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 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 to describe cloud workloads as a topology
template, which is a graph of node templates modeling the components a workload
is made up of and as 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 type 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 (see Appendix C). 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 existing types, for
example by providing a customized ‘create’ script for some software.
3
A “hello world” template for TOSCA Simple Profile in YAML
As mentioned before, the TOSCA
simple profile assumes the existence of a base set of node types (e.g., a ‘Compute’
node) and other types for creating TOSCA Service Templates. It is envisioned
that many additional node types for building service templates will be created
by communities. Consequently, a most basic TOSCA template for deploying just a
single server would look like the following:
Example 1 - TOSCA Simple "Hello World"
|
tosca_definitions_version:
tosca_simple_yaml_1_0_0
description: Template for
deploying a single server with predefined properties.
topology_template:
node_templates:
my_server:
type: tosca.nodes.Compute
properties:
# Compute properties
num_cpus: 2
disk_size: 10 GB
mem_size: 4 MB
capabilities:
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 the definition of one single ‘Compute’ node template with
predefined (hardcoded) values for number of CPUs, memory size, etc. When
instantiated in a provider environment, the provider would allocate a physical
or virtual server that meets those specifications. The set of properties of any
node type, as well as their schema definition, is defined by the respective
node type definitions, which a TOSCA orchestration engine can resolve to
validate the properties provided in a template. The Compute node also has
built-in TOSCA Capabilities; one is named “os”, which is used to
provide values to indicate what host operating system the Compute node should
have when it is instantiated.
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 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_0_0
description: Template for
deploying a single server with predefined 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: tosca.nodes.Compute
properties:
# Compute properties
num_cpus: { get_input:
cpus }
mem_size: 4 MB
disk_size: 10 GB
outputs:
server_ip:
description: The IP address
of the provisioned server.
value: { get_attribute: [
my_server, ip_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.
4
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 shall 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_0_0
description: Template for
deploying a single server with MySQL software on top.
topology_template:
inputs:
# omitted here for sake of
brevity
node_templates:
mysql:
type: tosca.nodes.DBMS.MySQL
properties:
dbms_root_password: {
get_input: my_mysql_rootpw }
dbms_port: { get_input:
my_mysql_port }
requirements:
- host: db_server
db_server:
type: tosca.nodes.Compute
properties:
# omitted here for sake of
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 dbms_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 value for the dbms_root_password property.
The same is true for the dbms_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 feature 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 node type defines a requirement called host, which needs to be fulfilled by
pointing to a node template of type tosca.nodes.Compute.
Within the requirements section, all entries contain the
name of a requirement as key and the identifier of the fulfilling entity as
value, expressing basically a named reference to some other node. In the
example above, the host
requirement is fulfilled by referencing the db_server
node template.
Node types in TOSCA have
associated implementations that provide the automation (e.g. in the form of
scripts or Chef recipes) for lifecycle operations of a node. For example, the
node type implementation for MySQL will provide the scripts to configure,
start, or stop MySQL at runtime.
If it is desired to use a
custom script for one of the operation defined by a node type in the context of
a specific template, the default implementation can be easily overridden by
providing a reference to the own automation in the template as shown in the following
example:
Example 4 - Node Template overriding its Node Type's
"configure" interface
|
tosca_definitions_version:
tosca_simple_yaml_1_0_0
description: Template for
deploying a single server with MySQL software on top.
topology_template:
inputs:
# omitted here for sake of
brevity
node_templates:
mysql:
type: tosca.nodes.DBMS.MySQL
properties:
dbms_root_password: {
get_input: my_mysql_rootpw }
dbms_port: { get_input:
my_mysql_port }
requirements:
- host: db_server
interfaces:
Standard:
configure:
scripts/my_own_configure.sh
db_server:
type: tosca.nodes.Compute
properties:
# omitted here for sake of
brevity
|
In the example above, an own script for the configure
operation of the MySQL node type’s lifecycle interface is provided. The path
given in the example above is interpreted relative to the template file, but it
would also be possible to provide an absolute URI to the location of the
script.
