the specified
node template that contains the named attribute into which the output value
must be stored.
|
|
<attribute_name>
|
yes
|
string
|
The name of the attribute into which the output value must
be stored.
|
|
<nested_attribute_name_or_index_or_key_*>
|
no
|
string| integer
|
Some TOSCA attributes are complex (i.e., composed as
nested structures). These parameters are used to dereference into the names
of these nested structures when needed.
Some attributes represent
list or
map types.
In these cases, an index or key may be provided to reference a specific entry
in the list or map (as named in the previous parameter) to return.
|
Note that it is possible for multiple operations to define
outputs that map onto the same attribute value. For example, a create
operation could include an output value that sets an attribute to an initial
value, and the subsequence configure operation could then update that
same attribute to a new value.
It is also possible that a node template assigns a value to
an attribute that has an operation output mapped to it (including a value that
is the result of calling an intrinsic function). Orchestrators could use the
assigned value for the attribute as its initial value. After the operation runs
that maps an output value onto that attribute, the orchestrator must then use
the updated value, and the value specified in the node template will no longer
be used.
3.6.16 Operation implementation
definition
An operation implementation definition specifies one or more
artifacts (e.g. scripts) to be used as the implementation for an operation in
an interface.
3.6.16.1 Keynames
The following is the list of recognized keynames for
a TOSCA operation implementation definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
primary
|
no
|
artifact definition
|
The optional implementation artifact (i.e., the primary
script file within a TOSCA CSAR file).
|
|
dependencies
|
no
|
list of
artifact definition
|
The optional list of one or more dependent or secondary
implementation artifacts which are referenced by the primary implementation
artifact (e.g., a library the script installs or a
secondary script).
|
|
timeout
|
No
|
integer
|
Timeout value in seconds
|
|
operation_host
|
no
|
string
|
The node on which operations should be executed (for TOSCA
call_operation activities).
If the operation is associated with an interface on a node
type or a relationship template, valid_values are SELF or HOST – referring to
the node itself or to the node that is the target of the HostedOn
relationship for that node.
If the operation is associated with a relationship type or
a relationship template, valid_values are SOURCE or TARGET – referring to the
relationship source or target node.
In both cases, the value can also be set to ORCHESTRATOR
to indicated that the operation must be executed in the orchestrator
environment rather than within the context of the service being orchestrated.
|
3.6.16.2 Grammar
Operation implementation definitions have the
following grammars:
3.6.16.2.1 Short notation for use with single artifact
The following single-line grammar may be used when
only a primary implementation artifact name is needed:
This notation can be used when the primary artifact
name uniquely identifies the artifact, either because it refers to a named
artifact specified in the artifacts section of a type or template, or because
it represents the name of a script in the CSAR file that contains the
definition.
3.6.16.2.2 Short notation for use with multiple artifact
The following multi-line short-hand grammar may be
used when multiple artifacts are needed, but each of the artifacts can be
uniquely identified by name as before:
|
implementation:
primary: <primary_artifact_name>
dependencies:
-
<list_of_dependent_artifact_names>
operation_host : SELF
timeout : 60
|
3.6.16.2.3 Extended notation for use with single artifact
The following multi-line grammar may be used in Node
or Relationship Type or Template definitions when only a single artifact is
used but additional information about the primary artifact is needed (e.g. to
specify the repository from which to obtain the artifact, or to specify the
artifact type when it cannot be derived from the artifact file extension):
3.6.16.2.4 Extended notation for use with multiple artifacts
The following multi-line grammar may be used in Node
or Relationship Type or Template definitions when there are multiple artifacts
that may be needed for the operation to be implemented and additional
information about each of the artifacts is required:
|
implementation:
primary:
<primary_artifact_definition>
dependencies:
- <list_of_dependent_artifact definitions>
operation_host: HOST
timeout: 120
|
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
primary_artifact_name:
represents the optional name (string) of an
implementation artifact definition (defined elsewhere), or the direct name of
an implementation artifact’s relative filename (e.g., a service
template-relative, path-inclusive filename or absolute file location using a
URL).
·
primary_artifact_definition:
represents a full inline definition of an implementation artifact.
·
list_of_dependent_artifact_names:
represents the optional ordered list of one or more dependent or secondary implementation
artifact names (as strings) which are referenced by the primary implementation
artifact. TOSCA orchestrators will copy these files to the same location as
the primary artifact on the target node so as to make them accessible to the
primary implementation artifact when it is executed.
·
list_of_dependent_artifact_definitions:
represents the ordered list of one or more inline definitions of dependent or
secondary implementation artifacts. TOSCA orchestrators will copy these artifacts
to the same location as the primary artifact on the target node so as to make
them accessible to the primary implementation artifact when it is executed.
3.6.17 Operation definition
An operation definition defines a named function or
procedure that can be bound to an operation implementation.
3.6.17.1 Keynames
The following is the list of recognized keynames for
a TOSCA operation definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
description
|
no
|
description
|
The optional description string for the associated named
operation.
|
|
implementation
|
no
|
Operation implementation definition
|
The optional definition of the operation implementation
|
|
inputs
|
no
|
map of
parameter
definitions
|
The optional map of input properties definitions (i.e.,
parameter definitions) for operation definitions that are within TOSCA Node
or Relationship Type definitions. This includes when operation definitions
are included as part of a Requirement definition in a Node Type.
|
|
no
|
map of
property
assignments
|
The optional map of input property assignments (i.e.,
parameters assignments) for operation definitions that are within TOSCA Node
or Relationship Template definitions. This includes when operation
definitions are included as part of a Requirement assignment in a Node
Template.
|
|
outputs
|
no
|
map of
attribute mappings
|
The optional map of attribute mappings that specify named
operation output values and their mappings onto attributes of the node_type
or relationship that contains the interface within which the operation is
defined.
|
3.6.17.2 Grammar
Operation definitions have the following grammars:
3.6.17.2.1 Short notation
The following single-line grammar may be used when the
operation’s implementation definition is the only keyname that is needed, and
when the operation implementation definition itself can be specified using a
single line grammar
3.6.17.2.2 Extended notation for use in Type definitions
The following multi-line grammar may be used in Node
or Relationship Type definitions when additional information about the
operation is needed:
3.6.17.2.3 Extended notation for use in Template definitions
The following multi-line grammar may be used in Node
or Relationship Template definitions when additional information about the
operation is needed:
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
operation_name:
represents the required symbolic name of the operation as a string.
·
operation_description:
represents the optional description
string for the corresponding operation_name.
·
operation_implementation_definition:
represents the optional specification of the operation’s implementation).
·
property_definitions:
represents the optional map of property
definitions which the TOSCA orchestrator would make available (i.e., or pass)
to the corresponding implementation artifact during its execution.
·
property_assignments:
represents the optional map of property assignments for passing parameters to
Node or Relationship Template operations providing values for properties
defined in their respective type definitions.
·
attribute_mappings: represents
the optional map of of attribute_mappings that consists of named output values
returned by operation implementations (i.e. artifacts) and associated mappings
that specify the attribute into which this output value must be stored.
3.6.17.3 Additional requirements
·
The default sub-classing behavior for implementations of
operations SHALL be override. That is, implementation artifacts assigned in
subclasses override any defined in its parent class.
·
Template authors MAY provide property assignments on operation
inputs on templates that do not necessarily have a property definition defined
in its corresponding type.
·
Implementation artifact file names (e.g., script filenames) may
include file directory path names that are relative to the TOSCA service
template file itself when packaged within a TOSCA Cloud Service ARchive (CSAR)
file.
3.6.17.4 Examples
3.6.17.4.1 Single-line example
|
interfaces:
Standard:
start: scripts/start_server.sh
|
3.6.17.4.2 Multi-line example with shorthand implementation definitions
|
interfaces:
Configure:
pre_configure_source:
implementation:
primary:
scripts/pre_configure_source.sh
dependencies:
- scripts/setup.sh
- binaries/library.rpm
- scripts/register.py
|
3.6.17.4.3 Multi-line example with extended implementation definitions
|
interfaces:
Configure:
pre_configure_source:
implementation:
primary:
file:
scripts/pre_configure_source.sh
type: tosca.artifacts.Implementation.Bash
repository:
my_service_catalog
dependencies: -
file : scripts/setup.sh
type :
tosca.artifacts.Implementation.Bash
Repository :
my_service_catalog
|
A notification implementation definition specifies one or
more artifacts to be used by the orchestrator to subscribe to that particular
notification. We use the primary and dependencies keynames as in
the operation implementation definition.
3.6.18.1 Keynames
The following is the list of recognized keynames for
a TOSCA notification implementation definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
primary
|
no
|
artifact definition
|
The optional implementation artifact (i.e., the primary
script file within a TOSCA CSAR file).
|
|
dependencies
|
no
|
list of
artifact definition
|
The optional list of one or more dependent or secondary
implementation artifacts which are referenced by the primary implementation
artifact (e.g., a library the script installs or a
secondary script).
|
3.6.18.2 Grammar
Notification implementation definitions have the
following grammars:
3.6.18.2.1 Short notation for use with single artifact
The following single-line grammar may be used when
only a primary implementation artifact name is needed:
This notation can be used when the primary artifact
name uniquely identifies the artifact, either because it refers to a named
artifact specified in the artifacts section of a type or template, or because
it represents the name of a script in the CSAR file that contains the
definition.
3.6.18.2.2 Short notation for use with multiple artifact
The following multi-line short-hand grammar may be
used when multiple artifacts are needed, but each of the artifacts can be
uniquely identified by name as before:
|
implementation:
primary: <primary_artifact_name>
dependencies:
-
<list_of_dependent_artifact_names>
|
3.6.19 Notification definition
A notification definition defines a named notification that
can be associated with an interface. The notification is a way for an external
event to be transmitted to the TOSCA orchestrator. Parameter values can be sent
together with a notification and we can map them to node/relationship
attributes imilarly to the way operation outputs are mapped to attributes. The
artifact that the orchestrator is registering with in order to receive the
notification is specified using the “implementation” keyname in a similar way
to operations.
When the notification is received an event is generated
within the orchestrator that can be associated to triggers in policies to call
other internal operations and workflows. The notification name (the unqualified
full name) itself identifies the event type that is generated and can be
textually used when defining the associated triggers.
3.6.19.1 Keynames
The following is the list of recognized keynames for
a TOSCA notification definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
description
|
no
|
description
|
The optional description string for the associated named
notification.
|
|
implementation
|
no
|
notification implementation definition
|
The optional definition of the notification
implementation.
|
|
outputs
|
no
|
map of attribute mappings
|
The optional map of property mappings that specify named
notification output values and their mappings onto attributes of the node or
relationship that contains the interface within which the notification is
defined.
|
3.6.19.2 Grammar
The following multi-line grammar may be used in Node
or Relationship Template or Type definitions:
|
<notification_name>:
description:
<notification_description>
implementation:
<notification_implementation_definition>
outputs:
<attribute_mappings>
|
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
notification_name:
represents the required symbolic name of the notification as a string.
·
notification_description:
represents the optional description string for the corresponding
notification_name.
·
notification_implementation_definition:
representes the optional specification of the notification implementation (i.e.
the external artifact that is may send notifications)
·
attribute_mappings:
represents the optional map of attribute assignments for mapping the outputs
values to the respective attributes of the node or relationship.
3.6.20 Interface definition
An interface definition defines a named interface that can
be associated with a Node or Relationship Type
3.6.20.1 Keynames
The following is the list of recognized keynames for
a TOSCA interface definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
inputs
|
no
|
map of
property definitions
|
The optional map of input property definitions available
to all defined operations for interface definitions that are within TOSCA
Node or Relationship Type definitions. This includes when interface
definitions are included as part of a Requirement definition in a Node Type.
|
|
no
|
map of
property
assignments
|
The optional map of input property assignments (i.e.,
parameters assignments) for interface definitions that are within TOSCA Node
or Relationship Template definitions. This includes when interface definitions
are referenced as part of a Requirement assignment in a Node Template.
|
|
operations
|
no
|
map of operation
definitions
|
The optional map of operations defined for this interface.
|
|
notifications
|
no
|
map of notification
definitions
|
The optional map of notifications defined for this
interface.
|
3.6.20.2 Grammar
Interface definitions have the following grammar:
3.6.20.2.1 Extended notation for use in Type definitions
The following multi-line grammar may be used in Node
or Relationship Type definitions:
3.6.20.2.2 Extended notation for use in Template definitions
The following multi-line grammar may be used in Node
or Relationship Template definitions:
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
interface_definition_name: represents
the required symbolic name of the interface as a string.
·
interface_type_name: represents the
required name of the Interface Type for the interface definition.
·
property_definitions:
represents the optional map of property
definitions (i.e., parameters) which the TOSCA orchestrator would make
available (i.e., or pass) to all defined operations.
-
This means these properties and their values would be
accessible to the implementation artifacts (e.g., scripts) associated to each
operation during their execution.
·
property_assignments:
represents the optional map of property
assignments for passing parameters to Node or Relationship Template
operations providing values for properties defined in their respective type
definitions.
·
operation_definitions: represents the required name of one or more operation definitions.
·
notification_definitions:
represents the required name of one or more notification definitions.
3.6.20.3 Notes
Starting with Version 1.3 of this specification, interface definition
grammar was changed to support notifications as well as operations. As a result,
operations must now be specified under the newly-introduced operations keyname and the notifications
under the new notifications keyname. For
backward compatibility if neither the operations or notifications are specified
then we assume the symbolic names in the interface definition to mean
operations, but this use is deprecated. Operations and notifications names
should not overlap.
An event filter definition defines criteria for selection of
an attribute, for the purpose of monitoring it, within a TOSCA entity, or one
its capabilities.
3.6.21.1 Keynames
The following is the list of recognized keynames for
a TOSCA event filter definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
node
|
yes
|
string
|
The required name of the node type
or template that contains either the attribute to be monitored or contains
the requirement that references the node that contains the attribute to be
monitored.
|
|
requirement
|
no
|
string
|
The optional name of the
requirement within the filter’s node that can be used to locate a referenced
node that contains an attribute to monitor.
|
|
capability
|
no
|
string
|
The optional name of a capability
within the filter’s node or within the node referenced by its requirement
that contains the attribute to monitor.
|
3.6.21.2 Grammar
Event filter definitions have following grammar:
|
node: <node_type_name> | <node_template_name>
requirement:
<requirement_name>
capability:
<capability_name>
|
In the above grammar, the pseudo values that appear in
angle brackets have the following meaning:
·
node_type_name: represents
the required name of the node type that would be used to select (filter) the
node that contains the attribute to monitor or contains the requirement that
references another node that contains the attribute to monitor.
·
node_template_name: represents
the required name of the node template that would be used to select (filter)
the node that contains the attribute to monitor or contains the requirement
that references another node that contains the attribute to monitor.
·
requirement_name: represents
the optional name of the requirement that would be used to select (filter) a
referenced node that contains the attribute to monitor.
·
capability_name: represents
the optional name of a capability that would be used to select (filter) the
attribute to monitor. If a requirement_name is specified, then the
capability_name refers to a capability of the node that is targeted by the
requirement.
3.6.22 Trigger definition
A trigger definition defines the event, condition and action
that is used to “trigger” a policy it is associated with.
3.6.22.1 Keynames
The following is the list of recognized keynames for
a TOSCA trigger definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
description
|
no
|
description
|
The optional description string for the named trigger.
|
|
event
|
yes
|
string
|
The required name of the event that activates the
trigger’s action. A deprecated form of this keyname is “event_type”.
|
|
schedule
|
no
|
TimeInterval
|
The optional time interval during which the trigger is
valid (i.e., during which the declared actions will be processed).
|
|
target_filter
|
no
|
event filter
|
The optional filter used to locate the attribute to
monitor for the trigger’s defined condition. This filter helps locate the
TOSCA entity (i.e., node or relationship) or further a specific capability of
that entity that contains the attribute to monitor.
|
|
condition
|
no
|
condition
clause definition
|
The optional condition which contains a condition clause
definition specifying one or multiple attribute constraint that can be
monitored. Note: this is optional since sometimes the event occurrence
itself is enough to trigger the action.
|
|
action
|
yes
|
list of activity definition
|
The list of sequential activities to be performed when the
event is triggered and the condition is met (i.e. evaluates to true).
|
3.6.22.2 Additional keynames for the extended condition notation
|
Keyname
|
Required
|
Type
|
Description
|
|
constraint
|
no
|
condition
clause definition
|
The optional condition which contains a condition clause
definition specifying one or multiple attribute constraint that can be
monitored. Note: this is optional since sometimes the event occurrence
itself is enough to trigger the action.
|
|
period
|
no
|
scalar-unit.time
|
The optional period to use to evaluate for the condition.
|
|
evaluations
|
no
|
integer
|
The optional number of evaluations that must be performed
over the period to assert the condition exists.
|
|
method
|
no
|
string
|
The optional statistical method name to use to perform the
evaluation of the condition.
|
3.6.22.3 Grammar
Trigger definitions have the following grammars:
3.6.22.3.1 Short notation
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
trigger_name: represents
the required symbolic name of the trigger as a string.
·
trigger_description:
represents the optional description
string for the corresponding trigger_name.
·
event_name: represents
the required name of an event associated with an interface notification on the identified
resource (node).
·
time_interval_for_trigger: represents the
optional time interval that the trigger is valid for.
·
event_filter_definition: represents
the optional filter to use to locate the resource (node) or capability
attribute to monitor.
·
condition_clause_definition: represents
one or multiple attribute constraint that can be monitored.and that would be
used to test for a specific condition on the monitored resource.
·
list_of_activity_definition:
represents the list of activities that are performed if the event and
(optionally) condition are met. The activity definitions are the same as the
ones used in a workflow step. One could regard these activities as an anonymous
workflow that is invoked by this trigger and is applied to the target(s) of this
trigger’s policy.
An activity defines an operation to be performed in a TOSCA
workflow step or in an action body of a policy trigger.
Activity definitions can be of the following types:
·
Delegate workflow activity definition
o
Defines the name of the delegate workflow and optional input
assignments. This activity requires the target to be provided by the
orchestrator (no-op node or relationship).
·
Set state activity definition
o
Sets the state of a node.
·
Call operation activity definition
o
Calls an operation defined on a TOSCA interface of a node, relationship
or group. The operation name uses the
<interface_name>.<operation_name> notation. Optionally, assignments
for the operation inputs can also be provided. If provided, they will override
for this operation call the operation inputs assignment in the node template.
·
Inline workflow activity definition
Inline another workflow defined in the
topology (to allow reusability). The definition includes the name of a workflow
to be inlined and optional workflow input assignments.
3.6.23.1 Delegate workflow activity definition
3.6.23.1.1 Keynames
The following is a list of recognized keynames for a
delegate activity definition.
|
Keyname
|
Required
|
Type
|
Description
|
|
delegate
|
yes
|
string
or empty
(see
grammar below)
|
Defines the name of the delegate workflow
and optional input assignments.
This
activity requires the target to be provided by the orchestrator (no-op node
or relationship).
|
|
workflow
|
no
|
string
|
The
name of the delegate workflow. Required in the extended notation.
|
|
inputs
|
no
|
map
of
parameter assignments
|
The
optional map of input parameter assignments for the delegate workflow.
|
3.6.23.1.2 Grammar
A delegate activity definition has the following grammar.
The short notation can be used if no input assignments are provided.
3.6.23.1.2.1 Short notation
3.6.23.1.2.2 Extended notation
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
- delegate_workflow_name:
represents the name of the
workflow of the node provided by the TOSCA orchestrator
- parameter_assignments:
represents the optional map of property assignments for passing parameters
as inputs to this workflow delegation.
3.6.23.2 Set state activity definition
Sets the state of the target node.
3.6.23.2.1 Keynames
The following is a list of recognized keynames for a set
state activity definition.
|
Keyname
|
Required
|
Type
|
Description
|
|
set_state
|
yes
|
string
|
Value
of the node state.
|
3.6.23.2.2 Grammar
A set state activity definition has the following grammar.
|
- set_state: <new_node_state>
|
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
new_node_state: represents the state that will be affected to the node once
the activity is performed.
3.6.23.3 Call operation activity definition
This activity is used to call an operation on the target
node. Operation input assignments can be optionally provided.
3.6.23.3.1 Keynames
The following is a list of recognized keynames for a call
operation activity definition.
|
Keyname
|
Required
|
Type
|
Description
|
|
call_operation
|
yes
|
string
or empty
(see
grammar below)
|
Defines the opration call. The operation name uses the <interface_name>.<operation_name>
notation.
Optionally,
assignments for the operation inputs can also be provided. If provided, they
will override for this operation call the operation inputs assignment in the
node template.
|
|
operation
|
no
|
string
|
The
name of the operation to call, using the
<interface_name>.<operation_name> notation.
Required
in the extended notation.
|
|
inputs
|
no
|
map
of
parameter assignments
|
The
optional map of input parameter assignments for the called operation. Any
provided input assignments will override the operation input assignment in
the target node template for this operation call.
|
3.6.23.3.2 Grammar
A call operation activity definition has the following
grammar. The short notation can be used if no input assignments are provided.
3.6.23.3.2.1 Short notation
|
- call_operation:
<operation_name>
|
3.6.23.3.2.2 Extended notation
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
operation_name: represents the name of the operation that will be called
during the workflow execution. The notation used is <interface_sub_name>.<operation_sub_name>,
where interface_sub_name is the interface name and the operation_sub_name is the name of the operation whitin this interface.
·
parameter_assignments:
represents the optional map of property assignments for passing parameters as
inputs to this workflow delegation.
3.6.23.4 Inline workflow activity definition
This activity is used to inline a workflow in the activities
sequence. The definition includes the name of the inlined workflow and optional
input assignments.
3.6.23.4.1 Keynames
The following is a list of recognized keynames for an inline
workflow activity definition.
|
Keyname
|
Required
|
Type
|
Description
|
|
inline
|
yes
|
string
or empty
(see
grammar below)
|
The
definition includes the name of a workflow to be inlined and optional
workflow input assignments.
|
|
workflow
|
no
|
string
|
The
name of the inlined workflow. Required in the extended notation.
|
|
inputs
|
no
|
map
of
parameter assignments
|
The
optional map of input parameter assignments for the inlined workflow.
|
3.6.23.4.2 Grammar
An inline workflow activity definition has the following
grammar. The short notation can be used if no input assignments are provided.
3.6.23.4.2.1 Short notation
|
- inline: <inlined_workflow_name>
|
3.6.23.4.2.2 Extended notation
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
inlined_workflow_name: represents the name of the workflow to inline.
·
parameter_assignments:
represents the optional map of property assignments for passing parameters as
inputs to this workflow delegation.
3.6.23.5 Example
The following represents a list of activity
definitions (using the short notation):
|
- delegate: deploy
- set_state: started
- call_operation: tosca.interfaces.node.lifecycle.Standard.start
- inline: my_workflow
|
A workflow assertion is used to specify a single condition
on a workflow filter definition. The assertion allows to assert the value of an
attribute based on TOSCA constraints.
3.6.24.1 Keynames
The TOSCA workflow assertion definition has no
keynames.
3.6.24.2 Grammar
Workflow assertion definitions have the following
grammar:
|
<attribute_name>: <list_of_constraint_clauses>
|
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
attribute_name: represents the name of an attribute
defined on the assertion context entity (node instance, relationship instance,
group instance) and from which value will be evaluated against the defined
constraint clauses.
·
list_of_constraint_clauses: represents the list of
constraint clauses that will be used to validate the attribute assertion.
3.6.24.3 Example
Following represents a workflow assertion with a
single equals constraint:
|
my_attribute: [{equal :
my_value}]
|
Following represents a workflow assertion with
mutliple constraints:
|
my_attribute:
- min_length: 8
- max_length : 10
|
3.6.25 Condition
clause definition
A workflow condition clause definition is used to specify a
condition that can be used within a workflow precondition or workflow filter.
3.6.25.1 Keynames
The following is the list of recognized keynames for
a TOSCA workflow condition definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
and
|
no
|
list of condition
clause definition
|
An and clause allows to define sub-filter
clause definitions that must all be evaluated truly so the and clause is
considered as true.
|
|
or
|
no
|
list of condition
clause definition
|
An or clause allows to define sub-filter
clause definitions where one of them must all be evaluated truly so the or
clause is considered as true.
|
|
not
|
no
|
list of condition
clause definition
|
A not clause allows to define sub-filter clause
definitions where one or more of them must be evaluated as false.
|
|
assert
|
no
|
deprecated list of assertion definition
|
An assert clause defines a list of filter
assertions that must be evaluated on entity attributes. Assert
acts as an and
clause, i.e. every defined filter assertion must be true so the assertion is
considered as true.Because assert and and are logically
identical, the assert keyname has been deprecated.
|
Note : It is allowed to add direct assertion
definitions directly to the condition clause definition without using any of
the supported keynames. . In that case, an and clause is performed for
all direct assertion definition.
3.6.25.2 Grammar
Condition clause definitions have the following grammars:
3.6.25.2.1 And clause
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
list_of_condition_clause_definition:
represents the list of condition clauses. All condition clauses MUST be
asserted to true so that the and clause is asserted to true.
3.6.25.2.2 Or clause
|
or: <list_of_condition_clause_definition>
|
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
list_of_condition_clause_definition:
represents the list of condition clauses. One of the condition clause have to
be asserted to true so that the or clause is asserted to true.
3.6.25.2.3 Not clause
|
not:
<list_of_condition_clause_definition>
|
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
list_of_condition_clause_definition:
represents the list of condition clauses. One of the condition clause have to
be asserted to false so that the not clause is asserted to true.
3.6.25.3 Direct assertion definition
|
<attribute_name>:
<list_of_constraint_clauses>
|
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
attribute_name: represents the name of an attribute
defined on the assertion context entity (node instance, relationship instance,
group instance) and from which value will be evaluated against the defined
constraint clauses.
·
list_of_constraint_clauses: represents the list of constraint clauses that will be used to
validate the attribute assertion.
3.6.25.4 Additional Requirement
·
Keynames are mutually exclusive, i.e. a filter definition can
define only one of and, or, or not keyname.
3.6.25.5 Notes
·
The TOSCA processor SHOULD perform assertion in the order of the
list for every defined condition clause or direct assertion definition.
3.6.25.6 Example
Following represents a workflow condition clause
with a single direct assertion definition:
|
condition:
- my_attribute: [{equal:
my_value}]
|
Following represents a workflow condition clause
with single equals constraints on two different attributes.
|
condition:
- my_attribute: [{equal:
my_value}]
- my_other_attribute: [{equal:
my_other_value}]
|
Note that these two direct assertion constraints are
logically and-ed. This means that the following is logically identical
to the previous example:
|
condition:
- and:
- my_attribute: [{equal:
my_value}]
- my_other_attribute: [{equal:
my_other_value}]
|
Following represents a workflow condition clause
with a or constraint on two different assertions:
|
condition:
- or:
- my_attribute: [{equal: my_value}]
- my_other_attribute: [{equal:
my_other_value}]
|
The following shows an example of the not
operator. The condition yields TRUE when the attribute my_attribute1 takes any
value other than value1:
|
condition:
- not:
- my_attribute1: [{equal:
value1}]}
|
The following condition yields TRUE when none of the
attributes my_attribute1 and my_attribute2 is equal to value1.
|
condition:
- not:
- and:
- my_attribute1: [{equal:
value1}]
- my_attribute2: [{equal:
value1}]
|
The following condition is a functional equivalent
of the previous example:
|
condition:
- or:
- not:
- my_attribute1: [{equal:
value1}]
- not:
- my_attribute2: [{equal:
value1}]
|
Following represents multiple levels of condition
clauses with direct assertion definitions to build the following logic: use
http on port 80 or https on port 431:
|
condition:
- or:
- and:
- protocol: { equal: http }
- port: { equal: 80 }
- and:
- protocol: { equal: https }
- port: { equal: 431 }
|
A workflow condition can be used as a filter or precondition
to check if a workflow can be processed or not based on the state of the
instances of a TOSCA topology deployment. When not met, the workflow will not
be triggered.
3.6.26.1 Keynames
The following is the list of recognized keynames for
a TOSCA workflow condition definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
target
|
yes
|
string
|
The target of the precondition (this can be a node
template name, a group name)
|
|
target_relationship
|
no
|
string
|
The optional name of a requirement of the target in case
the precondition has to be processed on a relationship rather than a node or
group. Note that this is applicable only if the target is a node.
|
|
condition
|
no
|
list of condition
clause definitions
|
A list of workflow condition clause definitions. Assertion
between elements of the condition are evaluated as an AND condition.
|
3.6.26.2 Grammar
Workflow precondition definitions have the following
grammars:
|
- target: <target_name>
target_relationship:
<target_requirement_name>
condition:
<list_of_condition_clause_definition>
|
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
target_name: represents the name of a node template or group in the
topology.
·
target_requirement_name:
represents the name of a requirement of the node template (in case target_name
refers to a node template.
·
list_of_condition_clause_definition:
represents the list of condition clauses to be evaluated.
The value of the resulting condition is evaluated as an AND clause between the
different elements.
A workflow step allows to define one or multiple sequenced
activities in a workflow and how they are connected to other steps in the
workflow. They are the building blocks of a declarative workflow.
3.6.27.1 Keynames
The following is the list of recognized keynames for
a TOSCA workflow step definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
target
|
yes
|
string
|
The target of the step (this can be a node template name,
a group name)
|
|
target_relationship
|
no
|
string
|
The optional name of a requirement of the target in case
the step refers to a relationship rather than a node or group. Note that this
is applicable only if the target is a node.
|
|
operation_host
|
no
|
string
|
The node on which operations should be executed (for TOSCA
call_operation activities).
This element is required only for relationships and groups
target.
If target is a relationships operation_host is required
and valid_values are SOURCE or TARGET – referring to the relationship source
or target node.
If target is a group operation_host is optional.
If not specified the operation will be triggered on every
node of the group.
If specified the valid_value is a node_type or the name of
a node template.
|
|
filter
|
no
|
list of constraint
clauses
|
Filter is a map of attribute name, list of constraint
clause that allows to provide a filtering logic.
|
|
activities
|
yes
|
list of activity
definition
|
The list of sequential activities to be performed in this step.
|
|
on_success
|
no
|
list of string
|
The optional list of step names to be performed after this
one has been completed with success (all activities has been correctly
processed).
|
|
on_failure
|
no
|
list of string
|
The optional list of step names to be called after this
one in case one of the step activity failed.
|
3.6.27.2 Grammar
Workflow step definitions have the following
grammars:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
target_name: represents the name of a node template or group in the
topology.
·
target_requirement_name:
represents the name of a requirement of the node template (in case target_name
refers to a node template.
·
operation_host: the node
on which the operation should be executed
·
list_of_condition_clause_definition: represents a list of condition clause definition.
·
list_of_activity_definition: represents a list of activity definition
·
target_step_name: represents the name of another step of the workflow.
An Entity Type is the common, base, polymorphic schema type which
is extended by TOSCA base entity type schemas (e.g., Node Type, Relationship
Type, Artifact Type, etc.) and serves to define once all the commonly shared
keynames and their types. This is a “meta” type which is abstract and not
directly instantiatable.
3.7.1.1 Keynames
The following is the list of recognized keynames for
a TOSCA Entity Type definition:
|
Keyname
|
Required
|
Type
|
Constraints
|
Description
|
|
derived_from
|
no
|
string
|
‘None’
is the only allowed value
|
An optional parent Entity Type name the Entity Type
derives from.
|
|
version
|
no
|
version
|
N/A
|
An optional version for the Entity Type definition.
|
|
metadata
|
no
|
map of string
|
N/A
|
Defines a section used to declare additional metadata
information.
|
|
description
|
no
|
description
|
N/A
|
An optional description for the Entity Type.
|
3.7.1.2 Grammar
Entity Types have following grammar:
|
<entity_keyname>:
# The only allowed value is
‘None’
derived_from: None
version: <version_number>
metadata:
<metadata_map>
description: <interface_description>
|
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
version_number:
represents the optional TOSCA version number
for the entity.
·
entity_description:
represents the optional description
string for the entity.
·
metadata_map: represents
the optional map of string.
3.7.1.3 Additional Requirements
·
The TOSCA Entity Type SHALL be the common base type used to
derive all other top-level base TOSCA Types.
·
The TOSCA Entity Type SHALL NOT be used to derive or create new
base types apart from those defined in this specification or a profile of this
specification.
A capability definition defines a named, typed set of data
that can be associated with Node Type or Node Template to describe a
transparent capability or feature of the software component the node describes.
3.7.2.1 Keynames
The following is the list of recognized keynames for
a TOSCA capability definition:
|
Keyname
|
Required
|
Type
|
Constraints
|
Description
|
|
type
|
yes
|
string
|
N/A
|
The required name of the Capability Type the capability
definition is based upon.
|
|
description
|
no
|
description
|
N/A
|
The optional description of the Capability definition.
|
|
properties
|
no
|
map of
property definitions
|
N/A
|
An optional map of property definitions for the Capability
definition.
|
|
attributes
|
no
|
map of
attribute definitions
|
N/A
|
An optional map of attribute definitions for the
Capability definition.
|
|
valid_source_types
|
no
|
string[]
|
N/A
|
An optional list of one or more valid names of Node Types
that are supported as valid sources of any relationship established to the
declared Capability Type.
|
|
occurrences
|
no
|
range of integer
|
implied default of [1,UNBOUNDED]
|
The optional minimum and maximum
occurrences for the capability. By default, an exported Capability should
allow at least one relationship to be formed with it with a maximum of
UNBOUNDED relationships.
Note: the keyword UNBOUNDED is also supported to represent any positive
integer.
|
3.7.2.2 Grammar
Capability definitions have one of the following
grammars:
3.7.2.2.1 Short notation
The following single-line grammar may be used when
only the capability definition name needs to be declared, without further
refinement of the capability type definitions:
3.7.2.2.2 Extended notation
The following multi-line grammar may be used when
additional information on the capability definition is needed:
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
capability_definition_name:
represents the symbolic name of the capability as a string.
·
capability_type:
represents the required name of a capability
type the capability definition is based upon.
·
capability_description:
represents the optional description of
the capability definition.
·
property_definitions:
represents the optional map of property
definitions for the capability definition.
·
attribute_definitions:
represents the optional map of attribute
definitions for the capability definition.
·
node_type_names:
represents the optional list of one or more names of Node Types that the Capability definition
supports as valid sources for a successful relationship to be established to
itself.
·
Range_of_occurrences:
represents he optional minimum and maximum occurrences for the capability.
3.7.2.3 Examples
The following examples show capability definitions
in both simple and full forms:
3.7.2.3.1 Simple notation example
|
# Simple notation, no properties
defined or augmented
some_capability:
mytypes.mycapabilities.MyCapabilityTypeName
|
|
# Full notation, augmenting
properties of the referenced capability type
some_capability:
type:
mytypes.mycapabilities.MyCapabilityTypeName
properties:
limit:
type: integer
default: 100
|
3.7.2.4 Additional requirements
·
Any Node Type (names) provides as values for the valid_source_types keyname SHALL be
type-compatible (i.e., derived from the same parent Node Type) with any Node
Types defined using the same keyname in the parent Capability Type.
·
Capability symbolic names SHALL be unique; it is an error if a
capability name is found to occur more than once.
3.7.2.5 Notes
- The Capability Type, in this example MyCapabilityTypeName, would be defined elsewhere and have an integer
property named limit.
- This definition directly maps to the CapabilitiesDefinition of the Node Type
entity as defined in the TOSCA v1.0 specification.
3.7.3 Requirement
definition
The Requirement definition describes a named requirement
(dependencies) of a TOSCA Node Type or Node template which needs to be
fulfilled by a matching Capability definition declared by another TOSCA
modelable entity. The requirement definition may itself include the specific
name of the fulfilling entity (explicitly) or provide an abstract type, along
with additional filtering characteristics, that a TOSCA orchestrator can use to
fulfill the capability at runtime (implicitly).
3.7.3.1 Keynames
The following is the list of recognized keynames for
a TOSCA requirement definition:
|
Keyname
|
Required
|
Type
|
Constraints
|
Description
|
|
capability
|
yes
|
string
|
N/A
|
The required reserved keyname used that can be used to
provide the name of a valid Capability
Type that can fulfill the requirement.
|
|
node
|
no
|
string
|
N/A
|
The optional reserved keyname used to provide the name of
a valid Node Type that contains the
capability definition that can be used to fulfill the requirement.
|
|
relationship
|
no
|
string
|
N/A
|
The optional reserved keyname used to provide the name of
a valid Relationship Type to
construct when fulfilling the requirement.
|
|
occurrences
|
no
|
range of integer
|
implied default of [1,1]
|
The optional minimum and maximum occurrences for the
requirement.
Note: the keyword UNBOUNDED is also supported to represent any positive
integer.
|
3.7.3.1.1 Additional Keynames for multi-line relationship grammar
The Requirement definition contains the Relationship
Type information needed by TOSCA Orchestrators to construct relationships to
other TOSCA nodes with matching capabilities; however, it is sometimes
recognized that additional properties may need to be passed to the relationship
(perhaps for configuration). In these cases, additional grammar is provided so
that the Node Type may declare additional Property definitions to be used as
inputs to the Relationship Type’s declared interfaces (or specific operations
of those interfaces).
|
Keyname
|
Required
|
Type
|
Constraints
|
Description
|
|
type
|
yes
|
string
|
N/A
|
The optional reserved keyname used to provide the name of
the Relationship Type for the requirement definition’s relationship keyname.
|
|
interfaces
|
no
|
map of interface
definitions
|
N/A
|
The optional reserved keyname used to reference declared
(named) interface definitions of the corresponding Relationship Type in order
to declare additional Property definitions for these interfaces or operations
of these interfaces.
|
3.7.3.2 Grammar
Requirement definitions have one of the following
grammars:
3.7.3.2.1 Simple grammar (Capability Type only)
3.7.3.2.2 Extended grammar (with Node and Relationship Types)
3.7.3.2.3 Extended grammar for declaring Property Definitions on the
relationship’s Interfaces
The following additional multi-line grammar is
provided for the relationship keyname in order to declare new Property
definitions for inputs of known Interface definitions of the declared
Relationship Type.
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
requirement_definition_name: represents
the required symbolic name of the requirement definition as a string.
·
capability_type_name:
represents the required name of a Capability type that can be used to fulfill
the requirement.
·
node_type_name: represents
the optional name of a TOSCA Node Type that contains the Capability Type
definition the requirement can be fulfilled by.
·
relationship_type_name:
represents the optional name of a Relationship
Type to be used to construct a relationship between this requirement
definition (i.e., in the source node) to a matching capability definition (in a
target node).
·
min_occurrences, max_occurrences:
represents the optional minimum and maximum occurrences of the requirement
(i.e., its cardinality).
·
interface_definitions:
represents one or more already declared interface definitions in the
Relationship Type (as declared on the type
keyname) allowing for the declaration of new Property definition for these
interfaces or for specific Operation definitions of these interfaces.
3.7.3.3 Additional Requirements
·
Requirement symbolic names SHALL be unique; it is an error if a
requirement name is found to occur more than once.
·
If the occurrences
keyname is not present, then the occurrence of the requirement SHALL be
one and only one; that is a default declaration as follows would be assumed:
o
occurrences: [1,1]
3.7.3.4 Notes
·
This element directly maps to the RequirementsDefinition of the Node Type
entity as defined in the TOSCA v1.0 specification.
·
The requirement symbolic name is used for identification of the
requirement definition only and not relied upon for establishing any
relationships in the topology.
3.7.3.5 Requirement Type definition is a tuple
A requirement definition allows type designers to
govern which types are allowed (valid) for fulfillment using three levels of
specificity with only the Capability Type being required.
1. Node Type
(optional)
2. Relationship
Type (optional)
3. Capability
Type (required)
The first level allows selection, as shown in both
the simple or complex grammar, simply providing the node’s type using the node keyname. The second level allows
specification of the relationship type to use when connecting the requirement
to the capability using the relationship
keyname. Finally, the specific named capability type on the target node is
provided using the capability keyname.
3.7.3.5.1 Property filter
In addition to the node, relationship and capability types,
a filter, with the keyname node_filter,
may be provided to constrain the allowed set of potential target nodes based
upon their properties and their capabilities’ properties. This allows TOSCA
orchestrators to help find the “best fit” when selecting among multiple
potential target nodes for the expressed requirements.
An Artifact Type is a reusable entity that defines the type
of one or more files that are used to define implementation or deployment
artifacts that are referenced by nodes or relationships on their operations.
3.7.4.1 Keynames
The Artifact Type is a TOSCA Entity and has the common
keynames listed in section 3.7.1 TOSCA Entity Schema.
In addition, the Artifact Type has the following
recognized keynames:
|
Keyname
|
Required
|
Type
|
Constraints
|
Description
|
|
mime_type
|
no
|
string
|
None
|
The required mime type property for the Artifact Type.
|
|
file_ext
|
no
|
string[]
|
None
|
The required file extension property for the Artifact
Type.
|
|
properties
|
no
|
map of
property definitions
|
No
|
Anoptional map of property definitions for the Artifact
Type.
|
3.7.4.2 Grammar
Artifact Types have following grammar:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
artifact_type_name:
represents the name of the Artifact Type being declared as a string.
·
parent_artifact_type_name:
represents the name of the Artifact Type this Artifact Type
definition derives from (i.e., its “parent” type).
·
version_number:
represents the optional TOSCA version number
for the Artifact Type.
·
artifact_description:
represents the optional description
string for the Artifact Type.
·
mime_type_string:
represents the optional Multipurpose Internet Mail Extensions (MIME) standard
string value that describes the file contents for this type of Artifact Type as
a string.
·
file_extensions:
represents the optional list of one or more recognized file extensions for this
type of artifact type as strings.
·
property_definitions:
represents the optional map of property
definitions for the artifact type.
3.7.4.3 Examples
|
my_artifact_type:
description: Java Archive
artifact type
derived_from:
tosca.artifact.Root
mime_type: application/java-archive
file_ext: [ jar ]
properties:
id:
description: Identifier of
the jar
type: string
required: true
creator:
description: Vendor of the
java implementation on which the jar is based
type: string
required: false
|
3.7.4.4 Additional Requirements
·
The ‘mime_type’ keyname is meant to have values that are Apache
mime types such as those defined here: http://svn.apache.org/repos/asf/httpd/httpd/trunk/docs/conf/mime.types
3.7.4.5 Notes
Information about artifacts can be broadly classified in two
categories that serve different purposes :
1. Selection
of artifact processor – This category includes informational elements such as
artifact version, checksum, checksum algorithm etc. and s used by TOSCA
Orchestrator to select the correct artifact processor for the artifact. These informational
elements are captured in TOSCA as keywords for the artifact.
2. Properties
processed by artifact processor - Some properties are not processed by the
Orchestrator, but passed on to the artifact processor to assist with proper
processing of the artifact. These informational elements are described through
artifact properties.
·
.
An Interface Type is a reusable entity that
describes a set of operations that can be used to interact with or manage a
node or relationship in a TOSCA topology.
3.7.5.1 Keynames
The Interface Type is a TOSCA Entity and has the
common keynames listed in section 3.7.1 TOSCA Entity Schema.
In addition, the Interface Type has the following
recognized keynames:
|
Keyname
|
Required
|
Type
|
Description
|
|
inputs
|
no
|
map of
property definitions
|
The optional map of input parameter definitions.
|
|
operations
|
no
|
map of operation
definitions
|
The optional map of operations defined for this interface.
|
|
notifications
|
no
|
map of notification
definitions
|
The optional map of notifications defined for this
interface.
|
3.7.5.2 Grammar
Interface Types have following grammar:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
interface_type_name:
represents the required name of the interface as a string.
·
parent_interface_type_name:
represents the name of the Interface Type
this Interface Type definition derives from (i.e., its “parent” type).
·
version_number:
represents the optional TOSCA version number
for the Interface Type.
·
interface_description:
represents the optional description
string for the Interface Type.
·
property_definitions:
represents the optional map of property
definitions (i.e., parameters) which the TOSCA orchestrator would make
available (i.e., or pass) to all implementation artifacts for operations
declared on the interface during their execution.
·
operation_definitions:
represents the required map of one or more operation definitions.
·
notification_definitions:
represents the required name of one or more notification definitions.
3.7.5.3 Example
The following example shows a custom interface used
to define multiple configure operations.
|
mycompany.mytypes.myinterfaces.MyConfigure:
derived_from: tosca.interfaces.relationship.Root
description: My custom configure
Interface Type
inputs:
mode:
type: string
operations:
pre_configure_service:
description: pre-configure
operation for my service
post_configure_service:
description: post-configure
operation for my service
|
3.7.5.4 Additional Requirements
·
Interface Types MUST NOT include any implementations for
defined operations or notifications; that is, the implementation keyname is
invalid in this context.
·
The inputs keyname is
reserved and SHALL NOT be used for an operation name.
3.7.5.5 Notes
Starting with Version 1.3 of this specification, interface
type definition grammar was changed to support notifications as well as
operations. As a result, operations must now be specified under the
newly-introduced operations keyname and
the notifications under the new notifications
keyname. For backward compatibility if neither the operations or notifications
are specified then we assume the symbolic names in the interface definition to
mean operations, but this use is deprecated. Operations and notifications names
should not overlap.
A Data Type definition defines the schema for new named
datatypes in TOSCA.
3.7.6.1 Keynames
The Data Type is a TOSCA Entity and has the common
keynames listed in section 3.7.1 TOSCA Entity Schema.
In addition, the Data Type has the following
recognized keynames:
|
Keyname
|
Required
|
Type
|
Description
|
|
constraints
|
no
|
list of
constraint clauses
|
The optional list of sequenced
constraint clauses for the Data Type.
|
|
properties
|
no
|
map of
property definitions
|
The optional map property
definitions that comprise the schema for a complex Data Type in TOSCA.
|
|
key_schema
|
no
|
schema_definition
|
For data types that derive from
the TOSCA map data type, the optional schema definition for the keys used to
identify entries in properties of this data type.
|
|
entry_schema
|
no
|
schema_definition
|
For data types that derive from
the TOSCA map or list data types, the optional schema definition for the
entries in properties of this data type.
|
3.7.6.2 Grammar
Data Types have the following grammar:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
data_type_name:
represents the required symbolic name of the Data Type as a string.
·
version_number:
represents the optional TOSCA version number
for the Data Type.
·
datatype_description: represents
the optional description for the Data Type.
·
existing_type_name: represents
the optional name of a valid TOSCA type this new Data Type would derive from.
·
type_constraints:
represents the optional list of one or more type-compatible constraint clauses that restrict
the Data Type.
·
property_definitions:
represents the optional map of one or more property
definitions that provide the schema for the Data Type.
·
key_schema_definition: if
the data_type derives from the TOSCA map type (i.e existing_type_name is a map
or derives from a map), represents the optional schema definition for they keys
used to identify entries properties of this type..
·
entry_schema_definition: if
the data_type derives from the TOSCA map or list types (i.e. existing_type name
is a map or list or derives from a map or list), represents the optional schema
definition for the entries in properties of this type.
3.7.6.3 Additional Requirements
·
A valid datatype definition MUST have either a valid derived_from declaration or at least one
valid property definition.
·
Any constraint clauses SHALL
be type-compatible with the type declared by the derived_from keyname.
·
If a properties keyname
is provided, it SHALL contain one or more valid property definitions.
3.7.6.4 Examples
The following example represents a Data Type definition based
upon an existing string type:
3.7.6.4.1 Defining a complex datatype
|
# define a new complex datatype
mytypes.phonenumber:
description: my phone number
datatype
properties:
countrycode:
type: integer
areacode:
type: integer
number:
type: integer
|
3.7.6.4.2 Defining a datatype derived from an existing datatype
|
# define a new datatype that
derives from existing type and extends it
mytypes.phonenumber.extended:
derived_from:
mytypes.phonenumber
description: custom phone number
type that extends the basic phonenumber type
properties:
phone_description:
type: string
constraints:
- max_length: 128
|
A Capability Type is a reusable entity that
describes a kind of capability that a Node Type can declare to expose.
Requirements (implicit or explicit) that are declared as part of one node can
be matched to (i.e., fulfilled by) the Capabilities declared by another node.
3.7.7.1 Keynames
The Capability Type is a TOSCA Entity and has the
common keynames listed in section 3.7.1 TOSCA Entity Schema.
In addition, the Capability Type has the following
recognized keynames:
|
Keyname
|
Required
|
Type
|
Description
|
|
properties
|
no
|
map of
property definitions
|
An optional map of property definitions for the Capability
Type.
|
|
attributes
|
no
|
map of
attribute
definitions
|
An optional map of attribute definitions for the
Capability Type.
|
|
valid_source_types
|
no
|
string[]
|
An optional list of one or more valid names of Node Types
that are supported as valid sources of any relationship established to the
declared Capability Type.
|
3.7.7.2 Grammar
Capability Types have following grammar:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
capability_type_name:
represents the required name of the Capability Type being declared as a string.
·
parent_capability_type_name:
represents the name of the Capability
Type this Capability Type definition derives from (i.e., its “parent”
type).
·
version_number:
represents the optional TOSCA version number
for the Capability Type.
·
capability_description:
represents the optional description
string for the corresponding capability_type_name.
·
property_definitions:
represents an optional map of property
definitions that the Capability type exports.
·
attribute_definitions:
represents the optional map of attribute
definitions for the Capability Type.
·
node_type_names:
represents the optional list of one or more names of Node Types that the Capability Type supports
as valid sources for a successful relationship to be established to itself.
3.7.7.3 Example
|
mycompany.mytypes.myapplication.MyFeature:
derived_from:
tosca.capabilities.Root
description: a custom feature of
my company’s application
properties:
my_feature_setting:
type: string
my_feature_value:
type: integer
|
A Requirement Type is a reusable entity that
describes a kind of requirement that a Node Type can declare to expose. The
TOSCA Simple Profile seeks to simplify the need for declaring specific
Requirement Types from nodes and instead rely upon nodes declaring their
features sets using TOSCA Capability Types along with a named Feature notation.
Currently, there are no use cases in this TOSCA Simple
Profile in YAML specification that utilize an independently defined Requirement
Type. This is a desired effect as part of the simplification of the TOSCA v1.0
specification.
A Node Type is a reusable entity that defines the type of
one or more Node Templates. As such, a Node Type defines the structure of
observable properties via a Properties Definition, the Requirements and
Capabilities of the node as well as its supported interfaces.
3.7.9.1 Keynames
The Node Type is a TOSCA Entity and has the common
keynames listed in section 3.7.1 TOSCA Entity Schema.
In addition, the Node Type has the following
recognized keynames:
|
Keyname
|
Required
|
Type
|
Description
|
|
attributes
|
no
|
map of
attribute
definitions
|
An optional map of attribute definitions for the Node
Type.
|
|
properties
|
no
|
map of
property definitions
|
An optional map of property definitions for the Node Type.
|
|
requirements
|
no
|
list of
requirement
definitions
|
An optional list of requirement definitions for the Node
Type.
|
|
capabilities
|
no
|
map of
capability
definitions
|
An optional map of capability definitions for the Node
Type.
|
|
interfaces
|
no
|
map of
interface
definitions
|
An optional map of interface definitions supported by the
Node Type.
|
|
artifacts
|
no
|
map of
artifact definitions
|
An optional map of named artifact definitions for the Node
Type.
|
Node Types have following grammar:
In the above grammar, the
pseudo values that appear in angle brackets have the following meaning:
·
node_type_name:
represents the required symbolic name of the Node Type being declared.
·
parent_node_type_name:
represents the name (string) of the Node Type this Node Type definition derives
from (i.e., its “parent” type).
·
version_number:
represents the optional TOSCA version number
for the Node Type.
·
node_type_description:
represents the optional description
string for the corresponding node_type_name.
·
property_definitions:
represents the optional map of property
definitions for the Node Type.
·
attribute_definitions:
represents the optional map of attribute
definitions for the Node Type.
·
requirement_definitions:
represents the optional list of requirement
definitions for the Node Type.
·
capability_definitions:
represents the optional map of capability
definitions for the Node Type.
·
interface_definitions:
represents the optional map of one or more interface
definitions supported by the Node Type.
·
artifact_definitions:
represents the optional map of artifact
definitions for the Node Type.
3.7.9.3 Additional Requirements
·
Requirements are intentionally expressed as a list of TOSCA Requirement definitions which SHOULD
be resolved (processed) in sequence order by TOSCA Orchestrators.
It is recommended that all Node Types SHOULD
derive directly (as a parent) or indirectly (as an ancestor) of the TOSCA Root
Node Type (i.e., tosca.nodes.Root) to
promote compatibility and portability. However, it is permitted to author Node
Types that do not do so.
TOSCA Orchestrators, having a full view of the complete
application topology template and its resultant dependency graph of nodes and
relationships, MAY prioritize how they instantiate the nodes and
relationships for the application (perhaps in parallel where possible) to achieve
the greatest efficiency
3.7.9.5 Example
|
my_company.my_types.my_app_node_type:
derived_from:
tosca.nodes.SoftwareComponent
description: My company’s custom
applicaton
properties:
my_app_password:
type: string
description: application password
constraints:
- min_length: 6
- max_length: 10
attributes:
my_app_port:
type: integer
description: application
port number
requirements:
- some_database:
capability: EndPoint.Database
node: Database
relationship: ConnectsTo
|
A Relationship Type is a reusable entity that defines the
type of one or more relationships between Node Types or Node Templates.
3.7.10.1 Keynames
The Relationship Type is a TOSCA Entity and has the
common keynames listed in section 3.7.1 TOSCA Entity Schema.
In addition, the Relationship Type has the following
recognized keynames:
|
Keyname
|
Required
|
Definition/Type
|
Description
|
|
properties
|
no
|
map of
property definitions
|
An optional map of property definitions for the
Relationship Type.
|
|
attributes
|
no
|
map of
attribute
definitions
|
An optional map of attribute definitions for the
Relationship Type.
|
|
interfaces
|
no
|
map of
interface definitions
|
An optional map of interface definitions interfaces
supported by the Relationship Type.
|
|
valid_target_types
|
no
|
string[]
|
An optional list of one or more names of Capability Types
that are valid targets for this relationship.
|
3.7.10.2 Grammar
Relationship Types have following grammar:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
relationship_type_name:
represents the required symbolic name of the Relationship Type being declared
as a string.
·
parent_relationship_type_name:
represents the name (string) of the Relationship Type this Relationship
Type definition derives from (i.e., its “parent” type).
·
relationship_description:
represents the optional description
string for the corresponding relationship_type_name.
·
version_number:
represents the optional TOSCA version number
for the Relationship Type.
·
property_definitions:
represents the optional map of property
definitions for the Relationship Type.
·
attribute_definitions:
represents the optional map of attribute
definitions for the Relationship Type.
·
interface_definitions:
represents the optional map of one or more names of valid interface definitions supported by the
Relationship Type.
·
capability_type_names:
represents one or more names of valid target types for the relationship (i.e., Capability Types).
3.7.10.3 Best Practices
·
For TOSCA application portability, it is recommended that
designers use the normative Relationship types defined in this specification
where possible and derive from them for customization purposes.
·
The TOSCA Root Relationship Type (tosca.relationships.Root) SHOULD be used to
derive new types where possible when defining new relationships types. This
assures that its normative configuration interface (tosca.interfaces.relationship.Configure) can
be used in a deterministic way by TOSCA orchestrators.
3.7.10.4 Examples
|
mycompanytypes.myrelationships.AppDependency:
derived_from: tosca.relationships.DependsOn
valid_target_types: [
mycompanytypes.mycapabilities.SomeAppCapability ]
|
A Group Type defines logical grouping types for nodes,
typically for different management purposes. Conceptually, group definitions
allow the creation of logical “membership” relationships to nodes in a service
template that are not a part of the application’s explicit requirement
dependencies in the topology template (i.e. those required to actually get the
application deployed and running). Instead, such logical membership allows for
the introduction of things such as group management and uniform application of
policies (i.e., requirements that are also not bound to the application itself)
to the group’s members.
3.7.11.1 Keynames
The Group Type is a TOSCA Entity and has the common
keynames listed in section 3.7.1 TOSCA Entity Schema.
In addition, the Group Type has the following
recognized keynames:
|
Keyname
|
Required
|
Type
|
Description
|
|
attributes
|
no
|
map of
attribute
definitions
|
An optional map of attribute definitions for the Group
Type.
|
|
properties
|
no
|
map of
property definitions
|
An optional map of property definitions for the Group
Type.
|
|
members
|
no
|
string[]
|
An optional list of one or more names of Node Types that are
valid (allowed) as members of the Group Type.
Note: This can be viewed by TOSCA Orchestrators as an
implied relationship from the listed members nodes to the group, but one that
does not have operational lifecycle considerations. For example, if we were
to name this as an explicit Relationship Type we might call this “MemberOf”
(group).
|
3.7.11.2 Grammar
Group Types have one the following grammars:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
group_type_name: represents
the required symbolic name of the Group Type being declared as a string.
·
parent_group_type_name:
represents the name (string) of the Group Type this Group Type definition
derives from (i.e., its “parent” type).
·
version_number:
represents the optional TOSCA version number
for the Group Type.
·
group_description:
represents the optional description string for the corresponding group_type_name.
·
attribute_definitions:
represents the optional map of attribute_definitions
for the Group Type.
·
property_definitions:
represents the optional map of property
definitions for the Group Type.
·
list_of_valid_member_types:
represents the optional list of TOSCA types (e.g.,., Node, Capability or even
other Group Types) that are valid member types for being added to (i.e., members
of) the Group Type.
3.7.11.3 Notes
Note that earlier versions of this specification support
interface definitions, capability definitions, and requirement definitions in
group types. These definitions have been deprecated in this version based on
the realization that groups in TOSCA only exist for purposes of uniform
application of policies to collections of nodes. Consequently, groups do not
have a lifecycle of their own that is independent of the lifeycle of their
members.
3.7.11.4 Additional Requirements
·
Group definitions SHOULD NOT be used to define or
redefine relationships (dependencies) between nodes that can be expressed using
normative TOSCA Relationships (e.g., HostedOn, ConnectsTo, etc.) within a TOSCA
topology template.
·
The list of values associated with the “members” keyname MUST
only contain types that or homogenous (i.e., derive from the same type
hierarchy).
3.7.11.5 Example
The following represents a Group Type definition:
|
group_types:
mycompany.mytypes.groups.placement:
description: My company’s
group type for placing nodes of type Compute
members: [ tosca.nodes.Compute
]
|
A Policy Type defines a type of requirement that affects or
governs an application or service’s topology at some stage of its lifecycle,
but is not explicitly part of the topology itself (i.e., it does not prevent
the application or service from being deployed or run if it did not exist).
3.7.12.1 Keynames
The Policy Type is a TOSCA Entity and has the common
keynames listed in section 3.7.1 TOSCA Entity Schema.
In addition, the Policy Type has the following
recognized keynames:
|
Keyname
|
Required
|
Type
|
Description
|
|
properties
|
no
|
map of
property definitions
|
An optional map of property definitions for the Policy
Type.
|
|
targets
|
no
|
string[]
|
An optional list of valid Node Types or Group Types the
Policy Type can be applied to.
Note: This can be viewed by TOSCA Orchestrators as an
implied relationship to the target nodes, but one that does not have
operational lifecycle considerations. For example, if we were to name this
as an explicit Relationship Type we might call this “AppliesTo” (node or
group).
|
|
triggers
|
no
|
map of trigger
definitions
|
An optional map of policy triggers for the Policy Type.
|
3.7.12.2 Grammar
Policy Types have the following grammar:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
policy_type_name: represents
the required symbolic name of the Policy Type being declared as a string.
·
parent_policy_type_name:
represents the name (string) of the Policy Type
this Policy Type definition derives from (i.e., its “parent” type).
·
version_number:
represents the optional TOSCA version number
for the Policy Type.
·
policy_description:
represents the optional description string for the corresponding policy_type_name.
·
property_definitions:
represents the optional map of property definitions
for the Policy Type.
·
list_of_valid_target_types:
represents the optional list of TOSCA types (i.e., Group or Node Types) that
are valid targets for this Policy Type.
·
trigger_definitions:
represents the optional map of trigger definitions
for the policy.
3.7.12.3 Example
The following represents a Policy Type definition:
|
policy_types:
mycompany.mytypes.policies.placement.Container.Linux:
description: My company’s
placement policy for linux
derived_from:
tosca.policies.Root
|
The definitions in this section provide reusable modeling
element grammars that are specific to the Node or Relationship templates.
A capability assignment allows node template authors to
assign values to properties and attributes for a named capability definition
that is part of a Node Template’s type definition.
3.8.1.1 Keynames
The following is the list of recognized keynames for
a TOSCA capability assignment:
|
Keyname
|
Required
|
Type
|
Description
|
|
properties
|
no
|
map of
property
assignments
|
An optional map of property definitions for the Capability
definition.
|
|
attributes
|
no
|
map of
attribute
assignments
|
An optional map of attribute definitions for the
Capability definition.
|
|
occurrences
|
no
|
range of integer
|
An optional range that further refines the minimum and
maximum occurrences specified in the corresponding capability definition. If
no range is specified, the range from the corresponding capability definition
is used.
|
3.8.1.2 Grammar
Capability assignments have one of the following
grammars:
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
capability_definition_name: represents the symbolic name
of the capability as a string.
·
property_assignments:
represents the optional map of property
assignments for the capability definition.
·
attribute_assignments:
represents the optional map of attribute assignments for
the capability definition.
·
min_occurrences, max_occurrences:
lower and upper bounds of the range that further refines the minimum and
maximum occurrences for this capability specified in the corresponding
capability definition. The range specified here must fall completely within the
occurrences range specified in the corresponding capability definition
3.8.1.3 Example
The following example shows a capability assignment:
3.8.1.3.1 Notation example
|
node_templates:
some_node_template:
capabilities:
some_capability:
properties:
limit: 100
|
A Requirement assignment allows template authors to provide
either concrete names of TOSCA templates or provide abstract selection criteria
for providers to use to find matching TOSCA templates that are used to fulfill
a named requirement’s declared TOSCA Node Type.
3.8.2.1 Keynames
The following is the list of recognized keynames for
a TOSCA requirement assignment:
|
Keyname
|
Required
|
Type
|
Description
|
|
capability
|
no
|
string
|
The optional reserved keyname used to provide the name of
either a:
·
Capability definition within a target node
template that can fulfill the requirement.
·
Capability Type that the provider will use to select a
type-compatible target node template to fulfill the requirement at
runtime.
|
|
node
|
no
|
string
|
The optional reserved keyname used to identify the target
node of a relationship. specifically, it is used to provide either a:
·
Node Template name that can fulfill the target node
requirement.
·
Node Type name that the provider will use to select a
type-compatible node template to fulfill the requirement at runtime.
|
|
relationship
|
no
|
string
|
The optional reserved keyname used to provide the name of
either a:
·
Relationship Template to use to relate the source
node to the (capability in the) target node when fulfilling the
requirement.
·
Relationship Type that the provider will use to select a
type-compatible relationship template to relate the source node to the
target node at runtime.
|
|
node_filter
|
no
|
node filter
|
The optional filter definition that TOSCA orchestrators or
providers would use to select a type-compatible target node that can
fulfill the associated abstract requirement at runtime.
|
|
occurrences
|
no
|
range of integer
|
An optional range that further refines the optional
minimum and maximum occurrences for this requirement. If no range is
specified, the range from the corresponding requirement definition is used.
|
The following is the list of recognized keynames for
a TOSCA requirement assignment’s relationship
keyname which is used when property assignments or inputs of declared
interfaces (or their operations) need to be provided:
|
Keyname
|
Required
|
Type
|
Description
|
|
type
|
no
|
string
|
The optional reserved keyname used to provide the name of
the Relationship Type for the requirement assignment’s relationship keyname.
|
|
properties
|
no
|
map of
property
assignments
|
An optional map of property assignments for the relationship.
|
|
interfaces
|
no
|
map of
interface definitions
|
The optional reserved keyname used to reference declared
(named) interface definitions of the corresponding Relationship Type in order
to provide Property assignments for these interfaces or operations of these
interfaces.
|
3.8.2.2 Grammar
Named requirement assignments have one of the
following grammars:
3.8.2.2.1 Short notation:
The following single-line grammar may be used if only
a concrete Node Template for the target node needs to be declared in the
requirement:
This notation is only valid if the corresponding
Requirement definition in the Node Template’s parent Node Type declares (at a
minimum) a valid Capability Type which can be found in the declared target Node
Template. A valid capability definition always needs to be provided in the
requirement declaration of the source node to identify a specific
capability definition in the target node the requirement will form a
TOSCA relationship with.
3.8.2.2.2 Extended notation:
The following grammar would be used if the requirement
assignment needs to provide more information than just the Node Template name:
3.8.2.2.3 Extended grammar with Property Assignments for the relationship’s
Interfaces
The following additional multi-line grammar is
provided for the relationship keyname in order to provide new Property assignments
for inputs of known Interface definitions of the declared Relationship Type.
Examples of uses for the extended requirement
assignment grammar include:
·
The need to allow runtime selection of the target node based upon
an abstract Node Type rather than a concrete Node Template. This may include
use of the node_filter keyname to provide node and capability filtering
information to find the “best match” of a concrete Node Template at runtime.
·
The need to further clarify the concrete Relationship Template or
abstract Relationship Type to use when relating the source node’s requirement
to the target node’s capability.
·
The need to further clarify the concrete capability (symbolic)
name or abstract Capability Type in the target node to form a relationship
between.
·
The need to (further) constrain the occurrences of the
requirement in the instance model.
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
·
requirement_name: represents
the symbolic name of a requirement assignment as a string.
·
node_template_name: represents
the optional name of a Node Template that contains the capability this
requirement will be fulfilled by.
·
relationship_template_name:
represents the optional name of a Relationship Template to be used when
relating the requirement appears to the capability in the target node.
·
capability_symbolic_name:
represents the required named capability definition within the target Node Type
or Template.
·
node_type_name: represents
the optional name of a TOSCA Node Type the associated named requirement can be
fulfilled by. This must be a type that is compatible with the Node Type
declared on the matching requirement (same symbolic name) the requirement’s
Node Template is based upon.
·
relationship_type_name:
represents the optional name of a Relationship
Type that is compatible with the Capability Type in the target node.
·
property_assignments:
represents the optional map of property value assignments for the declared
relationship.
·
interface_assignments:
represents the optional map of interface definitions for the declared
relationship used to provide property assignments on inputs of interfaces and
operations.
·
capability_type_name:
represents the optional name of a Capability Type definition within the target
Node Type this requirement needs to form a relationship with.
·
node_filter_definition:
represents the optional node filter
TOSCA orchestrators would use to fulfill the requirement for selecting a target
node. Note that this SHALL only be valid if the node keyname’s value is a Node Type and is
invalid if it is a Node Template.
3.8.2.3 min_occurrences, max_occurrences: lower and
upper bounds of the range that further refines the minimum and maximum
occurrences for this requirement specified in the corresponding requirement
definition. The range specified here must fall completely within the
occurrences range specified in the corresponding requirement definitionExamples
3.8.2.3.1 Example 1 – Abstract hosting requirement on a Node Type
A web application node template named ‘my_application_node_template’ of type WebApplication declares a requirement named ‘host’ that needs to be fulfilled by any node
that derives from the node type WebServer.
In this case, the node template’s type is WebApplication which already declares the
Relationship Type HostedOn to use to
relate to the target node and the Capability Type of Container to be the specific target of the
requirement in the target node.
3.8.2.3.2 Example 2 - Requirement with Node Template and a custom
Relationship Type
This example is similar to the previous example;
however, the requirement named ‘database’
describes a requirement for a connection to a database endpoint (Endpoint.Database) Capability Type in a named
node template (my_database). However,
the connection requires a custom Relationship Type (my.types.CustomDbConnection’) declared on the
keyname ‘relationship’.
|
# Example of a (database)
requirement that is fulfilled by a node template named
# “my_database”, but also requires
a custom database connection relationship
my_application_node_template:
requirements:
- database:
node: my_database
capability: Endpoint.Database
relationship:
my.types.CustomDbConnection
|
3.8.2.3.3 Example 3 - Requirement for a Compute node with additional
selection criteria (filter)
This example shows how to
extend an abstract ‘host’ requirement for a Compute node with a filter definition that further constrains TOSCA
orchestrators to include additional properties and capabilities on the target
node when fulfilling the requirement.
A Node Template specifies the occurrence of a manageable
software component as part of an application’s topology model which is defined
in a TOSCA Service Template. A Node template is an instance of a specified
Node Type and can provide customized properties, constraints or operations
which override the defaults provided by its Node Type and its implementations.
3.8.3.1 Keynames
The following is the list of recognized keynames for
a TOSCA Node Template definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
type
|
yes
|
string
|
The required name of the Node Type the Node Template is
based upon.
|
|
description
|
no
|
description
|
An optional description for the Node Template.
|
|
metadata
|
no
|
map of string
|
Defines a section used to declare additional metadata
information.
|
|
directives
|
no
|
string[]
|
An optional list of directive values to provide processing
instructions to orchestrators and tooling.
|
|
properties
|
no
|
map of
property
assignments
|
An optional map of property value assignments for the Node
Template.
|
|
attributes
|
no
|
map of
attribute
assignments
|
An optional map of attribute value assignments for the
Node Template.
|
|
requirements
|
no
|
list of
requirement
assignments
|
An optional list of requirement assignments for the Node
Template.
|
|
capabilities
|
no
|
map of
capability
assignments
|
An optional map of capability assignments for the Node
Template.
|
|
interfaces
|
no
|
map of
interface definitions
|
An optional map of named interface definitions for the
Node Template.
|
|
artifacts
|
no
|
map of
artifact definitions
|
An optional map of named artifact definitions for the Node
Template.
|
|
node_filter
|
no
|
node filter
|
The optional filter definition that TOSCA orchestrators
would use to select the correct target node.
|
|
copy
|
no
|
string
|
The optional (symbolic) name of another node template to
copy into (all keynames and values) and use as a basis for this node
template.
|
3.8.3.2 Grammar
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
node_template_name:
represents the required symbolic name of the Node Template being declared.
·
node_type_name:
represents the name of the Node Type the Node Template is based upon.
·
node_template_description:
represents the optional description
string for Node Template.
·
directives: represents
the optional list of processing instruction keywords (as strings) for use by tooling
and orchestrators.
·
property_assignments:
represents the optional map of property
assignments for the Node Template that provide values for properties
defined in its declared Node Type.
·
attribute_assignments:
represents the optional map of attribute assignments for
the Node Template that provide values for attributes defined in its declared Node
Type.
·
requirement_assignments:
represents the optional list of requirement
assignments for the Node Template that allow assignment of type-compatible
capabilities, target nodes, relationships and target (node filters) for use
when fulfilling the requirement at runtime.
·
capability_assignments:
represents the optional map of capability
assignments for the Node Template that augment those provided by its
declared Node Type.
·
interface_definitions:
represents the optional map of interface
definitions for the Node Template that augment those provided by its
declared Node Type.
·
artifact_definitions:
represents the optional map of artifact
definitions for the Node Template that augment those provided by its
declared Node Type.
·
node_filter_definition:
represents the optional node filter
TOSCA orchestrators would use for selecting a matching node template.
·
source_node_template_name:
represents the optional (symbolic) name of another node template to copy into
(all keynames and values) and use as a basis for this node template.
3.8.3.3 Additional requirements
·
The source node template provided as a value on the copy keyname MUST NOT itself
use the copy keyname (i.e., it must
itself be a complete node template description and not copied from another node
template).
3.8.3.4 Example
|
node_templates:
mysql:
type: tosca.nodes.DBMS.MySQL
properties:
root_password: { get_input:
my_mysql_rootpw }
port: { get_input:
my_mysql_port }
requirements:
- host: db_server
interfaces:
Standard:
configure:
scripts/my_own_configure.sh
|
A Relationship Template specifies the occurrence of a
manageable relationship between node templates as part of an application’s
topology model that is defined in a TOSCA Service Template. A Relationship
template is an instance of a specified Relationship Type and can provide
customized properties, constraints or operations which override the defaults
provided by its Relationship Type and its implementations.
3.8.4.1 Keynames
The following is the list of recognized keynames for
a TOSCA Relationship Template definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
type
|
yes
|
string
|
The required name of the Relationship Type the
Relationship Template is based upon.
|
|
description
|
no
|
description
|
An optional description for the Relationship Template.
|
|
metadata
|
no
|
map of string
|
Defines a section used to declare additional metadata
information.
|
|
properties
|
no
|
map of
property
assignments
|
An optional map of property assignments for the
Relationship Template.
|
|
attributes
|
no
|
map of
attribute
assignments
|
An optional map of attribute assignments for the
Relationship Template.
|
|
interfaces
|
no
|
map of
interface definitions
|
An optional map of named interface definitions for the
Node Template.
|
|
copy
|
no
|
string
|
The optional (symbolic) name of another relationship
template to copy into (all keynames and values) and use as a basis for this
relationship template.
|
3.8.4.2 Grammar
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
relationship_template_name:
represents the required symbolic name of the Relationship Template being
declared.
·
relationship_type_name:
represents the name of the Relationship Type the Relationship Template is based
upon.
·
relationship_template_description:
represents the optional description
string for the Relationship Template.
·
property_assignments:
represents the optional map of property
assignments for the Relationship Template that provide values for
properties defined in its declared Relationship Type.
·
attribute_assignments:
represents the optional map of attribute assignments for
the Relationship Template that provide values for attributes defined in its
declared Relationship Type.
·
interface_definitions:
represents the optional map of interface
definitions for the Relationship Template that augment those provided by
its declared Relationship Type.
·
source_relationship_template_name:
represents the optional (symbolic) name of another relationship template to
copy into (all keynames and values) and use as a basis for this relationship
template.
3.8.4.3 Additional requirements
·
The source relationship template provided as a value on the copy keyname MUST NOT itself use the copy keyname (i.e., it must itself be a
complete relationship template description and not copied from another
relationship template).
3.8.4.4 Example
|
relationship_templates:
storage_attachment:
type: AttachesTo
properties:
location: /my_mount_point
|
3.8.5
Group definition
A group definition defines a logical grouping of node
templates, typically for management purposes, but is separate from the
application’s topology template.
3.8.5.1 Keynames
The following is the list of recognized keynames for
a TOSCA group definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
type
|
yes
|
string
|
The required name of the group type the group definition
is based upon.
|
|
description
|
no
|
description
|
The optional description for the group definition.
|
|
metadata
|
no
|
map of string
|
Defines a section used to declare additional metadata
information.
|
|
properties
|
no
|
map of
property
assignments
|
An optional map of property value assignments for the group
definition.
|
|
members
|
no
|
list of string
|
The optional list of one or more node template names that
are members of this group definition.
|
3.8.5.2 Grammar
Group definitions have one the following grammars:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
group_name: represents
the required symbolic name of the group as a string.
·
group_type_name:
represents the name of the Group Type the definition is based upon.
·
group_description:
contains an optional description of the group.
·
attribute_assigments:
represents the optional map of attribute_assignments for
the group definition that provide values for attributes defined in its declared
Group Type.
·
property_assignments:
represents the optional map of property
assignments for the group definition that provide values for properties
defined in its declared Group Type.
·
list_of_node_templates:
contains the required list of one or more node template names (within the same
topology template) that are members of this logical group.
3.8.5.3 Notes
Note that earlier versions of this specification support
interface definitions in group definitions. These definitions have been
deprecated in this version based on the realization that groups in TOSCA only
exist for purposes of uniform application of policies to collections of nodes.
Consequently, groups do not have a lifecycle of their own that is independent
of the lifeycle of their members.
3.8.5.4 Additional Requirements
·
Group definitions SHOULD NOT be used to define or
redefine relationships (dependencies) for an application that can be expressed
using normative TOSCA Relationships within a TOSCA topology template.
3.8.5.5 Example
The following represents a group definition:
|
groups:
my_app_placement_group:
type: tosca.groups.Root
description: My application’s
logical component grouping for placement
members: [ my_web_server,
my_sql_database ]
|
A policy definition defines a policy that can be associated
with a TOSCA topology or top-level entity definition (e.g., group definition,
node template, etc.).
3.8.6.1 Keynames
The following is the list of recognized keynames for
a TOSCA policy definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
type
|
yes
|
string
|
The required name of the policy type the policy definition
is based upon.
|
|
description
|
no
|
description
|
The optional description for the policy definition.
|
|
metadata
|
no
|
map of string
|
Defines a section used to declare additional metadata
information.
|
|
properties
|
no
|
map of
property
assignments
|
An optional map of property value assignments for the policy
definition.
|
|
targets
|
no
|
string[]
|
An optional list of valid Node Templates or Groups the
Policy can be applied to.
|
|
triggers
|
no
|
map of trigger definitions
|
An optional map of trigger definitions to invoke when the
policy is applied by an orchestrator against the associated TOSCA entity.
|
3.8.6.2 Grammar
Policy definitions have one the following grammars:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
policy_name: represents
the required symbolic name of the policy as a string.
·
policy_type_name:
represents the name of the policy the definition is based upon.
·
policy_description:
contains an optional description of the policy.
·
property_assignments:
represents the optional map of property
assignments for the policy definition that provide values for properties
defined in its declared Policy Type.
·
list_of_policy_targets:
represents the optional list of names of node templates or groups that the
policy is to applied to.
·
trigger_definitions:
represents the optional map of trigger
definitions for the policy.
3.8.6.3 Example
The following represents a policy definition:
|
policies:
- my_compute_placement_policy:
type:
tosca.policies.placement
description: Apply my
placement policy to my application’s servers
targets: [ my_server_1,
my_server_2 ]
# remainder of policy
definition left off for brevity
|
A workflow definition defines an imperative workflow that is
associated with a TOSCA topology. A workflow definition can either include the
steps that make up the workflow, or it can refer to an artifact that expresses
the workflow using an external workflow language.
3.8.7.1 Keynames
The following is the list of recognized keynames for
a TOSCA workflow definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
description
|
no
|
description
|
The optional description for the workflow definition.
|
|
metadata
|
no
|
map of string
|
Defines a section used to declare additional metadata
information.
|
|
inputs
|
no
|
map of
property definitions
|
The optional map of input parameter definitions.
|
|
preconditions
|
no
|
list of precondition
definitions
|
List of preconditions to be validated before the workflow
can be processed.
|
|
steps
|
no
|
map of step
definitions
|
An optional map of valid imperative workflow step
definitions.
|
|
implementation
|
no
|
operation
implementation definition
|
The optional definition of an external workflow definition.
This keyname is mutually exclusive with the steps keyname above.
|
|
outputs
|
no
|
map of
attribute mappings
|
The optional map of attribute mappings that specify named
workflow output values and their mappings onto attributes of a node or
relationship defined in the topology
|
3.8.7.2 Grammar
Imperative workflow definitions have the following
grammar:
In the above grammar, the pseudo values
that appear in angle brackets have the following meaning:
·
workflow_name:
·
workflow_description:
·
property_definitions:
·
workflow_precondition_definition:
·
workflow_steps:
·
operation_implementation_definition:
represents a full inline definition of an implementation artifact
·
attribute_mappings: represents
the optional map of of attribute_mappings that consists of named output values
returned by operation implementations (i.e. artifacts) and associated mappings
that specify the attribute into which this output value must be stored.
A property mapping allows to map the property of a
substituted node type an input of the topology template.
3.8.8.1 Keynames
The following is the list of recognized
keynames for a TOSCA property mapping:
|
Keyname
|
Required
|
Type
|
Description
|
|
mapping
|
no
|
list of strings
|
An array with 1 string element that references an input of
the topology..
|
|
value
|
no
|
matching the type of this property
|
This deprecated keyname allows to explicitly assigne
a value to this property. This field is mutually exclusive with the mapping
keyname.
|
3.8.8.2 Grammar
The single-line grammar of a property_mapping is as follows:
|
<property_name>:
<property_value> # This use is deprecated
<property_name>:
[ <input_name> ]
|
The multi-line grammar is as follows :
|
<property_name>:
mapping: [ < input_name > ]
<property_name>:
value:
<property_value> # This use is deprecated
|
3.8.8.3 Notes
·
Single line grammar for a property value assignment is not
allowed for properties of type in order to avoid collision with the mapping
single line grammar.
·
The property_value mapping
grammar has been deprecated. The original intent of the property-to-constant-value
mapping was not to provide a mapping,
but rather to present a matching
mechanism to drive selection of the appropriate substituting template when more
than one template was available as a substitution for the abstract node. In
that case, a topology template was only a valid candidate for substitution if
the property value in the abstract node template matched the constant value
specified in the property_value mapping
for that property. With the introduction of substitution filter syntax to drive
matching, there is no longer a need for the property-to-constant-value mapping
functionality.
·
The previous version of the specification allowed direct mappings
from properties of the abstract node template to properties of node templates
in the substituting topology template. Support for these mappings has been
deprecated since they would have resulted in unpredictable behavior, for the
following reason. If the substituting template is a valid TOSCA template, then
all the (required) properties of all its node templates must have valid
property assignments already defined. If the substitution mappings of the
substituting template include direct property-to-property mappings, the the
substituting template ends up with two conflicting property assignments: one
defined in the substituting template itself, and one defined by the substitution
mappings. These conflicting assignments lead to unpredictable behavior.
3.8.8.4 Additional constraints
·
When Input mapping it may be referenced by multiple nodes in the
topologies with resulting attributes values that may differ later on in the
various nodes. In any situation, the attribute reflecting the property of the
substituted type will remain a constant value set to the one of the input at
deployment time.
3.8.9 Attribute mapping
An attribute mapping allows to map the attribute of a
substituted node type an output of the topology template.
3.8.9.1 Keynames
The following is the list of recognized
keynames for a TOSCA attribute mapping:
|
Keyname
|
Required
|
Type
|
Description
|
|
mapping
|
no
|
list of strings
|
An array with 1 string element that references an output
of the topology..
|
3.8.9.2 Grammar
The single-line grammar of an attribute_mapping is as follows:
|
<attribute_name>:
[ <output_name> ]
|
3.8.10 Capability mapping
A capability mapping allows to map the capability of one of
the node of the topology template to the capability of the node type the
service template offers an implementation for.
3.8.10.1 Keynames
The following is the list of recognized
keynames for a TOSCA capability mapping:
|
Keyname
|
Required
|
Type
|
Description
|
|
mapping
|
no
|
list of strings (with 2 members)
|
A list of strings with 2 members, the first one being the
name of a node template, the second the name of a capability of the specified
node template.
|
|
properties
|
no
|
map of property assignments
|
This field is mutually exclusive with the mapping keyname
and allows to provide a capability assignment for the template and specify
it’s related properties.
|
|
attributes
|
no
|
map of attributes assignments
|
This field is mutually exclusive with the mapping keyname
and allows to provide a capability assignment for the template and specify
it’s related attributes.
|
3.8.10.2 Grammar
The single-line grammar of a capability_mapping is as follows:
|
<capability_name>:
[ <node_template_name>, <node_template_capability_name> ]
|
The multi-line grammar is as follows :
|
<capability_name>:
mapping: [ <node_template_name>, <node_template_capability_name>
]
properties:
<property_name>: <property_value>
attributes:
<attribute_name>: <attribute_value>
|
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
capability_name:
represents the name of the capability as it appears in the Node Type definition
for the Node Type (name) that is declared as the value for on the
substitution_mappings’ “node_type” key.
·
node_template_name:
represents a valid name of a Node Template definition (within the same
topology_template declaration as the substitution_mapping is declared).
·
node_template_capability_name: represents a valid name of a capability definition within the <node_template_name> declared in this mapping.
·
property_name: represents the name of a property of the capability.
·
property_value: represents the value to assign to a property of the capability.
·
attribute_name: represents the name a an attribute of the capability.
·
attribute_value: represents the value to assign to an attribute of the capability.
3.8.10.3 Additional requirements
·
Definition of capability assignment in a capability mapping
(through properties and attribute keynames) SHOULD be prohibited for
connectivity capabilities as tosca.capabilities.Endpoint.
3.8.11 Requirement mapping
A requirement mapping allows to map the requirement of one
of the node of the topology template to the requirement of the node type the
service template offers an implementation for.
3.8.11.1 Keynames
The following is the list of recognized
keynames for a TOSCA requirement mapping:
|
Keyname
|
Required
|
Type
|
Description
|
|
mapping
|
no
|
list of strings (2 members)
|
A list of strings with 2 elements, the first one being the
name of a node template, the second the name of a requirement of the
specified node template.
|
|
properties
|
no
|
List of property assignment
|
This field is mutually exclusive with the mapping keyname
and allow to provide a requirement for the template and specify it’s related
properties.
|
|
attributes
|
no
|
List of attributes assignment
|
This field is mutually exclusive with the mapping keyname
and allow to provide a requirement for the template and specify it’s related
attributes.
|
3.8.11.2 Grammar
The single-line grammar of a requirement_mapping is as follows:
|
<requirement_name>:
[ <node_template_name>, <node_template_requirement_name> ]
|
The multi-line grammar is as follows :
|
<requirement_name>:
mapping: [ <node_template_name>, <node_template_requirement_name>
]
properties:
<property_name>: <property_value>
attributes:
<attribute_name>: <attribute_value>
|
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
requirement_name:
represents the name of the requirement as it appears in the Node Type
definition for the Node Type (name) that is declared as the value for on the
substitution_mappings’ “node_type” key.
·
node_template_name:
represents a valid name of a Node Template definition (within the same
topology_template declaration as the substitution_mapping is declared).
·
node_template_requirement_name: represents a valid name of a requirement definition within the
<node_template_name> declared in this mapping.
·
property_name: represents the name of a property of the requirement.
·
property_value: represents the value to assign to a property of the requirement.
·
attribute_name: represents the name a an attribute of the requirement.
·
attribute_value: represents the value to assign to an attribute of the requirement.
3.8.11.3 Additional requirements
·
Definition of capability assignment in a
capability mapping (through properties and attribute keynames) SHOULD be
prohibited for connectivity capabilities as tosca.capabilities.Endpoint.
3.8.12 Interface mapping
An interface mapping allows to map a workflow of the
topology template to an operation of the node type the service template offers
an implementation for.
3.8.12.1 Grammar
The grammar of an interface_mapping
is as follows:
|
<interface_name>:
<operation_name>: <workflow_name>
|
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
interface_name: represents the name of the interface as it
appears in the Node Type definition for the Node Type (name) that is declared
as the value for on the substitution_mappings’ “node_type”
key. Or the name of a new management interface to add to the generated type.