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 shown in section
4 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_0_0
description: Template for
deploying MySQL and database content.
topology_template:
inputs:
# omitted here for sake of brevity
node_templates:
my_db:
type:
tosca.nodes.Database.MySQLDatabase
properties:
db_name: { get_input:
database_name }
db_user: { get_input:
database_user }
db_password: { get_input:
database_password }
db_port: { get_input:
database_port }
artifacts:
- db_content:
files/my_db_content.txt
type:
tosca.artifacts.File
requirements:
- host: mysql
mysql:
type: tosca.nodes.DBMS.MySQL
properties:
dbms_root_password: {
get_input: mysql_rootpw }
dbms_port: { get_input:
mysql_port }
requirements:
- host: db_server
db_server:
type: tosca.nodes.Compute
properties:
# omitted here for sake of
brevity
|
In the example above, the my_db node template
or type tosca.nodes.Database.MySQL represents an actual MySQL database
instance managed by a MySQL DBMS installation. In its artifacts section,
the node template points to a text file (i.e., my_db_content.txt)
which can be used to help create the database content during deployment time.
The requirements section of the my_db node template expresses
that the database is hosted on a MySQL DBMS represented by the mysql
node.
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 distinguishes between middleware node types and application layer node
types. This allows at the one hand to have better re-use of generic middleware
node types without binding them to content running on top, and on the other
hand this allows for better substitutability of, for example, middleware
components during the deployment of TOSCA models.
The definition of multi-tier
applications in TOSCA is quite similar to the example shown in section 4, 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_0_0
description: Template for
deploying a two-tier application servers on two
topology_template:
inputs:
# Admin user name and password
to use with the WordPress application
wp_admin_username:
type: string
wp_admin_password:
type string
wp_db_name:
type: string
wp_db_user:
type: string
wp_db_password:
type: string
wp_db_port:
type: integer
mysql_root_password:
type string
mysql_port:
type integer
node_templates:
wordpress:
type:
tosca.nodes.WebApplication.WordPress
properties:
admin_user: { get_input:
wp_admin_username }
admin_password: {
get_input: wp_admin_password }
db_host: { get_property: [
db_server, ip_address ] }
requirements:
- host: apache
- database_endpoint:
wordpress_db
interfaces:
Standard:
inputs:
db_host: {
get_property: [ db_server, ip_address ] }
db_port: {
get_property: [ wordpress_db, db_port ] }
db_name: {
get_property: [ wordpress_db, db_name ] }
db_user: {
get_property: [ wordpress_db, db_user ] }
db_password: {
get_property: [ wordpress_db, db_password ] }
apache:
type:
tosca.nodes.WebServer.Apache
properties:
# omitted here for sake of
brevity
requirements:
- host: web_server
web_server:
type: tosca.nodes.Compute
properties:
# omitted here for sake of
brevity
wordpress_db:
type:
tosca.nodes.Database.MySQL
properties:
db_name: { get_input:
wp_db_name }
db_user: { get_input:
wp_db_user }
db_password: { get_input:
wp_db_password }
db_port: { get_input:
wp_db_port }
requirements:
- host: mysql
mysql:
type: tosca.nodes.DBMS.MySQL
properties:
dbms_root_password: {
get_input: mysql_rootpw }
dbms_port: { get_input:
mysql_port }
requirements:
- host: db_server
db_server:
type: tosca.nodes.Compute
properties:
# omitted here for sake of
brevity
|
The web application stack
consists of the wordpress, the 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 respective input parameters (as defined for the
configure operation of node type tosca.nodes.WebApplication.WordPress –
see section 6) are mapped to properties of the wordpress_db node via the
get_property function.
Note: besides the configure
lifecycle operation (i.e., from the tosca.interfaces.node.lifecycle.Standard
interface) of the wordpress node
template, more operations would be listed in a complete TOSCA template. Those
other operations have been omitted for the sake of brevity.