·
operation_name: represents the
name of the operation as it appears in the interface type definition.
·
workflow_name: represents the name of a
workflow of the template to map to the specified operation.
3.8.12.2 Notes
·
Declarative workflow generation will be applied by the TOSCA
orchestrator after the topology template have been substituted. Unless one of
the normative operation of the standard interface is mapped through an
interface mapping. In that case the declarative workflow generation will
consider the substitution node as any other node calling the create, configure
and start mapped workflows as if they where single operations.
·
Operation implementation being TOSCA workflows the TOSCA
orchestrator replace the usual operation_call activity by an inline activity
using the specified workflow.
3.8.13 Substitution mapping
A substitution mapping allows a given topology template to
be used as an implementation of abstract node templates of a specific node type.
This allows the consumption of complex systems using a simplified vision.
3.8.13.1 Keynames
|
Keyname
|
Required
|
Type
|
Description
|
|
node_type
|
yes
|
string
|
The required name of the Node Type the Topology Template
is providing an implementation for.
|
|
substitution_filter
|
no
|
node filter
|
The optional filter that further constrains the abstract
node templates for which this topology template can provide an
implementation.
|
|
properties
|
no
|
map of property mappings
|
The optional map of properties mapping allowing to map
properties of the node_type to inputs of the topology template.
|
|
attributes
|
no
|
map of attribute mappings
|
The optional map of attribute mappings allowing to map
outputs from the topology template to attributes of the node_type.
|
|
capabilities
|
no
|
map of capability mappings
|
The optional map of capabilities mapping.
|
|
requirements
|
no
|
map of requirement mappings
|
The optional map of requirements mapping.
|
|
interfaces
|
no
|
map of interfaces mappings
|
The optional map of interface mapping allows to map an
interface and operations of the node type to implementations that could be
either workflows or node template interfaces/operations.
|
3.8.13.2 Grammar
The grammar of the substitution_mapping
section is as follows:
|
node_type:
<node_type_name>
substitution_filter :
<node_filter>
properties:
<property_mappings>
capabilities:
<capability_mappings>
requirements:
<requirement_mappings>
attributes:
<attribute_mappings>
interfaces:
<interface_mappings>
|
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
node_type_name:
represents the required Node Type name that the Service Template’s topology is
offering an implementation for.
·
node_filter: represents
the optional node filter that reduces the set of abstract node templates for
which this topology template is an implementation by only substituting for
those node templates whose properties and capabilities satisfy the constraints
specified in the node filter.
·
properties: represents the
<optional> map of properties mappings.
·
capability_mappings: represents
the <optional> map of capability mappings.
·
requirement_mappings: represents
the <optional> map of requirement mappings.
·
attributes:
represents the <optional> map of attributes mappings.
·
interfaces: represents the <optional> map of
interfaces mappings.
3.8.13.3 Examples
3.8.13.4 Additional requirements
·
The substitution mapping MUST provide mapping for every property,
capability and requirement defined in the specified <node_type>
3.8.13.5 Notes
·
The node_type specified in the substitution mapping SHOULD be
abstract (does not provide implementation for normative operations).
This section defines the topology template of a cloud application.
The main ingredients of the topology template are node templates representing
components of the application and relationship templates representing links
between the components. These elements are defined in the nested node_templates section and the nested relationship_templates sections,
respectively. Furthermore, a topology template allows for defining input
parameters, output parameters as well as grouping of node templates.
The following is the list of recognized keynames for
a TOSCA Topology Template:
|
Keyname
|
Required
|
Type
|
Description
|
|
description
|
no
|
description
|
The optional description for the Topology Template.
|
|
inputs
|
no
|
map of
parameter definitions
|
An optional map of input parameters (i.e., as parameter definitions)
for the Topology Template.
|
|
node_templates
|
no
|
map of
node templates
|
An optional map of node template definitions for the
Topology Template.
|
|
relationship_templates
|
no
|
map of
relationship
templates
|
An optional map of relationship templates for the Topology
Template.
|
|
groups
|
no
|
map of
group definitions
|
An optional map of Group definitions whose members are
node templates defined within this same Topology Template.
|
|
policies
|
no
|
list of
policy definitions
|
An optional list of Policy definitions for the Topology
Template.
|
|
outputs
|
no
|
map of
parameter
definitions
|
An optional map of output parameters (i.e., as parameter definitions)
for the Topology Template.
|
|
substitution_mappings
|
no
|
substitution_mapping
|
An optional declaration that exports the topology template
as an implementation of a Node type.
This also includes the mappings between the external Node
Types named capabilities and requirements to existing implementations of
those capabilities and requirements on Node templates declared within the
topology template.
|
|
workflows
|
no
|
map of imperative workflow definitions
|
An optional map of imperative workflow definition for the
Topology Template.
|
The overall grammar of the topology_template section is shown
below.–Detailed grammar definitions of the each sub-sections are provided in
subsequent subsections.
|
topology_template:
description: <template_description>
inputs: <input_parameters>
outputs: <output_parameters>
node_templates:
<node_templates>
relationship_templates:
<relationship_templates>
groups: <group_definitions>
policies:
- <policy_definition_list>
workflows: <workflows>
# Optional declaration that
exports the Topology Template
# as an implementation of a Node
Type.
substitution_mappings:
<substitution_mappings>
|
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
template_description:
represents the optional description
string for Topology Template.
·
input_parameters:
represents the optional map of input parameters (i.e., as property definitions)
for the Topology Template.
·
output_parameters:
represents the optional map of output parameters (i.e., as property
definitions) for the Topology Template.
·
group_definitions:
represents the optional map of group
definitions whose members are node templates that also are defined within
this Topology Template.
·
policy_definition_list:
represents the optional list of sequenced policy definitions for the Topology
Template.
·
workflows: represents the optional
map of imperative workflow definitions for the Topology Template.
·
node_templates:
represents the optional map of node
template definitions for the Topology Template.
·
relationship_templates:
represents the optional map of relationship
templates for the Topology Template.
·
node_type_name:
represents the optional name of a Node Type
that the Topology Template implements as part of the substitution_mappings.
·
map_of_capability_mappings_to_expose:
represents the mappings that expose internal capabilities from node templates
(within the topology template) as capabilities of the Node Type definition that
is declared as part of the substitution_mappings.
·
map_of_requirement_mappings_to_expose:
represents the mappings of link requirements of the Node Type definition that
is declared as part of the substitution_mappings
to internal requirements implementations within node templates (declared within
the topology template).
More detailed explanations for each of the Topology Template
grammar’s keynames appears in the sections below.
3.9.2.1 inputs
The inputs section
provides a means to define parameters using TOSCA parameter definitions, their
allowed values via constraints and default values within a TOSCA Simple Profile
template. Input parameters defined in the inputs
section of a topology template can be mapped to properties of node templates or
relationship templates within the same topology template and can thus be used
for parameterizing the instantiation of the topology template.
This section defines topology template-level input parameter
section.
·
Inputs here would ideally be mapped to BoundaryDefinitions in
TOSCA v1.0.
·
Treat input parameters as fixed global variables (not settable
within template)
·
If not in input take default (nodes use default)
3.9.2.1.1 Grammar
The grammar of the inputs
section is as follows:
3.9.2.1.2 Examples
This section provides a set of examples for the
single elements of a topology template.
Simple inputs
example without any constraints:
|
inputs:
fooName:
type: string
description: Simple string
typed property definition with no constraints.
default: bar
|
Example of inputs
with constraints:
|
inputs:
SiteName:
type: string
description: string typed
property definition with constraints
default: My Site
constraints:
- min_length: 9
|
3.9.2.2 node_templates
The node_templates
section lists the Node Templates that describe the (software) components that
are used to compose cloud applications.
3.9.2.2.1 grammar
The grammar of the node_templates
section is a follows:
3.9.2.2.2 Example
Example of node_templates
section:
|
node_templates:
my_webapp_node_template:
type: WebApplication
my_database_node_template:
type: Database
|
3.9.2.3 relationship_templates
The relationship_templates
section lists the Relationship Templates that describe the relations between
components that are used to compose cloud applications.
Note that in the TOSCA Simple Profile, the explicit
definition of relationship templates as it was required in TOSCA v1.0 is
optional, since relationships between nodes get implicitly defined by
referencing other node templates in the requirements sections of node
templates.
3.9.2.3.1 Grammar
The grammar of the relationship_templates
section is as follows:
3.9.2.3.2 Example
Example of relationship_templates
section:
|
relationship_templates:
my_connectsto_relationship:
type: tosca.relationships.ConnectsTo
interfaces:
Configure:
inputs:
speed: { get_attribute:
[ SOURCE, connect_speed ] }
|
3.9.2.4 outputs
The outputs section
provides a means to define the output parameters that are available from a
TOSCA Simple Profile service template. It allows for exposing attributes of
node templates or relationship templates within the containing topology_template to users of a service.
3.9.2.4.1 Grammar
The grammar of the outputs
section is as follows:
3.9.2.4.2 Example
Example of the outputs
section:
|
outputs:
server_address:
description: The first private
IP address for the provisioned server.
value: { get_attribute: [ HOST,
networks, private, addresses, 0 ] }
|
3.9.2.5 groups
The groups section
allows for grouping one or more node templates within a TOSCA Service Template
and for assigning special attributes like policies to the group.
3.9.2.5.1 Grammar
The grammar of the groups
section is as follows:
3.9.2.5.2 Example
The following example shows the definition of three
Compute nodes in the node_templates
section of a topology_template as well
as the grouping of two of the Compute nodes in a group server_group_1.
|
node_templates:
server1:
type: tosca.nodes.Compute
# more details ...
server2:
type: tosca.nodes.Compute
# more details ...
server3:
type: tosca.nodes.Compute
# more details ...
groups:
# server2 and server3 are part
of the same group
server_group_1:
type: tosca.groups.Root
members: [ server2, server3 ]
|
3.9.2.6 policies
The policies section
allows for declaring policies that can be applied to entities in the topology
template.
3.9.2.6.1 Grammar
The grammar of the policies
section is as follows:
3.9.2.6.2 Example
The following example shows the definition of a
placement policy.
|
policies:
- my_placement_policy:
type: mycompany.mytypes.policy.placement
|
3.9.2.7 substitution_mapping
3.9.2.7.1 requirement_mapping
The grammar of a requirement_mapping
is as follows:
|
<requirement_name>: [
<node_template_name>, <node_template_requirement_name> ]
|
The multi-line grammar is as follows :
|
<requirement_name>:
mapping: [ <node_template_name>, <node_template_capability_name>
]
properties:
<property_name>: <property_value>
|
·
requirement_name:
represents the name of the requirement as it appears in the Node Type
definition for the Node Type (name) that is declared as the value for on the
substitution_mappings’ “node_type” key.
·
node_template_name:
represents a valid name of a Node Template definition (within the same
topology_template declaration as the substitution_mapping is declared).
·
node_template_requirement_name:
represents a valid name of a requirement
definition within the <node_template_name> declared in this mapping.
3.9.2.7.2 Example
The following example shows the definition of a
placement policy.
|
topology_template:
inputs:
cpus:
type: integer
constraints:
less_than: 2 # OR
use “defaults” key
substitution_mappings:
node_type:
MyService
properties: # Do not care if running or matching (e.g., Compute node)
#
get from outside? Get from contsraint?
num_cpus:
cpus # Implied “PUSH”
#
get from some node in the topology…
num_cpus:
[ <node>, <cap>, <property> ]
# 1) Running
architecture:
# a) Explicit
value: { get_property: [some_service, architecture] }
# b) implicit
value: [ some_service, <req | cap name>, <property name>
architecture ]
default: “amd”
# c) INPUT mapping?
???
# 2) Catalog (Matching)
architecture:
contraints:
equals: “x86”
capabilities:
bar:
[ some_service, bar ]
requirements:
foo: [ some_service, foo ]
node_templates:
some_service:
type: MyService
properties:
rate: 100
capabilities:
bar:
...
requirements:
- foo:
...
|
3.9.2.8 Notes
·
The parameters (properties) that are part of the inputs block can be mapped to PropertyMappings provided as part of BoundaryDefinitions as described by the TOSCA
v1.0 specification.
·
The node templates that are part of the node_templates block can be mapped to the NodeTemplate definitions provided as part of TopologyTemplate of a ServiceTemplate as described by the TOSCA
v1.0 specification.
·
The relationship templates that are part of the relationship_templates block can be mapped to
the RelationshipTemplate definitions provided
as part of TopologyTemplate of a ServiceTemplate as described by the TOSCA
v1.0 specification.
·
The output parameters that are part of the outputs section of a topology template can be
mapped to PropertyMappings provided as
part of BoundaryDefinitions as
described by the TOSCA v1.0 specification.
o
Note, however, that TOSCA v1.0 does not define a direction (input
vs. output) for those mappings, i.e. TOSCA v1.0 PropertyMappings are underspecified in that
respect and TOSCA Simple Profile’s inputs
and outputs provide a more concrete
definition of input and output parameters.
A TOSCA Service Template (YAML)
document contains element definitions of building blocks for cloud application,
or complete models of cloud applications. This section describes the top-level
structural elements (TOSCA keynames) along with their grammars, which are
allowed to appear in a TOSCA Service Template document.
The following is the list of recognized keynames for
a TOSCA Service Template definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
tosca_definitions_version
|
yes
|
string
|
Defines the version of the TOSCA Simple Profile
specification the template (grammar) complies with.
|
|
namespace
|
no
|
URI
|
The default (target) namespace for all unqualified Types
defined within the Service Template.
|
|
metadata
|
no
|
map of string
|
Defines a section used to declare additional metadata
information. Domain-specific TOSCA profile specifications may define
keynames that are required for their implementations.
|
|
description
|
no
|
description
|
Declares a description for this Service Template and its
contents.
|
|
dsl_definitions
|
no
|
N/A
|
Declares optional DSL-specific definitions and
conventions. For example, in YAML, this allows defining reusable YAML macros
(i.e., YAML alias anchors) for use throughout the TOSCA Service Template.
|
|
repositories
|
no
|
map of
Repository
definitions
|
Declares the map of external repositories which contain
artifacts that are referenced in the service template along with their
addresses and necessary credential information used to connect to them in
order to retrieve the artifacts.
|
|
imports
|
no
|
list of
Import Definitions
|
Declares a list import statements pointing to external
TOSCA Definitions documents. For example, these may be file location or URIs
relative to the service template file within the same TOSCA CSAR file.
|
|
artifact_types
|
no
|
map of
Artifact Types
|
This section contains an optional map of artifact type
definitions for use in the service template
|
|
data_types
|
no
|
map of
Data Types
|
Declares a map of optional TOSCA Data Type definitions.
|
|
capability_types
|
no
|
map of
Capability Types
|
This section contains an optional map of capability type
definitions for use in the service template.
|
|
interface_types
|
no
|
map of
Interface Types
|
This section contains an optional map of interface type
definitions for use in the service template.
|
|
relationship_types
|
no
|
map of
Relationship
Types
|
This section contains a map of relationship type
definitions for use in the service template.
|
|
node_types
|
no
|
map of
Node Types
|
This section contains a map of node type definitions for
use in the service template.
|
|
group_types
|
no
|
map of
Group Types
|
This section contains a map of group type definitions for
use in the service template.
|
|
policy_types
|
no
|
list of
Policy Types
|
This section contains a list of policy type definitions
for use in the service template.
|
|
topology_template
|
no
|
Topology Template definition
|
Defines the topology template of an application or
service, consisting of node templates that represent the application’s or
service’s components, as well as relationship templates representing
relations between the components.
|
3.10.1.1 Metadata keynames
The following is the list of recognized metadata
keynames for a TOSCA Service Template definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
template_name
|
no
|
string
|
Declares a descriptive name for the template.
|
|
template_author
|
no
|
string
|
Declares the author(s) or owner of the template.
|
|
template_version
|
no
|
string
|
Declares the version string for the template.
|
The overall structure of a TOSCA
Service Template and its top-level key collations using the TOSCA Simple
Profile is shown below:
|
# Required TOSCA Definitions
version string
tosca_definitions_version: <value>
# Required, see section 3.1 for usage
namespace: <URI> #
Optional, see section 3.2 for usage
# Optional metadata keyname: value
pairs
metadata:
template_name: <value>
# Optional, name of this service template
template_author: <value> #
Optional, author of this service template
template_version: <value>
# Optional, version of this service template
# More optional entries of
domain or profile specific metadata keynames
# Optional description of the
definitions inside the file.
description: <template_type_description>
dsl_definitions:
# map of YAML alias anchors (or
macros)
repositories:
# map of external repository
definitions which host TOSCA artifacts
imports:
# ordered list of import
definitions
artifact_types:
# map of artifact
type definitions
data_types:
# map of datatype definitions
capability_types:
# map of capability
type definitions
# map of interface
type definitions
relationship_types:
# map of relationship
type definitions
node_types:
# map of node type definitions
group_types:
# map of group type definitions
policy_types:
# map of policy type definitions
topology_template:
# topology template definition
of the cloud application or service
|
·
The URI value “http://docs.oasis-open.org/tosca”,
as well as all (path) extensions to it, SHALL be reserved for TOSCA approved
specifications and work. That means Service Templates that do not originate
from a TOSCA approved work product MUST NOT use it, in any form, when declaring
a (default) Namespace.
·
The key “tosca_definitions_version”
SHOULD be the first line of each Service Template.
3.10.2.2 Notes
·
TOSCA Service Templates do not have to contain a
topology_template and MAY contain simply type definitions (e.g., Artifact,
Interface, Capability, Node, Relationship Types, etc.) and be imported for use
as type definitions in other TOSCA Service Templates.
This required element provides a means to include a
reference to the TOSCA Simple Profile specification within the TOSCA
Definitions YAML file. It is an indicator for the version of the TOSCA grammar
that should be used to parse the remainder of the document.
3.10.3.1.1 Keyname
|
tosca_definitions_version
|
3.10.3.1.2 Grammar
Single-line form:
|
tosca_definitions_version: <tosca_simple_profile_version>
|
3.10.3.1.3 Examples:
TOSCA Simple Profile version 1.3 specification using
the defined namespace alias (see Section 3.1):
|
tosca_definitions_version: tosca_simple_yaml_1_3
|
TOSCA Simple Profile version 1.3 specification using
the fully defined (target) namespace (see Section 3.1):
|
tosca_definitions_version: http://docs.oasis-open.org/tosca/ns/simple/yaml/1.3
|
This keyname is used to associate domain-specific metadata
with the Service Template. The metadata keyname allows a declaration of a map
of keynames with string values.
3.10.3.2.1 Keyname
3.10.3.2.2 Grammar
|
metadata:
<map_of_string_values>
|
3.10.3.2.3 Example
|
metadata:
creation_date: 2015-04-14
date_updated: 2015-05-01
status: developmental
|
3.10.3.3 template_name
This optional metadata keyname can be used to declare the
name of service template as a single-line string value.
3.10.3.3.1 Keyname
3.10.3.3.2 Grammar
|
template_name: <name string>
|
3.10.3.3.3 Example
|
template_name: My service template
|
3.10.3.3.4 Notes
·
Some service templates are designed to be referenced and reused
by other service templates. Therefore, in these cases, the template_name value SHOULD be designed to be
used as a unique identifier through the use of namespacing techniques.
This optional metadata keyname can be used to declare the author(s)
of the service template as a single-line string value.
3.10.3.4.1 Keyname
3.10.3.4.2 Grammar
|
template_author: <author string>
|
3.10.3.4.3 Example
|
template_author: My service
template
|
This optional metadata keyname can be used to declare a
domain specific version of the service template as a single-line string value.
3.10.3.5.1 Keyname
3.10.3.5.2 Grammar
3.10.3.5.3 Example
3.10.3.5.4 Notes:
·
Some service templates are designed to be referenced and reused
by other service templates and have a lifecycle of their own. Therefore, in
these cases, a template_version value
SHOULD be included and used in conjunction with a unique template_name value to enable lifecycle
management of the service template and its contents.
This optional keyname provides a means to include single or
multiline descriptions within a TOSCA Simple Profile template as a scalar
string value.
3.10.3.6.1 Keyname
3.10.3.7 dsl_definitions
This optional keyname provides a section to define macros
(e.g., YAML-style macros when using the TOSCA Simple Profile in YAML
specification).
3.10.3.7.1 Keyname
3.10.3.7.2 Grammar
3.10.3.7.3 Example
|
dsl_definitions:
ubuntu_image_props:
&ubuntu_image_props
architecture: x86_64
type: linux
distribution: ubuntu
os_version: 14.04
redhat_image_props:
&redhat_image_props
architecture: x86_64
type: linux
distribution: rhel
os_version: 6.6
|
This optional keyname provides a section to define external
repositories which may contain artifacts or other TOSCA Service Templates which
might be referenced or imported by the TOSCA Service Template definition.
3.10.3.8.1 Keyname
3.10.3.8.2 Grammar
3.10.3.8.3 Example
|
repositories:
my_project_artifact_repo:
description: development
repository for TAR archives and Bash scripts
url: http://mycompany.com/repository/myproject/
|
3.10.3.9 imports
This optional keyname provides a way to import a block
sequence of one or more TOSCA Definitions documents. TOSCA Definitions
documents can contain reusable TOSCA type definitions (e.g., Node Types,
Relationship Types, Artifact Types, etc.) defined by other authors. This
mechanism provides an effective way for companies and organizations to define
normative types and/or describe their software applications for reuse in other
TOSCA Service Templates.
3.10.3.9.1 Keyname
3.10.3.9.2 Grammar
3.10.3.9.3 Example
|
# An example import of definitions
files from a location relative to the
# file location of the service
template declaring the import.
imports:
- some_definitions:
relative_path/my_defns/my_typesdefs_1.yaml
- file:
my_defns/my_typesdefs_n.yaml
repository: my_company_repo
namespace_prefix: mycompany
|
3.10.3.10 artifact_types
This optional keyname lists the Artifact Types that are
defined by this Service Template.
3.10.3.10.1 Keyname
3.10.3.10.2 Grammar
3.10.3.10.3 Example
|
artifact_types:
mycompany.artifacttypes.myFileType:
derived_from:
tosca.artifacts.File
|
3.10.3.11 data_types
This optional keyname provides a section to define new data types
in TOSCA.
3.10.3.11.1 Keyname
3.10.3.11.2 Grammar
3.10.3.11.3 Example
|
data_types:
# A complex datatype definition
simple_contactinfo_type:
properties:
name:
type: string
email:
type: string
phone:
type: string
# datatype definition derived
from an existing type
full_contact_info:
derived_from:
simple_contact_info
properties:
street_address:
type: string
city:
type: string
state:
type: string
postalcode:
type: string
|
This optional keyname lists the Capability Types that
provide the reusable type definitions that can be used to describe features Node
Templates or Node Types can declare they support.
3.10.3.12.1 Keyname
3.10.3.12.2 Grammar
3.10.3.12.3 Example
|
capability_types:
mycompany.mytypes.myCustomEndpoint:
derived_from:
tosca.capabilities.Endpoint
properties:
# more details ...
mycompany.mytypes.myCustomFeature:
derived_from:
tosca.capabilities.Feature
properties:
# more details ...
|
This optional keyname lists the Interface Types that provide
the reusable type definitions that can be used to describe operations for on
TOSCA entities such as Relationship Types and Node Types.
3.10.3.13.1 Keyname
3.10.3.13.2 Grammar
3.10.3.13.3 Example
|
interface_types:
mycompany.interfaces.service.Signal:
signal_begin_receive:
description: Operation to
signal start of some message processing.
signal_end_receive:
description: Operation to
signal end of some message processed.
|
3.10.3.14 relationship_types
This optional keyname lists the Relationship Types that
provide the reusable type definitions that can be used to describe dependent
relationships between Node Templates or Node Types.
3.10.3.14.1 Keyname
3.10.3.14.2 Grammar
3.10.3.14.3 Example
|
relationship_types:
mycompany.mytypes.myCustomClientServerType:
derived_from: tosca.relationships.HostedOn
properties:
# more details ...
mycompany.mytypes.myCustomConnectionType:
derived_from:
tosca.relationships.ConnectsTo
properties:
# more details ...
|
3.10.3.15 node_types
This optional keyname lists the Node Types that provide the
reusable type definitions for software components that Node Templates can be
based upon.
3.10.3.15.1 Keyname
3.10.3.15.2 Grammar
3.10.3.15.3 Example
|
node_types:
my_webapp_node_type:
derived_from: WebApplication
properties:
my_port:
type: integer
my_database_node_type:
derived_from: Database
capabilities:
mytypes.myfeatures.transactSQL
|
3.10.3.15.4 Notes
·
The node types that are part of the node_types block can be mapped to the NodeType definitions as described by the
TOSCA v1.0 specification.
This optional keyname lists the Group Types that are defined
by this Service Template.
3.10.3.16.1 Keyname
3.10.3.16.2 Grammar
3.10.3.16.3 Example
|
group_types:
mycompany.mytypes.myScalingGroup:
derived_from:
tosca.groups.Root
|
3.10.3.17 policy_types
This optional keyname lists the Policy Types that are
defined by this Service Template.
3.10.3.17.1 Keyname
3.10.3.17.2 Grammar
3.10.3.17.3 Example
|
policy_types:
mycompany.mytypes.myScalingPolicy:
derived_from:
tosca.policies.Scaling
|
Except for the examples, this section is normative
and includes functions that are supported for use within a TOSCA Service
Template.
The following keywords MAY be used in some TOSCA function in
place of a TOSCA Node or Relationship Template name. A TOSCA orchestrator will
interpret them at the time the function would be evaluated at runtime as
described in the table below. Note that some keywords are only valid in the
context of a certain TOSCA entity as also denoted in the table.
|
Keyword
|
Valid Contexts
|
Description
|
|
SELF
|
Node Template or Relationship Template
|
A TOSCA orchestrator will interpret this keyword as the
Node or Relationship Template instance that contains the function at the time
the function is evaluated.
|
|
SOURCE
|
Relationship Template only.
|
A TOSCA orchestrator will interpret this keyword as the
Node Template instance that is at the source end of the relationship that
contains the referencing function.
|
|
TARGET
|
Relationship Template only.
|
A TOSCA orchestrator will interpret this keyword as the
Node Template instance that is at the target end of the relationship that
contains the referencing function.
|
|
HOST
|
Node Template only
|
A TOSCA orchestrator will interpret this keyword to refer
to the all nodes that “host” the node using this reference (i.e., as
identified by its HostedOn relationship).
Specifically, TOSCA orchestrators that encounter this
keyword when evaluating the get_attribute or get_property functions
SHALL search each node along the “HostedOn” relationship chain starting at
the immediate node that hosts the node where the function was evaluated (and
then that node’s host node, and so forth) until a match is found or the
“HostedOn” relationship chain ends.
|
TOSCA orchestrators utilize certain reserved keywords in the
execution environments that implementation artifacts for Node or Relationship
Templates operations are executed in. They are used to provide information to
these implementation artifacts such as the results of TOSCA function evaluation
or information about the instance model of the TOSCA application
The following keywords are reserved environment variable
names in any TOSCA supported execution environment:
|
Keyword
|
Valid Contexts
|
Description
|
|
TARGETS
|
Relationship Template only.
|
·
For an implementation artifact
that is executed in the context of a relationship, this keyword, if present,
is used to supply a list of Node Template instances in a TOSCA application’s
instance model that are currently target of the context relationship.
·
The value of this environment
variable will be a comma-separated list of identifiers of the single target
node instances (i.e., the tosca_id attribute of the node).
|
|
TARGET
|
Relationship Template only.
|
·
For an implementation artifact
that is executed in the context of a relationship, this keyword, if present,
identifies a Node Template instance in a TOSCA application’s instance model
that is a target of the context relationship, and which is being acted upon
in the current operation.
·
The value of this environment
variable will be the identifier of the single target node instance (i.e., the
tosca_id attribute of
the node).
|
|
SOURCES
|
Relationship Template only.
|
·
For an implementation artifact
that is executed in the context of a relationship, this keyword, if present,
is used to supply a list of Node Template instances in a TOSCA application’s
instance model that are currently source of the context relationship.
·
The value of this environment
variable will be a comma-separated list of identifiers of the single source
node instances (i.e., the tosca_id attribute of the node).
|
|
SOURCE
|
Relationship Template only.
|
·
For an implementation artifact
that is executed in the context of a relationship, this keyword, if present,
identifies a Node Template instance in a TOSCA application’s instance model
that is a source of the context relationship, and which is being acted upon
in the current operation.
·
The value of this environment
variable will be the identifier of the single source node instance (i.e., the
tosca_id attribute of
the node).
|
For scripts (or implementation artifacts in general) that
run in the context of relationship operations, select properties and attributes
of both the relationship itself as well as select properties and attributes of
the source and target node(s) of the relationship can be provided to the
environment by declaring respective operation inputs.
Declared inputs from mapped properties or attributes of the
source or target node (selected via the SOURCE
or TARGET keyword) will be provided to
the environment as variables having the exact same name as the inputs. In
addition, the same values will be provided for the complete set of source or
target nodes, however prefixed with the ID if the respective nodes. By means of
the SOURCES or TARGETS variables holding the complete set of
source or target node IDs, scripts will be able to iterate over corresponding
inputs for each provided ID prefix.
The following example snippet shows an imaginary
relationship definition from a load-balancer node to worker nodes. A script is
defined for the add_target operation of
the Configure interface of the relationship, and the ip_address attribute of the target is
specified as input to the script:
|
node_templates:
load_balancer:
type: some.vendor.LoadBalancer
requirements:
- member:
relationship:
some.vendor.LoadBalancerToMember
interfaces:
Configure:
add_target:
inputs:
member_ip: {
get_attribute: [ TARGET, ip_address ] }
implementation:
scripts/configure_members.py
|
The add_target
operation will be invoked, whenever a new target member is being added to the
load-balancer. With the above inputs declaration, a member_ip environment variable that will hold
the IP address of the target being added will be provided to the configure_members.py script. In addition, the
IP addresses of all current load-balancer members will be provided as
environment variables with a naming scheme of <target
node ID>_member_ip. This will allow, for example, scripts that always
just write the complete list of load-balancer members into a configuration file
to do so instead of updating existing list, which might be more complicated.
Assuming that the TOSCA application instance
includes five load-balancer members, node1
through node5, where node5 is the current target being added, the
following environment variables (plus potentially more variables) would be
provided to the script:
|
# the ID of the current target and
the IDs of all targets
TARGET=node5
TARGETS=node1,node2,node3,node4,node5
# the input for the current target
and the inputs of all targets
member_ip=10.0.0.5
node1_member_ip=10.0.0.1
node2_member_ip=10.0.0.2
node3_member_ip=10.0.0.3
node4_member_ip=10.0.0.4
node5_member_ip=10.0.0.5
|
With code like shown in the snippet below, scripts
could then iterate of all provided member_ip
inputs:
|
#!/usr/bin/python
import os
targets =
os.environ['TARGETS'].split(',')
for t in targets:
target_ip =
os.environ.get('%s_member_ip' % t)
# do something with target_ip
...
|
The list target node types assigned to the TARGETS key in an
execution environment would have names prefixed by unique IDs that distinguish
different instances of a node in a running model Future drafts of this
specification will show examples of how these names/IDs will be expressed.
4.2.2.1 Notes
·
Target of interest is always un-prefixed. Prefix is the target
opaque ID. The IDs can be used to find the environment var. for the
corresponding target. Need an example here.
·
If you have one node that contains multiple targets this would
also be used (add or remove target operations would also use this you would get
set of all current targets).
These functions are supported within the TOSCA template for
manipulation of template data.
The concat function
is used to concatenate two or more string values within a TOSCA service
template.
4.3.1.1 Grammar
|
concat:
[<string_value_expressions_*> ]
|
4.3.1.2 Parameters
|
Parameter
|
Required
|
Type
|
Description
|
|
<string_value_expressions_*>
|
yes
|
list of
string or
string value expressions
|
A list of one or more strings (or expressions that result
in a string value) which can be concatenated together into a single string.
|
4.3.1.3 Examples
|
outputs:
description: Concatenate the URL
for a server from other template values
server_url:
value: { concat: [
'http://',
get_attribute: [ server, public_address ],
':',
get_attribute: [ server, port ] ] }
|
The join function is
used to join an array of strings into a single string with optional delimiter.
4.3.2.1 Grammar
|
join: [<list of string_value_expressions_*>
[ <delimiter> ] ]
|
4.3.2.2 Parameters
|
Parameter
|
Required
|
Type
|
Description
|
|
<list of string_value_expressions_*>
|
yes
|
list of
string or
string value expressions
|
A list of one or more strings (or expressions that result
in a list of string values) which can be joined together into a single
string.
|
|
<delimiter>
|
no
|
string
|
An optional delimiter used to join the string in the
provided list.
|
4.3.2.3 Examples
|
outputs:
example1:
# Result: prefix_1111_suffix
value: { join: [
["prefix", 1111, "suffix" ], "_" ] }
example2:
# Result: 9.12.1.10,9.12.1.20
value: { join: [
{ get_input: my_IPs }, “,” ]
}
|
4.3.3 token
The token function
is used within a TOSCA service template on a string to parse out (tokenize) substrings
separated by one or more token characters within a larger string.
4.3.3.1 Grammar
|
token: [ <string_with_tokens>,
<string_of_token_chars>, <substring_index> ]
|
4.3.3.2 Parameters
|
Parameter
|
Required
|
Type
|
Description
|
|
string_with_tokens
|
yes
|
string
|
The composite string that contains one or more substrings
separated by token characters.
|
|
string_of_token_chars
|
yes
|
string
|
The string that contains one or more token characters that
separate substrings within the composite string.
|
|
substring_index
|
yes
|
integer
|
The integer indicates the index of the substring to return
from the composite string. Note that the first substring is denoted by using
the ‘0’ (zero) integer value.
|
4.3.3.3 Examples
|
outputs:
webserver_port:
description: the port
provided at the end of my server’s endpoint’s IP address
value: { token: [
get_attribute: [ my_server, data_endpoint, ip_address ],
‘:’,
1 ] }
|
These functions are used within a service template to obtain
property values from property definitions declared elsewhere in the same
service template. These property definitions can appear either directly in the
service template itself (e.g., in the inputs section) or on entities (e.g.,
node or relationship templates) that have been modeled within the template.
Note that the get_input
and get_property functions may only
retrieve the static values of property definitions of a TOSCA application as
defined in the TOSCA Service Template. The get_attribute
function should be used to retrieve values for attribute definitions (or
property definitions reflected as attribute definitions) from the runtime
instance model of the TOSCA application (as realized by the TOSCA
orchestrator).
The get_input function
is used to retrieve the values of properties declared within the inputs section of a TOSCA Service Template.
|
get_input:
<input_property_name>
|
or
|
get_input: [
<input_property_name>, <nested_input_property_name_or_index_1>,
..., <nested_input_property_name_or_index_n> ]
|
|
Parameter
|
Required
|
Type
|
Description
|
|
<input_property_name>
|
yes
|
string
|
The name of the property as defined in the inputs section
of the service template.
|
|
<nested_input_property_name_or_index_*>
|
no
|
string| integer
|
Some TOSCA input properties are complex (i.e., composed as
nested structures). These parameters are used to dereference into the names
of these nested structures when needed.
Some properties represent list types.
In these cases, an index may be provided to reference a specific entry in the
list (as named in the previous parameter) to return.
|
4.4.1.3 Examples
The following snippet shows an example of the simple
get_input grammar:
|
inputs:
cpus:
type: integer
node_templates:
my_server:
type: tosca.nodes.Compute
capabilities:
host:
properties:
num_cpus: { get_input: cpus }
|
The following template shows an example of the nested
get_input grammar. The template expects two input values, each of which has a
complex data type. The get_input function is used to retrieve individual fields
from the complex input data.
|
data_types:
NetworkInfo:
derived_from: tosca.Data.Root
properties:
name:
type: string
gateway:
type: string
RouterInfo:
derived_from: tosca.Data.Root
properties:
ip:
type: string
external:
type: string
topology_template:
inputs:
management_network:
type: NetworkInfo
router:
type: RouterInfo
node_templates:
Bono_Main:
type: vRouter.Cisco
directives: [ substitutable
]
properties:
mgmt_net_name: {
get_input: [management_network, name]}
mgmt_cp_v4_fixed_ip: {
get_input: [router, ip]}
mgmt_cp_gateway_ip: {
get_input: [management_network, gateway]}
mgmt_cp_external_ip: {
get_input: [router, external]}
requirements:
- lan_port:
node: host_with_net
capability:
virtualBind
- mgmt_net: mgmt_net
|
4.4.2 get_property
The get_property function
is used to retrieve property values between modelable entities defined in the
same service template.
4.4.2.1 Grammar
|
get_property: [ <modelable_entity_name>,
<optional_req_or_cap_name>, <property_name>, <nested_property_name_or_index_1>,
..., <nested_property_name_or_index_n> ]
|
4.4.2.2 Parameters
|
Parameter
|
Required
|
Type
|
Description
|
|
<modelable entity name> |
SELF | SOURCE | TARGET | HOST
|
yes
|
string
|
The required name of a modelable entity (e.g., Node
Template or Relationship Template name) as declared in the service template
that contains the named property definition the function will return the
value from. See section B.1 for valid keywords.
|
|
<optional_req_or_cap_name>
|
no
|
string
|
The optional name of the requirement or capability name
within the modelable entity (i.e., the <modelable_entity_name> which
contains the named property definition the function will return the value
from.
Note: If the property definition is located in the
modelable entity directly, then this parameter MAY be omitted.
|
|
<property_name>
|
yes
|
string
|
The name of the property definition the function will
return the value from.
|
|
<nested_property_name_or_index_*>
|
no
|
string| integer
|
Some TOSCA properties are complex (i.e., composed as
nested structures). These parameters are used to dereference into the names
of these nested structures when needed.
Some properties represent list types. In these cases, an
index may be provided to reference a specific entry in the list (as named in
the previous parameter) to return.
|
4.4.2.3 Examples
The following example shows how to use the get_property function with an actual Node
Template name:
|
node_templates:
mysql_database:
type: tosca.nodes.Database
properties:
name: sql_database1
wordpress:
type:
tosca.nodes.WebApplication.WordPress
...
interfaces:
Standard:
configure:
inputs:
wp_db_name: { get_property: [
mysql_database, name ] }
|
The following example shows
how to use the get_property function using the SELF keyword:
|
node_templates:
mysql_database:
type: tosca.nodes.Database
...
capabilities:
database_endpoint:
properties:
port: 3306
wordpress:
type:
tosca.nodes.WebApplication.WordPress
requirements:
...
- database_endpoint:
mysql_database
interfaces:
Standard:
create:
wordpress_install.sh
configure:
implementation:
wordpress_configure.sh
inputs:
...
wp_db_port: { get_property: [ SELF,
database_endpoint, port ] }
|
The following example shows how to use the
get_property function using the TARGET keyword:
|
relationship_templates:
my_connection:
type: ConnectsTo
interfaces:
Configure:
inputs:
targets_value: {
get_property: [ TARGET, value ] }
|
These functions (attribute functions) are used within an
instance model to obtain attribute values from instances of nodes and
relationships that have been created from an application model described in a
service template. The instances of nodes or relationships can be referenced by
their name as assigned in the service template or relative to the context where
they are being invoked.
The get_attribute
function is used to retrieve the values of named attributes declared by the
referenced node or relationship template name.
4.5.1.1 Grammar
|
get_attribute: [ <modelable_entity_name>,
<optional_req_or_cap_name>, <attribute_name>, <nested_attribute_name_or_index_1>,
..., <nested_attribute_name_or_index_n> ]
|
4.5.1.2 Parameters
|
Parameter
|
Required
|
Type
|
Description
|
|
<modelable entity name> |
SELF | SOURCE | TARGET | HOST
|
yes
|
string
|
The required name of a modelable entity (e.g., Node
Template or Relationship Template name) as declared in the service template
that contains the named attribute definition the function will return the
value from. See section B.1 for valid keywords.
|
|
<optional_req_or_cap_name>
|
no
|
string
|
The optional name of the requirement or capability name
within the modelable entity (i.e., the <modelable_entity_name> which
contains the named attribute definition the function will return the value
from.
Note: If the attribute definition is located in
the modelable entity directly, then this parameter MAY be omitted.
|
|
<attribute_name>
|
yes
|
string
|
The name of the attribute definition the function will
return the value from.
|
|
<nested_attribute_name_or_index_*>
|
no
|
string| integer
|
Some TOSCA attributes are complex (i.e., composed as nested
structures). These parameters are used to dereference into the names of
these nested structures when needed.
Some attributes represent list types. In these cases, an index may be
provided to reference a specific entry in the list (as named in the previous
parameter) to return.
|
4.5.1.3 Examples:
The attribute functions are used in the same way as the
equivalent Property functions described above. Please see their examples and
replace “get_property” with “get_attribute” function name.
4.5.1.4 Notes
These functions are used to obtain attributes from instances
of node or relationship templates by the names they were given within the
service template that described the application model (pattern).
- These functions only work when the orchestrator
can resolve to a single node or relationship instance for the named node
or relationship. This essentially means this is acknowledged to work only
when the node or relationship template being referenced from the service
template has a cardinality of 1 (i.e., there can only be one instance of
it running).
These functions are used within an instance model to obtain
values from interface operations. These can be used in order to set an
attribute of a node instance at runtime or to pass values from one operation to
another.
The get_operation_output
function is used to retrieve the values of variables exposed / exported from an
interface operation.
4.6.1.1 Grammar
|
get_operation_output:
<modelable_entity_name>, <interface_name>,
<operation_name>, <output_variable_name>
|
4.6.1.2 Parameters
|
Parameter
|
Required
|
Type
|
Description
|
|
<modelable entity name> |
SELF | SOURCE | TARGET
|
yes
|
string
|
The required name of a modelable entity (e.g., Node
Template or Relationship Template name) as declared in the service template
that implements the named interface and operation.
|
|
<interface_name>
|
Yes
|
string
|
The required name of the interface which defines the
operation.
|
|
<operation_name>
|
yes
|
string
|
The required name of the operation whose value we would
like to retrieve.
|
|
<output_variable_name>
|
Yes
|
string
|
The required name of the variable that is exposed /
exported by the operation.
|
4.6.1.3 Notes
·
If operation failed, then ignore its outputs. Orchestrators
should allow orchestrators to continue running when possible past deployment in
the lifecycle. For example, if an update fails, the application should be
allowed to continue running and some other method would be used to alert
administrators of the failure.
·
This version of the TOSCA Simple Profile does not define any
model navigation functions.
The get_nodes_of_type
function can be used to retrieve a list of all known instances of nodes of the
declared Node Type.
4.7.1.1 Grammar
|
get_nodes_of_type:
<node_type_name>
|
4.7.1.2 Parameters
|
Parameter
|
Required
|
Type
|
Description
|
|
<node_type_name>
|
yes
|
string
|
The required name of a Node Type that a TOSCA orchestrator
would use to search a running application instance in order to return all
unique, named node instances of that type.
|
4.7.1.3 Returns
|
Return Key
|
Type
|
Description
|
|
TARGETS
|
<see above>
|
The list of node instances from the current application
instance that match the node_type_name supplied as an input
parameter of this function.
|
The get_artifact function
is used to retrieve artifact location between modelable entities defined in the
same service template.
4.8.1.1 Grammar
|
get_artifact: [
<modelable_entity_name>, <artifact_name>, <location>,
<remove> ]
|
4.8.1.2 Parameters
|
Parameter
|
Required
|
Type
|
Description
|
|
<modelable entity name> |
SELF | SOURCE | TARGET | HOST
|
yes
|
string
|
The required name of a modelable
entity (e.g., Node Template or Relationship Template name) as declared in the
service template that contains the named property definition the function
will return the value from. See section B.1 for valid keywords.
|
|
<artifact_name>
|
yes
|
string
|
The name of the artifact
definition the function will return the value from.
|
|
<location> | LOCAL_FILE
|
no
|
string
|
Location value must be either a
valid path e.g. ‘/etc/var/my_file’ or ‘LOCAL_FILE’.
If the value is LOCAL_FILE the
orchestrator is responsible for providing a path as the result of the get_artifact call where the artifact file
can be accessed. The orchestrator will also remove the artifact from this
location at the end of the operation.
If the location is a path
specified by the user the orchestrator is responsible to copy the artifact to
the specified location. The orchestrator will return the path as the value of
the get_artifact function
and leave the file here after the execution of the operation.
|
|
remove
|
no
|
boolean
|
Boolean flag to override the
orchestrator default behavior so it will remove or not the artifact at the
end of the operation execution.
If not specified the removal
will depends of the location e.g. removes it in case of ‘LOCAL_FILE’ and
keeps it in case of a path.
If true the artifact will be
removed by the orchestrator at the end of the operation execution, if false
it will not be removed.
|
4.8.1.3 Examples
The following example uses a snippet of a WordPress
[WordPress] web application to show how to use the
get_artifact
function with an actual Node Template name:
4.8.1.3.1 Example: Retrieving artifact without specified location
|
node_templates:
wordpress:
type:
tosca.nodes.WebApplication.WordPress
...
interfaces:
Standard:
configure:
create:
implementation:
wordpress_install.sh
inputs
wp_zip: { get_artifact: [
SELF, zip ] }
artifacts:
zip: /data/wordpress.zip
|
In such implementation the TOSCA orchestrator may
provide the wordpress.zip archive as
·
a local URL (example: file://home/user/wordpress.zip)
or
·
a remote one (example: http://cloudrepo:80/files/wordpress.zip)
where some orchestrator may indeed provide some global artifact repository
management features.
4.8.1.3.2 Example: Retrieving artifact as a local path
The following example explains how to force the orchestrator
to copy the file locally before calling the operation’s implementation script:
|
node_templates:
wordpress:
type:
tosca.nodes.WebApplication.WordPress
...
interfaces:
Standard:
configure:
create:
implementation:
wordpress_install.sh
inputs
wp_zip: { get_artifact: [
SELF, zip, LOCAL_FILE] }
artifacts:
zip: /data/wordpress.zip
|
In such implementation the TOSCA orchestrator must
provide the wordpress.zip archive as a local path (example: /tmp/wordpress.zip) and will
remove it after the operation is completed.
4.8.1.3.3 Example: Retrieving artifact in a specified location
The following example explains how to force the orchestrator
to copy the file locally to a specific location before calling the operation’s
implementation script :
|
node_templates:
wordpress:
type:
tosca.nodes.WebApplication.WordPress
...
interfaces:
Standard:
configure:
create:
implementation:
wordpress_install.sh
inputs
wp_zip: { get_artifact: [
SELF, zip, C:/wpdata/wp.zip ] }
artifacts:
zip: /data/wordpress.zip
|
In such implementation the TOSCA orchestrator must
provide the wordpress.zip archive as a local path (example: C:/wpdata/wp.zip ) and will let it after the
operation is completed.
Future versions of this specification will address methods
to access entity names based upon the context in which they are declared or
defined.
4.9.1.1 Goals
·
Using the full paths of modelable entity names to qualify context
with the future goal of a more robust get_attribute function: e.g.,
get_attribute( <context-based-entity-name>, <attribute name>)
Except for the examples, this section is normative
and contains normative type definitions which must be supported for conformance
to this specification.
The declarative approach is heavily dependent of the
definition of basic types that a declarative container must understand. The
definition of these types must be very clear such that the operational
semantics can be precisely followed by a declarative container to achieve the
effects intended by the modeler of a topology in an interoperable manner.
·
Assumes alignment with/dependence on XML normative types proposal
for TOSCA v1.1
·
Assumes that the normative types will be versioned and the TOSCA
TC will preserve backwards compatibility.
·
Assumes that security and access control will be addressed in
future revisions or versions of this specification.
Every normative type has three names declared:
1. Type
URI – This is the unique identifying name for the type.
a. These are
reserved names within the TOSCA namespace.
2. Shorthand
Name – This is the shorter (simpler) name that can be used in place of
its corresponding, full Type URI name.
a. These are
reserved names within TOSCA namespace that MAY be used in place of the full
Type URI.
b. Profiles
of the OASIS TOSCA Simple Profile specifcaition SHALL assure non-collision of
names for new types when they are introduced.
c. TOSCA type
designers SHOULD NOT create new types with names that would collide with any
TOSCA normative type Shorthand Name.
3. Type
Qualified Name – This is a modified Shorthand Name
that includes the “tosca:” namespace prefix which clearly
qualifies it as being part of the TOSCA namespace.
a. This name MAY
be used to assure there is no collision when types are imported from other
(non) TOSCA approved sources.
·
Case sensitivity - TOSCA Type URI, Shorthand and
Type Qualified names SHALL be treated as case sensitive.
o
The case of each type name has been carefully selected by the
TOSCA working group and TOSCA orchestrators and processors SHALL strictly
recognize the name casing as specified in this specification or any of its
approved profiles.
This is the default (root) TOSCA Root Type
definition that all complex TOSCA Data Types derive from.
5.3.1.1 Definition
The TOSCA Root type is defined as follows:
|
tosca.datatypes.Root:
description: The TOSCA root Data
Type all other TOSCA base Data Types derive from
|
The json type is a TOSCA data Type used to define a
string that containst data in the JavaScript Object Notation (JSON) format.
|
Shorthand Name
|
json
|
|
Type Qualified Name
|
tosca:json
|
|
Type URI
|
tosca.datatypes.json
|
5.3.2.1 Definition
The json type is defined as follows:
|
tosca.datatypes.json:
derived_from: string
|
5.3.2.2 Examples
5.3.2.2.1 Type declaration example
Simple declaration of an ‘event_object’ property
declared to be a ‘json’ data type with its associated JSON Schema:
|
properties:
event_object:
type: json
constraints:
schema: >
{
"$schema":
"http://json-schema.org/draft-04/schema#",
"title":
"Event",
"description":
"Example Event type schema",
"type":
"object",
"properties":
{
"uuid": {
"description": "The unique ID for the event.",
"type":
"string"
},
"code": {
"type":
"integer"
},
"message": {
"type":
"string"
}
},
"required":
["uuid", "code"]
}
|
5.3.2.2.2 Template definition example
This example shows a valid JSON datatype value for
the ‘event_object’ schema declare in the previous example.
|
# properties snippet from a TOSCA
template definition.
properties:
event_object: <
{
“uuid”:
“cadf:1234-56-0000-abcd”,
“code”: 9876
}
|
5.3.3 Additional Requirements
·
The json datatype SHOULD only be assigned string values
that contain valid JSON syntax as defined by the “The JSON Data Interchange
Format Standard” (see reference [JSON-Spec]).
5.3.4 tosca.datatypes.xml
The xml type is a TOSCA data Type used to define a
string that containst data in the Extensible Markup Language (XML) format.
|
Shorthand Name
|
xml
|
|
Type Qualified Name
|
tosca:xml
|
|
Type URI
|
tosca.datatypes.xml
|
5.3.4.1 Definition
The xml type is defined as follows:
|
tosca.datatypes.xml:
derived_from: string
|
5.3.4.2 Examples
5.3.4.2.1 Type declaration example
Simple declaration of an ‘event_object’ property
declared to be an ‘xml’ data type with its associated XML Schema:
|
properties:
event_object:
type: xml
constraints:
schema: >
<xs:schema
xmlns:xs="http://www.w3.org/2001/XMLSchema"
targetNamespace="http://cloudplatform.org/events.xsd"
xmlns="http://tempuri.org/po.xsd"
elementFormDefault="qualified">
<xs:annotation>
<xs:documentation
xml:lang="en">
Event
object.
</xs:documentation>
</xs:annotation>
<xs:element
name="eventObject">
<xs:complexType>
<xs:sequence>
<xs:element
name="uuid" type="xs:string"/>
<xs:element
name="code" type="xs:integer"/>
<xs:element name="message"
type="xs:string"
minOccurs="0"/>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>
|
5.3.4.2.2 Template definition example
This example shows a valid XML datatype value for
the ‘event_object’ schema declare in the previous example.
|
# properties snippet from a TOSCA
template definition.
properties:
event_object: <
<eventObject>
<uuid>cadf:1234-56-0000-abcd</uuid>
<code>9876</code>
</eventObject>
|
5.3.5 Additional Requirements
The xml datatype SHOULD only be assigned string values
that contain valid XML syntax as defined by the “Extensible Markup Language
(XML)” specification” (see reference [XMLSpec]).
5.3.6 tosca.datatypes.Credential
The Credential type is a complex TOSCA data Type
used when describing authorization credentials used to access network
accessible resources.
|
Shorthand Name
|
Credential
|
|
Type Qualified Name
|
tosca:Credential
|
|
Type URI
|
tosca.datatypes.Credential
|
5.3.6.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
protocol
|
no
|
string
|
None
|
The optional protocol name.
|
|
token_type
|
yes
|
string
|
default: password
|
The required token type.
|
|
token
|
yes
|
string
|
None
|
The required token used as a credential for authorization
or access to a networked resource.
|
|
keys
|
no
|
map of string
|
None
|
The optional map of protocol-specific keys or assertions.
|
|
user
|
no
|
string
|
None
|
The optional user (name or ID) used for non-token based
credentials.
|
5.3.6.2 Definition
The TOSCA Credential type is defined as follows:
|
tosca.datatypes.Credential:
derived_from:
tosca.datatypes.Root
properties:
protocol:
type: string
required: false
token_type:
type: string
default: password
token:
type: string
keys:
type: map
required: false
entry_schema:
type: string
user:
type: string
required: false
|
5.3.6.3 Additional requirements
·
TOSCA Orchestrators SHALL interpret and validate the value of the
token property based upon the value of
the token_type property.
5.3.6.4 Notes
·
Specific token types and encoding them using network protocols
are not defined or covered in this specification.
·
The use of transparent user names (IDs) or passwords are not
considered best practice.
5.3.6.5 Examples
5.3.6.5.1 Provide a simple user name and password without a protocol or
standardized token format
|
<some_tosca_entity>:
properties:
my_credential:
type: Credential
properties:
user: myusername
token: mypassword
|
5.3.6.5.2 HTTP Basic access authentication credential
|
<some_tosca_entity>:
properties:
my_credential: # type:
Credential
protocol: http
token_type: basic_auth
# Username and password are
combined into a string
# Note: this would be base64
encoded before transmission by any impl.
token: myusername:mypassword
|
5.3.6.5.3 X-Auth-Token credential
|
<some_tosca_entity>:
properties:
my_credential: # type:
Credential
protocol: xauth
token_type: X-Auth-Token
# token encoded in Base64
token:
604bbe45ac7143a79e14f3158df67091
|
5.3.6.5.4 OAuth bearer token credential
|
<some_tosca_entity>:
properties:
my_credential: # type:
Credential
protocol: oauth2
token_type: bearer
# token encoded in
Base64
token: 8ao9nE2DEjr1zCsicWMpBC |
5.3.6.6 OpenStack SSH Keypair
|
<some_tosca_entity>:
properties:
my_ssh_keypair: # type:
Credential
protocol: ssh
token_type: identifier
# token is a reference (ID)
to an existing keypair (already installed)
token: <keypair_id> |
The TimeInterval type is a complex TOSCA data Type
used when describing a period of time using the YAML ISO 8601 format to declare
the start and end times.
|
Shorthand Name
|
TimeInterval
|
|
Type Qualified Name
|
tosca:TimeInterval
|
|
Type URI
|
tosca.datatypes.TimeInterval
|
5.3.7.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
start_time
|
yes
|
timestamp
|
None
|
The inclusive start time for the time interval.
|
|
end_time
|
yes
|
timestamp
|
None
|
The inclusive end time for the time interval.
|
5.3.7.2 Definition
The TOSCA TimeInterval type is defined as follows:
|
tosca.datatypes.TimeInterval:
derived_from:
tosca.datatypes.Root
properties:
start_time:
type: timestamp
required: true
end_time:
type: timestamp
required: true
|
5.3.7.3 Examples
5.3.7.3.1 Multi-day evaluation time period
|
properties:
description:
evaluation_period: Evaluate a
service for a 5-day period across time zones
type: TimeInterval
start_time: 2016-04-04-15T00:00:00Z end_time: 2016-04-08T21:59:43.10-06:00 |
The Network type is a complex TOSCA data type used to
describe logical network information.
|
Shorthand Name
|
NetworkInfo
|
|
Type Qualified Name
|
tosca:NetworkInfo
|
|
Type URI
|
tosca.datatypes.network.NetworkInfo
|
5.3.8.1 Properties
|
Name
|
Type
|
Constraints
|
Description
|
|
network_name
|
string
|
None
|
The name of the logical network.
e.g., “public”, “private”, “admin”. etc.
|
|
network_id
|
string
|
None
|
The unique ID of for the network generated by the network
provider.
|
|
addresses
|
string []
|
None
|
The list of IP addresses assigned from the underlying network.
|
5.3.8.2 Definition
The TOSCA NetworkInfo data type is defined as
follows:
|
tosca.datatypes.network.NetworkInfo:
derived_from:
tosca.datatypes.Root
properties:
network_name:
type: string
network_id:
type: string
addresses:
type: list
entry_schema:
type: string
|
5.3.8.3 Examples
Example usage of the NetworkInfo data type:
|
<some_tosca_entity>:
properties:
private_network:
network_name: private
network_id: 3e54214f-5c09-1bc9-9999-44100326da1b
addresses: [ 10.111.128.10 ]
|
5.3.8.4 Additional Requirements
·
It is expected that TOSCA orchestrators MUST be able to map the network_name from the TOSCA model to underlying
network model of the provider.
·
The properties (or attributes) of NetworkInfo may or may not be
required depending on usage context.
The PortInfo type is a complex TOSCA data type used
to describe network port information.
|
Shorthand Name
|
PortInfo
|
|
Type Qualified Name
|
tosca:PortInfo
|
|
Type URI
|
tosca.datatypes.network.PortInfo
|
5.3.9.1 Properties
|
Name
|
Type
|
Constraints
|
Description
|
|
port_name
|
string
|
None
|
The logical network port name.
|
|
port_id
|
string
|
None
|
The unique ID for the network port generated by the
network provider.
|
|
network_id
|
string
|
None
|
The unique ID for the network.
|
|
mac_address
|
string
|
None
|
The unique media access control address (MAC address)
assigned to the port.
|
|
addresses
|
string []
|
None
|
The list of IP address(es) assigned to the port.
|
5.3.9.2 Definition
The TOSCA PortInfo type is defined as follows:
|
tosca.datatypes.network.PortInfo:
derived_from:
tosca.datatypes.Root
properties:
port_name:
type: string
port_id:
type: string
network_id:
type: string
mac_address:
type: string
addresses:
type: list
entry_schema:
type: string
|
5.3.9.3 Examples
Example usage of the PortInfo data type:
|
<some_tosca_entity>:
properties:
ethernet_port:
port_name: port1
port_id:
2c0c7a37-691a-23a6-7709-2d10ad041467
network_id: 3e54214f-5c09-1bc9-9999-44100326da1b
mac_address: f1:18:3b:41:92:1e
addresses: [ 172.24.9.102 ]
|
5.3.9.4 Additional Requirements
·
It is expected that TOSCA orchestrators MUST be able to map the port_name from the TOSCA model to underlying
network model of the provider.
·
The properties (or attributes) of PortInfo may or may not be
required depending on usage context.
The PortDef type is a TOSCA data Type used to define
a network port.
|
Shorthand Name
|
PortDef
|
|
Type Qualified Name
|
tosca:PortDef
|
|
Type URI
|
tosca.datatypes.network.PortDef
|
5.3.10.1 Definition
The TOSCA PortDef type is defined as follows:
|
tosca.datatypes.network.PortDef:
derived_from: integer
constraints:
- in_range: [ 1, 65535 ]
|
5.3.10.2 Examples
Simple usage of a PortDef property type:
|
properties:
listen_port: 9090
|
Example declaration of a property for a custom type
based upon PortDef:
|
properties:
listen_port:
type: PortDef
default: 9000
constraints:
- in_range: [ 9000, 9090 ]
|
The PortSpec type is a complex TOSCA data Type used
when describing port specifications for a network connection.
|
Shorthand Name
|
PortSpec
|
|
Type Qualified Name
|
tosca:PortSpec
|
|
Type URI
|
tosca.datatypes.network.PortSpec
|
5.3.11.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
protocol
|
yes
|
string
|
default: tcp
|
The required protocol used on the port.
|
|
source
|
no
|
PortDef
|
See PortDef
|
The optional source port.
|
|
source_range
|
no
|
range
|
in_range: [ 1, 65536 ]
|
The optional range for source port.
|
|
target
|
no
|
PortDef
|
See PortDef
|
The optional target port.
|
|
target_range
|
no
|
range
|
in_range: [ 1, 65536 ]
|
The optional range for target port.
|
5.3.11.2 Definition
The TOSCA PortSpec type is defined as follows:
|
tosca.datatypes.network.PortSpec:
derived_from:
tosca.datatypes.Root
properties:
protocol:
type: string
required: true
default: tcp
constraints:
- valid_values: [ udp,
tcp, igmp ]
target:
type: PortDef
required: false
target_range:
type: range
required: false
constraints:
- in_range: [ 1, 65535 ]
source:
type: PortDef
required: false
source_range:
type: range
required: false
constraints:
- in_range: [ 1, 65535 ]
|
5.3.11.3 Additional requirements
·
A valid PortSpec MUST have at least one of the following
properties: target, target_range, source or source_range.
·
A valid PortSpec MUST have a value for the source property that is within the numeric
range specified by the property source_range
when source_range is specified.
·
A valid PortSpec MUST have a value for the target property that is within the numeric
range specified by the property target_range
when target_range is specified.
5.3.11.4 Examples
Example usage of the PortSpec data type:
|
# example properties in a node
template
some_endpoint:
properties:
ports:
user_port:
protocol: tcp
target: 50000
target_range: [ 20000,
60000 ]
source: 9000
source_range: [ 1000,
10000 ]
|
TOSCA Artifacts Types represent the types of packages and
files used by the orchestrator when deploying TOSCA Node or Relationship Types
or invoking their interfaces. Currently, artifacts are logically divided into
three categories:
·
Deployment Types: includes those artifacts that are used
during deployment (e.g., referenced on create and install operations) and
include packaging files such as RPMs, ZIPs, or TAR files.
·
Implementation Types: includes those artifacts that
represent imperative logic and are used to implement TOSCA Interface
operations. These typically include scripting languages such as Bash (.sh),
Chef [Chef] and Puppet [Puppet].
·
Runtime Types: includes those artifacts that are used
during runtime by a service or component of the application. This could
include a library or language runtime that is needed by an application such as
a PHP or Java library.
·
Template Types: includes those artifacts that are executed
by template engines which play the role of artifact processors. Typically,
template artifact types are static files. At runtime, the template engine
processes the artifact by replacing variables in a template file with actual
values. Some examples of template files are Twig [Twig] and
Jinja2 [Jinja2].
Note: Additional TOSCA Artifact Types will be
developed in future drafts of this specification.
This is the default (root) TOSCA Artifact Type definition that all other
TOSCA base Artifact Types derive from.
5.4.1.1 Definition
|
tosca.artifacts.Root:
description: The TOSCA Artifact
Type all other TOSCA Artifact Types derive from
|
This artifact type is used when an artifact
definition needs to have its associated file simply treated as a file and no
special handling/handlers are invoked (i.e., it is not treated as either an
implementation or deployment artifact type).
|
Shorthand Name
|
File
|
|
Type Qualified Name
|
tosca:File
|
|
Type URI
|
tosca.artifacts.File
|
5.4.2.1 Definition
This artifact type represents the parent type for
all deployment artifacts in TOSCA. This class of artifacts typically represents
a binary packaging of an application or service that is used to install/create
or deploy it as part of a node’s lifecycle.
5.4.3.1.1 Definition
|
tosca.artifacts.Deployment:
derived_from: tosca.artifacts.Root
description: TOSCA base type
for deployment artifacts
|
|
|
|
5.4.3.2 Additional Requirements
·
TOSCA Orchestrators MAY throw an error if it encounters a
non-normative deployment artifact type that it is not able to process.
This artifact type represents a parent type for any
“image” which is an opaque packaging of a TOSCA Node’s deployment (whether real
or virtual) whose contents are typically already installed and pre-configured
(i.e., “stateful”) and prepared to be run on a known target container.
|
Shorthand Name
|
Deployment.Image
|
|
Type Qualified Name
|
tosca:Deployment.Image
|
|
Type URI
|
tosca.artifacts.Deployment.Image
|
5.4.3.3.1 Definition
This artifact represents the parent type for all Virtual
Machine (VM) image and container formatted deployment artifacts. These images
contain a stateful capture of a machine (e.g., server) including operating
system and installed software along with any configurations and can be run on
another machine using a hypervisor which virtualizes typical server (i.e.,
hardware) resources.
5.4.3.4.1 Definition
5.4.3.4.2 Notes
·
Future drafts of this specification may include popular standard
VM disk image (e.g., ISO, VMI, VMDX, QCOW2, etc.) and container (e.g., OVF,
bare, etc.) formats. These would include consideration of disk formats such
as:
This artifact type represents the parent type for
all implementation artifacts in TOSCA. These artifacts are used to implement
operations of TOSCA interfaces either directly (e.g., scripts) or indirectly
(e.g., config. files).
5.4.4.1.1 Definition
|
tosca.artifacts.Implementation:
derived_from: tosca.artifacts.Root
description: TOSCA base type
for implementation artifacts
|
|
|
|
5.4.4.2 Additional Requirements
·
TOSCA Orchestrators MAY throw an error if it encounters a
non-normative implementation artifact type that it is not able to process.
5.4.4.3 tosca.artifacts.Implementation.Bash
This artifact type represents a Bash script type
that contains Bash commands that can be executed on the Unix Bash shell.
|
Shorthand Name
|
Bash
|
|
Type Qualified Name
|
tosca:Bash
|
|
Type URI
|
tosca.artifacts.Implementation.Bash
|
5.4.4.3.1 Definition
|
tosca.artifacts.Implementation.Bash:
derived_from: tosca.artifacts.Implementation
description: Script artifact for
the Unix Bash shell
mime_type: application/x-sh
file_ext: [ sh ]
|
5.4.4.4 tosca.artifacts.Implementation.Python
This artifact type represents a Python file that
contains Python language constructs that can be executed within a Python
interpreter.
|
Shorthand Name
|
Python
|
|
Type Qualified Name
|
tosca:Python
|
|
Type URI
|
tosca.artifacts.Implementation.Python
|
5.4.4.4.1 Definition
|
tosca.artifacts.Implementation.Python:
derived_from: tosca.artifacts.Implementation
description: Artifact for the
interpreted Python language
mime_type: application/x-python
file_ext: [ py ]
|
5.4.5.1 tosca.artifacts.template
This artifact type represents the parent type for
all template type artifacts in TOSCA. This class of artifacts typically
represent template files that are dependent artifacts for implementation of an
interface or deployment of a node.
Like the case of other dependent artifacts, the
TOSCA orchestrator copies the dependent artifacts to the same location as the
primary artifact for its access during execution. However, the template
artifact processor need not be deployed in the environment where the primary
artifact executes. At run time, the Orchestrator can invoke the artifact
processor (i.e. template engine) to fill in run time values and provide the
“filled template” to the primary artifact processor for further processing.
This reduces the requirements on the primary
artifact target environment and the processing time of template artifacts.
5.4.5.1.1 Definition
|
tosca.artifacts.template:
derived_from: tosca.artifacts.Root
description: TOSCA base type
for template type artifacts
|
|
|
|
This is the default (root) TOSCA Capability Type definition
that all other TOSCA Capability Types derive from.
5.5.1.1 Definition
|
tosca.capabilities.Root:
description: The TOSCA root
Capability Type all other TOSCA Capability Types derive from
|
The Node capability indicates the base capabilities
of a TOSCA Node Type.
|
Shorthand Name
|
Node
|
|
Type Qualified Name
|
tosca:Node
|
|
Type URI
|
tosca.capabilities.Node
|
5.5.2.1 Definition
The Compute capability, when included on a Node Type
or Template definition, indicates that the node can provide hosting on a named
compute resource.
|
Shorthand Name
|
Compute
|
|
Type Qualified Name
|
tosca:Compute
|
|
Type URI
|
tosca.capabilities.Compute
|
5.5.3.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
name
|
no
|
string
|
None
|
The otional name (or identifier) of a specific compute
resource for hosting.
|
|
num_cpus
|
no
|
integer
|
greater_or_equal: 1
|
Number of (actual or virtual) CPUs associated with the
Compute node.
|
|
cpu_frequency
|
no
|
scalar-unit.frequency
|
greater_or_equal: 0.1 GHz
|
Specifies the operating frequency of CPU's core. This
property expresses the expected frequency of one (1) CPU as provided by the
property “num_cpus”.
|
|
disk_size
|
no
|
scalar-unit.size
|
greater_or_equal: 0 MB
|
Size of the local disk available to applications running
on the Compute node (default unit is MB).
|
|
mem_size
|
no
|
scalar-unit.size
|
greater_or_equal: 0 MB
|
Size of memory available to applications running on the
Compute node (default unit is MB).
|
5.5.3.2 Definition
|
tosca.capabilities.Compute:
derived_from: tosca.capabilities.Container
properties:
name:
type: string
required: false
num_cpus:
type: integer
required: false
constraints:
- greater_or_equal: 1
cpu_frequency:
type: scalar-unit.frequency
required: false
constraints:
- greater_or_equal: 0.1
GHz
disk_size:
type: scalar-unit.size
required: false
constraints:
- greater_or_equal: 0 MB
mem_size:
type: scalar-unit.size
required: false
constraints:
- greater_or_equal: 0 MB
|
The Storage capability, when included on a Node Type
or Template definition, indicates that the node can provide addressiblity for
the resource a named network with the specified ports.
|
Shorthand Name
|
Network
|
|
Type Qualified Name
|
tosca:Network
|
|
Type URI
|
tosca.capabilities.Network
|
5.5.4.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
name
|
no
|
string
|
None
|
The otional name (or identifier) of a specific network
resource.
|
5.5.4.2 Definition
The Storage capability, when included on a Node Type
or Template definition, indicates that the node can provide a named storage
location with specified size range.
|
Shorthand Name
|
Storage
|
|
Type Qualified Name
|
tosca:Storage
|
|
Type URI
|
tosca.capabilities.Storage
|
5.5.5.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
name
|
no
|
string
|
None
|
The otional name (or identifier) of a specific storage
resource.
|
5.5.5.2 Definition
The Container capability, when included on a Node
Type or Template definition, indicates that the node can act as a container for
(or a host for) one or more other declared Node Types.
|
Shorthand Name
|
Container
|
|
Type Qualified Name
|
tosca:Container
|
|
Type URI
|
tosca.capabilities.Container
|
5.5.6.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
5.5.6.2 Definition
This is the default
TOSCA type that should be used or extended to define a network endpoint
capability. This includes the information to express a basic endpoint with a
single port or a complex endpoint with multiple ports. By default the Endpoint
is assumed to represent an address on a private network unless otherwise
specified.
|
Shorthand Name
|
Endpoint
|
|
Type Qualified Name
|
tosca:Endpoint
|
|
Type URI
|
tosca.capabilities.Endpoint
|
5.5.7.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
protocol
|
yes
|
string
|
default: tcp
|
The name of the protocol (i.e., the protocol prefix) that the
endpoint accepts (any OSI Layer 4-7 protocols)
Examples: http, https, ftp, tcp, udp, etc.
|
|
port
|
no
|
PortDef
|
greater_or_equal: 1
less_or_equal: 65535
|
The optional port of the
endpoint.
|
|
secure
|
no
|
boolean
|
default: false
|
Requests for the endpoint to be secure and use credentials
supplied on the ConnectsTo relationship.
|
|
url_path
|
no
|
string
|
None
|
The optional URL path of the endpoint’s address if
applicable for the protocol.
|
|
port_name
|
no
|
string
|
None
|
The optional name (or ID)
of the network port this endpoint should be bound to.
|
|
network_name
|
no
|
string
|
default: PRIVATE
|
The optional name (or ID) of the network this endpoint
should be bound to.
network_name: PRIVATE | PUBLIC |<network_name> |
<network_id>
|
|
initiator
|
no
|
string
|
one of:
·
source
·
target
·
peer
default: source
|
The optional indicator of the direction of the connection.
|
|
ports
|
no
|
map of PortSpec
|
None
|
The optional map of ports
the Endpoint supports (if more than one)
|
5.5.7.2 Attributes
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
ip_address
|
yes
|
string
|
None
|
Note: This is the IP address as propagated up by the
associated node’s host (Compute) container.
|
5.5.7.3 Definition
|
tosca.capabilities.Endpoint:
derived_from: tosca.capabilities.Root
properties:
protocol:
type: string
required: true
default: tcp
port:
type: PortDef
required: false
secure:
type: boolean
required: false
default: false
url_path:
type: string
required: false
port_name:
type: string
required: false
network_name:
type: string
required: false
default: PRIVATE
initiator:
type: string
required: false
default: source
constraints:
- valid_values: [ source,
target, peer ]
ports:
type: map
required: false
constraints:
- min_length: 1
entry_schema:
type: PortSpec
attributes:
ip_address:
type: string
|
5.5.7.4 Additional requirements
·
Although both the port and ports properties are not required, one
of port or ports must be provided in a valid Endpoint.
This capability represents a public endpoint which
is accessible to the general internet (and its public IP address ranges).
This public endpoint capability also can be used to
create a floating (IP) address that the underlying network assigns from a pool
allocated from the application’s underlying public network. This floating
address is managed by the underlying network such that can be routed an application’s
private address and remains reliable to internet clients.
|
Shorthand Name
|
Endpoint.Public
|
|
Type Qualified Name
|
tosca:Endpoint.Public
|
|
Type URI
|
tosca.capabilities.Endpoint.Public
|
5.5.8.1 Definition
|
tosca.capabilities.Endpoint.Public:
derived_from: tosca.capabilities.Endpoint
properties:
# Change the default
network_name to use the first public network found
network_name:
type: string
default: PUBLIC
constraints:
- equal: PUBLIC
floating:
description: >
indicates that the public
address should be allocated from a pool of floating IPs that are associated
with the network.
type: boolean
default: false
status: experimental
dns_name:
description: The optional
name to register with DNS
type: string
required: false
status: experimental
|
5.5.8.2 Additional requirements
·
If the network_name is
set to the reserved value PRIVATE or if
the value is set to the name of network (or subnetwork) that is not public
(i.e., has non-public IP address ranges assigned to it) then TOSCA
Orchestrators SHALL treat this as an error.
·
If a dns_name is set,
TOSCA Orchestrators SHALL attempt to register the name in the (local) DNS
registry for the Cloud provider.
This is the default TOSCA type that should be used
or extended to define a specialized administrator endpoint capability.
|
Shorthand Name
|
Endpoint.Admin
|
|
Type Qualified Name
|
tosca:Endpoint.Admin
|
|
Type URI
|
tosca.capabilities.Endpoint.Admin
|
5.5.9.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
None
|
N/A
|
N/A
|
N/A
|
N/A
|
5.5.9.2 Definition
|
tosca.capabilities.Endpoint.Admin:
derived_from: tosca.capabilities.Endpoint
# Change Endpoint secure
indicator to true from its default of false
properties:
secure:
type: boolean
default: true
constraints:
- equal: true
|
5.5.9.3 Additional requirements
·
TOSCA Orchestrator implementations of Endpoint.Admin (and
connections to it) SHALL assure that network-level security is enforced
if possible.
This is the default TOSCA type that should be used or
extended to define a specialized database endpoint capability.
|
Shorthand Name
|
Endpoint.Database
|
|
Type Qualified Name
|
tosca:Endpoint.Database
|
|
Type URI
|
tosca.capabilities.Endpoint.Database
|
5.5.10.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
None
|
N/A
|
N/A
|
N/A
|
N/A
|
5.5.10.2 Definition
This is the default TOSCA type that should be used
or extended to define an attachment capability of a (logical) infrastructure
device node (e.g., BlockStorage
node).
|
Shorthand Name
|
Attachment
|
|
Type Qualified Name
|
tosca:Attachment
|
|
Type URI
|
tosca.capabilities.Attachment
|
5.5.11.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
5.5.11.2 Definition
This is the default TOSCA type that should be used
to express an Operating System capability for a node.
|
Shorthand Name
|
OperatingSystem
|
|
Type Qualified Name
|
tosca:OperatingSystem
|
|
Type URI
|
tosca.capabilities.OperatingSystem
|
5.5.12.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
architecture
|
no
|
string
|
None
|
The Operating System (OS) architecture.
Examples of valid values include:
x86_32, x86_64, etc.
|
|
type
|
no
|
string
|
None
|
The Operating System (OS) type.
Examples of valid values include:
linux, aix, mac, windows, etc.
|
|
distribution
|
no
|
string
|
None
|
The Operating System (OS) distribution.
Examples of valid values for an “type” of “Linux” would
include: debian, fedora, rhel and ubuntu.
|
|
version
|
no
|
version
|
None
|
The Operating System version.
|
5.5.12.2 Definition
|
tosca.capabilities.OperatingSystem:
derived_from: tosca.capabilities.Root
properties:
architecture:
type: string
required: false
type:
type: string
required: false
distribution:
type: string
required: false
version:
type: version
required: false
|
5.5.12.3 Additional Requirements
·
Please note that the string values for the properties architecture, type and distribution
SHALL be normalized to lowercase by processors of the service template for
matching purposes. For example, if a “type”
value is set to either “Linux”, “LINUX” or “linux” in a service template, the
processor would normalize all three values to “linux” for matching purposes.
This is the default TOSCA type that should be used
to express a scalability capability for a node.
|
Shorthand Name
|
Scalable
|
|
Type Qualified Name
|
tosca:Scalable
|
|
Type URI
|
tosca.capabilities.Scalable
|
5.5.13.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
min_instances
|
yes
|
integer
|
default: 1
|
This property is used to indicate the minimum number of
instances that should be created for the associated TOSCA Node Template by a
TOSCA orchestrator.
|
|
max_instances
|
yes
|
integer
|
default: 1
|
This property is used to indicate the maximum number of
instances that should be created for the associated TOSCA Node Template by a
TOSCA orchestrator.
|
|
default_instances
|
no
|
integer
|
N/A
|
An optional property that indicates the requested default
number of instances that should be the starting number of instances a TOSCA
orchestrator should attempt to allocate.
Note: The value for this property MUST be in the
range between the values set for ‘min_instances’ and ‘max_instances’
properties.
|
5.5.13.2 Definition
5.5.13.3 Notes
·
The actual number of instances for a node may be governed by a
separate scaling policy which conceptually would be associated to either a
scaling-capable node or a group of nodes in which it is defined to be a part
of. This is a planned future feature of the TOSCA Simple Profile and not
currently described.
A node type that includes the Bindable capability
indicates that it can be bound to a logical network association via a network
port.
|
Shorthand Name
|
network.Bindable
|
|
Type Qualified Name
|
tosca:network.Bindable
|
|
Type URI
|
tosca.capabilities.network.Bindable
|
5.5.14.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
5.5.14.2 Definition
There are no normative Requirement Types currently
defined in this working draft. Typically, Requirements are described against a
known Capability Type
This is the default (root) TOSCA Relationship Type
definition that all other TOSCA Relationship Types derive from.
5.7.1.1 Attributes
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
tosca_id
|
yes
|
string
|
None
|
A unique identifier of the realized instance of a
Relationship Template that derives from any TOSCA normative type.
|
|
tosca_name
|
yes
|
string
|
None
|
This attribute reflects the name of the Relationship
Template as defined in the TOSCA service template. This name is not unique
to the realized instance model of corresponding deployed application as each
template in the model can result in one or more instances (e.g., scaled) when
orchestrated to a provider environment.
|
|
state
|
yes
|
string
|
default: initial
|
The state of the relationship instance. See section “Relationship States” for
allowed values.
|
5.7.1.2 Definition
|
tosca.relationships.Root:
description: The TOSCA root Relationship
Type all other TOSCA base Relationship Types derive from
attributes:
tosca_id:
type: string
tosca_name:
type: string
interfaces:
Configure:
type: tosca.interfaces.relationship.Configure
|
This type represents a general dependency
relationship between two nodes.
|
Shorthand Name
|
DependsOn
|
|
Type Qualified Name
|
tosca:DependsOn
|
|
Type URI
|
tosca.relationships.DependsOn
|
5.7.2.1 Definition
This type represents
a hosting relationship between two nodes.
|
Shorthand Name
|
HostedOn
|
|
Type Qualified Name
|
tosca:HostedOn
|
|
Type URI
|
tosca.relationships.HostedOn
|
5.7.3.1 Definition
This type represents
a network connection relationship between two nodes.
|
Shorthand Name
|
ConnectsTo
|
|
Type Qualified Name
|
tosca:ConnectsTo
|
|
Type URI
|
tosca.relationships.ConnectsTo
|
5.7.4.1 Definition
5.7.4.2 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
credential
|
no
|
Credential
|
None
|
The security credential to use to present to the target
endpoint to for either authentication or authorization purposes.
|
This type represents
an attachment relationship between two nodes. For example, an AttachesTo
relationship type would be used for attaching a storage node to a Compute node.
|
Shorthand Name
|
AttachesTo
|
|
Type Qualified Name
|
tosca:AttachesTo
|
|
Type URI
|
tosca.relationships.AttachesTo
|
5.7.5.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
location
|
yes
|
string
|
min_length: 1
|
The relative location (e.g., path on the file system),
which provides the root location to address an attached node.
e.g., a mount point / path such as ‘/usr/data’
Note: The user must provide it and it cannot be “root”.
|
|
device
|
no
|
string
|
None
|
The logical device name which for the attached device
(which is represented by the target node in the model).
e.g., ‘/dev/hda1’
|
5.7.5.2 Attributes
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
device
|
no
|
string
|
None
|
The logical name of the device as exposed to the instance.
Note: A runtime property that gets set when the model gets
instantiated by the orchestrator.
|
5.7.5.3 Definition
This type represents
an intentional network routing between two Endpoints in different networks.
|
Shorthand Name
|
RoutesTo
|
|
Type Qualified Name
|
tosca:RoutesTo
|
|
Type URI
|
tosca.relationships.RoutesTo
|
5.7.6.1 Definition
Interfaces are reusable
entities that define a set of operations that that can be included as part of a
Node type or Relationship Type definition. Each named operations may have code
or scripts associated with them that orchestrators can execute for when
transitioning an application to a given state.
·
Designers of Node or Relationship types are not required to
actually provide/associate code or scripts with every operation for a given
interface it supports. In these cases, orchestrators SHALL consider that a “No
Operation” or “no-op”.
·
The default behavior when providing scripts for an operation in a
sub-type (sub-class) or a template of an existing type which already has a
script provided for that operation SHALL be override. Meaning that the
subclasses’ script is used in place of the parent type’s script.
·
When TOSCA Orchestrators substitute an implementation for an
abstract node in a deployed service template it SHOULD be able to present a
confirmation to the submitter to confirm the implementation chosen would be
acceptable.
This is the default (root) TOSCA Interface Type definition
that all other TOSCA Interface Types derive from.
5.8.3.1 Definition
|
tosca.interfaces.Root:
derived_from: tosca.entity.Root
description: The TOSCA root
Interface Type all other TOSCA Interface Types derive from
|
This lifecycle interface defines the essential,
normative operations that TOSCA nodes may support.
|
Shorthand Name
|
Standard
|
|
Type Qualified Name
|
tosca: Standard
|
|
Type URI
|
tosca.interfaces.node.lifecycle.Standard
|
5.8.4.1 Definition
|
tosca.interfaces.node.lifecycle.Standard:
derived_from: tosca.interfaces.Root
create:
description: Standard
lifecycle create operation.
configure:
description: Standard
lifecycle configure operation.
start:
description: Standard
lifecycle start operation.
stop:
description: Standard
lifecycle stop operation.
delete:
description: Standard
lifecycle delete operation.
|
The create operation is generally used to create the
resource or service the node represents in the topology. TOSCA orchestrators
expect node templates to provide either a deployment artifact or an
implementation artifact of a defined artifact type that it is able to process.
This specification defines normative deployment and implementation artifact
types all TOSCA Orchestrators are expected to be able to process to support
application portability.
5.8.4.3 TOSCA Orchestrator processing of Deployment artifacts
TOSCA Orchestrators, when encountering a deployment artifact
on the create operation; will automatically attempt to deploy the artifact
based upon its artifact type. This means that no implementation artifacts
(e.g., scripts) are needed on the create operation to provide commands that
deploy or install the software.
For example, if a TOSCA Orchestrator is processing an
application with a node of type SoftwareComponent and finds that the node’s
template has a create operation that provides a filename (or references to an
artifact which describes a file) of a known TOSCA deployment artifact type such
as an Open Virtualization Format (OVF) image it will automatically deploy that
image into the SoftwareComponent’s host Compute node.
5.8.4.4 Operation sequencing and node state
The following diagrams show how TOSCA orchestrators sequence
the operations of the Standard lifecycle in normal node startup and shutdown
procedures.
The following key should be used to interpret the diagrams:
5.8.4.4.1 Normal node startup sequence diagram
The following diagram shows how the TOSCA orchestrator would invoke operations
on the Standard lifecycle to startup a node.
5.8.4.4.2 Normal node shutdown sequence diagram
The following diagram shows how the TOSCA orchestrator would
invoke operations on the Standard lifecycle to shut down a node.
The lifecycle
interfaces define the essential, normative operations that each TOSCA Relationship
Types may support.
|
Shorthand Name
|
Configure
|
|
Type Qualified Name
|
tosca:Configure
|
|
Type URI
|
tosca.interfaces.relationship.Configure
|
5.8.5.1 Definition
|
tosca.interfaces.relationship.Configure:
derived_from: tosca.interfaces.Root
pre_configure_source:
description: Operation to
pre-configure the source endpoint.
pre_configure_target:
description: Operation to
pre-configure the target endpoint.
post_configure_source:
description: Operation to
post-configure the source endpoint.
post_configure_target:
description: Operation to
post-configure the target endpoint.
add_target:
description: Operation to notify
the source node of a target node being added via a relationship.
add_source:
description: Operation to
notify the target node of a source node which is now available via a
relationship.
target_changed:
description: Operation to
notify source some property or attribute of the target changed
remove_target:
description: Operation to
remove a target node.
|
5.8.5.2
Invocation Conventions
TOSCA relationships are
directional connecting a source node to a target node. When TOSCA Orchestrator
connects a source and target node together using a relationship that supports
the Configure interface it will “interleave” the operations invocations of the
Configure interface with those of the node’s own Standard lifecycle interface.