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 script to establish a
connection
|
tosca_definitions_version:
tosca_simple_yaml_1_0_0
description:
Template for deploying a two-tier application on two servers.
topology_template:
inputs:
# omitted here for sake of brevity
node_templates:
wordpress:
type: tosca.nodes.WebApplication.WordPress
properties:
# omitted here for sake of brevity
requirements:
- host: apache
- database_endpoint:
node: wordpress_db
relationship:
interfaces:
tosca.interfaces.relationships.Configure:
pre_configure_source: scripts/wp_db_configure.sh
wordpress_db:
type: tosca.nodes.Database.MySQL
properties:
# omitted here for the sake of brevity
requirements:
- host: mysql
# other resources not shown for this example ...
|
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 a
DatabaseEndpoint Capability Type using a ConnectsTo
relationship. The wordpress_db node template’s underlying MySQL
type definition indeed provides the DatabaseEndpoint 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 C.5.4) 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_0_0
description: Template for
deploying a two-tier application on two servers.
topology_template:
inputs:
# omitted here for sake of
brevity
node_templates:
wordpress:
type:
tosca.nodes.WebApplication.WordPress
properties:
# omitted here for sake of
brevity
requirements:
- host: apache
- database_endpointase:
node: wordpress_db
relationship: my.types.WordpressDbConnection
wordpress_db:
type: tosca.nodes.Database.MySQL
properties:
# omitted here for the
sake of 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) attribute 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_0_0
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 the above example, the Configure
interface is the specified alias or shorthand name for the TOSCA interface type
with the full name of tosca.interfaces.relationship.Configure
which is defined in the appendix.
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 C.7.1).
Example 10 - Simple dependency relationship between
two nodes
|
tosca_definitions_version:
tosca_simple_yaml_1_0_0
description: Template with a
generic dependency between two nodes.
topology_template:
inputs:
# omitted here for sake of
brevity
node_templates:
my_app:
type: my.types.MyApplication
properties:
# omitted here for sake of
brevity
requirements:
- dependency: some_service
some_service:
type: some.type.SomeService
properties:
# omitted here for sake of
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 8), 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.
Instead of defining software
installations and the hosting infrastructure (the servers) in the same
template, it is also 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.
The following example shows how
such generic hosting requirements can be expressed in the requirements section of node templates.
|
tosca_definitions_version:
tosca_simple_yaml_1_0_0
description: Template with
requirements against hosting infrastructure.
topology_template:
inputs:
# omitted here for sake of
brevity
node_templates:
mysql:
type: tosca.nodes.DBMS.MySQL
properties:
# omitted here for sake of
brevity
requirements:
- host:
node:
tosca.nodes.Compute
target_filter:
properties:
- num_cpus: {
in_range: [ 1, 4 ] }
- mem_size: {
greater_or_equal: 2 }
capabilities:
- os:
properties:
-
architecture: x86_64
- type:
linux
-
distribution: ubuntu
|
In the example above, it is expressed that the mysql
component requires a host of type Compute.
In contrast to previous examples, there is no reference to any node template
but just a specification of the type of required node. At deployment time, the
provider will thus have to allocate or assign a resource of the given type.
In the constraints section, the
characteristics of the required compute node can be narrowed down by defining
boundaries for the memory size, number of CPUs, etc. Those constraints can
either be expressed by means of concrete values (e.g. for the architecture attribute) which will require a
perfect match, or by means of qualifier functions such as greater_or_equal.
In the same way requirements can
be defined on the hosting infrastructure 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.
|
tosca_definitions_version:
tosca_simple_yaml_1_0_0
description: Template with a
database requirement.
topology_template:
inputs:
# omitted here for sake of
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, db_endpoint_url ] }
requirements:
- database_endpoint:
node:
tosca.nodes.DBMS.MySQL
target_filter:
properties:
- mysql_version: {
greater_or_equal: 5.5 }
|
In the example above, the application my_app
needs a MySQL database, where the version of MySQL must be 5.5 or higher. The
example shows an additional feature of referencing a property of the database
to get the database connection endpoint URL at runtime via the get_property
intrinsic function. The get_property function allows for getting a
property via a reference expressed in the requirements section. The
first argument is a keyword (SELF) to indicate the requirement is in the
current node, the second parameter is the name of a reference to another node,
in this case as described by the requirement named database in the
example above – and the last argument is the name of the property of the
referenced node, which must be defined by the respective node type tosca.nodes.DBMS.MySQL.
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 at 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.
When a topology template is
instantiated by a TOSCA Orchestrator, the orchestrator has to look for
realizations of the single node templates according to the node types specified
for each 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
get “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 (db_user, db_password, db_name) are assigned to the database using
hardcoded values in this simple example.