This concept is illustrated below:
5.8.5.3 Normal node start sequence with Configure relationship operations
The following diagram shows how the TOSCA orchestrator would invoke Configure
lifecycle operations in conjunction with Standard lifecycle operations during a
typical startup sequence on a node.
5.8.5.4 Node-Relationship configuration sequence
Depending on which side (i.e., source or target) of
a relationship a node is on, the orchestrator will:
·
Invoke either the pre_configure_source
or pre_configure_target operation as
supplied by the relationship on the node.
·
Invoke the node’s configure
operation.
·
Invoke either the post_configure_source
or post_configure_target as supplied by
the relationship on the node.
Note that
the pre_configure_xxx and post_configure_xxx are invoked only once per
node instance.
5.8.5.4.1 Node-Relationship add, remove and changed sequence
Since a topology template contains nodes that can dynamically
be added (and scaled), removed or changed as part of an application instance,
the Configure lifecycle includes operations that are invoked on node instances
that to notify and address these dynamic changes.
For example, a source node, of a relationship that uses the
Configure lifecycle, will have the relationship operations add_target, or remove_target invoked on it whenever a target
node instance is added or removed to the running application instance. In
addition, whenever the node state of its target node changes, the target_changed operation is invoked on it to
address this change. Conversely, the add_source
and remove_source operations are invoked
on the source node of the relationship.
5.8.5.5 Notes
·
The target (provider) MUST be active and running (i.e., all its
dependency stack MUST be fulfilled) prior to invoking add_target
·
In other words, all Requirements MUST be satisfied before it
advertises its capabilities (i.e., the attributes of the matched Capabilities
are available).
·
In other words, it cannot be “consumed” by any dependent node.
·
Conversely, since the source (consumer) needs information
(attributes) about any targets (and their attributes) being removed before it
actually goes away.
·
The remove_target operation
should only be executed if the target has had add_target
executed. BUT in truth we’re first informed about a target in pre_configure_source, so if we execute that
the source node should see remove_target
called to cleanup.
·
Error handling: If any node operation of the topology
fails processing should stop on that node template and the failing operation
(script) should return an error (failure) code when possible.
The TOSCA Root Node
Type is the default type that all other TOSCA base Node Types derive from.
This allows for all TOSCA nodes to have a consistent set of features for
modeling and management (e.g., consistent definitions for requirements,
capabilities and lifecycle interfaces).
|
Shorthand Name
|
Root
|
|
Type Qualified Name
|
tosca:Root
|
|
Type URI
|
tosca.nodes.Root
|
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
The TOSCA Root Node type has no specified properties.
|
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
tosca_id
|
yes
|
string
|
None
|
A unique identifier of the realized instance of a Node
Template that derives from any TOSCA normative type.
|
|
tosca_name
|
yes
|
string
|
None
|
This attribute reflects the name of the Node Template as
defined in the TOSCA service template. This name is not unique to the
realized instance model of corresponding deployed application as each
template in the model can result in one or more instances (e.g., scaled) when
orchestrated to a provider environment.
|
|
state
|
yes
|
string
|
default: initial
|
The state of the node instance. See section “Node States” for allowed values.
|
5.9.1.3 Definition
All Node Type definitions that wish to adhere to the
TOSCA Simple Profile SHOULD extend from the TOSCA Root Node Type to be
assured of compatibility and portability across implementations.
5.9.2 tosca.nodes.Abstract.Compute
The TOSCA Abstract.Compute node represents an abstract compute
resource without any requirements on storage or network resources.
|
Shorthand Name
|
Abstract.Compute
|
|
Type Qualified Name
|
tosca:Abstract.Compute
|
|
Type URI
|
tosca.nodes.Abstract.Compute
|
5.9.2.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
5.9.2.2 Attributes
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
5.9.2.3 Definition
|
tosca.nodes.Abstract.Compute:
derived_from: tosca.nodes.Root
capabilities:
host:
type: tosca.capabilities.Compute
valid_source_types: []
|
5.9.3 tosca.nodes.Compute
The TOSCA Compute
node represents one or more real or virtual processors of software applications
or services along with other essential local resources. Collectively, the
resources the compute node represents can logically be viewed as a (real or
virtual) “server”.
|
Shorthand Name
|
Compute
|
|
Type Qualified Name
|
tosca:Compute
|
|
Type URI
|
tosca.nodes.Compute
|
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
private_address
|
no
|
string
|
None
|
The primary private IP address assigned by the cloud
provider that applications may use to access the Compute node.
|
|
public_address
|
no
|
string
|
None
|
The primary public IP address assigned by the cloud
provider that applications may use to access the Compute node.
|
|
networks
|
no
|
map of NetworkInfo
|
None
|
The map of logical networks assigned to the compute host
instance and information about them.
|
|
ports
|
no
|
map of PortInfo
|
None
|
The map of logical ports assigned to the compute host
instance and information about them.
|
5.9.3.3 Definition
·
The underlying implementation of the Compute node SHOULD have the
ability to instantiate guest operating systems (either actual or virtualized)
based upon the OperatingSystem capability properties if they are supplied in
the a node template derived from the Compute node type.
The TOSCA SoftwareComponent
node represents a generic software component that can be managed and run by a
TOSCA Compute Node Type.
|
Shorthand Name
|
SoftwareComponent
|
|
Type Qualified Name
|
tosca:SoftwareComponent
|
|
Type URI
|
tosca.nodes.SoftwareComponent
|
5.9.4.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
component_version
|
no
|
version
|
None
|
The optional software component’s version.
|
|
admin_credential
|
no
|
Credential
|
None
|
The optional credential that can be used to authenticate
to the software component.
|
5.9.4.2 Attributes
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
5.9.4.3 Definition
5.9.4.4 Additional Requirements
·
Nodes that can directly be managed and run by a TOSCA Compute Node Type SHOULD extend from
this type.
This TOSA WebServer
Node Type represents an abstract software component or service that is capable
of hosting and providing management operations for one or more WebApplication nodes.
|
Shorthand Name
|
WebServer
|
|
Type Qualified Name
|
tosca:WebServer
|
|
Type URI
|
tosca.nodes.WebServer
|
5.9.5.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
None
|
N/A
|
N/A
|
N/A
|
N/A
|
5.9.5.2 Definition
5.9.5.3 Additional Requirements
·
This node SHALL export both a secure endpoint capability
(i.e., admin_endpoint), typically for
administration, as well as a regular endpoint (i.e., data_endpoint) for serving data.
The TOSCA WebApplication
node represents a software application that can be managed and run by a TOSCA WebServer node. Specific types of web
applications such as Java, etc. could be derived from this type.
|
Shorthand Name
|
WebApplication
|
|
Type Qualified Name
|
tosca: WebApplication
|
|
Type URI
|
tosca.nodes.WebApplication
|
5.9.6.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
context_root
|
no
|
string
|
None
|
The web application’s
context root which designates the application’s URL path within the web
server it is hosted on.
|
5.9.6.2 Definition
The TOSCA DBMS node represents
a typical relational, SQL Database Management System software component or
service.
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
root_password
|
no
|
string
|
None
|
The optional root password for the DBMS server.
|
|
port
|
no
|
integer
|
None
|
The DBMS server’s port.
|
5.9.7.2 Definition
|
tosca.nodes.DBMS:
derived_from: tosca.nodes.SoftwareComponent
properties:
root_password:
type: string
required: false
description: the optional root
password for the DBMS service
port:
type: integer
required: false
description: the port the
DBMS service will listen to for data and requests
capabilities:
host:
type: tosca.capabilities.Compute
valid_source_types: [ tosca.nodes.Database ]
|
The TOSCA Database
node represents a logical database that can be managed and hosted by a TOSCA DBMS node.
|
Shorthand Name
|
Database
|
|
Type Qualified Name
|
tosca:Database
|
|
Type URI
|
tosca.nodes.Database
|
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
name
|
yes
|
string
|
None
|
The logical database Name
|
|
port
|
no
|
integer
|
None
|
The port the database service will use to listen for
incoming data and requests.
|
|
user
|
no
|
string
|
None
|
The special user account used for database administration.
|
|
password
|
no
|
string
|
None
|
The password associated with the user account provided in
the ‘user’ property.
|
|
tosca.nodes.Database:
derived_from: tosca.nodes.Root
properties:
name:
type: string
description: the logical
name of the database
port:
type: integer
description: the port the
underlying database service will listen to for data
user:
type: string
description: the optional user
account name for DB administration
required: false
password:
type: string
description: the optional password
for the DB user account
required: false
requirements:
- host:
capability: tosca.capabilities.Compute
node: tosca.nodes.DBMS
relationship: tosca.relationships.HostedOn
capabilities:
database_endpoint:
type: tosca.capabilities.Endpoint.Database
|
The TOSCA Abstract.Storage
node represents an abstract storage resource without any requirements on
compute or network resources.
|
Shorthand Name
|
AbstractStorage
|
|
Type Qualified Name
|
tosca:Abstract.Storage
|
|
Type URI
|
tosca.nodes.Abstract.Storage
|
5.9.9.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
name
|
yes
|
string
|
None
|
The logical name (or ID) of the storage resource.
|
|
size
|
no
|
scalar-unit.size
|
greater_or_equal: 0 MB
|
The requested initial storage size (default unit is in
Gigabytes).
|
5.9.9.2 Definition
|
tosca.nodes.Abstract.Storage:
derived_from: tosca.nodes.Root
properties:
name:
type: string
size:
type: scalar-unit.size
default: 0 MB
constraints:
- greater_or_equal: 0 MB
capabilities:
# TBD
|
5.9.10 tosca.nodes.Storage.ObjectStorage
The TOSCA ObjectStorage
node represents storage that provides the ability to store data as objects (or
BLOBs of data) without consideration for the underlying filesystem or devices.
|
Shorthand Name
|
ObjectStorage
|
|
Type Qualified Name
|
tosca:ObjectStorage
|
|
Type URI
|
tosca.nodes.Storage.ObjectStorage
|
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
maxsize
|
no
|
scalar-unit.size
|
greater_or_equal: 1 GB
|
The requested maximum storage size (default unit is in
Gigabytes).
|
5.9.10.3 Notes:
·
Subclasses of the tosca.nodes.Storage.ObjectStorage
node type may impose further constraints on properties. For example, a
subclass may constrain the (minimum or maximum) length of the ‘name’ property or include a regular
expression to constrain allowed characters used in the ‘name’ property.
The TOSCA BlockStorage
node currently represents a server-local block storage device (i.e., not
shared) offering evenly sized blocks of data from which raw storage volumes can
be created.
Note: In this draft of the TOSCA Simple
Profile, distributed or Network Attached Storage (NAS) are not yet considered
(nor are clustered file systems), but the TC plans to do so in future drafts.
|
Shorthand Name
|
BlockStorage
|
|
Type Qualified Name
|
tosca:BlockStorage
|
|
Type URI
|
tosca.nodes.Storage.BlockStorage
|
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
size
|
yes *
|
scalar-unit.size
|
greater_or_equal: 1 MB
|
The requested storage size (default unit is MB).
* Note:
·
Required when an existing volume (i.e., volume_id) is
not available.
·
If volume_id is provided, size is ignored. Resize of
existing volumes is not considered at this time.
|
|
volume_id
|
no
|
string
|
None
|
ID of an existing volume (that is in the accessible scope
of the requesting application).
|
|
snapshot_id
|
no
|
string
|
None
|
Some identifier that represents an existing snapshot that
should be used when creating the block storage (volume).
|
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
5.9.11.3 Definition
5.9.11.4 Additional Requirements
·
The size property is
required when an existing volume (i.e., volume_id)
is not available. However, if the property volume_id
is provided, the size property is
ignored.
5.9.11.5 Notes
·
Resize is of existing volumes is not considered at this time.
·
It is assumed that the volume contains a single filesystem that
the operating system (that is hosting an associate application) can recognize
and mount without additional information (i.e., it is operating system
independent).
·
Currently, this version of the Simple Profile does not consider
regions (or availability zones) when modeling storage.
The TOSCA Container
Runtime node represents operating system-level virtualization technology used
to run multiple application services on a single Compute host.
|
Shorthand Name
|
Container.Runtime
|
|
Type Qualified Name
|
tosca:Container.Runtime
|
|
Type URI
|
tosca.nodes.Container.Runtime
|
5.9.12.1 Definition
The TOSCA Container
Application node represents an application that requires Container-level virtualization technology.
|
Shorthand Name
|
Container.Application
|
|
Type Qualified Name
|
tosca:Container.Application
|
|
Type URI
|
tosca.nodes.Container.Application
|
5.9.13.1 Definition
5.9.14 tosca.nodes.LoadBalancer
The TOSCA Load
Balancer node represents logical function that be used in conjunction
with a Floating Address to distribute an application’s traffic (load) across a
number of instances of the application (e.g., for a clustered or scaled
application).
|
Shorthand Name
|
LoadBalancer
|
|
Type Qualified Name
|
tosca:LoadBalancer
|
|
Type URI
|
tosca.nodes.LoadBalancer
|
5.9.14.1 Definition
5.9.14.2 Notes:
·
A LoadBalancer node can
still be instantiated and managed independently of any applications it would
serve; therefore, the load balancer’s application
requirement allows for zero occurrences.
TOSCA Group Types represent logical groupings of TOSCA nodes
that have an implied membership relationship and may need to be orchestrated or
managed together to achieve some result. Some use cases being developed by the
TOSCA TC use groups to apply TOSCA policies for software placement and scaling
while other use cases show groups can be used to describe cluster
relationships.
Note: Additional normative TOSCA Group Types and use
cases for them will be developed in future drafts of this specification.
This is the default (root) TOSCA Group Type definition that all other
TOSCA base Group Types derive from.
5.10.1.1 Definition
5.10.1.2 Notes:
·
Group operations are not necessarily tied directly to member
nodes that are part of a group.
·
Future versions of this specification will create sub types of
the tosca.groups.Root type that will
describe how Group Type operations are to be orchestrated.
TOSCA Policy Types represent logical grouping of TOSCA nodes
that have an implied relationship and need to be orchestrated or managed
together to achieve some result. Some use cases being developed by the TOSCA
TC use groups to apply TOSCA policies for software placement and scaling while
other use cases show groups can be used to describe cluster relationships.
This is the default (root) TOSCA Policy Type
definition that all other TOSCA base Policy Types derive from.
5.11.1.1 Definition
|
tosca.policies.Root:
description: The TOSCA Policy
Type all other TOSCA Policy Types derive from
|
This is the default (root) TOSCA Policy Type
definition that is used to govern placement of TOSCA nodes or groups of nodes.
5.11.2.1 Definition
|
tosca.policies.Placement:
derived_from: tosca.policies.Root
description: The TOSCA Policy
Type definition that is used to govern placement of TOSCA nodes or groups of
nodes.
|
This is the default (root) TOSCA Policy Type
definition that is used to govern scaling of TOSCA nodes or groups of nodes.
5.11.3.1 Definition
|
tosca.policies.Scaling:
derived_from: tosca.policies.Root
description: The TOSCA Policy
Type definition that is used to govern scaling of TOSCA nodes or groups of
nodes.
|
This is the default (root) TOSCA Policy Type
definition that is used to govern update of TOSCA nodes or groups of nodes.
5.11.4.1 Definition
|
tosca.policies.Update:
derived_from: tosca.policies.Root
description: The TOSCA Policy
Type definition that is used to govern update of TOSCA nodes or groups of
nodes.
|
This is the default (root) TOSCA Policy Type
definition that is used to declare performance requirements for TOSCA nodes or
groups of nodes.
5.11.5.1 Definition
|
tosca.policies.Performance:
derived_from: tosca.policies.Root
description: The TOSCA Policy
Type definition that is used to declare performance requirements for TOSCA
nodes or groups of nodes.
|
Except for the examples, this section is normative
and defines changes to the TOSCA archive format relative to the TOSCA v1.0 XML
specification.
TOSCA Simple Profile definitions along with all accompanying
artifacts (e.g. scripts, binaries, configuration files) can be packaged
together in a CSAR file as already defined in the TOSCA version 1.0
specification [TOSCA-1.0]. In contrast to the TOSCA
1.0 CSAR file specification (see chapter 16 in [TOSCA-1.0]),
this simple profile makes a few simplifications both in terms of overall CSAR
file structure as well as meta-file content as described below.
A CSAR zip file is required to contain one of the
following:
·
a TOSCA-Metadata
directory, which in turn contains the TOSCA.meta
metadata file that provides entry information for a TOSCA orchestrator
processing the CSAR file.
·
a yaml (.yml or .yaml) file at the root of the archive. The yaml
file being a valid tosca definition template that MUST define a metadata
section where template_name and template_version are required.
The CSAR file may contain other directories with arbitrary
names and contents. Note that in contrast to the TOSCA 1.0 specification, it is
not required to put TOSCA definitions files into a special “Definitions”
directory, but definitions YAML files can be placed into any directory within
the CSAR file.
The TOSCA.meta
file structure follows the exact same syntax as defined in the TOSCA 1.0
specification. However, it is only required to include block_0 (see
section 16.2 in [TOSCA-1.0]) with the Entry-Definitions keyword pointing to a
valid TOSCA definitions YAML file that a TOSCA orchestrator should use as entry
for parsing the contents of the overall CSAR file.
Note that it is not required to explicitly list
TOSCA definitions files in subsequent blocks of the TOSCA.meta file, but any TOSCA definitions files besides
the one denoted by the Entry-Definitions
keyword can be found by a TOSCA orchestrator by processing respective imports statements in the entry
definitions file (or in recursively imported files).
Note also that any additional artifact files (e.g.
scripts, binaries, configuration files) do not have to be declared explicitly
through blocks in the TOSCA.meta
file. Instead, such artifacts will be fully described and pointed to by
relative path names through artifact definitions in one of the TOSCA
definitions files contained in the CSAR.
Due to the simplified structure of the CSAR file and TOSCA.meta file compared to TOSCA 1.0,
the CSAR-Version keyword
listed in block_0 of the meta-file is required to denote version 1.1.
The Other-Definitions
key in block_0 is used to declare an unambiguous set of files containing
substitution templates that can be used to implement nodes defined in the main
template (i.e. the file declared in Entry-Definitions).
Thus, all the topology templates defined in files listed under the Other-Definitions key are to be used
only as substitution templates, and not as standalone services. If such a
topology template cannot act as a substitution template, it will be ignored by
the orchestrator.
The value of the Other-Definitions
key is a list of filenames relative to the root of the CSAR archive delimited
by a blank space. If the filenames contain spaces, the filename should be
enclosed by double quotation marks (“). Note that according to the TOSCA.meta
structure definition, a value can extend in a new line as long as the new line
starts with a blank space.
Due to the changes to the TOSCA.meta file compared to TOSCA
1.2 the TOSCA-Meta-File-Version
keyword listed in block_0 of the the meta-file is required to denote
version 1.1.
6.2.1 Custom keynames in the TOSCA.meta file
Besides using the normative keynames in block_0 (i.e. TOSCA-Meta-File-Version,
CSAR-Version,
Created-By, Entry-Definitions,
Other-Definitions) users can populate further blocks in the TOSCA.meta file with custom key-value
pairs that follow the entry syntax of the TOSCA.meta
file, but which are outside the scope of the TOSCA specifications.
Nevertheless, future versions of the TOSCA specification may
add definitions of new keynames to be used in the TOSCA.meta file. In case of a keyname collision (with a
custom keyname) the TOSCA specification definitions take precedence.
To minimize such keyname collisions the specification
reserves the use of keynames starting with “TOSCA” and “tosca” (the strings
within, but not including, the double quotation marks). It is recommended as a
good practice to use a specific prefix (e.g. identifying the organization,
scope, etc.) when using custom keynames.
The following listing represents a valid TOSCA.meta file according to this TOSCA
Simple Profile specification.
|
TOSCA-Meta-File-Version: 1.1
CSAR-Version: 1.1
Created-By: OASIS TOSCA TC
Entry-Definitions: definitions/tosca_elk.yaml
Other-Definitions: definitions/tosca_moose.yaml
definitions/tosca_deer.yaml
|
This TOSCA.meta
file indicates its simplified TOSCA Simple Profile structure by means of the CSAR-Version keyword with value 1.1. The Entry-Definitions keyword points to a TOSCA definitions
YAML file with the name tosca_elk.yaml
which is contained in a directory called definitions
within the root of the CSAR file. Additionally, it specifies that substitution
templates can be found in the files tosca_moose.yaml
and tosca_deer.yaml also found
in the directory called defintions
in the root of the CSAR file.
In case the archive doesn’t contains a TOSCA-Metadata
directory the archive is required to contains a single YAML file at the root of
the archive (other templates may exits in sub-directories).
This file must be a valid TOSCA definitions YAML file with
the additional restriction that the metadata section (as defined in 3.9.3.2) is
required and template_name and template_version metadata are also required.
TOSCA processors should recognized this file as
being the CSAR Entry-Definitions file. The CSAR-Version is defined by the
template_version metadata section. The Created-By value is defined by the
template_author metadata.
Note that in an archive without TOSCA-metadata it is not
possible to unambiguously include defintions for substitution templates as we
can have only one topology template defined in a yaml file.
The following represents a valid TOSCA template file
acting as the CSAR Entry-Definitions file in an archive without TOSCA-Metadata
directory.
|
tosca_definitions_version:
tosca_simple_yaml_1_3
metadata:
template_name: my_template
template_author: OASIS TOSCA TC
template_version: 1.0
|
TOSCA defines two different kinds of workflows that can be
used to deploy (instantiate and start), manage at runtime or undeploy (stop and
delete) a TOSCA topology: declarative workflows and imperative workflows.
Declarative workflows are automatically generated by the TOSCA orchestrator
based on the nodes, relationships, and groups defined in the topology.
Imperative workflows are manually specified by the author of the topology and
allows the specification of any use-case that has not been planned in the
definition of node and relationships types or for advanced use-case (including
reuse of existing scripts and workflows).
Workflows can be triggered on deployment of a topology (deploy
workflow) on undeployment (undeploy workflow) or during runtime, manually, or
automatically based on policies defined for the topology.
Note: The TOSCA orchestrators will execute a single
workflow at a time on a topology to guarantee that the defined workflow can be
consistent and behave as expected.
TOSCA defines several normative workflows that are
used to operate a Topology. That is, reserved names of workflows that should be
preserved by TOSCA orchestrators and that, if specified in the topology will
override the workflow generated by the orchestrator :
·
deploy: is the workflow used to instantiate
and perform the initial deployment of the topology.
·
undeploy: is the workflow used to
remove all instances of a topology.
Future versions of the specification will describe
the normative naming and declarative generation of additional workflows used to
operate the topology at runtime.
·
scaling workflows: defined for every
scalable nodes or based on scaling policies
·
auto-healing workflows: defined in
order to restart nodes that may have failed
Declarative workflows are the result of the weaving of
topology’s node, relationships, and groups workflows.
The weaving process generates the workflow of every
single node in the topology, insert operations from the relationships and
groups and finally add ordering consideration. The weaving process will also
take care of the specific lifecycle of some nodes and the TOSCA orchestrator is
responsible to trigger errors or warnings in case the weaving cannot be
processed or lead to cycles for example.
This section aims to describe and explain how a TOSCA
orchestrator will generate a workflow based on the topology entities (nodes,
relationships and groups).
This section details specific constraints and considerations
that applies during the weaving process.
7.2.1.1 Orchestrator provided nodes lifecycle and weaving
When a node is abstract the orchestrator is responsible for
providing a valid matching resources for the node in order to deploy the
topology. This consideration is also valid for dangling requirements (as they
represents a quick way to define an actual node).
The lifecycle of such nodes is the responsibility of the
orchestrator and they may not answer to the normative TOSCA lifecycle. Their
workflow is considered as "delegate" and acts as a black-box between
the initial and started state in the install workflow and the started to
deleted states in the uninstall workflow.
If a relationship to some of this node defines operations
or lifecycle dependency constraint that relies on intermediate states, the
weaving SHOULD fail and the orchestrator SHOULD raise an error.
This section explains how relationships impacts the workflow
generation to enable the composition of complex topologies.
7.2.2.1 tosca.relationships.DependsOn
The depends on relationship is used to establish a
dependency from a node to another. A source node that depends on a target node
will be created only after the other entity has been started.
7.2.2.2 Note
DependsOn relationship SHOULD not be implemented. Even if
the Configure interface can be implemented this is not considered as a
best-practice. If you need specific implementation, please have a look at the
ConnectsTo relationship.
7.2.2.2.1 Example DependsOn
This example show the usage of a generic DependsOn
relationship between two custom software components.
In this example the relationship configure interface
doesn’t define operations so they don’t appear in the generated lifecycle.
7.2.2.3 tosca.relationships.ConnectsTo
The connects to relationship is similar to the
DependsOn relationship except that it is intended to provide an implementation.
The difference is more theoretical than practical but helps users to make an
actual distinction from a meaning perspective.
7.2.2.4 tosca.relationships.HostedOn
The hosted_on dependency relationship allows to define a
hosting relationship between an entity and another. The hosting relationship
has multiple impacts on the workflow and execution:
·
The implementation artifacts of the source node is executed on
the same host as the one of the target node.
·
The create operation of the source node is executed only once the
target node reach the started state.
·
When multiple nodes are hosted on the same host node, the defined
operations will not be executed concurrently even if the theoretical workflow
could allow it (actual generated workflow will avoid concurrency).
7.2.2.4.1 Example Software Component HostedOn Compute
This example explain the TOSCA weaving operation of a custom
SoftwareComponent on a tosca.nodes.Compute instance. The compute node is an
orchestrator provided node meaning that it’s lifecycle is delegated to the
orchestrator. This is a black-box and we just expect a started compute node to
be provided by the orchestrator.
The software node lifecycle operations will be executed on
the Compute node (host) instance.
7.2.2.4.2 Example Software Component HostedOn Software Component
Tosca allows some more complex hosting scenarios where a
software component could be hosted on another software component.
In such scenarios the software create operation is
triggered only once the software_base node has reached the started state.
7.2.2.4.3 Example 2 Software Components HostedOn Compute
This example illustrate concurrency constraint introduced
by the management of multiple nodes on a single compute.
7.2.3.1 Hosted nodes concurrency
TOSCA implementation currently does not allow concurrent
executions of scripts implementation artifacts (shell, python, ansible, puppet,
chef etc.) on a given host. This limitation is not applied on multiple hosts.
This limitation is expressed through the HostedOn relationship limitation
expressing that when multiple components are hosted on a given host node then
their operations will not be performed concurrently (generated workflow will
ensure that operations are not concurrent).
7.2.3.2 Dependent nodes concurrency
When a node depends on another node no operations will be
processed concurrently. In some situations, especially when the two nodes lies
on different hosts we could expect the create operation to be executed
concurrently for performance optimization purpose. The current version of the
specification will allow to use imperative workflows to solve this use-case. However,
this scenario is one of the scenario that we want to improve and handle in the
future through declarative workflows.
7.2.3.3 Target operations and get_attribute on source
The current ConnectsTo workflow implies that the target node
is started before the source node is even created. This means that
pre_configure_target and post_configure_target operations cannot use any input
based on source attribute. It is however possible to refer to get_property
inputs based on source properties. For advanced configurations the add_source
operation should be used.
Note also that future plans on declarative workflows
improvements aims to solve this kind of issues while it is currently possible
to use imperative workflows.
Imperative workflows are user defined and can define any
really specific constraints and ordering of activities. They are really
flexible and powerful and can be used for any complex use-case that cannot be
solved in declarative workflows. However, they provide less reusability as they
are defined for a specific topology rather than being dynamically generated
based on the topology content.
Imperative workflow grammar defines two ways to
define the sequence of operations in an imperative workflow:
·
Leverage the on_success
definition to define the next steps that will be executed in parallel.
·
Leverage a sequence of activity in a step.
7.3.1.1 Using on_success to define steps ordering
The graph of workflow steps is build based on the values
of on_success elements of the various
defined steps. The graph is built based on the following rules:
·
All steps that defines an on_success
operation must be executed before the next step can be executed. So if A and C
defines an on_success operation to B,
then B will be executed only when both A and C have been successfully executed.
·
The multiple nodes defined by an on_success construct can be executed in
parallel.
·
Every step that doesn’t have any predecessor is considered as an
initial step and can run in parallel.
·
Every step that doesn’t define any successor is considered as
final. When all the final nodes executions are completed then the workflow is
considered as completed.
7.3.1.1.1 Example
The following example defines multiple steps and the on_success relationship between them.
|
topology_template:
workflows:
deploy:
description: Workflow to
deploy the application
steps:
A:
on_success:
- B
- C
B:
on_success:
- D
C:
on_success:
- D
D:
E:
on_success:
- C
- F
F:
|
The following schema is the visualization of the
above definition in term of sequencing of the steps.
7.3.1.2 Define a sequence of activity on the same element
The step definition of a TOSCA imperative workflow
allows multiple activities to be defined :
|
workflows:
my_workflow:
steps:
create_my_node:
target: my_node
activities:
- set_state: creating
- call_operation:
tosca.interfaces.node.lifecycle.Standard.create
- set_state: created
|
The sequence defined here defines three different activities
that will be performed in a sequential way. This is just equivalent to writing
multiple steps chained by an on_success together :
|
workflows:
my_workflow:
steps:
creating_my_node:
target: my_node
activities:
- set_state: creating
on_success:
create_my_node
create_my_node:
target: my_node
activities:
- call_operation:
tosca.interfaces.node.lifecycle.Standard.create
on_success:
created_my_node
created_my_node:
target: my_node
activities:
- set_state: created
|
In both situations the resulting workflow is a
sequence of activities:
Imperative workflow allow user to define custom workflows
allowing them to add operations that are not normative, or for example, to
execute some operations in parallel when TOSCA would have performed sequential
execution.
As Imperative workflows are related to a topology, adding a
workflow is as simple as adding a workflows section to your topology template
and specifying the workflow and the steps that compose it.
7.3.2.1 Example: Adding a non-normative custom workflow
This sample topology add a very simple custom
workflow to trigger the mysql backup operation.
|
topology_template:
node_templates:
my_server:
type: tosca.nodes.Compute
mysql:
type: tosca.nodes.DBMS.MySQL
requirements:
- host: my_server
interfaces:
tosca.interfaces.nodes.custom.Backup:
operations:
backup: backup.sh
workflows:
backup:
description: Performs a
snapshot of the MySQL data.
steps:
my_step:
target: mysql
activities:
- call_operation: tosca.interfaces.nodes.custom.Backup.backup
|
In such topology the TOSCA container will still use
declarative workflow to generate the deploy and undeploy workflows as they are
not specified and a backup workflow will be available for user to trigger.
7.3.2.2 Example: Creating two nodes hosted on the same compute in parallel
TOSCA declarative workflow generation constraint the
workflow so that no operations are called in parallel on the same host. Looking
at the following topology this means that the mysql and tomcat nodes will not
be created in parallel but sequentially. This is fine in most of the situations
as packet managers like apt or yum doesn’t not support concurrency, however if
both create operations performs a download of zip package from a server most of
people will hope to do that in parallel in order to optimize throughput.
Imperative workflows can help to solve this issue.
Based on the above topology we will design a workflow that will create tomcat
and mysql in parallel but we will also ensure that tomcat is started after
mysql is started even if no relationship is defined between the components:
To achieve such workflow, the following topology
will be defined:
|
topology_template:
node_templates:
my_server:
type: tosca.nodes.Compute
mysql:
type: tosca.nodes.DBMS.MySQL
requirements:
- host: my_server
tomcat:
type:
tosca.nodes.WebServer.Tomcat
requirements:
- host: my_server
workflows:
deploy:
description: Override the
TOSCA declarative workflow with the following.
steps:
compute_install
target: my_server
activities:
- delegate: deploy
on_success:
- mysql_install
- tomcat_install
tomcat_install:
target:
tomcat
activities:
- set_state: creating
- call_operation: tosca.interfaces.node.lifecycle.Standard.create
- set_state: created
on_success:
- tomcat_starting
mysql_install:
target: mysql
activities:
- set_state: creating
- call_operation: tosca.interfaces.node.lifecycle.Standard.create
- set_state: created
- set_state: starting
- call_operation: tosca.interfaces.node.lifecycle.Standard.start
- set_state: started
on_success:
- tomcat_starting
tomcat_starting:
target: tomcat
activities:
- set_state: starting
- call_operation: tosca.interfaces.node.lifecycle.Standard.start
- set_state: started
|
Pre conditions allows the TOSCA orchestrator to determine if
a workflow can be executed based on the states and attribute values of the
topology’s node. Preconditions must be added to the initial workflow.
7.3.3.1 Example : adding precondition to custom backup workflow
In this example we will use precondition so that we
make sure that the mysql node is in the correct state for a backup.
|
topology_template:
node_templates:
my_server:
type: tosca.nodes.Compute
mysql:
type: tosca.nodes.DBMS.MySQL
requirements:
- host: my_server
interfaces:
tosca.interfaces.nodes.custom.Backup:
operations:
backup: backup.sh
workflows:
backup:
description: Performs a
snapshot of the MySQL data.
preconditions:
- target: my_server
condition:
- assert:
- state: [{equal: available}]
- target: mysql
condition:
- assert:
- state: [{valid_values:
[started, available]}]
- my_attribute:
[{equal: ready }]
steps:
my_step:
target: mysql
activities:
- call_operation:
tosca.interfaces.nodes.custom.Backup.backup
|
When the backup workflow will be triggered (by user
or policy) the TOSCA engine will first check that preconditions are fulfilled.
In this situation the engine will check that my_server node is in available
state AND that mysql node is in started OR available
states AND that mysql my_attribute value is equal to ready.
TOSCA allows the reusability of a workflow in other
workflows. Such concepts can be achieved thanks to the inline activity.
7.3.4.1 Reusing a workflow to build multiple workflows
The following example show how a workflow can inline
an existing workflow and reuse it.
|
topology_template:
node_templates:
my_server:
type: tosca.nodes.Compute
mysql:
type: tosca.nodes.DBMS.MySQL
requirements:
- host: my_server
interfaces:
tosca.interfaces.nodes.custom.Backup:
operations:
backup: backup.sh
workflows:
start_mysql:
steps:
start_mysql:
target: mysql
activities :
- set_state: starting
- call_operation:
tosca.interfaces.node.lifecycle.Standard.start
- set_state: started
stop_mysql:
steps:
stop_mysql:
target: mysql
activities:
- set_state: stopping
- call_operation:
tosca.interfaces.node.lifecycle.Standard.stop
- set_state: stopped
backup:
description: Performs a
snapshot of the MySQL data.
preconditions:
- target: my_server
condition:
- assert:
- state: [{equal:
available}]
- target: mysql
condition:
- assert:
- state:
[{valid_values: [started, available]}]
- my_attribute:
[{equal: ready }]
steps:
backup_step:
activities:
- inline: stop
- call_operation:
tosca.interfaces.nodes.custom.Backup.backup
- inline: start
restart:
steps:
backup_step:
activities:
- inline: stop
- inline: start
|
The example above defines three workflows and show
how the start_mysql and stop_mysql workflows are reused in the backup and
restart workflows.
Inlined workflows are inlined sequentially in the
existing workflow for example the backup workflow would look like this:
7.3.4.2 Inlining a complex workflow
It is possible of course to inline more complex
workflows. The following example defines an inlined workflows with multiple
steps including concurrent steps:
|
topology_template:
workflows:
inlined_wf:
steps:
A:
target: node_a
activities:
- call_operation: a
on_success:
- B
- C
B:
target: node_a
activities:
- call_operation: b
on_success:
- D
C:
target: node_a
activities:
- call_operation: c
on_success:
- D
D:
target: node_a
activities:
- call_operation: d
E:
target: node_a
activities:
- call_operation: e
on_success:
- C
- F
F:
target: node_a
activities:
- call_operation: f
main_workflow:
steps:
G:
target: node_a
activities:
- set_state: initial
- inline: inlined_wf
- set_state: available
|
To describe the following workflow:
Preconditions are used to validate if the workflow should be
executed only for the initial workflow. If a workflow that is inlined defines
some preconditions theses preconditions will be used at the instance level to
define if the operations should be executed or not on the defined instance.
This construct can be used to filter some steps on a
specific instance or under some specific circumstances or topology state.
|
topology_template:
node_templates:
my_server:
type: tosca.nodes.Compute
cluster:
type: tosca.nodes.DBMS.Cluster
requirements:
- host: my_server
interfaces:
tosca.interfaces.nodes.custom.Backup:
operations:
backup: backup.sh
workflows:
backup:
description: Performs a
snapshot of the MySQL data.
preconditions:
- target: my_server
condition:
- assert:
- state: [{equal:
available}]
- target: mysql
condition:
- assert:
- state:
[{valid_values: [started, available]}]
- my_attribute:
[{equal: ready }]
steps:
backup_step:
target: cluster
filter: # filter is a
list of clauses. Matching between clauses is and.
- or: # only one of
sub-clauses must be true.
- assert:
- foo: [{equals:
true}]
- assert:
- bar: [{greater_than:
2}, {less_than: 20}]
activities:
- call_operation:
tosca.interfaces.nodes.custom.Backup.backup
|
Inputs can be defined in a workflow and will be provided in
the execution context of the workflow. If an operation defines a get_input
function on one of its parameter the input will be retrieved from the workflow
input, and if not found from the topology inputs.
7.3.6.1 Example
|
topology_template:
node_templates:
my_server:
type: tosca.nodes.Compute
mysql:
type: tosca.nodes.DBMS.MySQL
requirements:
- host: my_server
interfaces:
tosca.interfaces.nodes.custom.Backup:
operations:
backup:
implementation:
backup.sh
inputs:
storage_url: {
get_input: storage_url }
workflows:
backup:
description: Performs a
snapshot of the MySQL data.
preconditions:
- target: my_server
valid_states: [available]
- target: mysql
valid_states: [started,
available]
attributes:
my_attribute: [ready]
inputs:
storage_url:
type: string
steps:
my_step:
target: mysql
activities:
- call_operation:
tosca.interfaces.nodes.custom.Backup.backup
|
To trigger such a workflow, the TOSCA engine must
allow user to provide inputs that match the given definitions.
By default, failure of any activity of the workflow will
result in the failure of the workflow and will results in stopping the steps to
be executed.
Exception: uninstall workflow operation failure SHOULD not
prevent the other operations of the workflow to run (a failure in an uninstall
script SHOULD not prevent from releasing resources from the cloud).
For any workflow other than install and uninstall failures
may leave the topology in an unknown state. In such situation the TOSCA engine
may not be able to orchestrate the deployment. Implementation of on_failure construct allows to execute
rollback operations and reset the state of the affected entities back to an
orchestrator known state.
7.3.7.1 Example
|
topology_template:
node_templates:
my_server:
type: tosca.nodes.Compute
mysql:
type: tosca.nodes.DBMS.MySQL
requirements:
- host: my_server
interfaces:
tosca.interfaces.nodes.custom.Backup:
operations:
backup:
implementation:
backup.sh
inputs:
storage_url: {
get_input: storage_url }
workflows:
backup:
steps:
backup_step:
target: mysql
activities:
- set_state: backing_up
# this state is not a TOSCA known state
- call_operation:
tosca.interfaces.nodes.custom.Backup.backup
- set_state: available
# this state is known by TOSCA orchestrator
on_failure:
- rollback_step
rollback_step:
target: mysql
activities:
- call_operation:
tosca.interfaces.nodes.custom.Backup.backup
- set_state: available
# this state is known by TOSCA orchestrator
|
7.3.8 Use a custom workflow language
TOSCA orchestrators may support additional workflow
languages beyond the one which has been described in this specification.
7.3.8.1 Example
|
topology_template:
workflows:
my_workflow:
implementation:
my_workflow.bpmn.xml
|
The implementation
refers to the artifact my_workflow.bpmn.xml
containing the workflow definition written in BPMN (Business Process Modeling
Notation).
7.3.8.2 Example
|
topology_template:
workflows:
my_workflow:
implementation:
description:
workflow implemented in Mistral
type:
mycompany.artifacts.Implementation.Mistral
file:
my_workflow.workbook.mistral.yaml
|
The implementation
refers to the artifact my_workflow_script
which is in fact a Mistral workbook written in the Mistral workflow definition
language.
Except for the examples, this section is normative
and describes how to express and control the application centric network
semantics available in TOSCA.
TOSCA Service Templates are application centric in
the sense that they focus on describing application components in terms of
their requirements and interrelationships. In order to provide cloud
portability, it is important that a TOSCA Service Template avoid cloud specific
requirements and details. However, at the same time, TOSCA must provide the
expressiveness to control the mapping of software component connectivity to the
network constructs of the hosting cloud.
TOSCA Networking takes the following approach.
1. The
application component connectivity semantics and expressed in terms of
Requirements and Capabilities and the relationships between these. Service
Template authors are able to express the interconnectivity requirements of
their software components in an abstract, declarative, and thus highly portable
manner.
2. The
information provided in TOSCA is complete enough for a TOSCA implementation to
fulfill the application component network requirements declaratively (i.e., it
contains information such as communication initiation and layer 4 port
specifications) so that the required network semantics can be realized on
arbitrary network infrastructures.
3. TOSCA
Networking provides full control of the mapping of software component
interconnectivity to the networking constructs of the hosting cloud network
independently of the Service Template, providing the required separation
between application and network semantics to preserve Service Template
portability.
4. Service
Template authors have the choice of specifying application component networking
requirements in the Service Template or completely separating the application
component to network mapping into a separate document. This allows application
components with explicit network requirements to express them while allowing
users to control the complete mapping for all software components which may not
have specific requirements. Usage of these two approaches is possible
simultaneously and required to avoid having to re-write components network
semantics as arbitrary sets of components are assembled into Service Templates.
5. Defining a
set of network semantics which are expressive enough to address the most common
application connectivity requirements while avoiding dependencies on specific
network technologies and constructs. Service Template authors and cloud
providers are able to express unique/non-portable semantics by defining their
own specialized network Requirements and Capabilities.
TOSCA’s application centric approach includes the modeling
of network connectivity semantics from an application component connectivity
perspective. The basic premise is that applications contain components which
need to communicate with other components using one or more endpoints over a
network stack such as TCP/IP, where connectivity between two components is expressed
as a <source component, source address, source port, target component,
target address, target port> tuple. Note that source and target components
are added to the traditional 4 tuple to provide the application centric
information, mapping the network to the source or target component involved in
the connectivity.
Software components are expressed as Node Types in TOSCA
which can express virtually any kind of concept in a TOSCA model. Node Types
offering network based functions can model their connectivity using a special
Endpoint Capability, tosca.capabilities.Endpoint,
designed for this purpose. Node Types which require an Endpoint can specify
this as a TOSCA requirement. A special Relationship Type,
tosca.relationships.ConnectsTo, is used to implicitly or explicitly relate the
source Node Type’s endpoint to the required endpoint in the target node type.
Since tosca.capabilities.Endpoint and tosca.relationships.ConnectsTo are TOSCA
types, they can be used in templates and extended by subclassing in the usual
ways, thus allowing the expression of additional semantics as needed.
The following diagram shows how the TOSCA node, capability and relationship
types enable modeling the application layer decoupled from the network model
intersecting at the Compute node using the
Bindable capability type.
As you can see, the Port
node type effectively acts a broker node between the Network node description
and a host Compute node of an application.
This section describes how TOSCA supports the typical
client/server and group communication semantics found in application
architectures.
The tosca.relationships.ConnectsTo expresses that
requirement that a source application component needs to be able to communicate
with a target software component to consume the services of the target.
ConnectTo is a component interdependency semantic in the most general sense and
does not try imply how the communication between the source and target
components is physically realized.
Application component intercommunication typically has
conventions regarding which component(s) initiate the communication. Connection
initiation semantics are specified in tosca.capabilities.Endpoint.
Endpoints at each end of the tosca.relationships.ConnectsTo
must indicate identical connection initiation semantics.
The following sections describe the normative connection
initiation semantics for the tosca.relationships.ConnectsTo Relationship Type.
8.3.1.1 Source to Target
The Source to Target communication initiation semantic is
the most common case where the source component initiates communication with
the target component in order to fulfill an instance of the
tosca.relationships.ConnectsTo relationship. The typical case is a “client”
component connecting to a “server” component where the client initiates a
stream oriented connection to a pre-defined transport specific port or set of
ports.
It is the responsibility of the TOSCA implementation to
ensure the source component has a suitable network path to the target component
and that the ports specified in the respective tosca.capabilities.Endpoint are not
blocked. The TOSCA implementation may only represent state of the
tosca.relationships.ConnectsTo relationship as fulfilled after the actual
network communication is enabled and the source and target components are in
their operational states.
Note that the connection initiation semantic only impacts
the fulfillment of the actual connectivity and does not impact the node
traversal order implied by the tosca.relationships.ConnectsTo Relationship
Type.
8.3.1.2 Target to Source
The Target to Source communication initiation semantic is a
less common case where the target component initiates communication with the
source comment in order to fulfill an instance of the
tosca.relationships.ConnectsTo relationship. This “reverse” connection initiation
direction is typically required due to some technical requirements of the
components or protocols involved, such as the requirement that SSH mush only be
initiated from target component in order to fulfill the services required by
the source component.
It is the responsibility of the TOSCA implementation to
ensure the source component has a suitable network path to the target component
and that the ports specified in the respective tosca.capabilities.Endpoint are
not blocked. The TOSCA implementation may only represent state of the
tosca.relationships.ConnectsTo relationship as fulfilled after the actual
network communication is enabled and the source and target components are in
their operational states.
Note that the connection initiation semantic only impacts
the fulfillment of the actual connectivity and does not impact the node
traversal order implied by the tosca.relationships.ConnectsTo Relationship
Type.
8.3.1.3 Peer-to-Peer
The Peer-to-Peer communication initiation semantic allows
any member of a group to initiate communication with any other member of the
same group at any time. This semantic typically appears in clustering and
distributed services where there is redundancy of components or services.
It is the responsibility of the TOSCA implementation to
ensure the source component has a suitable network path between all the member
component instances and that the ports specified in the respective
tosca.capabilities.Endpoint are not blocked, and the appropriate multicast
communication, if necessary, enabled. The TOSCA implementation may only
represent state of the tosca.relationships.ConnectsTo relationship as fulfilled
after the actual network communication is enabled such that at least one-member
component of the group may reach any other member component of the group.
Endpoints specifying the Peer-to-Peer initiation semantic need
not be related with a tosca.relationships.ConnectsTo relationship for the
common case where the same set of component instances must communicate with
each other.
Note that the connection initiation semantic only impacts
the fulfillment of the actual connectivity and does not impact the node
traversal order implied by the tosca.relationships.ConnectsTo Relationship
Type.
TOSCA Service Templates must express enough details about
application component intercommunication to enable TOSCA implementations to
fulfill these communication semantics in the network infrastructure. TOSCA
currently focuses on TCP/IP as this is the most pervasive in today’s cloud
infrastructures. The layer 4 ports required for application component
intercommunication are specified in tosca.capabilities.Endpoint. The union of
the port specifications of both the source and target tosca.capabilities.Endpoint
which are part of the tosca.relationships.ConnectsTo Relationship Template are
interpreted as the effective set of ports which must be allowed in the network
communication.
The meaning of Source and Target port(s) corresponds to the
direction of the respective tosca.relationships.ConnectsTo.
TOSCA orchestrators are responsible for the provisioning of
the network connectivity for declarative TOSCA Service Templates (Declarative TOSCA
Service Templates don’t contain explicit plans). This means that the TOSCA
orchestrator must be able to infer a suitable logical connectivity model from
the Service Template and then decide how to provision the logical connectivity,
referred to as “fulfillment”, on the available underlying infrastructure. In
order to enable fulfillment, sufficient technical details still must be
specified, such as the required protocols, ports and QOS information. TOSCA
connectivity types, such as tosca.capabilities.Endpoint, provide well defined
means to express these details.
TOSCA Service Templates are by default network agnostic.
TOSCA’s application centric approach only requires that a TOSCA Service
Template contain enough information for a TOSCA orchestrator to infer suitable
network connectivity to meet the needs of the application components. Thus
Service Template designers are not required to be aware of or provide specific
requirements for underlying networks. This approach yields the most portable
Service Templates, allowing them to be deployed into any infrastructure which
can provide the necessary component interconnectivity.
TOSCA provides mechanisms for providing control over network
fulfillment.
This mechanism allows the application network designer to
express in service template or network template how the networks should be
provisioned.
For the use cases described below let’s assume we have a
typical 3-tier application which is consisting of FE (frontend), BE (backend)
and DB (database) tiers. The simple application topology diagram can be shown
below:
Figure‑5: Typical 3-Tier Network
8.4.3.1 Use case: OAM Network
When deploying an application in service provider’s on-premise
cloud, it’s very common that one or more of the application’s services should
be accessible from an ad-hoc OAM (Operations, Administration and Management)
network which exists in the service provider backbone.
As an application network designer, I’d like to express in
my TOSCA network template (which corresponds to my TOSCA service template) the
network CIDR block, start ip, end ip and segmentation ID (e.g. VLAN id).
The diagram below depicts a typical 3-tiers application with
specific networking requirements for its FE tier server cluster:
8.4.3.2 Use case: Data Traffic network
The diagram below defines a set of networking requirements
for the backend and DB tiers of the 3-tier app mentioned above.
8.4.3.3 Use case: Bring my own DHCP
The same 3-tier app requires for its admin traffic network
to manage the IP allocation by its own DHCP which runs autonomously as part of
application domain.
For this purpose, the app network designer would like to
express in TOSCA that the underlying provisioned network will be set with
DHCP_ENABLED=false. See this illustrated in the figure below:
The TOSCA Network
node represents a simple, logical network service.
|
Shorthand Name
|
Network
|
|
Type Qualified Name
|
tosca:Network
|
|
Type URI
|
tosca.nodes.network.Network
|
8.5.1.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
ip_version
|
no
|
integer
|
valid_values: [4, 6]
default: 4
|
The IP version of the requested network
|
|
cidr
|
no
|
string
|
None
|
The cidr block of the requested network
|
|
start_ip
|
no
|
string
|
None
|
The IP address to be used as the 1st one in a
pool of addresses derived from the cidr block full IP range
|
|
end_ip
|
no
|
string
|
None
|
The IP address to be used as the last one in a pool of
addresses derived from the cidr block full IP range
|
|
gateway_ip
|
no
|
string
|
None
|
The gateway IP address.
|
|
network_name
|
no
|
string
|
None
|
An Identifier that represents an existing Network instance
in the underlying cloud infrastructure – OR – be used as the name of the new
created network.
·
If network_name is provided along with network_id
they will be used to uniquely identify an existing network and not creating a
new one, means all other possible properties are not allowed.
·
network_name
should be more convenient for using. But in case that network name uniqueness
is not guaranteed then one should provide a network_id as well.
|
|
network_id
|
no
|
string
|
None
|
An Identifier that represents an existing Network instance
in the underlying cloud infrastructure.
This property is mutually exclusive with all other
properties except network_name.
·
Appearance of network_id in network template
instructs the Tosca container to use an existing network instead of creating
a new one.
·
network_name
should be more convenient for using. But in case that network name uniqueness
is not guaranteed then one should add a network_id as well.
·
network_name
and network_id
can be still used together to achieve both uniqueness and convenient.
|
|
segmentation_id
|
no
|
string
|
None
|
A segmentation identifier in the underlying cloud
infrastructure (e.g., VLAN id, GRE tunnel id). If
the segmentation_id is
specified, the network_type or physical_network properties should be provided as well.
|
|
network_type
|
no
|
string
|
None
|
Optionally, specifies the nature
of the physical network in the underlying cloud infrastructure. Examples are
flat, vlan, gre or vxlan. For flat and vlan types, physical_network should be provided too.
|
|
physical_network
|
no
|
string
|
None
|
Optionally, identifies the
physical network on top of which the network is implemented, e.g. physnet1.
This property is required if network_type is flat or vlan.
|
|
dhcp_enabled
|
no
|
boolean
|
default: true
|
Indicates the TOSCA container to create a virtual network
instance with or without a DHCP service.
|
8.5.1.2 Attributes
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
segmentation_id
|
no
|
string
|
None
|
The actual segmentation_id that is been assigned to
the network by the underlying cloud infrastructure.
|
8.5.1.3 Definition
|
tosca.nodes.network.Network:
derived_from: tosca.nodes.Root
properties:
ip_version:
type: integer
required: false
default: 4
constraints:
- valid_values: [ 4, 6 ]
cidr:
type: string
required: false
start_ip:
type: string
required: false
end_ip:
type: string
required: false
gateway_ip:
type: string
required: false
network_name:
type: string
required: false
network_id:
type: string
required: false
segmentation_id:
type: string
required: false
network_type:
type: string
required: false
physical_network:
type: string
required: false
capabilities:
link:
type: tosca.capabilities.network.Linkable
|
The TOSCA Port node
represents a logical entity that associates between Compute and Network
normative types.
The Port node type effectively represents a single
virtual NIC on the Compute node instance.
|
Shorthand Name
|
Port
|
|
Type Qualified Name
|
tosca:Port
|
|
Type URI
|
tosca.nodes.network.Port
|
8.5.2.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
ip_address
|
no
|
string
|
None
|
Allow the user to set a fixed IP address.
Note that this address is a request to the provider which
they will attempt to fulfill but may not be able to dependent on the network
the port is associated with.
|
|
order
|
no
|
integer
|
greater_or_equal: 0
default: 0
|
The order of the NIC on the compute instance (e.g. eth2).
Note:
when binding more than one port to a single compute (aka multi vNICs) and
ordering is desired, it is *mandatory* that all ports will be set with an
order value and. The order values must represent a positive,
arithmetic progression that starts with 0 (e.g. 0, 1, 2, …, n).
|
|
is_default
|
no
|
boolean
|
default: false
|
Set is_default=true
to apply a default gateway route on the running compute instance to the
associated network gateway.
Only one port that is associated to single compute node
can set as default=true.
|
|
ip_range_start
|
no
|
string
|
None
|
Defines the starting IP of a range to be allocated for the
compute instances that are associated by this Port.
Without setting this property the IP allocation is done
from the entire CIDR block of the network.
|
|
ip_range_end
|
no
|
string
|
None
|
Defines the ending IP of a range to be allocated for the
compute instances that are associated by this Port.
Without setting this property the IP allocation is done
from the entire CIDR block of the network.
|
8.5.2.2 Attributes
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
ip_address
|
no
|
string
|
None
|
The IP address would be assigned to the associated compute
instance.
|
8.5.2.3 Definition
A node type that includes the Linkable capability
indicates that it can be pointed to by a tosca.relationships.network.LinksTo
relationship type.
|
Shorthand Name
|
Linkable
|
|
Type Qualified Name
|
tosca:.Linkable
|
|
Type URI
|
tosca.capabilities.network.Linkable
|
8.5.3.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
8.5.3.2 Definition
This relationship type represents an association
relationship between Port and Network node types.
|
Shorthand Name
|
LinksTo
|
|
Type Qualified Name
|
tosca:LinksTo
|
|
Type URI
|
tosca.relationships.network.LinksTo
|
8.5.4.1 Definition
This type represents a network association
relationship between Port and Compute node types.
|
Shorthand Name
|
network.BindsTo
|
|
Type Qualified Name
|
tosca:BindsTo
|
|
Type URI
|
tosca.relationships.network.BindsTo
|
8.5.5.1 Definition
This approach allows someone who understands the
application’s networking requirements, mapping the details of the underlying
network to the appropriate node templates in the application.
The motivation for this approach is providing the
application network designer a fine-grained control on how networks are
provisioned and stitched to its application by the TOSCA orchestrator and
underlying cloud infrastructure while still preserving the portability of his
service template. Preserving the portability means here not doing any
modification in service template but just “plug-in” the desired network
modeling. The network modeling can reside in the same service template file but
the best practice should be placing it in a separated self-contained network
template file.
This “pluggable” network template approach introduces a new
normative node type called Port, capability called tosca.capabilities.network.Linkable
and relationship type called tosca.relationships.network.LinksTo.
The idea of the Port is to elegantly associate the desired
compute nodes with the desired network nodes while not “touching” the compute
itself.
The following diagram series demonstrate the plug-ability
strength of this approach.
Let’s assume an application designer has modeled a
service template as shown in Figure 1 that describes the application topology
nodes (compute, storage, software components, etc.) with their relationships.
The designer ideally wants to preserve this service template and use it in any
cloud provider environment without any change.
Figure‑6: Generic Service Template
When the application designer comes to consider its
application networking requirement they typically call the network
architect/designer from their company (who has the correct expertise).
The network designer, after understanding the
application connectivity requirements and optionally the target cloud provider
environment, is able to model the network template and plug it to the service
template as shown in Figure 2:
Figure‑7: Service template with network template A
When there’s a new target cloud environment to run
the application on, the network designer is simply creates a new network
template B that corresponds to the new environmental conditions and provide it
to the application designer which packs it into the application CSAR.
Figure‑8: Service template with network template B
The node templates for these three networks would be
defined as follows:
|
node_templates:
frontend:
type: tosca.nodes.Compute
properties: # omitted for
brevity
backend:
type: tosca.nodes.Compute
properties: # omitted for
brevity
database:
type: tosca.nodes.Compute
properties: # omitted for
brevity
oam_network:
type: tosca.nodes.network.Network
properties: # omitted for
brevity
admin_network:
type: tosca.nodes.network.Network
properties: # omitted for
brevity
data_network:
type: tosca.nodes.network.Network
properties: # omitted for
brevity
# ports definition
fe_oam_net_port:
type: tosca.nodes.network.Port
properties:
is_default: true
ip_range_start: { get_input:
fe_oam_net_ip_range_start }
ip_range_end: { get_input:
fe_oam_net_ip_range_end }
requirements:
- link: oam_network
- binding: frontend
fe_admin_net_port:
type: tosca.nodes.network.Port
requirements:
- link: admin_network
- binding: frontend
be_admin_net_port:
type: tosca.nodes.network.Port
properties:
order: 0
requirements:
- link: admin_network
- binding: backend
be_data_net_port:
type: tosca.nodes.network.Port
properties:
order: 1
requirements:
- link: data_network
- binding: backend
db_data_net_port:
type: tosca.nodes.network.Port
requirements:
- link: data_network
- binding: database
|
This approach allows the Service Template designer to map an
endpoint to a logical network.
The use case shown below examines a way to express
in the TOSCA YAML service template a typical 3-tier application with their
required networking modeling:
|
node_templates:
frontend:
type: tosca.nodes.Compute
properties: # omitted for
brevity
requirements:
- network_oam: oam_network
- network_admin:
admin_network
backend:
type: tosca.nodes.Compute
properties: # omitted for
brevity
requirements:
- network_admin:
admin_network
- network_data: data_network
database:
type: tosca.nodes.Compute
properties: # omitted for
brevity
requirements:
- network_data: data_network
oam_network:
type: tosca.nodes.network.Network
properties:
ip_version: { get_input:
oam_network_ip_version }
cidr: { get_input:
oam_network_cidr }
start_ip: { get_input:
oam_network_start_ip }
end_ip: { get_input:
oam_network_end_ip }
admin_network:
type: tosca.nodes.network.Network
properties:
ip_version: { get_input:
admin_network_ip_version }
dhcp_enabled: { get_input:
admin_network_dhcp_enabled }
data_network:
type: tosca.nodes.network.Network
properties:
ip_version: { get_input:
data_network_ip_version }
cidr: { get_input:
data_network_cidr }
|
This section defines non-normative types which are used
only in examples and use cases in this specification and are included only for
completeness for the reader. Implementations of this specification are not
required to support these types for conformance.
9.1 Artifact Types
This section contains are non-normative Artifact Types used
in use cases and examples.
This artifact represents a Docker “image” (a TOSCA
deployment artifact type) which is a binary comprised of one or more (a union
of read-only and read-write) layers created from snapshots within the
underlying Docker Union File System.
9.1.1.1 Definition
A Virtual Machine (VM) formatted as an ISO standard disk
image.
9.1.2.1 Definition
|
tosca.artifacts.Deployment.Image.VM.ISO:
derived_from: tosca.artifacts.Deployment.Image.VM
description: Virtual Machine
(VM) image in ISO disk format
mime_type:
application/octet-stream
file_ext: [ iso ]
|
A Virtual Machine (VM) formatted as a QEMU emulator version 2 standard
disk image.
9.1.3.1 Definition
|
tosca.artifacts.Deployment.Image.VM.QCOW2:
derived_from: tosca.artifacts.Deployment.Image.VM
description: Virtual Machine
(VM) image in QCOW v2 standard disk format
mime_type:
application/octet-stream
file_ext: [ qcow2 ]
|
This artifact type represents a template file written in
Jinja2 templating language [Jinja2].
|
Shorthand Name
|
Template.Jinja2
|
|
Type Qualified Name
|
tosca:template.jinja2
|
|
Type URI
|
tosca.artifacts.template.Jinja2
|
9.1.4.1 Definition
9.1.4.2 Example
|
dbServer:
type:
tosca.nodes.Compute
properties:
name:
description:
artifacts:
configuration:
type:
tosca.artifacts.Implementation.Ansible
file: implementation/configuration/Ansible/configure.yml
template_configuration:
type:
tosca.artifacts.template.Jinja2
file:
implementation/configuration/templates/template_configuration.jinja2
interfaces:
Standard:
configure:
inputs:
input1: . . .
implementation:
primary:
configuration
dependencies:
[ template_configuration ]
|
9.1.5 tosca.artifacts.template.Twig
This artifact type represents a template file written in
Twig templating language [Twig].
|
Shorthand Name
|
Template.Twig
|
|
Type Qualified Name
|
tosca:template.Twig
|
|
Type URI
|
tosca.artifacts.template.Twig
|
9.1.5.1 Definition
This section contains are non-normative Capability Types
used in use cases and examples.
The type indicates capabilities of a Docker runtime
environment (client).
|
Shorthand Name
|
Container.Docker
|
|
Type Qualified Name
|
tosca:Container.Docker
|
|
Type URI
|
tosca.capabilities.Container.Docker
|
9.2.1.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
version
|
no
|
version[]
|
None
|
The Docker version capability (i.e., the versions
supported by the capability).
|
|
publish_all
|
no
|
boolean
|
default: false
|
Indicates that all ports (ranges) listed in the dockerfile
using the EXPOSE keyword be published.
|
|
publish_ports
|
no
|
list of PortSpec
|
None
|
List of ports mappings from source (Docker container) to
target (host) ports to publish.
|
|
expose_ports
|
no
|
list of PortSpec
|
None
|
List of ports mappings from source (Docker container) to
expose to other Docker containers (not accessible outside host).
|
|
volumes
|
no
|
list of string
|
None
|
The dockerfile VOLUME command which is used to enable
access from the Docker container to a directory on the host machine.
|
|
host_id
|
no
|
string
|
None
|
The optional identifier of an existing host resource that
should be used to run this container on.
|
|
volume_id
|
no
|
string
|
None
|
The optional identifier of an existing storage volume
(resource) that should be used to create the container’s mount point(s) on.
|
9.2.1.2 Definition
|
tosca.capabilities.Container.Docker:
derived_from: tosca.capabilities.Container
properties:
version:
type: list
required: false
entry_schema: version
publish_all:
type: boolean
default: false
required: false
publish_ports:
type: list
entry_schema: PortSpec
required: false
expose_ports:
type: list
entry_schema: PortSpec
required: false
volumes:
type: list
entry_schema: string
required: false
|
9.2.1.3 Notes
·
When the expose_ports
property is used, only the source
and source_range properties of PortSpec would be valid for supplying port numbers or
ranges, the target and target_range properties would be ignored.
This section contains non-normative node types referenced in
use cases and examples. All additional Attributes, Properties, Requirements
and Capabilities shown in their definitions (and are not inherited from
ancestor normative types) are also considered to be non-normative.
9.3.1 tosca.nodes.Database.MySQL
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
9.3.2.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
9.3.2.2 Definition
|
tosca.nodes.DBMS.MySQL:
derived_from: tosca.nodes.DBMS
properties:
port:
description: reflect the
default MySQL server port
default: 3306
root_password:
# MySQL requires a
root_password for configuration
# Override parent DBMS
definition to make this property required
required: true
capabilities:
# Further constrain the ‘host’
capability to only allow MySQL databases
host:
valid_source_types: [ tosca.nodes.Database.MySQL ]
|
9.3.3.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
9.3.3.2 Definition
This section defines a non-normative Node type for the
WordPress [WordPress] application.
9.3.4.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
9.3.4.2 Definition
This non-normative node type represents a Node.js [NodeJS] web application server.
9.3.5.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
9.3.5.2 Definition
|
tosca.nodes.WebServer.Nodejs:
derived_from: tosca.nodes.WebServer
properties:
# Property to supply the
desired implementation in the Github repository
github_url:
required: no
type: string
description: location of the
application on the github.
default:
https://github.com/mmm/testnode.git
interfaces:
Standard:
inputs:
github_url:
type: string
|
9.3.6.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
9.3.6.2 Definition
This section is non-normative and includes use cases
that explore how to model components and their relationships using TOSCA Simple
Profile in YAML.
This use case examines the ways TOSCA YAML can be used to
express a simple hosting relationship (i.e., HostedOn)
using the normative TOSCA WebServer and
WebApplication node types defined in
this specification.
10.1.1.1 WebServer declares its “host” capability
For convenience, relevant parts of the normative TOSCA
Node Type for WebServer are shown
below:
As can be seen, the WebServer Node Type declares its capability
to “contain” (i.e., host) other nodes using the symbolic name “host” and providing the Capability Type tosca.capabilities.Container. It should be
noted that the symbolic name of “host”
is not a reserved word, but one assigned by the type designer that implies at
or betokens the associated capability. The Container
capability definition also includes a required list of valid Node Types that
can be contained by this, the WebServer,
Node Type. This list is declared using the keyname of valid_source_types and in this case it
includes only allowed type WebApplication.
10.1.1.2 WebApplication declares its “host” requirement
The WebApplication node
type needs to be able to describe the type of capability a target node would
have to provide in order to “host” it. The normative TOSCA capability type
tosca.capabilities.Container is used to describe all normative TOSCA hosting
(i.e., container-containee pattern) relationships. As can be seen below, the
WebApplication accomplishes this by declaring a requirement with the symbolic name
“host” with the capability keyname
set to tosca.capabilities.Container.
Again, for convenience, the relevant parts of the normative
WebApplication Node Type are shown below:
10.1.1.2.1 Notes
·
The symbolic name “host” is not a keyword and was selected for consistent
use in TOSCA normative node types to give the reader an indication of the type
of requirement being referenced. A valid HostedOn relationship could still be
established between WebApplicaton and WebServer in a TOSCA Service Template
regardless of the symbolic name assigned to either the requirement or
capability declaration.
This use case examines the ways TOSCA YAML can be used to
express a simple connection relationship (i.e., ConnectsTo) between some service
derived from the SoftwareComponent
Node Type, to the normative WebServer
node type defined in this specification.
The service template that would establish a ConnectsTo relationship as
follows:
|
node_types:
MyServiceType:
derived_from: SoftwareComponent
requirements:
# This type of service requires a connection to a WebServer’s data_endpoint
- connection1:
node: WebServer
relationship: ConnectsTo
capability: Endpoint
topology_template:
node_templates:
my_web_service:
type: MyServiceType
...
requirements:
- connection1:
node: my_web_server
my_web_server:
# Note, the normative WebServer node type declares the “data_endpoint”
# capability of type tosca.capabilities.Endpoint.
type: WebServer
|
Since the normative WebServer Node Type only declares one
capability of type tosca.capabilties.Endpoint
(or Endpoint, its shortname alias in
TOSCA) using the symbolic name data_endpoint,
the my_web_service node template does
not need to declare that symbolic name on its requirement declaration. If
however, the my_web_server node was
based upon some other node type that declared more than one capability of type Endpoint, then the capability keyname could be used to supply
the desired symbolic name if necessary.
10.1.2.1 Best practice
It should be noted that the best practice for
designing Node Types in TOSCA should not export two capabilities of the same
type if they truly offer different functionality (i.e., different capabilities)
which should be distinguished using different Capability Type definitions.
This use case examines the ways TOSCA YAML can be used to
express a simple AttachesTo relationship between a Compute node and a locally
attached BlockStorage node.
The service template that would establish an AttachesTo relationship follows:
|
node_templates:
my_server:
type: Compute
...
requirements:
# contextually this can only
be a relationship type
- local_storage:
# capability is provided by Compute Node Type
node: my_block_storage
relationship:
type: AttachesTo
properties:
location:
/path1/path2
# This maps the local
requirement name ‘local_storage’ to the
# target node’s capability
name ‘attachment’
my_block_storage:
type: BlockStorage
properties:
size: 10 GB
|
This builds upon the previous use case (10.1.3) to examine how a template author could attach multiple Compute nodes (templates) to the
same BlockStorage node (template), but with slightly different property values
for the AttachesTo relationship.
Specifically, several notation options are shown (in this
use case) that achieve the same desired result.
10.1.4.1 Simple Profile Rationale
Referencing an explicitly declared Relationship Template is
a convenience of the Simple Profile that allows template authors an entity to
set, constrain or override the properties and operations as defined in its
declared (Relationship) Type much as allowed now for Node Templates. It is
especially useful when a complex Relationship Type (with many configurable properties
or operations) has several logical occurrences in the same Service (Topology)
Template; allowing the author to avoid configuring these same properties and
operations in multiple Node Templates.
10.1.4.2 Notation Style #1: Augment AttachesTo Relationship Type directly
in each Node Template
This notation extends the methodology used for establishing
a HostedOn relationship, but allowing template author to supply (dynamic)
configuration and/or override of properties and operations.
Note: This option will remain valid for Simple
Profile regardless of other notation (copy or aliasing) options being discussed
or adopted for future versions.
|
node_templates:
my_block_storage:
type: BlockStorage
properties:
size: 10
my_web_app_tier_1:
type: Compute
requirements:
- local_storage:
node: my_block_storage
relationship: MyAttachesTo
# use default property
settings in the Relationship Type definition
my_web_app_tier_2:
type: Compute
requirements:
- local_storage:
node: my_block_storage
relationship:
type: MyAttachesTo
# Override default
property setting for just the ‘location’ property
properties:
location:
/some_other_data_location
relationship_types:
MyAttachesTo:
derived_from: AttachesTo
properties:
location: /default_location
interfaces:
Configure:
post_configure_target:
implementation: default_script.sh
|
10.1.4.3 Notation Style #2: Use the ‘template’ keyword on the Node
Templates to specify which named Relationship Template to use
This option shows how to explicitly declare
different named Relationship Templates within the Service Template as part of a
relationship_templates section (which
have different property values) and can be referenced by different Compute
typed Node Templates.
|
node_templates:
my_block_storage:
type: BlockStorage
properties:
size: 10
my_web_app_tier_1:
derived_from: Compute
requirements:
- local_storage:
node: my_block_storage
relationship: storage_attachesto_1
my_web_app_tier_2:
derived_from: Compute
requirements:
- local_storage:
node: my_block_storage
relationship: storage_attachesto_2
relationship_templates:
storage_attachesto_1:
type: MyAttachesTo
properties:
location: /my_data_location
storage_attachesto_2:
type: MyAttachesTo
properties:
location: /some_other_data_location
relationship_types:
MyAttachesTo:
derived_from: AttachesTo
interfaces:
some_interface_name:
some_operation:
implementation: default_script.sh
|
10.1.4.4 Notation Style #3: Using the “copy” keyname to define a similar Relationship
Template
How does TOSCA make it easier to create a new relationship
template that is mostly the same as one that exists without manually copying
all the same information? TOSCA provides the copy
keyname as a convenient way to copy an existing template definition into a new
template definition as a starting point or basis for describing a new
definition and avoid manual copy. The end results are cleaner TOSCA Service
Templates that allows the description of only the changes (or deltas) between
similar templates.
The example below shows that the Relationship
Template named storage_attachesto_1
provides some overrides (conceptually a large set of overrides) on its Type
which the Relationship Template named storage_attachesto_2
wants to “copy” before perhaps
providing a smaller number of overrides.
|
node_templates:
my_block_storage:
type: BlockStorage
properties:
size: 10
my_web_app_tier_1:
derived_from: Compute
requirements:
- attachment:
node: my_block_storage
relationship:
storage_attachesto_1
my_web_app_tier_2:
derived_from: Compute
requirements:
- attachment:
node: my_block_storage
relationship:
storage_attachesto_2
relationship_templates:
storage_attachesto_1:
type: MyAttachesTo
properties:
location: /my_data_location
interfaces:
some_interface_name:
some_operation_name_1: my_script_1.sh
some_operation_name_2: my_script_2.sh
some_operation_name_3: my_script_3.sh
storage_attachesto_2:
# Copy the contents
of the “storage_attachesto_1” template into this new one
copy: storage_attachesto_1
# Then change just the value of the location property
properties:
location: /some_other_data_location
relationship_types:
MyAttachesTo:
derived_from: AttachesTo
interfaces:
some_interface_name:
some_operation:
implementation: default_script.sh
|
11 Application
Modeling Use Cases
This section is non-normative and includes use cases
that show how to model Infrastructure-as-a-Service (IaaS),
Platform-as-a-Service (PaaS) and complete application uses cases using TOSCA
Simple Profile in YAML.
Many of the use cases listed below can be found under the following
link:
https://github.com/openstack/heat-translator/tree/master/translator/tests/data
|
Name
|
Description
|
|
Compute: Create a
single Compute instance with a host Operating System
|
Introduces a TOSCA Compute node type which is used to stand up a single
compute instance with a host Operating System Virtual Machine (VM) image
selected by the platform provider using the Compute node’s properties.
|
|
Software Component 1:
Automatic deployment of a Virtual Machine (VM) image artifact
|
Introduces the SoftwareComponent node type which declares software that is
hosted on a Compute instance. In this case, the
SoftwareComponent declares a VM image as a deployment artifact which includes
its own pre-packaged operating system and software. The TOSCA Orchestrator
detects this known deployment artifact type on the SoftwareComponent node template and
automatically deploys it to the Compute node.
|
|
BlockStorage-1:
Attaching Block Storage to a single Compute instance
|
Demonstrates how to attach a TOSCA BlockStorage
node to a Compute node using the normative AttachesTo relationship.
|
|
BlockStorage-2:
Attaching Block Storage using a custom Relationship Type
|
Demonstrates how to attach a TOSCA BlockStorage
node to a Compute node using a custom RelationshipType that
derives from the normative AttachesTo relationship.
|
|
BlockStorage-3:
Using a Relationship Template of type AttachesTo
|
Demonstrates how to attach a TOSCA BlockStorage node
to a Compute node using a TOSCA Relationship Template that is based upon
the normative AttachesTo Relationship Type.
|
|
BlockStorage-4:
Single Block Storage shared by 2-Tier Application with custom AttachesTo Type
and implied relationships
|
This use case shows 2 Compute
instances (2 tiers) with one BlockStorage node, and also uses a custom AttachesTo Relationship
that provides a default mount point (i.e., location)
which the 1st tier uses, but the 2nd tier provides a
different mount point.
|
|
BlockStorage-5:
Single Block Storage shared by 2-Tier Application with custom AttachesTo Type
and explicit Relationship Templates
|
This use case is like the previous BlockStorage-4 use case, but also creates
two relationship templates (one for each tier) each of which provide a
different mount point (i.e., location)
which overrides the default location defined in the custom Relationship Type.
|
|
BlockStorage-6:
Multiple Block Storage attached to different Servers
|
This use case demonstrates how two different TOSCA BlockStorage nodes
can be attached to two different Compute nodes (i.e., servers) each using the
normative AttachesTo relationship.
|
|
Object Storage 1:
Creating an Object Storage service
|
Introduces the TOSCA ObjectStorage node type and shows how it can be
instantiated.
|
|
Network-1: Server
bound to a new network
|
Introduces the TOSCA Network and Port nodes used for modeling logical networks
using the LinksTo and BindsTo Relationship Types. In this use case, the
template is invoked without an existing network_name as an input property so a new network is
created using the properties declared in the Network node.
|
|
Network-2: Server
bound to an existing network
|
Shows how to use a network_name as an input parameter to the template to allow a server to be
associated with (i.e. bound to) an existing Network.
|
|
Network-3: Two
servers bound to a single network
|
This use case shows how two servers (Compute nodes)
can be associated with the same Network node using two logical network Ports.
|
|
Network-4: Server
bound to three networks
|
This use case shows how three logical networks (Network nodes), each with its own IP
address range, can be associated with the same server (Compute
node).
|
|
WebServer-DBMS-1:
WordPress [WordPress] + MySQL, single instance
|
Shows how to host a TOSCA WebServer
with a TOSCA
WebApplication,
DBMS and Database Node
Types along with their dependent HostedOn and
ConnectsTo relationships.
|
|
WebServer-DBMS-2:
Nodejs with PayPal Sample App and MongoDB on separate instances
|
Instantiates a 2-tier application with Nodejs and its (PayPal sample) WebApplication on one tier which connects
a MongoDB database (which stores its application data) using a ConnectsTo relationship.
|
|
Multi-Tier-1: Elasticsearch, Logstash, Kibana (ELK)
|
Shows Elasticsearch,
Logstash and Kibana (ELK)
being used in a typical manner to collect, search and monitor/visualize data
from a running application.
This use case builds upon the previous Nodejs/MongoDB 2-tier application as the one being
monitored. The collectd and rsyslog components are added to both the WebServer
and Database tiers which work to collect data for Logstash.
In addition to the application tiers, a 3rd
tier is introduced with Logstash to collect data from the application tiers.
Finally a 4th tier is added to search the Logstash data with Elasticsearch
and visualize it using Kibana.
Note: This use case also shows the
convenience of using a single YAML macro (declared in the dsl_definitions section of the TOSCA
Service Template) on multiple Compute nodes.
|
|
Container-1:
Containers using Docker single Compute instance (Containers only)
|
Minimalist TOSCA Service Template description of 2 Docker
containers linked to each other. Specifically, one container runs wordpress
and connects to second mysql database container both on a single
server (i.e., Compute instance). The use case also demonstrates how TOSCA
declares and references Docker images from the Docker Hub repository.
Variation 1: Docker Container nodes
(only) providing their Docker Requirements allowing platform (orchestrator)
to select/provide the underlying Docker implementation (Capability).
|
|
Artifacts: Compute Node with multiple artifacts
|
Illustrates how multiple artifacts for different lifecycle
operations (create, terminate, configure, etc.) can be associated with a
node.
|
11.1.2 Compute: Create
a single Compute instance with a host Operating System
This use case demonstrates how the TOSCA Simple Profile
specification can be used to stand up a single Compute instance with a guest
Operating System using a normative TOSCA Compute
node. The TOSCA Compute node is declarative in that the service template
describes both the processor and host operating system platform characteristics
(i.e., properties declared on the capability named “os” sometimes called a “flavor”) that are
desired by the template author. The cloud provider would attempt to fulfill
these properties (to the best of its abilities) during orchestration.
11.1.2.2 Features
This use case introduces the following TOSCA Simple Profile
features:
·
A node template that uses the normative TOSCA Compute Node Type along with showing an
exemplary set of its properties being configured.
·
Use of the TOSCA Service Template inputs section to declare a configurable
value the template user may supply at runtime. In this case, the “host” property named “num_cpus” (of type integer) is declared.
o
Use of a property constraint to limit the allowed integer values
for the “num_cpus” property to a
specific list supplied in the property declaration.
·
Use of the TOSCA Service Template outputs section to declare a value the
template user may request at runtime. In this case, the property named “instance_ip” is declared
o
The “instance_ip” output property
is programmatically retrieved from the Compute
node’s “public_address” attribute using
the TOSCA Service Template-level get_attribute
function.
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
TOSCA simple profile that just
defines a single compute instance and selects a (guest) host Operating System
from the Compute node’s properties. Note, this example does not include default
values on inputs properties.
topology_template:
inputs:
cpus:
type: integer
description: Number of CPUs
for the server.
constraints:
- valid_values: [ 1, 2, 4,
8 ]
node_templates:
my_server:
type: Compute
capabilities:
host:
properties:
disk_size: 10 GB
num_cpus: { get_input: cpus }
mem_size: 1 GB
os:
properties:
architecture: x86_64
type: Linux
distribution: ubuntu
version: 12.04
outputs:
private_ip:
description: The private IP
address of the deployed server instance.
value: { get_attribute:
[my_server, private_address] }
|
·
This use case uses a versioned, Linux Ubuntu distribution on the
Compute node.
11.1.3.1 Description
This use case demonstrates how the TOSCA SoftwareComponent
node type can be used to declare software that is packaged in a standard
Virtual Machine (VM) image file format (i.e., in this case QCOW2) and is hosted
on a TOSCA Compute node (instance). In this variation, the SoftwareComponent
declares a VM image as a deployment artifact that includes its own pre-packaged
operating system and software. The TOSCA Orchestrator detects this known
deployment artifact type on the SoftwareComponent node template and automatically
deploys it to the Compute node.
11.1.3.2 Features
This use case introduces the following TOSCA Simple Profile
features:
·
A node template that uses the normative TOSCA SoftwareComponent Node Type along with
showing an exemplary set of its properties being configured.
·
Use of the TOSCA Service Template artifacts section to declare a Virtual
Machine (VM) image artifact type which is referenced by the SoftwareComponent node template.
·
The VM file format, in this case QCOW2, includes its own guest
Operating System (OS) and therefore does not “require” a TOSCA OperatingSystem capability from the TOSCA
Compute node.
11.1.3.3 Assumptions
This use case assumes the following:
·
That the TOSCA Orchestrator (working with the Cloud provider’s
underlying management services) is able to instantiate a Compute node that has
a hypervisor that supports the Virtual Machine (VM) image format, in this case
QCOW2, which should be compatible with many standard hypervisors such as XEN
and KVM.
·
This is not a “bare metal” use case and assumes the existence of
a hypervisor on the machine that is allocated to “host” the Compute instance
supports (e.g. has drivers, etc.) the VM image format in this example.
11.1.3.4 Logical Diagram
11.1.3.5 Sample YAML
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
TOSCA Simple Profile with a
SoftwareComponent node with a declared Virtual machine (VM) deployment
artifact that automatically deploys to its host Compute node.
topology_template:
node_templates:
my_virtual_machine:
type: SoftwareComponent
artifacts:
my_vm_image:
file: images/fedora-18-x86_64.qcow2
type:
tosca.artifacts.Deployment.Image.VM.QCOW2
topology:
my_VMs_topology.yaml
requirements:
- host: my_server
# Automatically deploy the
VM image referenced on the create operation
interfaces:
Standard:
create: my_vm_image
# Compute instance with no
Operating System guest host
my_server:
type: Compute
capabilities:
# Note: no guest OperatingSystem requirements as these are in the image.
host:
properties:
disk_size: 10 GB
num_cpus: { get_input: cpus }
mem_size: 4 GB
outputs:
private_ip:
description: The private IP
address of the deployed server instance.
value: { get_attribute:
[my_server, private_address] }
|
11.1.3.6 Notes
·
The use of the type
keyname on the artifact definition
(within the my_virtual_machine node
template) to declare the ISO image deployment artifact type (i.e., tosca.artifacts.Deployment.Image.VM.ISO) is
redundant since the file extension is “.iso” which associated with this known, declared
artifact type.
·
This use case references a filename on the my_vm_image artifact, which indicates a
Linux, Fedora 18, x86 VM image, only as one possible example.
11.1.4 Block Storage
1: Using the normative AttachesTo Relationship Type
This use case demonstrates how to attach a TOSCA BlockStorage
node to a Compute
node using the normative AttachesTo relationship.
11.1.4.3 Sample YAML
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
TOSCA simple profile with server
and attached block storage using the normative AttachesTo Relationship Type.
topology_template:
inputs:
cpus:
type: integer
description: Number of CPUs
for the server.
constraints:
- valid_values: [ 1, 2, 4,
8 ]
storage_size:
type: scalar-unit.size
description: Size of the
storage to be created.
default: 1 GB
storage_snapshot_id:
type: string
description: >
Optional identifier for an
existing snapshot to use when creating storage.
storage_location:
type: string
description: Block storage
mount point (filesystem path).
node_templates:
my_server:
type: Compute
capabilities:
host:
properties:
disk_size: 10 GB
num_cpus: { get_input:
cpus }
mem_size: 1 GB
os:
properties:
architecture: x86_64
type: linux
distribution: fedora
version: 18.0
requirements:
- local_storage:
node: my_storage
relationship:
type: AttachesTo
properties:
location: {
get_input: storage_location }
my_storage:
type: BlockStorage
properties:
size: { get_input:
storage_size }
snapshot_id: { get_input:
storage_snapshot_id }
outputs:
private_ip:
description: The private IP
address of the newly created compute instance.
value: { get_attribute: [my_server,
private_address] }
volume_id:
description: The volume id
of the block storage instance.
value: { get_attribute: [my_storage,
volume_id] }
|
11.1.5 Block Storage 2: Using a custom
AttachesTo Relationship Type
11.1.5.1 Description
This use case demonstrates how to attach a TOSCA BlockStorage
node to a Compute
node using a custom RelationshipType that derives from the normative AttachesTo
relationship.
11.1.5.2 Logical Diagram
11.1.5.3 Sample YAML
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
TOSCA simple profile with server
and attached block storage using a custom AttachesTo Relationship Type.
relationship_types:
MyCustomAttachesTo:
derived_from: AttachesTo
topology_template:
inputs:
cpus:
type: integer
description: Number of CPUs
for the server.
constraints:
- valid_values: [ 1, 2, 4,
8 ]
storage_size:
type: scalar-unit.size
description: Size of the
storage to be created.
default: 1 GB
storage_snapshot_id:
type: string
description: >
Optional identifier for an
existing snapshot to use when creating storage.
storage_location:
type: string
description: Block storage
mount point (filesystem path).
node_templates:
my_server:
type: Compute
capabilities:
host:
properties:
disk_size: 10 GB
num_cpus: { get_input:
cpus }
mem_size: 4 GB
os:
properties:
architecture: x86_64
type: Linux
distribution: Fedora
version: 18.0
requirements:
- local_storage:
node: my_storage
# Declare custom
AttachesTo type using the ‘relationship’ keyword
relationship:
type: MyCustomAttachesTo
properties:
location: {
get_input: storage_location }
my_storage:
type: BlockStorage
properties:
size: { get_input:
storage_size }
snapshot_id: { get_input:
storage_snapshot_id }
outputs:
private_ip:
description: The private IP
address of the newly created compute instance.
value: { get_attribute: [my_server,
private_address] }
volume_id:
description: The volume id
of the block storage instance.
value: { get_attribute:
[my_storage, volume_id] }
|
11.1.6 Block Storage 3: Using a Relationship
Template of type AttachesTo
11.1.6.1 Description
This use case demonstrates how to attach a TOSCA BlockStorage node to a Compute node using a TOSCA Relationship
Template that is based upon the normative AttachesTo
Relationship Type.