Note that in contrast to the
use case described in section 12 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 shall 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.
|
tosca_definitions_version:
tosca_simple_yaml_1_0
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
db:
type: tosca.nodes.Database
properties:
db_user: my_db_user
db_password:
secret
db_name: my_db_name
|
13.3 Definition of the
database stack in a service template
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.
|
tosca_definitions_version:
tosca_simple_yaml_1_0
topology_template:
description: Template of a database including its hosting stack.
inputs:
db_user:
type: string
db_password:
type: string
#
other inputs omitted for sake of brevity
substitution_mappings:
node_type: tosca.nodes.Database
capabilities:
database_endpoint: [ database, database_endpoint ]
node_templates:
database:
type: tosca.nodes.Database
properties:
db_user: { get_input: db_user }
# other properties omitted for sake of brevity
requirements:
- host: dbms
dbms:
type: tosca.nodes.DBMS
# details omitted for sake of brevity
server:
type: tosca.nodes.Compute
# details omitted for sake of brevity
|
The substitution_mappings
section in the sample above 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
capabilities of the database node contained in the topology
template.
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 have to match the 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.
14 Grouping
node templates
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 11 - Grouping Node Templates with same scaling
policy
|
tosca_definitions_version:
tosca_simple_yaml_1_0_0
description: Template for a
scaling web server.
topology_template:
inputs:
# omitted here for sake of
brevity
node_templates:
apache:
type:
tosca.nodes.WebServer.Apache
properties:
http_port: 8080
https_port: 8443
requirements:
- host: server
server:
type: tosca.nodes.Compute
properties:
# omitted here for sake of
brevity
group:
webserver_group:
members: [ apache, server ]
policies:
- my_scaling_policy:
# Specific policy
definitions are considered domain specific and
# are not included
here
|
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 11, 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.
|
tosca_definitions_version:
tosca_simple_yaml_1_0_0
description: Template hosting
requirements and placement policy.
topology_template:
inputs:
# omitted here for sake of
brevity
node_templates:
wordpress:
type:
tosca.nodes.WebApplication.Wordpress
properties:
# omitted here for sake of
brevity
requirements:
- host:
node:
tosca.nodes.Compute
target_filter:
properties:
- mem_size: {
greater_or_equal: 2 MB }
capabilities:
- os:
properties:
-
architecture: x86_64
- type:
linux
mysql:
type: tosca.nodes.DBMS.MySQL
properties:
# omitted here for sake of
brevity
requirements:
- host:
node:
tosca.nodes.Compute
target_filter:
properties:
- disk_size: { greater_or_equal:
10 }
capabilities:
- os:
properties:
-
architecture: x86_64
- type:
linux
groups:
my_collocation_group:
members: [ wordpress, mysql
]
policies:
-
my_anti_collocation_policy:
# Specific policy
definitions are considered domain specific and
# are not included
here
|
In the example above, both software components wordpress
and mysql
have identical hosting requirements. Therefore, a provider could decide to put
both on the same server. 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:
|
tosca_definitions_version:
tosca_simple_yaml_1_0_0
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: 4096 KB
topology_template:
node_templates:
my_server:
type: Compute
properties:
*my_compute_node_props
my_database:
type: Compute
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 as environment variables within the execution
environments in which the scripts associated with lifecycle operations are run.
|
node_templates:
wordpress:
type: tosca.nodes.WebApplication.WordPress
requirements:
...
- database_endpoint:
mysql_database
interfaces:
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:
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.
|
node_templates:
frontend:
type: tosca.nodes.WebApplication.WordPress
attributes:
url: { get_operation_output: [ SELF,
Standard, create, generated_url ] }
interfaces:
Standard:
create:
implementation:
scripts/frontend/create.sh
|
In this example, the Standard create operation exposes /
exports an environment variable named “generated_url”
attribute which will be assigned to the WordPress node’s url attribute.
|
node_templates:
frontend:
type: tosca.nodes.WebApplication.WordPress
interfaces:
Standard:
create:
implementation:
scripts/frontend/create.sh
configure:
implementation:
scripts/frontend/configure.sh
inputs:
data_dir: { get_operation_output: [ SELF, Standard, create, data_dir ] }
|
In this example, the Standard
lifecycle’s create operation exposes / exports an
environment variable named “data_dir” which will be
passed as an input to the Standard lifecycle’s configure
operation.
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,
Requirement and Capability Types) 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
making it available 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.
|
tosca_definitions_version:
tosca_simple_yaml_1_0_0
description: >
TOSCA simple profile that just
defines a YAML macro for commonly reused Compute
properties.
node_types:
ServerNode:
derived_from: SoftwareComponent
properties:
notification_port:
type: integer
capabilities:
# omitted here for sake of brevity
ClientNode:
derived_from: SoftwareComponent
properties:
# omitted here for sake of
brevity
requirements:
- server:
node: ServerNode
relationship:
type: ConnectsTo
# Augment resulting Relationship’s interfaces by providing inputs
interfaces:
Configure:
inputs:
targ_notify_port: { get_attribute: { [
TARGET, notification_port } }
# other operation definitions omitted here for sake of brevity
topology_template:
node_templates:
my_server:
type: ServerNode
properties:
notification_port: 8000
my_client:
type: ClientNode
requirements:
- server: my_server
|
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.
Appendix A. TOSCA Simple Profile definitions
in YAML
This section describes all of the YAML block structure for
all keys and mappings that are defined for the TOSCA Version 1.0 Simple Profile
specification that are needed to describe a TOSCA Service Template (in YAML).
A.1 TOSCA namespace and alias
The following table defines the namespace alias and
(target) namespace values that SHALL be used when referencing the TOSCA Simple
Profile version 1.0 specification.
A.1.1 Rules to avoid namespace
collisions
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
and service templates can be “nested” rules are needed so that TOSCA
Orchestrators know how to avoid collisions and apply their own namespaces when
import and nesting occur.
The following cases are considered:
- Duplicate property names within
same entity (e.g., Node Type, Node Template, Relationship Type, etc.)
- Duplicate requirement names within
same entity (e.g., Node Type, Node Template, Relationship Type, etc.)
- Duplicate capability names within
same entity (e.g., Node Type, Node Template, Relationship Type, etc.)
- Collisions that occurs from
“import” for any Type or Template.
- Collision that occurs from
“nesting” for any Type or Template.
A.2 Parameter and property
types
This clause describes the primitive types that are used for
declaring normative properties, parameters and grammar elements throughout this
specification.
A.2.1
Referenced YAML Types
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).
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:
A.2.1.1
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.
A.2.2 TOSCA base types
This specification defines the following types that may be
used when defining properties or parameters.
A.2.2.1 TOSCA version
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.
A.2.2.1.1
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 a required 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.
A.2.2.1.2
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.
A.2.2.1.3
Examples
Example of a version with
|
# basic version string
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
|
A.2.2.1.4
Notes
- [Maven-Version]
The TOSCA version type is compatible with the Apache Maven versioning
policy.
A.2.2.2 TOCSA range type
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.
A.2.2.2.1
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 lower_bound.
A.2.2.2.2
Examples
Example of a node template property with a range
value:
|
# numeric range between 1 and 100
a_range_property: [ 1, 100 ]
|
A.2.2.3 TOCSA scalar-unit type
The scalar-unit type can be used to define scalar values
along with a unit from the list of recognized units provided below.
A.2.2.3.1
Recognized Units
|
Unit
|
Usage
|
Description
|
|
B
|
size
|
byte
|
|
kB
|
size
|
kilobyte (1000 bytes)
|
|
MB
|
size
|
megabyte (1000000 bytes)
|
|
GB
|
size
|
gigabyte (1000000000 bytes)
|
|
TB
|
size
|
terabyte (1000000000000 bytes)
|
A.2.2.3.2
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.
A.2.2.3.3
Examples
|
Storage size in Gigabytes
properties:
storage_size: 10 GB
|
A.2.2.3.4
Additional requirements
·
Whitespace: any number of spaces (including zero or
none) is allowed between the scalar
value and the unit value.
·
When performing constraint clause evaluation on values of the
scalar-unit type, both the scalar value portion and unit value portion MUST 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’.
A.2.2.3.5
Notes
A.2.2.4
TOSCA list type
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 definition,
or input- or output parameter definition.