11.1.6.2 Logical Diagram
11.1.6.3 Sample YAML
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
TOSCA simple profile with server
and attached block storage using a named Relationship Template for the
storage attachment.
topology_template:
inputs:
cpus:
type: integer
description: Number of CPUs
for the server.
constraints:
- valid_values: [ 1, 2, 4,
8 ]
storage_size:
type: scalar-unit.size
description: Size of the
storage to be created.
default: 1 GB
storage_location:
type: string
description: Block storage
mount point (filesystem path).
node_templates:
my_server:
type: Compute
capabilities:
host:
properties:
disk_size: 10 GB
num_cpus: { get_input:
cpus }
mem_size: 4 GB
os:
properties:
architecture: x86_64
type: Linux
distribution: Fedora
version: 18.0
requirements:
- local_storage:
node: my_storage
# Declare template to
use with ‘relationship’ keyword
relationship:
storage_attachment
my_storage:
type: BlockStorage
properties:
size: { get_input:
storage_size }
relationship_templates:
storage_attachment:
type: AttachesTo
properties:
location: { get_input:
storage_location }
outputs:
private_ip:
description: The private IP
address of the newly created compute instance.
value: { get_attribute: [my_server,
private_address] }
volume_id:
description: The volume id
of the block storage instance.
value: { get_attribute:
[my_storage, volume_id] }
|
11.1.7 Block Storage
4: Single Block Storage shared by 2-Tier Application with custom AttachesTo
Type and implied relationships
11.1.7.1 Description
This use case shows 2 compute instances (2 tiers) with one
BlockStorage node, and also uses a custom AttachesTo Relationship that provides a
default mount point (i.e., location) which the 1st tier
uses, but the 2nd tier provides a different mount point.
Please note that this use case assumes both Compute nodes
are accessing different directories within the shared, block storage node to
avoid collisions.
11.1.7.2 Logical Diagram
11.1.7.3 Sample YAML
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
TOSCA simple profile with a Single
Block Storage node shared by 2-Tier Application with custom AttachesTo Type
and implied relationships.
relationship_types:
MyAttachesTo:
derived_from:
tosca.relationships.AttachesTo
properties:
location:
type: string
default: /default_location
topology_template:
inputs:
cpus:
type: integer
description: Number of CPUs
for the server.
constraints:
- valid_values: [ 1, 2, 4,
8 ]
storage_size:
type: scalar-unit.size
default: 1 GB
description: Size of the
storage to be created.
storage_snapshot_id:
type: string
description: >
Optional identifier for an
existing snapshot to use when creating storage.
node_templates:
my_web_app_tier_1:
type: tosca.nodes.Compute
capabilities:
host:
properties:
disk_size: 10 GB
num_cpus: { get_input:
cpus }
mem_size: 4096 MB
os:
properties:
architecture: x86_64
type: Linux
distribution: Fedora
version: 18.0
requirements:
- local_storage:
node: my_storage
relationship: MyAttachesTo
my_web_app_tier_2:
type: tosca.nodes.Compute
capabilities:
host:
properties:
disk_size: 10 GB
num_cpus: { get_input:
cpus }
mem_size: 4096 MB
os:
properties:
architecture: x86_64
type: Linux
distribution: Fedora
version: 18.0
requirements:
- local_storage:
node: my_storage
relationship:
type: MyAttachesTo
properties:
location:
/some_other_data_location
my_storage:
type: tosca.nodes.Storage.BlockStoragetosca.nodes.Storage.BlockStorage
properties:
size: { get_input:
storage_size }
snapshot_id: { get_input:
storage_snapshot_id }
outputs:
private_ip_1:
description: The private IP
address of the application’s first tier.
value: { get_attribute:
[my_web_app_tier_1, private_address] }
private_ip_2:
description: The private IP
address of the application’s second tier.
value: { get_attribute:
[my_web_app_tier_2, private_address] }
volume_id:
description: The volume id
of the block storage instance.
value: { get_attribute:
[my_storage, volume_id] }
|
11.1.8 Block Storage 5: Single Block Storage
shared by 2-Tier Application with custom AttachesTo Type and explicit
Relationship Templates
11.1.8.1 Description
This use case is like the Notation1 use case, but also
creates two relationship templates (one for each tier) each of which provide a
different mount point (i.e., location) which overrides the default
location defined in the custom Relationship Type.
Please note that this use case assumes both Compute nodes
are accessing different directories within the shared, block storage node to
avoid collisions.
11.1.8.2 Logical Diagram
11.1.8.3 Sample YAML
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
TOSCA simple profile with a single
Block Storage node shared by 2-Tier Application with custom AttachesTo Type
and explicit Relationship Templates.
relationship_types:
MyAttachesTo:
derived_from:
tosca.relationships.AttachesTo
properties:
location:
type: string
default: /default_location
topology_template:
inputs:
cpus:
type: integer
description: Number of CPUs
for the server.
constraints:
- valid_values: [ 1, 2, 4,
8 ]
storage_size:
type: scalar-unit.size
default: 1 GB
description: Size of the
storage to be created.
storage_snapshot_id:
type: string
description: >
Optional identifier for an
existing snapshot to use when creating storage.
storage_location:
type: string
description: >
Block storage mount point
(filesystem path).
node_templates:
my_web_app_tier_1:
type: tosca.nodes.Compute
capabilities:
host:
properties:
disk_size: 10 GB
num_cpus: { get_input:
cpus }
mem_size: 4096 MB
os:
properties:
architecture: x86_64
type: Linux
distribution: Fedora
version: 18.0
requirements:
- local_storage:
node: my_storage
relationship:
storage_attachesto_1
my_web_app_tier_2:
type: tosca.nodes.Compute
capabilities:
host:
properties:
disk_size: 10 GB
num_cpus: { get_input:
cpus }
mem_size: 4096 MB
os:
properties:
architecture: x86_64
type: Linux
distribution: Fedora
version: 18.0
requirements:
- local_storage:
node: my_storage
relationship:
storage_attachesto_2
my_storage:
type: tosca.nodes.Storage.BlockStorage
properties:
size: { get_input:
storage_size }
snapshot_id: { get_input:
storage_snapshot_id }
relationship_templates:
storage_attachesto_1:
type: MyAttachesTo
properties:
location:
/my_data_location
storage_attachesto_2:
type: MyAttachesTo
properties:
location:
/some_other_data_location
outputs:
private_ip_1:
description: The private IP
address of the application’s first tier.
value: { get_attribute:
[my_web_app_tier_1, private_address] }
private_ip_2:
description: The private IP
address of the application’s second tier.
value: { get_attribute:
[my_web_app_tier_2, private_address] }
volume_id:
description: The volume id
of the block storage instance.
value: { get_attribute:
[my_storage, volume_id] }
|
11.1.9.1 Description
This use case demonstrates how two different TOSCA BlockStorage
nodes can be attached to two different Compute nodes (i.e., servers) each using
the normative AttachesTo
relationship.
11.1.9.2 Logical Diagram
11.1.9.3 Sample YAML
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
TOSCA simple profile with 2 servers
each with different attached block storage.
topology_template:
inputs:
cpus:
type: integer
description: Number of CPUs
for the server.
constraints:
- valid_values: [ 1, 2, 4,
8 ]
storage_size:
type: scalar-unit.size
default: 1 GB
description: Size of the
storage to be created.
storage_snapshot_id:
type: string
description: >
Optional identifier for an
existing snapshot to use when creating storage.
storage_location:
type: string
description: >
Block storage mount point
(filesystem path).
node_templates:
my_server:
type: tosca.nodes.Compute
capabilities:
host:
properties:
disk_size: 10 GB
num_cpus: { get_input:
cpus }
mem_size: 4096 MB
os:
properties:
architecture: x86_64
type: Linux
distribution: Fedora
version: 18.0
requirements:
- local_storage:
node: my_storage
relationship:
type: AttachesTo
properties:
location: { get_input:
storage_location }
my_storage:
type: tosca.nodes.Storage.BlockStorage
properties:
size: { get_input:
storage_size }
snapshot_id: { get_input:
storage_snapshot_id }
my_server2:
type: tosca.nodes.Compute
capabilities:
host:
properties:
disk_size: 10 GB
num_cpus: { get_input:
cpus }
mem_size: 4096 MB
os:
properties:
architecture: x86_64
type: Linux
distribution: Fedora
version: 18.0
requirements:
- local_storage:
node: my_storage2
relationship:
type: AttachesTo
properties:
location: { get_input:
storage_location }
my_storage2:
type: tosca.nodes.Storage.BlockStorage
properties:
size: { get_input:
storage_size }
snapshot_id: { get_input:
storage_snapshot_id }
outputs:
server_ip_1:
description: The private IP
address of the application’s first server.
value: { get_attribute:
[my_server, private_address] }
server_ip_2:
description: The private IP
address of the application’s second server.
value: { get_attribute:
[my_server2, private_address] }
volume_id_1:
description: The volume id
of the first block storage instance.
value: { get_attribute:
[my_storage, volume_id] }
volume_id_2:
description: The volume id
of the second block storage instance.
value: { get_attribute:
[my_storage2, volume_id] }
|
11.1.10.1 Description
11.1.10.2 Logical Diagram
11.1.10.3 Sample YAML
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
Tosca template for creating an
object storage service.
topology_template:
inputs:
objectstore_name:
type: string
node_templates:
obj_store_server:
type: tosca.nodes.Storage.ObjectStorage
properties:
name: { get_input:
objectstore_name }
size: 4096 MB
maxsize: 20 GB
|
11.1.11.1 Description
Introduces the TOSCA Network and
Port nodes used for
modeling logical networks using the LinksTo and
BindsTo Relationship Types. In this use case, the
template is invoked without an existing network_name as an input property so a
new network is created using the properties declared in the Network node.
11.1.11.2 Logical Diagram
11.1.11.3 Sample YAML
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
TOSCA simple profile with 1
server bound to a new network
topology_template:
inputs:
network_name:
type: string
description: Network name
node_templates:
my_server:
type: tosca.nodes.Compute
capabilities:
host:
properties:
disk_size: 10 GB
num_cpus: 1
mem_size: 4096 MB
os:
properties:
architecture: x86_64
type: Linux
distribution: CirrOS
version: 0.3.2
my_network:
type:
tosca.nodes.network.Network
properties:
network_name: { get_input:
network_name }
ip_version: 4
cidr: '192.168.0.0/24'
start_ip: '192.168.0.50'
end_ip: '192.168.0.200'
gateway_ip: '192.168.0.1'
my_port:
type:
tosca.nodes.network.Port
requirements:
- binding: my_server
- link: my_network
|
11.1.12.1 Description
This use case shows how to use a network_name as an input parameter to the template to allow
a server to be associated with an existing network.
11.1.12.2 Logical Diagram
11.1.12.3 Sample YAML
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
TOSCA simple profile with 1
server bound to an existing network
topology_template:
inputs:
network_name:
type: string
description: Network name
node_templates:
my_server:
type: tosca.nodes.Compute
capabilities:
host:
properties:
disk_size: 10 GB
num_cpus: 1
mem_size: 4096 MB
os:
properties:
architecture: x86_64
type: Linux
distribution: CirrOS
version: 0.3.2
my_network:
type:
tosca.nodes.network.Network
properties:
network_name: { get_input:
network_name }
my_port:
type:
tosca.nodes.network.Port
requirements:
- binding:
node: my_server
- link:
node: my_network
|
11.1.13.1 Description
This use case shows how two servers (Compute nodes) can be bound to the same Network (node) using two logical network Ports.
11.1.13.2 Logical Diagram
11.1.13.3 Sample YAML
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
TOSCA simple profile with 2
servers bound to the 1 network
topology_template:
inputs:
network_name:
type: string
description: Network name
network_cidr:
type: string
default: 10.0.0.0/24
description: CIDR for the
network
network_start_ip:
type: string
default: 10.0.0.100
description: Start IP for
the allocation pool
network_end_ip:
type: string
default: 10.0.0.150
description: End IP for the
allocation pool
node_templates:
my_server:
type: tosca.nodes.Compute
capabilities:
host:
properties:
disk_size: 10 GB
num_cpus: 1
mem_size: 4096 MB
os:
properties:
architecture: x86_64
type: Linux
distribution: CirrOS
version: 0.3.2
my_server2:
type: tosca.nodes.Compute
capabilities:
host:
properties:
disk_size: 10 GB
num_cpus: 1
mem_size: 4096 MB
os:
properties:
architecture: x86_64
type: Linux
distribution: CirrOS
version: 0.3.2
my_network:
type:
tosca.nodes.network.Network
properties:
ip_version: 4
cidr: { get_input:
network_cidr }
network_name: { get_input:
network_name }
start_ip: { get_input:
network_start_ip }
end_ip: { get_input:
network_end_ip }
my_port:
type:
tosca.nodes.network.Port
requirements:
- binding: my_server
- link: my_network
my_port2:
type:
tosca.nodes.network.Port
requirements:
- binding: my_server2
- link: my_network
|
11.1.14.1 Description
This use case shows how three logical networks (Network),
each with its own IP address range, can be bound to with the same server
(Compute node).
11.1.14.2 Logical Diagram
11.1.14.3 Sample YAML
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
TOSCA simple profile with 1
server bound to 3 networks
topology_template:
node_templates:
my_server:
type: tosca.nodes.Compute
capabilities:
host:
properties:
disk_size: 10 GB
num_cpus: 1
mem_size: 4096 MB
os:
properties:
architecture: x86_64
type: Linux
distribution: CirrOS
version: 0.3.2
my_network1:
type:
tosca.nodes.network.Network
properties:
cidr: '192.168.1.0/24'
network_name: net1
my_network2:
type:
tosca.nodes.network.Network
properties:
cidr: '192.168.2.0/24'
network_name: net2
my_network3:
type:
tosca.nodes.network.Network
properties:
cidr: '192.168.3.0/24'
network_name: net3
my_port1:
type:
tosca.nodes.network.Port
properties:
order: 0
requirements:
- binding: my_server
- link: my_network1
my_port2:
type:
tosca.nodes.network.Port
properties:
order: 1
requirements:
- binding: my_server
- link: my_network2
my_port3:
type:
tosca.nodes.network.Port
properties:
order: 2
requirements:
- binding: my_server
- link: my_network3
|
11.1.15.1 Description
TOSCA simple profile service showing the WordPress web
application with a MySQL database hosted on a single server (instance).
11.1.15.2 Logical Diagram
11.1.15.3 Sample YAML
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
TOSCA simple profile with
WordPress, a web server, a MySQL DBMS hosting the application’s database
content on the same server. Does not have input defaults or constraints.
topology_template:
inputs:
cpus:
type: integer
description: Number of CPUs
for the server.
db_name:
type: string
description: The name of the
database.
db_user:
type: string
description: The username of
the DB user.
db_pwd:
type: string
description: The WordPress
database admin account password.
db_root_pwd:
type: string
description: Root password
for MySQL.
db_port:
type: PortDef
description: Port for the
MySQL database
node_templates:
wordpress:
type:
tosca.nodes.WebApplication.WordPress
properties:
context_root: { get_input:
context_root }
requirements:
- host: webserver
- database_endpoint:
mysql_database
interfaces:
Standard:
create: wordpress_install.sh
configure:
implementation: wordpress_configure.sh
inputs:
wp_db_name: {
get_property: [ mysql_database, name ] }
wp_db_user: {
get_property: [ mysql_database, user ] }
wp_db_password: {
get_property: [ mysql_database, password ] }
# In my own
template, find requirement/capability, find port property
wp_db_port: {
get_property: [ SELF, database_endpoint, port ] }
mysql_database:
type: Database
properties:
name: { get_input: db_name
}
user: { get_input: db_user
}
password: { get_input:
db_pwd }
port: { get_input: db_port
}
capabilities:
database_endpoint:
properties:
port: { get_input:
db_port }
requirements:
- host: mysql_dbms
interfaces:
Standard:
configure: mysql_database_configure.sh
mysql_dbms:
type: DBMS
properties:
root_password: {
get_input: db_root_pwd }
port: { get_input: db_port
}
requirements:
- host: server
interfaces:
Standard:
inputs:
db_root_password: {
get_property: [ mysql_dbms, root_password ] }
create: mysql_dbms_install.sh
start: mysql_dbms_start.sh
configure: mysql_dbms_configure.sh
webserver:
type: WebServer
requirements:
- host: server
interfaces:
Standard:
create: webserver_install.sh
start: webserver_start.sh
server:
type: Compute
capabilities:
host:
properties:
disk_size: 10 GB
num_cpus: { get_input:
cpus }
mem_size: 4096 MB
os:
properties:
architecture: x86_64
type: linux
distribution: fedora
version: 17.0
outputs:
website_url:
description: URL for
Wordpress wiki.
value: { get_attribute:
[server, public_address] }
|
11.1.15.4 Sample scripts
Where the referenced implementation scripts in the
example above would have the following contents
11.1.15.4.1 wordpress_install.sh
11.1.15.4.2 wordpress_configure.sh
|
sed -i "/Deny from
All/d" /etc/httpd/conf.d/wordpress.conf
sed -i "s/Require
local/Require all granted/" /etc/httpd/conf.d/wordpress.conf
sed -i s/database_name_here/name/
/etc/wordpress/wp-config.php
sed -i s/username_here/user/
/etc/wordpress/wp-config.php
sed -i s/password_here/password/
/etc/wordpress/wp-config.php
systemctl restart httpd.service
|
11.1.15.4.3 mysql_database_configure.sh
|
# Setup MySQL root password and
create user
cat << EOF | mysql -u root
--password=db_root_password
CREATE DATABASE name;
GRANT ALL PRIVILEGES ON name.* TO
"user"@"localhost"
IDENTIFIED BY
"password";
FLUSH PRIVILEGES;
EXIT
EOF
|
11.1.15.4.4 mysql_dbms_install.sh
|
yum -y install mysql mysql-server
# Use systemd to start MySQL
server at system boot time
systemctl enable mysqld.service
|
11.1.15.4.5 mysql_dbms_start.sh
|
# Start the MySQL service (NOTE:
may already be started at image boot time)
systemctl start mysqld.service
|
11.1.15.4.6 mysql_dbms_configure
|
# Set the MySQL server root
password
mysqladmin -u root password
db_root_password
|
11.1.15.4.7 webserver_install.sh
|
yum -y install httpd
systemctl enable httpd.service
|
11.1.15.4.8 webserver_start.sh
|
# Start the httpd service (NOTE:
may already be started at image boot time)
systemctl start httpd.service
|
11.1.16.1 Description
This use case Instantiates a 2-tier application with Nodejs
and its (PayPal sample) WebApplication on one tier which connects a MongoDB
database (which stores its application data) using a ConnectsTo relationship.
11.1.16.2 Logical Diagram
11.1.16.3 Sample YAML
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
TOSCA simple profile with a nodejs
web server hosting a PayPal sample application which connects to a mongodb
database.
imports:
- custom_types/paypalpizzastore_nodejs_app.yaml
dsl_definitions:
ubuntu_node: &ubuntu_node
disk_size: 10 GB
num_cpus: { get_input:
my_cpus }
mem_size: 4096 MB
os_capabilities:
&os_capabilities
architecture: x86_64
type: Linux
distribution: Ubuntu
version: 14.04
topology_template:
inputs:
my_cpus:
type: integer
description: Number of CPUs
for the server.
constraints:
- valid_values: [ 1, 2, 4,
8 ]
default: 1
github_url:
type: string
description: The URL to
download nodejs.
default:
https://github.com/sample.git
node_templates:
paypal_pizzastore:
type:
tosca.nodes.WebApplication.PayPalPizzaStore
properties:
github_url: { get_input:
github_url }
requirements:
- host:nodejs
- database_connection:
mongo_db
interfaces:
Standard:
configure:
implementation:
scripts/nodejs/configure.sh
inputs:
github_url: {
get_property: [ SELF, github_url ] }
mongodb_ip: {
get_attribute: [mongo_server, private_address] }
start:
scriptsscripts/nodejs/start.sh
nodejs:
type: tosca.nodes.WebServer.Nodejs
requirements:
- host: app_server
interfaces:
Standard:
create: scripts/nodejs/create.sh
mongo_db:
type: tosca.nodes.Database
requirements:
- host: mongo_dbms
interfaces:
Standard:
create:
create_database.sh
mongo_dbms:
type: tosca.nodes.DBMS
requirements:
- host: mongo_server
properties:
port: 27017
interfaces:
tosca.interfaces.node.lifecycle.Standard:
create:
mongodb/create.sh
configure:
implementation:
mongodb/config.sh
inputs:
mongodb_ip: {
get_attribute: [mongo_server, private_address] }
start: mongodb/start.sh
mongo_server:
type: tosca.nodes.Compute
capabilities:
os:
properties:
*os_capabilities
host:
properties: *ubuntu_node
app_server:
type: tosca.nodes.Compute
capabilities:
os:
properties:
*os_capabilities
host:
properties: *ubuntu_node
outputs:
nodejs_url:
description: URL for the
nodejs server, http://<IP>:3000
value: { get_attribute:
[app_server, private_address] }
mongodb_url:
description: URL for the
mongodb server.
value: { get_attribute: [
mongo_server, private_address ] }
|
·
Scripts referenced in this example are assumed to be placed by
the TOSCA orchestrator in the relative directory declared in TOSCA.meta of the
TOSCA CSAR file.
11.1.17.1 Description
TOSCA simple profile service showing the Nodejs, MongoDB, Elasticsearch,
Logstash, Kibana, rsyslog and collectd installed on a different server
(instance).
This use case also demonstrates:
·
Use of TOSCA macros or dsl_definitions
·
Multiple SoftwareComponents
hosted on same Compute node
·
Multiple tiers communicating to each other over ConnectsTo using
Configure interface.
11.1.17.2 Logical Diagram
11.1.17.3 Sample YAML
11.1.17.3.1 Master Service Template application (Entry-Definitions)
TheThe following YAML is the primary template (i.e., the
Entry-Definition) for the overall use case. The imported YAML for the various
subcomponents are not shown here for brevity.
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
This TOSCA simple profile deploys
nodejs, mongodb, elasticsearch, logstash and kibana each on a separate server
with monitoring enabled for nodejs server where a sample nodejs application
is running. The syslog and collectd are installed on a nodejs server.
imports:
-
paypalpizzastore_nodejs_app.yaml
- elasticsearch.yaml
- logstash.yaml
- kibana.yaml
- collectd.yaml
- rsyslog.yaml
dsl_definitions:
host_capabilities:
&host_capabilities
# container properties
(flavor)
disk_size: 10 GB
num_cpus: { get_input:
my_cpus }
mem_size: 4096 MB
os_capabilities:
&os_capabilities
architecture: x86_64
type: Linux
distribution: Ubuntu
version: 14.04
topology_template:
inputs:
my_cpus:
type: integer
description: Number of CPUs
for the server.
constraints:
- valid_values: [ 1, 2, 4,
8 ]
github_url:
type: string
description: The URL to
download nodejs.
default:
https://github.com/sample.git
node_templates:
paypal_pizzastore:
type:
tosca.nodes.WebApplication.PayPalPizzaStore
properties:
github_url: { get_input:
github_url }
requirements:
- host: nodejs
- database_connection:
mongo_db
interfaces:
Standard:
configure:
implementation:
scripts/nodejs/configure.sh
inputs:
github_url: {
get_property: [ SELF, github_url ] }
mongodb_ip: {
get_attribute: [mongo_server, private_address] }
start: scripts/nodejs/start.sh
nodejs:
type:
tosca.nodes.WebServer.Nodejs
requirements:
- host: app_server
interfaces:
Standard:
create: scripts/nodejs/create.sh
mongo_db:
type: tosca.nodes.Database
requirements:
- host: mongo_dbms
interfaces:
Standard:
create: create_database.sh
mongo_dbms:
type: tosca.nodes.DBMS
requirements:
- host: mongo_server
interfaces:
tosca.interfaces.node.lifecycle.Standard:
create: scripts/mongodb/create.sh
configure:
implementation: scripts/mongodb/config.sh
inputs:
mongodb_ip: {
get_attribute: [mongo_server, ip_address] }
start: scripts/mongodb/start.sh
elasticsearch:
type:
tosca.nodes.SoftwareComponent.Elasticsearch
requirements:
- host:
elasticsearch_server
interfaces:
tosca.interfaces.node.lifecycle.Standard:
create: scripts/elasticsearch/create.sh
start: scripts/elasticsearch/start.sh
logstash:
type: tosca.nodes.SoftwareComponent.Logstash
requirements:
- host: logstash_server
- search_endpoint:
elasticsearch
interfaces:
tosca.interfaces.relationship.Configure:
pre_configure_source:
implementation: python/logstash/configure_elasticsearch.py
input:
elasticsearch_ip: { get_attribute: [elasticsearch_server, ip_address] }
interfaces:
tosca.interfaces.node.lifecycle.Standard:
create: scripts/lostash/create.sh
configure: scripts/logstash/config.sh
start: scripts/logstash/start.sh
kibana:
type:
tosca.nodes.SoftwareComponent.Kibana
requirements:
- host: kibana_server
- search_endpoint:
elasticsearch
interfaces:
tosca.interfaces.node.lifecycle.Standard:
create: scripts/kibana/create.sh
configure:
implementation: scripts/kibana/config.sh
input:
elasticsearch_ip: {
get_attribute: [elasticsearch_server, ip_address] }
kibana_ip: {
get_attribute: [kibana_server, ip_address] }
start: scripts/kibana/start.sh
app_collectd:
type:
tosca.nodes.SoftwareComponent.Collectd
requirements:
- host: app_server
- collectd_endpoint:
logstash
interfaces:
tosca.interfaces.relationship.Configure:
pre_configure_target:
implementation: python/logstash/configure_collectd.py
interfaces:
tosca.interfaces.node.lifecycle.Standard:
create: scripts/collectd/create.sh
configure:
implementation: python/collectd/config.py
input:
logstash_ip: {
get_attribute: [logstash_server, ip_address] }
start: scripts/collectd/start.sh
app_rsyslog:
type:
tosca.nodes.SoftwareComponent.Rsyslog
requirements:
- host: app_server
- rsyslog_endpoint:
logstash
interfaces:
tosca.interfaces.relationship.Configure:
pre_configure_target:
implementation: python/logstash/configure_rsyslog.py
interfaces:
tosca.interfaces.node.lifecycle.Standard:
create: scripts/rsyslog/create.sh
configure:
implementation: scripts/rsyslog/config.sh
input:
logstash_ip: {
get_attribute: [logstash_server, ip_address] }
start: scripts/rsyslog/start.sh
app_server:
type: tosca.nodes.Compute
capabilities:
host:
properties:
*host_capabilities
os:
properties:
*os_capabilities
mongo_server:
type: tosca.nodes.Compute
capabilities:
host:
properties:
*host_capabilities
os:
properties:
*os_capabilities
elasticsearch_server:
type: tosca.nodes.Compute
capabilities:
host:
properties:
*host_capabilities
os:
properties:
*os_capabilities
logstash_server:
type: tosca.nodes.Compute
capabilities:
host:
properties:
*host_capabilities
os:
properties:
*os_capabilities
kibana_server:
type: tosca.nodes.Compute
capabilities:
host:
properties:
*host_capabilities
os:
properties:
*os_capabilities
outputs:
nodejs_url:
description: URL for the
nodejs server.
value: { get_attribute: [
app_server, private_address ] }
mongodb_url:
description: URL for the
mongodb server.
value: { get_attribute: [
mongo_server, private_address ] }
elasticsearch_url:
description: URL for the
elasticsearch server.
value: { get_attribute: [
elasticsearch_server, private_address ] }
logstash_url:
description: URL for the
logstash server.
value: { get_attribute: [
logstash_server, private_address ] }
kibana_url:
description: URL for the
kibana server.
value: { get_attribute: [ kibana_server, private_address ] }
|
11.1.17.4 Sample scripts
Where the referenced implementation scripts in the
example above would have the following contents
11.1.18 Container-1: Containers
using Docker single Compute instance (Containers only)
11.1.18.1 Description
This use case shows a minimal description of two Container
nodes (only) providing their Docker Requirements allowing platform
(orchestrator) to select/provide the underlying Docker implementation
(Capability). Specifically, wordpress and mysql Docker images are referenced
from Docker Hub.
This use case also demonstrates:
·
Abstract description of Requirements (i.e., Container and Docker)
allowing platform to dynamically select the appropriate runtime Capabilities
that match.
·
Use of external repository (Docker Hub) to reference image
artifact.
11.1.18.2 Logical Diagram
11.1.18.3 Sample YAML
11.1.18.3.1 Two Docker “Container” nodes (Only) with Docker Requirements
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: >
TOSCA simple profile with
wordpress, web server and mysql on the same server.
# Repositories to retrieve code
artifacts from
repositories:
docker_hub:
https://registry.hub.docker.com/
topology_template:
inputs:
wp_host_port:
type: integer
description: The host port
that maps to port 80 of the WordPress container.
db_root_pwd:
type: string
description: Root password
for MySQL.
node_templates:
# The MYSQL container based on
official MySQL image in Docker hub
mysql_container:
type: tosca.nodes.Container.Application.Docker
capabilities:
# This is a capability
that would mimic the Docker –link feature
database_link: tosca.capabilities.Docker.Link
artifacts:
my_image:
file: mysql
type: tosca.artifacts.Deployment.Image.Container.Docker
repository: docker_hub
interfaces:
Standard:
create:
implementation:
my_image
inputs:
db_root_password: {
get_input: db_root_pwd }
# The WordPress container
based on official WordPress image in Docker hub
wordpress_container:
type: tosca.nodes.Container.Application.Docker
requirements:
- database_link:
mysql_container
artifacts:
my_image:
file: wordpress
type: tosca.artifacts.Deployment.Image.Container.Docker
repository: docker_hub
<metadata-link> :
<topology_artifact_name> # defined outside and linked to from here
interfaces:
Standard:
create:
implementation:
my_image
inputs:
host_port: {
get_input: wp_host_port }
|
11.1.19 Artifacts: Compute Node with Multiple Artifacts
11.1.19.1 Description
This use case illustrates how multiple artifacts can be
associated with a node for different lifecycle operations of a node (create,
terminate, configure, etc.)
11.1.19.2 Sample YAML
|
tosca_definitions_version:
tosca_simple_yaml_1_3
description: Sample tosca archive
to illustrate use of a node with multiple artifacts for different life cycle
operations of the node
topology_template :
node_templates :
dbServer:
type: tosca.nodes.Compute
properties:
name: dbServer
description:
artifacts:
- sw_image:
type: tosca.artifacts.Deployment.SwImage
file: http://1.1.1.1/images/ubuntu-14.04.qcow2
name: ubuntu-14.04
version: 14.04
checksum: e5c1e205f62f3
- configuration:
type: tosca.artifacts.Implementation.Ansible
file: implementation/configuration/Ansible/configure.yml
version: 2.0
- terminate:
type: tosca.artifacts.Implementation.scripts
file:
implementation/configuration/scripts/terminate.sh
version: 6.2
|
This section is non-normative and describes the
approach TOSCA Simple Profile plans to take for policy description with TOSCA
Service Templates. In addition, it explores how existing TOSCA Policy Types
and definitions might be applied in the future to express operational policy
use cases.
TOSCA Policies are a type of requirement that govern use or
access to resources which can be expressed independently from specific applications
(or their resources) and whose fulfillment is not discretely expressed in the
application’s topology (i.e., via TOSCA Capabilities).
TOSCA deems it not desirable for a declarative model to
encourage external intervention for resolving policy issues (i.e., via imperative
mechanisms external to the Cloud). Instead, the Cloud provider is deemed to be
in the best position to detect when policy conditions are triggered, analyze
the affected resources and enforce the policy against the allowable actions
declared within the policy itself.
Natural language rules are not realistic, too much to
represent in our specification; however, regular expressions can be used that
include simple operations and operands that include symbolic names for TOSCA
metamodel entities, properties and attributes.
Complex rules can actually be directed to an external
policy engine (to check for violation) returns true|false then policy says what
to do (trigger or action).
Actions/Triggers could be:
Autonomic/Platform corrects
against user-supplied criteria
External monitoring service
could be utilized to monitor policy rules/conditions against metrics, the
monitoring service could coordinate corrective actions with external services
(perhaps Workflow engines that can analyze the application and interact with
the TOSCA instance model).
Policies typically address two major areas of concern for
customer workloads:
Access Control – assures
user and service access to controlled resources are governed by rules which
determine general access permission (i.e., allow or deny) and conditional
access dependent on other considerations (e.g., organization role, time of day,
geographic location, etc.).
Placement – assures
affinity (or anti-affinity) of deployed applications and their resources; that
is, what is allowed to be placed where within a Cloud provider’s
infrastructure.
·
Quality-of-Service (and continuity) - assures performance of
software components (perhaps captured as quantifiable, measure components
within an SLA) along with consideration for scaling and failover.
Although TOSCA Policy definitions could be used to express
and convey access control policies, definitions of policies in this area are
out of scope for this specification. At this time, TOSCA encourages organizations
that already have standards that express policy for access control to provide
their own guidance on how to use their standard with TOSCA.
There must be control mechanisms in place that can be
part of these patterns that accept governance policies that allow control
expressions of what is allowed when placing, scaling and managing the
applications that are enforceable and verifiable in Cloud.
These
policies need to consider the following:
·
Regulated industries need applications to control placement
(deployment) of applications to different countries or regions (i.e., different
logical geographical boundaries).
12.3.2.1 Placement for governance concerns
In general, companies and individuals have security concerns
along with general “loss of control” issues when considering deploying and
hosting their highly valued application and data to the Cloud. They want to
control placement perhaps to ensure their applications are only placed in
datacenter they trust or assure that their applications and data are not placed
on shared resources (i.e., not co-tenanted).
In addition, companies that are related to highly regulated
industries where compliance with government, industry and corporate policies is
paramount. In these cases, having the ability to control placement of
applications is an especially significant consideration and a prerequisite for
automated orchestration.
12.3.2.2 Placement for failover
Companies realize that their day-to-day business must
continue on through unforeseen disasters that might disable instances of the
applications and data at or on specific data centers, networks or servers.
They need to be able to convey placement policies for their software
applications and data that mitigate risk of disaster by assuring these cloud
assets are deployed strategically in different physical locations. Such
policies need to consider placement across geographic locations as wide as
countries, regions, datacenters, as well as granular placement on a network,
server or device within the same physical datacenter. Cloud providers must be able
to not only enforce these policies but provide robust and seamless failover
such that a disaster’s impact is never perceived by the end user.
Quality-of-Service (apart from failover placement
considerations) typically assures that software applications and data are
available and performant to the end users. This is usually something that is
measurable in terms of end-user responsiveness (or response time) and often
qualified in SLAs established between the Cloud provider and customer. These
QoS aspects can be taken from SLAs and legal agreements and further encoded as
performance policies associated with the actual applications and data when they
are deployed. It is assumed that Cloud provider is able to detect high
utilization (or usage load) on these applications and data that deviate from
these performance policies and is able to bring them back into compliance.
Performance policies can be related to scalability policies.
Scalability policies tell the Cloud provider exactly how to scale
applications and data when they detect an application’s performance policy is
(or about to be) violated (or triggered).
Scalability policies in turn are related to placement
policies which govern where the application and data can be scaled to.
There are general “tenant” considerations that restrict
what resources are available to applications and data based upon the contract a
customer has with the Cloud provider. This includes other constraints imposed
by legal agreements or SLAs that are not encoded programmatically or associated
directly with actual application or data..
12.5 Use Cases
This section includes some initial operation policy use
cases that we wish to describe using the TOSCA metamodel. More policy work
will be done in future versions of the TOSCA Simple Profile in YAML
specification.
12.5.1.1 Use Case 1: Simple placement for failover
12.5.1.1.1 Description
This use case shows a failover policy to keep at least 3
copies running in separate containers. In this simple case, the specific
containers to use (or name is not important; the Cloud provider must assure placement
separation (anti-affinity) in three physically separate containers.
12.5.1.1.2 Features
This use case introduces the following policy features:
·
Simple separation on different “compute” nodes (up to discretion
of provider).
·
Simple separation by region (a logical container type) using an
allowed list of region names relative to the provider.
o
Also, shows that set of allowed “regions” (containers) can be greater
than the number of containers requested.
12.5.1.1.3 Logical Diagram
Sample YAML: Compute separation
|
failover_policy_1:
type: tosca.policy.placement.Antilocate
description: My placement policy
for Compute node separation
properties:
# 3 diff target containers
container_type: Compute
container_number: 3
|
12.5.1.1.4 Notes
·
There may be availability (constraints) considerations especially
if these policies are applied to “clusters”.
·
There may be future considerations for controlling max # of
instances per container.
12.5.1.2 Use Case 2: Controlled placement by region
12.5.1.2.1 Description
This use case demonstrates the use of named “containers”
which could represent the following:
·
Datacenter regions
·
Geographic regions (e.g., cities, municipalities, states,
countries, etc.)
·
Commercial regions (e.g., North America, Eastern Europe, Asia
Pacific, etc.)
12.5.1.2.2 Features
This use case introduces the following policy features:
·
Separation of resources (i.e., TOSCA nodes) by logical regions,
or zones.
12.5.1.2.3 Sample YAML: Region separation amongst named set of regions
|
failover_policy_2:
type: tosca.policy.placement
description: My failover policy
with allowed target regions (logical containers)
properties:
container_type: region
container_number: 3
# If “containers” keyname is
provided, they represent the allowed set
# of target containers to use
for placement for .
containers: [ region1,
region2, region3, region4 ]
|
12.5.1.3 Use Case 3: Co-locate based upon Compute affinity
12.5.1.3.1 Description
Nodes that need to be co-located to achieve optimal
performance based upon access to similar Infrastructure (IaaS) resource types
(i.e., Compute, Network and/or Storage).
This use case demonstrates the co-location based upon
Compute resource affinity; however, the same approach could be taken for
Network as or Storage affinity as well. :
12.5.1.3.2 Features
This use case introduces the following policy features:
·
Node placement based upon Compute resource affinity.
12.5.1.4 Notes
·
The concept of placement based upon IaaS resource utilization is
not future-thinking, as Cloud should guarantee equivalent performance of
application performance regardless of placement. That is, all network access
between application nodes and underlying Compute or Storage should have
equivalent performance (e.g., network bandwidth, network or storage access
time, CPU speed, etc.).
12.5.1.4.1 Sample YAML: Region separation amongst named set of regions
|
keep_together_policy:
type:
tosca.policy.placement.Colocate
description: Keep associated
nodes (groups of nodes) based upon Compute
properties:
affinity: Compute
|
12.5.2.1 Use Case 1: Simple node autoscale
12.5.2.1.1 Description
Start with X nodes and scale up to Y nodes, capability to do
this from a dashboard for example.
12.5.2.1.2 Features
This use case introduces the following policy features:
·
Basic autoscaling policy
12.5.2.1.3 Sample YAML
|
my_scaling_policy_1:
type: tosca.policy.scaling
description: Simple node
autoscaling
properties:
min_instances: <integer>
max_instances: <integer>
default_instances:
<integer>
increment: <integer>
|
12.5.2.1.4 Notes
·
Assume horizontal scaling for this use case
o
Horizontal scaling, implies “stack-level” control using Compute
nodes to define a “stack” (i.e., The Compute node’s entire HostedOn
relationship dependency graph is considered part of its “stack”)
·
Assume Compute node has a
SoftwareComponent that represents a VM application.
·
Availability Zones (and Regions if
not same) need to be considered in further use cases.
·
If metrics are introduced, there is a control-loop (that
monitors). Autoscaling is a special concept that includes these
considerations.
·
Mixed placement and scaling use cases need to be considered:
o Example:
Compute1 and Compute2
are 2 node templates. Compute1 has 10 instances,
5 in one region 5 in other region.
TOSCA’s declarative modelling includes features that allow
service designers to model abstract components without having to specify
concrete implementations for these components. Declarative modeling is made
possible through the use of standardized TOSCA types. Any TOSCA-compliant
orchestrator is expected to know how to deploy these standard types.
Declarative modeling ensures optimal portability of service templates, since
any cloud-specific or technology specific implementation logic is provided by
the TOSCA orchestrator, not by the service template.
The examples in the previous chapter also demonstrate how
TOSCA allows service designers to extend built-in orchestrator behavior in a
number of ways:
-
Service designers can override or extend behavior of built-in
types by supplying service-specific implementations of lifecycle interface
operations in their node templates.
-
Service designers can create entirely new types that define
custom implementations of standard lifecycle interfaces.
Implementations of Interface operations are provided through
artifacts. The examples in the previous chapter showed shell script artifacts,
but many other types of artifacts can be used as well. The use of artifacts in
TOSCA service templates breaks pure declarative behavior since artifacts
effectively contain “imperative logic” that is opaque to the orchestrator. This
introduces the risk of non-portable templates. Since some artifacts may have
dependencies on specific technologies or infrastructure component, the use of
artifacts could result in service templates that cannot be used on all cloud
infrastructures.
The goal of this non-normative chapter is to ensure
portable and interoperable use of artifacts by providing a detailed description
of how TOSCA orchestrators process artifacts, by illustrating how a number of
standard TOSCA artifact types are expected to be processed, and by describing
TOSCA language features that allow artifact to provide metadata containing
artifact-specific processing instructions. These metadata around the artifact
allow the orchestrator to make descisions on the correct Artifact Processor and
runtime(s) needed to execute. The sole purpose of this chapter is to show TOSCA
template designers how to best leverage built-in TOSCA capabilities. It is not
intended to recommend specific orchestrator implementations.
This section is non-normative and outlines
various options to distribute artifacts to artifact processors as a part of
CSAR on-boarding.
CSAR On-boarding refers to the process of
- Creating
a CSAR and its contents
- Submitting
the CSAR to the Orchestrator to be included in the catalogue
- Uploading
CSAR to Orchestrator
- Processing
of CSAR by the Orchestrator
13.1.1 How is on-boarding done
CSAR on-boarding is achieved through the following
steps:
1.
Request for uploading a CSAR is received by the Orchestrator
2.
Orchestrator verifies integrity of package
3.
Orchestrator re-directs request with CSAR to Catalogue
4.
Catalogue receives CSAR and reads the Package content
5.
Catalogue validates the CSAR
The orchestrator distributes artifacts to artifact
processors from Catalogue
13.1.2 Artifact Distribution
Artifacts can be distributed to artifact processors through
the following mechanisms:
1. Synchronous on-boarding:
During onboarding, Orchestrator forcefully pushes artifacts to artifacts
processor and waits for success response, marks onboarding operation as
successful only after a success response is received from artifact processor.
2. Asynchronous on-boarding:
Orchestrator notifies artifact processors and lets artifact processors pull
artifacts
3. Do not
distribute artifacts during onboarding, let artifact processors pull them from
CSAR catalogue when they are called to execute the artifact
Note: Disabling artifact validation during
onboarding opens up possibilities of failures during deployment of CSAR in to
the cloud
13.1.3 Why is on-boarding needed
On-boarding eases deployment and reduces the first time
instantiation of cloud applications. It helps validation and detection of
errors early, prior to deployment.