A.2.2.4.1
Grammar
TOSCA lists normal YAML lists with the following
grammars:
A.2.2.4.2
Square bracket notation
|
[ <list_entry_1>,
<list_entry_2>, ... ]
|
A.2.2.4.3
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
A.2.2.4.4
Examples
Example of node template property with a list value:
A.2.2.4.5
Square bracket notation
|
listen_ports: [ 80, 8080 ]
|
A.2.2.4.6 Bulleted list notation
|
listen_ports:
- 80
- 8080
|
A.2.2.5 TOSCA map type
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.
A.2.2.5.1
Grammar
TOSCA maps are normal YAML dictionaries with
following grammar:
A.2.2.5.2
Single-line grammar
|
{ <entry_key_1>:
<entry_value_1>, ..., <entry_key_n>: <entry_value_n> }
...
<entry_key_n>:
<entry_value_n>
|
A.2.2.5.3
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
A.2.2.5.4
Examples
Example of a node template property with a map
value:
A.2.2.5.5
Single-line notation
|
# notation option for shorter maps
user_name_to_id_map: { user1:
1001, user2: 1002 }
|
A.2.2.5.6
Multi-line notation
|
# notation for longer maps
user_name_to_id_map:
user1: 1001
user2: 1002
|
In the examples above, two notation options are
given: option 1 is using a notation where each map entry is one 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. Option 2 is using a notation
that is useful for only short maps with simple entries.
A.3
Normative values
A.3.1 Node States
As components (i.e., nodes) of TOSCA applications are
deployed, instantiated and orchestrated over their lifecycle using normative
lifecycle operations (see section C.6 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.
|
A.3.1.1 Additional
requirements
·
None
A.4
TOSCA entity and element definitions (meta-model)
This section defines all modelable entities that comprise
the TOSCA Version 1.0 Simple Profile specification along with their key names,
grammar and requirements.
A.4.1 Description
element
This optional element provides a means include single or
multiline descriptions within a TOSCA Simple Profile template as a scalar
string value.
A.4.1.1 Keyname
The following keyname is used to provide a
description within the TOSCA Simple Profile specification:
A.4.1.2 Grammar
The description element is a YAML string.
A.4.1.3 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.
|
A.4.1.4 Notes
- Use of “folded” style is discouraged for the
YAML string type apart from when used with the description keyname.
A.4.2 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.
A.4.2.1 Operator keynames
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
|
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
|
Constrains the property or parameter to a value of a given
length.
|
|
min_length
|
scalar
|
string
|
Constrains the property or parameter to a value to a
minimum length.
|
|
max_length
|
scalar
|
string
|
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.
|
In the Value Type column
above, an entry of “comparable” includes integer,
float, timestamp,
string and version
types, while an entry of “any” refers to any type allowed in the TOSCA simple
profile in YAML.
A.4.2.2 Grammar
Constraint clauses take one of the following forms:
|
# 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>
|
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 A.4.2.1 “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.
A.4.2.3 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
|
A.4.2.4
Notes
- 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.
A.4.3 Constraints
element
The Constraints element specifies a sequenced list of
constraints on one or more of the Service Template’s properties, parameters or
other typed elements of the TOSCA Simple Profile. A constraints element is represented
as a YAML block collection that contains a sequenced list of nested constraint
clauses.
A.4.3.1
Keyname
The following keyname is used to provide a list of
constraints within the TOSCA Simple Profile specification:
A.4.3.2 Grammar
The constraints element is described as a YAML block
collection that contains a sequence of constraint clauses:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
some_typed_property_name:
represents the required symbolic name of a typed property definition, as a string, which can be associated to a TOSCA entity.
o
For example, a property (definition) can be declared as part of a
Node Type or Node Template definition or it can be used to define an input or
output property (parameter) for a Service Template’s.
·
constraint_clause_*:
represents constraint clauses
for the associated property or parameter.
A.4.3.3 Examples
Constraint on an integer-typed parameter definition:
|
# An example input parameter that
represents a number of CPUs
# and constrains its value to a
specific range.
inputs:
num_cpus:
type: integer
constraints:
- in_range: [ 2, 4 ]
|
Constraints on a string-typed parameter definition:
|
# An example input parameter that
represents a user ID and constrains its length.
inputs:
user_id:
type: string
constraints:
- min_length: 8
- max_length: 16
|
A.4.3.4 Notes
- Constraints of properties or parameters SHOULD
be type-compatible with the type defined for that property or parameter.
- 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.
A.4.4 Property
definition
A property definition defines a named, typed value and
related data that can be associated with an entity defined in this
specification. It is used to provide a transparent property or characteristic
of that entity which can either be set on or retrieved from it. Properties are
used by template authors to provide the “desired state”, as input to TOSCA
entities for use when they are instantiated. The value of a property can be
retrieved using the get_property
function within TOSCA Service Templates.
A.4.4.1 Keynames
The following is the list of recognized keynames
recognized 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).
If this key is not declared for property definition, then
the property SHALL be considered required by default.
|
|
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.
|
|
constraints
|
no
|
constraints
|
None
|
The optional list of sequenced constraints for the
property.
|
|
status
|
no
|
string
|
default: supported
|
The optional status of the property relative to the
specification or implementation. See table below for valid values.
|
|
entry_schema
|
no
|
schema
|
None
|
The optional key that is used to declare the schema
definition for entries of “container” types such as the TOSCA list or map.
|
A.4.4.2 Status values
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.
|
A.4.4.3 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_type: represents
the required data type of the property.
·
property_description:
represents the optional description 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 sequenced list of one or more constraint clauses (as shown in the
constraints element) on the property
definition.
·
schema_definition:
represents the optional entry schema used to declare the (anonymous type)
schema for set types (e.g., list).
A.4.4.4 Example
The following represents a required property definition:
|
num_cpus:
type: integer
description: Number of CPUs
requested for a Compute node instance.
default: 1
required: true
constraints:
- valid_values: [ 1, 2, 4, 8 ]
|
A.4.4.5 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.4.4.6 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.
A.4.5 Attribute definition
An attribute definition defines a named, typed value that
can be associated with an entity defined in this specification (e.g., a Node
Type or Relationship Type). Specifically, it is used to expose the “actual
state” of some property of a TOSCA entity (set by the orchestrator) after it
has been deployed and instantiated. Attribute values can be retrieved via the get_attribute function from the instance
model and used as inputs to other entities within TOSCA Service Templates.
A.4.5.1 Keynames
The following is the list of recognized keynames
recognized 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.
|
A.4.5.2 Grammar
Named 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.
·
default_value: contains a
type-compatible value that may be used as a default if not provided by another
means.
A.4.5.3 Example
The following represents a required attribute definition:
|
actual_cpus:
type: integer
description: Actual number of
CPUs allocated to the node instance.
|
A.4.5.4 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.
- 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.
- 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).
A.4.6 Parameter
definition
A parameter definition is map used to declare a name for a
parameter along with its value to be used as inputs for operations. This value
can either be a fixed value or one that is evaluated from a function or
expression.
A.4.6.1 Keynames
The following is the list of recognized keynames
recognized for a TOSCA parameter definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
A.4.6.2 Grammar
Named property definitions have the following
grammar:
|
<parameter_name> :
<value> | { <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.
·
value: represents the
required value to associate with the parameter name.
·
value_expression:
represents an expression, that when evaluated, provides the required value to
associate with the parameter name.
A.4.6.3 Example
The following represents a required property
definition:
|
...
interfaces:
Standard:
create:
inputs:
# Parameter definition
compute_memory: {
get_property: [ my_host, mem_size ] }
|
A.4.6.4 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.4.6.5 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.
A.4.7 Operation
definition
An operation definition defines a named function or
procedure that can be bound to an implementation artifact (e.g., a script).
A.4.7.1 Keynames
The following is the list of recognized keynames
recognized for a TOSCA operation definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
description
|
no
|
description
|
The optional description string for the associated named
operation.
|
|
implementation
|
no
|
string
|
The optional implementation artifact name (e.g., a script
file name within a TOSCA CSAR file).
|
|
inputs
|
no
|
list of parameter
definitions
|
The optional list of input parameter definitions.
|
A.4.7.2 Grammar
Named operation definitions have the following
grammars:
A.4.7.2.1
Short notation
The following single-line grammar may be used when
only an operation’s implementation artifact is needed:
A.4.7.2.2
Extended notation
The following multi-line grammar may be used 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.