Artifacts represent the content needed to realize a
deployment or implement a specific management action.
Artifacts can be of many different types. Artifacts could be
executables (such as scripts or executable program files) or pieces of data
required by those executables (e.g. configuration files, software libraries,
license keys, etc). Implementations for some operations may require the use of
multiple artifacts.
Different types of artifacts may require different
mechanisms for processing the artifact. However, the sequence of steps taken by
an orchestrator to process an artifcat is generally the same for all types of
artifacts:
13.2.1 Identify Artifact Processor
The first step is to identify an appropriate processor for
the specified artifact. A processor is any executable that knows how to process
the artifact in order to achieve the intended management operation. This
processor could be an interpreter for executable shell scripts or scripts
written in Python. It could be a tool such as Ansible, Puppet, or Chef for
playbook, manifest, or recipe artifacts, or it could be a container management
or cloud management system for image artifacts such as container images or
virtual machine images.
TOSCA includes a number of standard artifact types.
Standard-compliant TOSCA orchestrators are expected to include processors for
each of these types. For each type, there is a correspondent Artifact Processor
that is responsible for processing artifacts of that type.
Note that aside from selecting the proper artifact
processor, it may also be important to use the proper version of the processor.
For example, some python scripts may require Python 2.7 whereas other scripts
may require Python 3.4. TOSCA provides metadata to describe service
template-specific parameters for the Artifact Processor. In addition to
specifying specific versions, those metadata could also identify repositories
from which to retrieve the artifact processor.
Some templates may require the use of custom Artifact
Processors, for example to process non-standard artifacts or to provide a
custom Artifact Processor for standard artifact types. For such cases, TOSCA
allows service template designers to define Application Processors in service
templates as a top-level entity. Alternatively, service template designers can
also provide their own artifact processor by providing wrapper artifacts of a
supported type. These wrapper artifacts could be shell scripts, python scripts,
or artifacts of any other standard type that know how process or invoke the
custom artifact.
13.2.2 Establish an Execution Environment
The second step is to identify or create a proper execution
environment within which to run the artifact processor. There are generally
three options for where to run artifact processors :
1. One option
is to execute the artifact processor in the topology that is being orchestrated,
for example on a Compute node created by the orchestrator.
2. A second
option is to process the artifact in the same environment in which the
orchestrator is running (although for security reasons, orchestrators may
create sandboxes that shield the orchestrator from faulty or malicious
artifacts).
3. The third
option is to process the script in a management environment that is external to
both the orchestrator and the topology being orchestrated. This might be the
preferred option for scenarios where the environment already exists, but it is
also possible for orchestrators to create external execution environments.
It is often possible for the orchestrator to determine the
intended execution environment based on the type of the artifact as well as on
the topology context in which the the artifact was specified. For example,
shell script artifacts associated with software components typically contain
the install script that needs to be executed on the software component’s host
node in order to install that software component. However, other scripts may
not need to be run inside the topology being orchestrated. For example, a
script that creates a database on a database management system could run on the
compute node that hosts the database management system, or it could run in the
orchestrator environment and communicate with the DBMS across a management
network connection.
Similarly, there may be multiple options for other types of
artifacts as well. For example, puppet artifacts could get processed locally by
a puppet agent running on a compute node in the topology, or they could get
passed to a puppet master that is external to both the orchestrator and the
topology.
Different orchestrators could make different decisions about
the execution environments for various combinations of node types and artifact
types. However, service template designers must have the ability to specify
explicitly where artifacts are intended to be processed in those scneario where
correct operation depends on using a specific execution environment.
Need discussion on how this is done.
13.2.3 Configure Artifact Processor User Account
An artifact processor may need to run using a specific user
account in the execution environment to ensure that the processor has the
proper permissions to execute the required actions. Depending on the artifact,
existing user accounts might get used, or the orchestrator might have to create
a new user account specifically for the artifact processor. If new user
accounts are needed, the orchestrator may also have to create a home directory
for those users.
Depending on the security mechanisms used in the execution
environment, it may also be necessary to add user accounts to specific groups,
or to assign specific roles to the user account.
13.2.4 Deploy Artifact Processor
Once the orchestrator has identified the artifact processor
as well as the execution environment, it must make sure that the artifact
processor is deployed in the execution environment:
·
If the orchestrator’s own environment acts as the execution
environment for the artifact processor, orchestrator implementors can make sure
that a standard set of artifact processors is pre-installed in that
environment, and nothing further may need to be done.
·
When a Compute node in the orchestrated topology is selected as the
execution environment, typically only the most basic processors (such as bash
shells) are pre-installed on that compute node. All other execution processors
need to be installed on that compute node by the orchestrator.
·
When an external execution environment is specified, the
orchestrator must at the very least be able to verify that the proper artifact
processor is present in the external execution environment and generate an
error if it isn’t. Ideally, the orchestrator should be able to install the processor
if necessary.
The orchestrator may also take the necessary steps to make
sure the processor is run as a specific user in the execution environment.
13.2.5 Deploy Dependencies
The imperative logic contained in artifacts may in turn
install or configure software components that are not part of the service
topology, and as a result are opaque to the orchestrator. This means that the
orchestrator cannot reflect these components in an instance model, which also
means they cannot be managed by the orchestrator.
It is best practice to avoid this situation by explicitly
modeling any dependent components that are required by an artifact processor.
When deploying the artifact processor, the orchestrator can then deploy or
configure these dependencies in the execution environment and reflect them in
an instance model as appropriate.
For artifacts that require dependencies to to be installed,
TOSCA provides a generic way in which to describe those dependencies, which
will avoid the use of monolithic scripts.
Examples of dependent components include the
following :
·
Some executables may have dependencies on software libraries. For
tools like Python, required libraries might be specified in a requirements.txt
file and deployed into a virtual environment.
·
Environment variables may need to be set.
·
Configuration files may need to be created with proper settings
for the artifact processor. For example, configuration settings could include
DNS names (or IP addresses) for contacting a Puppet Master or Chef Server.
·
Artifact processors may require valid software licenses in order
to run.
·
Other artifacts specified in the template may need to be
deposited into the execution environment.
13.2.6 Identify Target
Orchestrators must pass information to the artifact
processor that properly identifies the target for each artifact being
processed.
·
In many cases, the target is the Compute node that acts as the
host for the node being created or configured. If that Compute node also acts
as the execution environment for the artifact processor, the target for the
artifacts being processed is the Compute node itself. If that scenario, there
is no need for the orchestrator to pass additional target information aside
from specifying that all actions are intended to be applied locally.
·
When artifact processors run externally to the topology being
deployed, they must establish a connection across a management network to the
target. In TOSCA, such targets are identified using Endpoint capabilities that
contain the necessary addressing information. This addressing information must
be passed to the artifact processor
Note that in addition to endpoint information about the
target, orchestrators may also need to pass information about the protocol that
must be used to connect to the target. For example, some networking devices
only accept CLI commands across a SSH connection, but others could also accept
REST API calls. Different python scripts could be used to configure such devices:
one that uses the CLI, and one that executes REST calls. The artifact must
include metadata about which connection mechanism is intended to be used, and
orchestrators must pass on this information to the artifact processor.
Finally, artifact processor may need proper credentials to
connect to target endpoints. Orchestrators must pass those credentials to the
artifact processor before the artifact can be processed.
13.2.7 Pass Inputs and Retrieve Results or Errors
Orchestrators must pass any required inputs to the artifact
processor. Some processors could take inputs through environment variables, but
others may prefer command line arguments. Named or positional command line
arguments could be used. TOSCA must be very specific about the mechanism for
passing input data to processors for each type of artifact.
Similarly, artifact processors must also pass results from
operations back to orchestrators so that results values can be reflected as
appropriate in node properties and attributes. If the operation fails, error
codes may need to be returned as well. TOSCA must be very specific about the
mechanism for returning results and error codes for each type of artifact.
13.2.8 Cleanup
After the artifact has been processed by the artifact
processor, the orchestrator could perform optional cleanup:
·
If an artifact processor was deployed within the topology that is
being orchestrated, the orchestrator could decide to remove the artifact
processor (and all its deployed dependencies) from the topology with the goal
of not leaving behind any components that are not explicitly modeled in the
service template.
·
Alternatively, the orchestrator MAY be able to reflect the
additional components/resources associated with the Artifact Processor as part
of the instance model (post deployment).
Artifact Processors that do not use the service template
topology as their execution environment do not impact the deployed topology. It
is up to each orchestrator implementation to decide if these artifact
processors need to be removed.
Detailed Artifacts may be generated on-the-fly as orchestration
happens. May be propagated to other nodes in the topology. How do we describe
those?
This section shows how orchestrators might execute the steps
listed above for a few common artifact types, in particular:
1. Shell
scripts
2. Python
scripts
3. Package
artifacts
4. VM images
5. Container
images
6. API
artifacts
7. Non-standard
artifacts
By illustrating how different types of artifacts are
intended to be processed, we identify the information needed by artifact
processors to properly process the artifacts, and we will also identify the
components in the topology from which this information is intended to be
obtained.
13.4.1 Shell Scripts
Many artifacts are simple bash scripts that provide implementations
for operations in a Node’s Lifecycle Interfaces. Bash scripts are typically
intended to be executed on Compute nodes that host the node with which these
scripts are associated.
We use the following example to illustrate the steps taken
by TOSCA orchestrators to process shell script artifacts.
|
tosca_definitions_version: tosca_simple_yaml_1_3
description: Sample tosca archive
to illustrate simple shell script usage.
template_name: tosca-samples-shell
template_version: 1.0.0-SNAPSHOT
template_author: TOSCA TC
node_types:
tosca.nodes.samples.LogIp:
derived_from:
tosca.nodes.SoftwareComponent
description: Simple linux
cross platform create script.
attributes:
log_attr: {
get_operation_output: [SELF, Standard, create, LOG_OUT] }
interfaces:
Standard:
create:
inputs:
SELF_IP: {
get_attribute: [HOST, ip_address] }
implementation:
scripts/create.sh
topology_template:
node_templates:
log_ip:
type:
tosca.nodes.samples.LogIp
requirements:
- host:
node: compute
capability:
tosca.capabilities.Container
relationship:
tosca.relationships.HostedOn
# Any linux compute.
compute:
type: tosca.nodes.Compute
capabilities:
os:
properties:
type: linux
|
This example uses the following script to install the LogIP
software :
|
#!/bin/bash
# This is exported so available to
fetch as output using the get_operation_output function
export LOG_OUT="Create script
: $SELF_IP"
# Just a simple example of create
operation, of course software installation is better
echo
"$LOG_OUT" >> /tmp/tosca_create.log
|
For this simple example, the artifact processing steps
outlined above are as follows:
1. Identify
Artifact Processor: The artifact processor for bash shell scripts is
the “bash” program.
2. Establish
Execution Environment: The typical execution environment for bash
scripts is the Compute node respresenting the Host of the node containing the
artifact.
3. Configure
User Account: The bash user account is the default user account created
when instantiating the Compute node. It is assumed that this account has been
configured with sudo privileges.
4. Deploy
Artifact Processor: TOSCA orchestrators can assume that bash is
pre-installed on all Compute nodes they orchestrate, and nothing further needs
to be done.
5. Deploy
Dependencies: Orchestrators should copy all provided artifacts using a
directory structure that mimics the directory structure in the original CSAR
file containing the artifacts. Since no dependencies are specified in the
example above, nothing further needs to be done.
6. Identify
Target: The target for bash is the Compute node itself.
7. Pass
Inputs and Retrieve Outputs: Inputs are passed to bash as environment
variables. In the example above, there is a single input declared for the
create operation called SELF_IP. Before processing the script, the Orchestrator
creates a corresponding environment variable in the execution environment.
Similarly, the script creates a single output that is passed back to the
orchestrator as an environment variable. This environment variable can be
accessed elsewhere in the service template using the get_operation_output
function.
13.4.1.1 Progression of Examples
The following examples show a number of potential use case
variations (not exhaustive) :
13.4.1.1.1 Simple install script that can run on all flavors for Unix.
For example, a Bash script called “create.sh” that is used
to install some software for a TOSCA Node; that this introduces imperative
logic points (all scripts perhaps) which MAY lead to the creation of “opaque
software” or topologies within the node
13.4.1.1.1.1 Notes
·
Initial examples used would be independent of the specific flavor
of Linux.
·
The “create” operation, as part of the normative Standard node
lifecycle, has special meaning in TOSCA in relation to a corresponding
deployment artifact; that is, the node is not longer “abstract” if it either
has an impl. Artifact on the create operation or a deployment artifact
(provided on the node).
“create.sh” prepares/configures environment/host/container
for other software (see below for VM image use case variants).
13.4.1.1.1.2 Variants
1. “create.sh”
followed by a “configure.sh” (or “stop.sh”, “start.sh” or a similar variant).
2. in Compute
node (i.e., within a widely-used, normative, abstract Node Type).
3. In
non-compute node like WebServer (is this the hello world)?
·
Container vs. Containee “hello worlds”; create is “special”;
speaks to where (target) the script is run at! i.e., Compute node does not have
a host.
·
What is BEST PRACTICE for compute? Should “create.sh” even be
allowed?
·
Luc: customer wanted to use an non-AWS cloud, used shell scripts
to cloud API.
i. Should
have specific Node type subclass for Compute for that other Cloud (OR) a
capability that represents that specific target Cloud.
13.4.1.1.2 Script that needs to be run as specific user
For example, a Postgres user
13.4.1.1.3 Simple script with dependencies
For example, using example from the meeting where script
depends on AWS CLI being installed.
·
How do you decide whether to install an RPM or python package for
the AWS dependency?
·
How do we decide whether to install python packages in virtualenv
vs. system-wide?
13.4.1.1.4 Different scripts for different Linux flavors
For example. run apt-get vs. yum
·
The same operation can be implemented by different artifacts
depending on the flavor of Linux on which the script needs to be run. We need
the ability to specify which artifacts to use based on the target.
·
How do we extend the “operation” grammar to allow for the
selection of one specific artifact out of a number of options?
·
How do we annotate the artifacts to indicate that they require a
specific flavor and/or version of Linux?
13.4.1.1.4.1 Variants
·
A variant would be to use different subclasses of abstract nodes,
one for each flavor of Linux on which the node is supposed to be deployed. This
would eliminate the need for different artifacts in the same node. Of course,
this significantly reduces the amount of “abstraction” in service templates.
13.4.1.1.5 Scripts with environment variables
·
Environment variables that may not correspond to input parameters
·
For example, OpenStack-specific environment variables
·
How do we specify that these environment variables need to be
set?
13.4.1.1.6 Scripts that require certain configuration files
For example, containing AWS credentials
·
This configuration file may need to be created dynamically
(rather than statically inside a CSAR file). How do we specify that these files
may need to be created?
·
Or does this require template files (e.g. Jinja2)?
13.4.2 Python Scripts
A second important class of artifacts are Python scripts.
Unlike Bash script artifacts, Python scripts are more commonly executed within
the context of the Orchestrator, but service template designers must also be
able to provide Python scripts artifacts that are intened to be excecuted
within the topology being orchestrated,
13.4.2.1 Python Scripts Executed in Orchestrator
Need a simple example of a Python script executed in the
Orchestrator context.
13.4.2.2 Python Scripts Executed in Topology
Need a simple example of a Python script executed in the topology
being orchestrated.
The following grammar is provided to allow service providers
to specify the execution environment within which the artifact is intended to
be processed :
Need to decide on grammar. Likely an additional keyword to the
“operation” section of lifecycle interface definitions.
13.4.2.3 Specifying Python Version
Some python scripts conform to Python version 2, whereas
others may require version 3. Artifact designers use the following grammar to
specify the required version of Python:
TODO
13.4.2.3.1.1 Assumptions/Questions
·
Need to decide on grammar. Is artifact processer version
associated with the processor, with the artifact, the artifact type, or the
operation implementation?
13.4.2.4 Deploying Dependencies
Most Python scripts rely on external packages that must be
installed in the execution environment. Typically, python packages are
installed using the ‘pip’ command. To provide isolation between different
environments, is is considered best practice to create virtual environments. A
virtual environment is a tool to keep the dependencies required by different
python scripts or projects in separate places, by creating virtual Python
environments for each of them.
The following example shows a Python script that has dependencies
on a number of external packages:
TODO
13.4.2.4.1.1 Assumptions/Questions
·
Python scripts often have dependencies on a number of external
packages (that are referenced by some package artifcat). How would these be
handled?
·
How do we account for the fact that most python packages are
available as Linux packages as well as pip packages?
·
Does the template designer need to specify the use of virtual
environments, or is this up to the orchestrator implementation? Must names be
provided for virtual environments?
13.4.2.4.1.2 Notes
·
Typically, dependent artifacts must be processed in a specific order.
TOSCA grammar must provide a way to define orders and groups (perhaps by
extending groups grammar by allowing indented sub-lists).
13.4.3 Package Artifacts
Most software components are distributed as software
packages that include an archive of files and information about the software,
such as its name, the specific version and a description. These packages are
processed by a package management system (PMS), such as rpm or YUM, that
automates the software installation process.
Linux packages are maintained in Software Repositories,
databases of available application installation packages and upgrade packages
for a number of Linux distributions. Linux installations come pre-configured
with a default Repository from which additional software components can be
installed.
While it is possible to install software packages using Bash
script artifacts that invoke the appropriate package installation commands
(e.g. using apt or yum), TOSCA provides improved portability by allowing
template designers to specify software package artifacts and leaving it up to
the orchestrator to invoke the appropriate package management system.
13.4.3.1 RPM Packages
The following example shows a software component with an RPM
package artifact.
Need a simple example
13.4.4 Debian Packages
The following example shows a software component with Debian
package artifact.
Need a simple example
13.4.4.1.1.1 Notes
·
In this scenario, the host on which the software component is
deployed must support RPM packages. This must be reflected in the software
component’s host requirement for a target container.
·
In this scenario, the host on which the software component is
deployed must support Debian packages. This must be reflected in the software
component’s host requirement for a target container.
13.4.4.2 Distro-Independent Service Templates
Some template designers may want to specify a generic
application software topology that can be deployed on a variety of Linux
distributions. Such templates may include software components that include
multiple package artifacts, one for each of the supported types of container platforms.
It is up to the orchestrator to pick the appropriate package depending on the
type of container chosed at deployment time.
Supporting this use case requires the following:
·
Allow multiple artifacts to be expressed for a given lifecycle
operation.
·
Associate the required target platform for which each of those
artfiacts was meant.
13.4.4.2.1.1 Assumptions/Questions
How do we specify multiple artifacts for the same operation?
How we we specify which platforms are support for each artifact?
In the artifact itself? In the artifact type?
13.4.5 VM Images
13.4.5.1.1.1 Premises
·
VM Images is a popular opaque deployment artifact that may deploy
an entire topology that is not declared itself within the service template.
13.4.5.1.1.2 Notes
·
The “create” operation, as part of the normative Standard node
lifecycle, has special meaning in TOSCA in relation to a corresponding
deployment artifact; that is, the node is not longer “abstract” if it either
has an impl. Artifact on the create operation or a deployment artifact
(provided on the node).
13.4.5.1.1.3 Assumptions/Questions
·
In the future, the image itself could contain TOSCA topological
information either in its metadata or externally as an associated file.
o
Can these embedded or external descriptions be brought into the
TOSCA Service Template or be reflected in an instance model for management
purposes?
·
Consider create.sh in conjunction with a VM image deployment
artifact
o
VM image only (see below)
o
Create.sh and VM image, both. (Need to address argument that they
belong in different nodes).
o
Configure.sh with a VM image.? (see below)
o
Create.sh only (no VM image)
·
Implementation Artifact (on TOSCA Operations):
o
Operations that have an artifact (implementation).
·
Deployment Artifacts:
o
Today: it must appear in the node under “artifacts” key (grammar)
o
In the Future, should it:
§
Appear directly in “create” operation, distinguish by “type”
(which indicates processor)?
§
<or> by artifact name (by reference) to artifact declared
in service template.
§
What happens if on create and in node (same artifact=ok?
Different=what happens? Error?)
§
What is best practice? And why? Which way is clearer (to user?)?
§
Processing order (use case variant) if config file and VM image
appear on same node?
13.4.5.2 Image Onboarding – Uploading image to image repository
In the case of onboarding of images, the cloud management
platform plays the role of artifact processor. Different cloud management
platforms have different image characteristics.
For example :.
·
Openstack (Glance) - disk_format, container_format,
min_disk, min_ram etc.
·
Vmware - vmware_disktype, vmware_ostype etc.
·
OpenshiftContainer - name, namespace, selfLink
,resourceVersion etc.
These are described as artifact properties. They are not
processed by the Orchestrator, but passed on to the cloud management platform
for further processing.
13.4.6 Container Images
13.4.7 API Artifacts
Some implementations may need to be implemented by invoking
an API on a remote endpoint. While such implementations could be provided by
shell or python scripts that invoke API client software or use
language-specific bindings for the API, it might be preferred to use generic
API artifacts that leave decisions about the tools and/or language bindings to
invoke the API to the orchestrator.
To support generic API artifacts, the following is required:
·
A format in which to express the target endpoint and the required
parameters for the API call
·
A mechanism for binding input parameters in the operation to the
appropriate parameters in the API call.
·
A mechanism for specifying the results and/or errors that will be
returned by the API call
Moreover, some operations may need to be implemented by
making more than one API call. Flexible API support requires a mechanism for
expressing the control logic that runs those API calls.
It should be possible to use a generic interface to describe
these various API attributes without being forced into using specific software
packages or API tooling. Of course, in order to “invoke” the API an
orchestrator must launch an API client (e.g. a python script, a Java program,
etc.) that uses the appropriate API language bindings. However, using generic
API Artifact types, the decision about which API clients and language bindings
to use can be left to the orchestrator. It is up to the API Artifact Processor
provided by the Orchestrator to create an execution environment within which to
deploy API language bindings and associated API clients based on Orchestrator
preferences. The API Artifact Processor then uses these API clients to
“process” the API artifact.
13.4.7.1 Examples
·
REST
·
SOAP
·
OpenAPI
·
IoT
·
Serverless
13.4.8 Non-Standard Artifacts with Execution Wrappers
TODO
To unambiguously describe how artifacts need to be
processed, TOSCA provides:
1. Artifact
types that define standard ways to process artifacts.
2. Keywords such
as checksum, version etc. that enable identification of suitable artifact
processor and transfer of artifact to artifact processor.
3. Artifact
Properties that enable the artifact processor to process the artifact
4. Descriptive metadata that provide
additional information needed to properly process the artifact.
The implementations subject to conformance are those introduced
in Section 11.3 “Implementations”. They are listed here for convenience:
·
TOSCA YAML service template
·
TOSCA processor
·
TOSCA orchestrator (also called orchestration engine)
·
TOSCA generator
·
TOSCA archive
A document conforms to this specification as TOSCA YAML
service template if it satisfies all the statements below:
(a) It is valid according
to the grammar, rules and requirements defined in section 3 “TOSCA Simple
Profile definitions in YAML”.
(b) When using functions
defined in section 4 “TOSCA functions”, it is valid according to the grammar
specified for these functions.
(c) When using or
referring to data types, artifact types, capability types, interface types,
node types, relationship types, group types, policy types defined in section 5 “TOSCA
normative type definitions”, it is valid according to the definitions given in section
5.
A processor or program conforms to this specification as
TOSCA processor if it satisfies all the statements below:
(a) It can parse and
recognize the elements of any conforming TOSCA YAML service template, and
generates errors for those documents that fail to conform as TOSCA YAML service
template while clearly intending to.
(b) It implements the
requirements and semantics associated with the definitions and grammar in
section 3 “TOSCA Simple Profile definitions in YAML”, including those listed in
the “additional requirements” subsections.
(c) It resolves the
imports, either explicit or implicit, as described in section 3 “TOSCA Simple
Profile definitions in YAML”.
(d) It generates errors as
required in error cases described in sections 3.1 (TOSCA Namespace URI and
alias), 3.2 (Parameter and property type) and 3.6 (Type-specific definitions).
(e) It normalizes string
values as described in section 5.4.9.3 (Additional Requirements)
A processor or program conforms to this specification as
TOSCA orchestrator if it satisfies all the statements below:
(a) It is conforming as a
TOSCA Processor as defined in conformance clause 2: TOSCA Processor.
(b) It can process all
types of artifact described in section 5.3 “Artifact types” according to the
rules and grammars in this section.
(c) It can process TOSCA
archives as intended in section 6 “TOSCA Cloud Service Archive (CSAR) format”
and other related normative sections.
(d) It can understand and
process the functions defined in section 4 “TOSCA functions” according to their
rules and semantics.
(e) It can understand and
process the normative type definitions according to their semantics and
requirements as described in section 5 “TOSCA normative type definitions”.
(f) It can
understand and process the networking types and semantics defined in section 7
“TOSCA Networking”.
(g) It generates errors as
required in error cases described in sections 2.10 (Using node template
substitution for chaining subsystems), 5.4 (Capabilities Types) and 5.7 (Interface
Types).).
A processor or program conforms to this specification as
TOSCA generator if it satisfies at least one of the statements below:
(a) When requested to
generate a TOSCA service template, it always produces a conforming TOSCA
service template, as defined in Clause 1: TOSCA YAML service template,
(b) When requested to
generate a TOSCA archive, it always produces a conforming TOSCA archive, as
defined in Clause 5: TOSCA archive.
A package artifact conforms to this specification as TOSCA
archive if it satisfies all the statements below:
(a)
It is valid according to the structure and rules defined in section 6 “TOSCA
Cloud Service Archive (CSAR) format”.
The following items will need to be reflected in the TOSCA
(XML) specification to allow for isomorphic mapping between the XML and YAML
service templates.
A.1 Model Changes
The “TOSCA Simple ‘Hello World’” example introduces this
concept in Section 2. Specifically, a
VM image assumed to accessible by the cloud provider.
Introduce template Input and Output parameters
The “Template with input and output parameter” example
introduces concept in Section 2.1.1.
“Inputs” could be mapped to
BoundaryDefinitions in TOSCA v1.0. Maybe needs some usability enhancement and
better description.
“outputs” are a new feature.
Grouping of Node Templates
This was part of original TOSCA
proposal, but removed early on from v1.0 This allows grouping of node
templates that have some type of logically managed together as a group (perhaps
to apply a scaling or placement policy).
Lifecycle Operation definition independent/separate from
Node Types or Relationship types (allows reuse). For now, we added definitions
for “node.lifecycle” and “relationship.lifecycle”.
Override of Interfaces (operations) in the Node
Template.
Service Template Naming/Versioning
Should include TOSCA spec. (or
profile) version number (as part of namespace)
Allow the referencing artifacts using a URL (e.g., as a
property value).
Repository definitions in Service Template.
Substitution mappings for Topology template.
Addition of Group Type, Policy Type, Group def., Policy
def. along with normative TOSCA base types for policies and groups.
Addition of Artifact Processors (AP) as first class
citizens
A.2 Normative Types
·
Types / Property / Parameters
o
list, map, range, scalar-unit types
o
Includes YAML intrinsic types
o
NetworkInfo, PortInfo, PortDef, PortSpec, Credential
o
TOSCA Version based on Maven
o
JSON and XML types (with schema constraints)
·
Constraints
o
constraint clauses, regex
o
External schema support
·
Node
o
Root, Compute, ObjectStorage, BlockStorage, Network, Port,
SoftwareComponent, WebServer, WebApplicaton, DBMS, Database, Container, and
others
·
Relationship
o
Root, DependsOn, HostedOn, ConnectsTo, AttachesTo, RoutesTo,
BindsTo, LinksTo and others
·
Artifact
o
Deployment: Image Types (e.g., VM, Container), ZIP, TAR, etc.
o
Implementation : File, Bash, Python, etc.
·
Artifact Processors
o
New in v1.2 as “first class” citizen
·
Requirements
o
None
·
Capabilities
o
Container, Endpoint, Attachment, Scalable, …
·
Lifecycle
o
Standard (for Node Types)
o
Configure (for Relationship Types)
·
Functions
o
get_input, get_attribute, get_property, get_nodes_of_type,
get_operation_output and others
o
concat, token
o
get_artifact
o
from (file)
·
Groups
o
Root
·
Policies
o
Root, Placement, Scaling, Update, Performance
·
Workflow
o
Complete declarative task-based workflow grammar.
·
Service Templates
o
Advanced “import” concepts
o
Repository definitions
·
CSAR
o
Allow multiple top-level Service Templates in same CSAR (with
equivalent functionality)
The following individuals have participated in the creation
of this specification and are gratefully acknowledged:
Contributors:
Alex Vul (alex.vul@intel.com), Intel
Anatoly Katzman (anatoly.katzman@att.com),
AT&T
Arturo Martin De Nicolas (arturo.martin-de-nicolas@ericsson.com),
Ericsson
Avi Vachnis (avi.vachnis@alcatel-lucent.com),
Alcatel-Lucent
Calin Curescu (calin.curescu@ericsson.com), Ericsson
Chris Lauwers (lauwers@ubicity.com)
Claude Noshpitz (claude.noshpitz@att.com), AT&T
Derek Palma (dpalma@vnomic.com), Vnomic
Dmytro Gassanov (dmytro.gassanov@netcracker.com), NetCracker
Frank Leymann (Frank.Leymann@informatik.uni-stuttgart.de),
Univ. of Stuttgart
Gábor Marton (gabor.marton@nokia.com), Nokia
Gerd Breiter (gbreiter@de.ibm.com), IBM
Hemal Surti (hsurti@cisco.com), Cisco
Ifat Afek (ifat.afek@alcatel-lucent.com),
Alcatel-Lucent
Idan Moyal, (idan@gigaspaces.com), Gigaspaces
Jacques Durand (jdurand@us.fujitsu.com), Fujitsu
Jin Qin, (chin.qinjin@huawei.com), Huawei
Jeremy Hess, (jeremy@gigaspaces.com) , Gigaspaces
John Crandall, (mailto:jcrandal@brocade.com), Brocade
Juergen Meynert (juergen.meynert@ts.fujitsu.com), Fujitsu
Kapil Thangavelu (kapil.thangavelu@canonical.com),
Canonical
Karsten Beins (karsten.beins@ts.fujitsu.com), Fujitsu
Kevin Wilson (kevin.l.wilson@hp.com), HP
Krishna Raman (kraman@redhat.com), Red Hat
Luc Boutier (luc.boutier@fastconnect.fr), FastConnect
Luca Gioppo, (luca.gioppo@csi.it), CSI-Piemonte
Matej Artač, (matej.artac@xlab.si), XLAB
Matt Rutkowski (mrutkows@us.ibm.com), IBM
Moshe Elisha (moshe.elisha@alcatel-lucent.com),
Alcatel-Lucent
Nate Finch (nate.finch@canonical.com), Canonical
Nikunj Nemani (nnemani@vmware.com), Wmware
Priya TG (priya.g@netcracker.com) NetCracker
Richard Probst (richard.probst@sap.com),
SAP AG
Sahdev Zala (spzala@us.ibm.com), IBM
Shitao li (lishitao@huawei.com), Huawei
Simeon Monov (sdmonov@us.ibm.com), IBM
Sivan Barzily, (sivan@gigaspaces.com), Gigaspaces
Sridhar Ramaswamy (sramasw@brocade.com), Brocade
Stephane Maes (stephane.maes@hp.com), HP
Steve Baillargeon (steve.baillargeon@ericsson.com),
Ericsson
Thinh Nguyenphu (thinh.nguyenphu@nokia.com), Nokia
Thomas Spatzier (thomas.spatzier@de.ibm.com), IBM
Ton Ngo (ton@us.ibm.com), IBM
Travis Tripp (travis.tripp@hp.com), HP
Vahid Hashemian (vahidhashemian@us.ibm.com), IBM
Wayne Witzel (wayne.witzel@canonical.com),
Canonical
Yaron Parasol (yaronpa@gigaspaces.com), Gigaspaces
|
Revision
|
Date
|
Editor
|
Changes Made
|
|
WDO1, Rev01
|
2018-02-06
|
Matt Rutkowski
|
· Initial WD02,
Revision 01 baseline for TOSCA Simple Profile in YAML v1.3
|
|
WDO1, Rev02
|
2018-02-27
|
Matt Rutkowski
|
· Updated Rev.
history to WD01, v1.3
· Upated all
namespaces to 1.3 (to match version).
· Updated TC Chairs
and Editors.
· Section 6.2.1- Entry Defintions - Added support for multiple (equivalent)
Entry Defintions as unordered list (declarative) of Service Templates.
· Added sections
6.2.2 Notes and 6.2.3 Use Cases to better inform reader about multiple Entry
Definitions usages and processing for/by Orchestrators.
· Section
3.8.5 – Added artifact definitions to Group definition
o
Note: we still have to discuss adding Artifact (Types/Defns._
to Group Type and this may affect Node Type schema and processing.
|
|
WD01, Rev03
|
2018-03-29
|
Calin Curescu Dmytro Gassanov, Priya T G, Chris Lauwers
|
· Updated definition
of get_input to allow structure parsing and dereference into the names of
these nested structures when needed similar to what get_propery and
get_attribute can do. See sections 4.4.1.1 and 4.4.1.2
· Section 3.7.4:
Deprecate the properties keyname in artifact type definitions
· Section 3.6.8.3:
Fix the “imports” example to be consistent with the grammar.
· Section 3.8.3.3:
Remove obsolete prose discussing the use of a “selectable” directive.
· Section 2.10.2;
Remove obsolete prose discussing the use of a “substitutable” directive
|
|
WD01 Rev03a
|
2018-04-02
|
Chris Lauwers
|
· Minor fix to
get_input grammar
· Section 3.3.6.7:
scalar-unit.bitrate
|
|
WD01 Rev04
|
2018-06-05
|
Chris Lauwers
|
· Section 3.3.6.3:
cleanup to prose that introduces the various scalar unit types
· Section 3.6.5.3:
remove filter_name from node_filter grammar
· Section 2.15:
operation output examples
· Section 3.6.14:
attribute mappings
· Sections 3.6.16 and
3.6.17: add output definitions to operation and interface definitions.
|
|
WD01 Rev05
|
2018-07-30
|
Chris Lauwers
|
· Section 3.3.5: add
key_schema keyword for property, attribute, and parameter definitions of type
map.
· Section 3.9: add
new schema_definition section that defines reusable schema definition
grammar. Schema definitions support recursion to support lists of lists, maps
of maps, maps of lists, and lists of maps.
· Section 3.6.10: use
new schema_definition grammar in property definitions
· Section 3.6.12: use
new schema_definition grammar in attribute definitions
· Section 3.6.14: use
new schema definition grammar in parameter definitions
· Section 3.7.6:
allow entry_schema and key_schema definitions for data type definitions that
derive from TOSCA set types such as list or map.
|
|
WD01 Rev06
|
2018-08-23
|
Calin Curescu
|
· The word “list” was
used to describe what are actually YAML maps throughout the document, e.g.
the map of property definitions was described as list of property
definitions. This created confusion with the real lists and the usage of
TOSCA list datatype. Thus I replaced “list” with “map” where the list actually
referred to a TOSCA map in sections: 3.6.17, 3.6.18, 3.7.2, 3.7.3.1.1, 3.7.4,
3.7.5, 3.7.6, 3.7.7, 3.7.9, 3.7.10, 3.7.11, 3.7.12, 3.8.1, 3.8.2, 3.8.3,
3.8.4, 3.8.5, 3.8.6, 3.8.7, 3.8.9, 3.8.12, 3.9, 3.10, 5.3.6.1, 5.9.3.2
· The word sequenced
list was used to describe a YAML list. As we changed the improper use of list
to map, we don’t need the “sequenced” list qualification, as all lists in
YAML are sequenced. So I removed the word “sequenced” when used before a list
in sections: 3.6.5, 3.6.9.2, 3.6.10.4, 3.6.16.1, 3.7.6, 3.7.9, 3.8.3, 3.9.2, 3.10
· Changed “array of 2
strings” to “list of strings (w. 2 members)” in sections: 3.8.9.1, 3.8.10.1.
· Changed the title
of section 3.3.4.1.2 from “Bulleted (sequenced) list notation” to “Bulleted
list notation” as all YAML lists are sequenced list and the bulleted list
notations is semantically not different from the bracket notation.
· Corrected the
improper use of a bulleted list usage when defining capabilities in example
22, in section 2.13 “Using YAML macros to simplify templates”.
|
|
WD01 Rev07
|
2018-11-05
|
Chris Lauwers
|
· Accept all changes
in the document and publish the “clean” version as a new baseline. No other
changes as compared to Rev06.
|
|
WD01 Rev08
|
2018-11-12
|
Chris Lauwers
|
· Incorporate Priya’s
Artifact Properties contribution
o
Reintroduce artifact property definitions in artifact type
definitions (these were previously depreceted in Rev03) Section 3.7.4
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Introduct artifact property assignments in artifact
definitions—Section 3.6.7
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Added an application modeling use case that shows an example
with multiple artifact definitions in a node template—Section 11.1.9
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Expand on the use artifact properties for VM Images—Section
13.3.5
· Various edits to
fix typos and grammatical errors—Sections 1 and 2
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WD01 Rev09
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2018-11-15
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Chris Lauwers
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· Correct PortInfo
assignment example in Section 5.3.9.3 (courtesy of Steve B.)
· Remove
get_operation_output examples (Section 2.14.3 and 2.14.4) in anticipation of
get_operation_output getting deprecated.
· Add introductory
section on notifications based on Calin’s proposal (Section 2.16)
· Add notification
definition and notification implementation definition grammar (Section
3.16.19 and 3.16.18)
· Add notification
definitions to interface definition grammar (Section 3.6.20)
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WD01 Rev10
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2018-11-26
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Matej Artač
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· Cleanup examples in
Chapter 2 to improve readability
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WD01 Rev11
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2018-11-27
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Thinh Nguyenphu
Gabor Marton
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· Support for
external workflow languages (Section 3.8.7)
· Add external
workflow example (Section 7.3.8)
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WD01 Rev12
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2018-12.10
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Calin Curescu
Thinh Nguyenphu
Anatoly Katzman
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· Minor editorial
corrections to notification definitions (Section 2.16 and Section 3.6.19)
· Various editorial
changes to improve correctness and consistency
· Introduce not
operator in condition clause definitions (Section 3.6.25)
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WD01 Rev13
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2018-12-17
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Priya TG
Chris Lauwers
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· Minor corrections
to the artifact definition section (Section 3.6.7)
· Deprecate “assert”
keyname in condition clauses (Section 3.6.25) and update the examples
accordingly.
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WD01 Rev14
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2018-12-22
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Calin Curescu
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· To eliminate
confusion around events and event_types in condition-event-action policy
triggers we have changed the keyname “event_type” to “event” in the trigger
definition. They serve the same purpose. The usage of “event_type” is
deprecated. (Section 3.6.22 Trigger definition).
· We have
consolidated the use of activities (as defined in the workflow step) and
action (as defined in the policy trigger). We have unified them so that the
“action” defined in the policy trigger refers to a list of activity
definitions instead of only one. (Section 3.6.23 Activity definitions and
Section 3.6.22 Trigger definition).
· To allow conditions
in policies to effect operations and workflow calls, and thus ensure a
meaningful use of event-condition-actions policies we have defined the
possibility to specify input values when calling operations or inlining
workflows from within the activity definition. Moreover specifying input
values is also needed when inlining external workflows, since they have no
access to template node attributes. Syntactically this is consolidated in a
short and long form of the activity definition, where the short form does not
specify input values and is fully backward compatible and the long form
allows the specification of input values. (Section 3.6.23 Activity definitions).
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WD01 Rev 15
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2019-01-22
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Chris Lauwers
Arturo Martin De Nicolas
Calin Curescu
Matej Artač
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· Minor corrections
to condition clause examples (Section 3.6.25)
· Fix single line map
grammar (Section 3.3.5.1.1)
· Remove reference to
‘selectable’ directive in node filter definition in node template
· Add missing section
number to artifact_types definitions section (become Section 3.10.3.10. All
sections below 3.10.3.10 have their section number incremented)
· Added the keyname
Other-Definitions to the TOSCA.meta file in the CSAR. Its value should point
to a list of yaml files that define substitution templates that may be used
for nodes defined in the main service template (Section 6. TOSCA Cloud
Service Archive (CSAR) format).
· Fix broken
bookmarks (Section 3.6.19 and 3.6.20)
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WD01 Rev 16
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2019-02-03
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Chris Lauwers
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· Consistently
use tosca_simple_yaml_1_3
· Clarify definitions
of abstract and no-op nodes (Section 1.9)
· (Re)-introduce the
‘substitute’ directive to indicate node templates as abstract (Sections 2.10
and 2.11).
· Introduce
substitution_filter example (new Section 2.12. all sections below 2.12 have
their section number incremented by 1)
· Add
substitution_filter keyname to the substitution_mappings grammar (Section 3.8.13)
· Add
attribute_mapping section (new Section 3.8.9. All subsequent subsections have
their section number incremented)
· Remove
property-to-constant-value and property-to-property options from
property_mapping syntax. Only property-to-input mappings are allowed (Section
3.8.8).
· Document the
substitute directive (Section 3.4.3)
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WD01 Rev 17
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2019-02-06
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Chris Lauwers
Calin Curescu
Priya TG
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· Eliminate
inconsistencies between ‘occurrences’ syntax in Capability Definitions,
Capability Assignments, Requirement Definitions, and Requirement Assignments
(Sections 3.7.2, 3.7.3, 3.8.1, and 3.8.2)
· Explicitly
specifying the possibility to add custom keynames in the TOSCA.meta file for
extended use of the TOSCA.meta beyond the scope of this TOSCA specification
(Section 6.2.1 Custom keynames in the TOSCA.meta file)
· Note about
deprecation (Section 1.6.1)
· Add normative and
non-normative template artifact types (Sections 5.4.5, 9.1.4, and 9.1.5)
· Introduce
discussion about CSAR onboarding in the Artifacts Processing chapter (Section
13.1)
· Experimental
support for creating multiple node instances from the same node template
(Section 2.20)
· Single-line grammar
for parameter definitions (Section 3.6.14.2)
· Property definition
refinement grammar (Sections 3.6.10.6 and 3.6.10.8)
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WD01 Rev 18
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2019-02-12
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Chris Lauwers
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· Use “select”
directive in abstract node template example that uses node_filter (Section
2.9.2)
· Document “select”
directive in node template grammar (Section 3.4.3)
· Deprecate interface
definitions, requirement definitions, and capability definitions in group
types (Section 3.7.11)
· Deprecated
interface definitions in group definitions (Section 3.8.5)
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WE01 Rev 19
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2019-02-19
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Chris Lauwers
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· Initial CSD
candidate.
· Identical to Rev 18
but with all changes accepted.
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WD01 Rev 20
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2019-03-28
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Chris Lauwers
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· Remove Chapter 14
· Remove Section 7.4
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WD01 Rev 22
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2019-04-25
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Calin Curescu
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· Definition of range
has been changed so that upper bound can be “greater than or equal to” lower
bound (and not just not strictly “greater than”). This solves inconsistencies
where such a range is needed (e.g. occurencies: [1,1] ) (Section 3.3.3)
· Added the changes
we introduced to “interface definition” (i.e. operations, notifications) also
to “interface type definitions” (Section 3.7.5)
· Reformulated the “activity
definitions” for better readability (Section 3.6.23)
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