- implementation_artifact_name:
represents the optional name (string) of
an 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).
- parameter_definitions:
represents the optional list of parameter definitions which the TOSCA
orchestrator would make available (i.e., or pass) to the corresponding
implementation artifact during its execution.
A.4.7.3 Notes
- 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.
A.4.8 Interface
definition
An interface definition defines a named interface that can
be associated with a Node or Relationship Type
A.4.8.1 Keynames
The following is the list of recognized keynames
recognized for a TOSCA interface definition:
|
Keyname
|
Type
|
Description
|
|
inputs
|
list of parameter
definitions
|
The optional list of input parameter definitions.
|
A.4.8.2 Grammar
The following keyname is used to provide a list of
properties within the TOSCA Simple Profile specification:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
- interface_definition_name:
represents the required symbolic name of the interface definition
as a string.
- parameter_definitions:
represents the optional list of parameter definitions 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_definition_*:
represents the required name of one or more operation definitions.
A.4.8.3 Example
The following example shows a custom interface used
to define multiple configure operations.
|
mycompany.mytypes.myinterfaces.MyConfigure:
configure_service_A:
description: My application’s
custom configuration interface for service A.
configure_service_B:
description: My application’s
custom configuration interface for service B.
|
A.4.9 Artifact
definition
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.
A.4.9.1 Keynames
The following is the list of recognized keynames
recognized for a TOSCA artifact definition:
|
Keyname
|
Type
|
Required
|
Description
|
|
type
|
string
|
no
|
The optional data type for the artifact definition.
|
|
description
|
description
|
no
|
The optional description for the artifact definition.
|
|
mime_type
|
string
|
no
|
The optional Mime type for finding the correct artifact
definition when it is not clear from the file extension.
|
|
deploy_path
|
string
|
no
|
The file path the associated file would be deployed into
within the target node’s container.
|
A.4.9.2 Grammar
Named artifact definitions have the following
grammars:
A.4.9.2.1
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:
A.4.9.2.2
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 definition as a string.
- artifact_file_URI: represents the
required URI string (relative or
absolute) which can be used to locate the artifact’s file.
- artifact_type_name:
represents the required artifact type
the artifact definition is based upon.
- artifact_description:
represents the optional description
string for the corresponding artifact_name.
- artifact_mime_type_name:
represents the optional, explicit Mime Type (as a string) for the associated artifact
definition when it is not clear from the file description.
A.4.9.3 Example
The following represents an artifact definition:
|
my_file_artifact:
../my_apps_files/operation_artifact.txt
|
A.4.10 Artifacts
element
The Artifacts element is used to associate one or more typed
artifact definitions with a TOSCA Node Type or Node Template.
A.4.10.1 Keynames
The following keyname is used to declare a list of artifacts
within the TOSCA Simple Profile specification:
A.4.10.2 Grammar
The artifacts element is described by a YAML block
collection that contains a sequenced list of artifact definitions:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
- some_typed_entity_name: represents the symbolic
name (string) of a typed TOSCA entity
(e.g., a Node Type, Node Template) that has, as part of its definition, a
list of artifacts.
- artifact_definition_*: represents one or
more Artifact definitions for
the associated entity.
A.4.10.3 Examples
The following examples show artifact definitions in
both simple and full forms being associated to Node Types:
A.4.11 Interfaces
element
The Interfaces element describes a list of one or more
interface definitions for a modelable entity (e.g., a Node or Relationship
Type) as defined within the TOSCA Simple Profile specification. Each interface
definition contains one or more interfaces for operations that can be invoked
on the associated entity.
A.4.11.1 Keyname
The following keyname is used to declare a list of interfaces
definition names within the TOSCA Simple Profile specification:
The following is the list of recognized keynames
recognized for a TOSCA interfaces element:
|
Keyname
|
Type
|
Required
|
Description
|
|
inputs
|
list of parameter
definitions
|
no
|
The optional list of input parameter definitions
|
A.4.11.2 Grammar
A.4.11.2.1
Short notation
The following grammar may be used when only a list
of interface definition names needs to be declared:
A.4.11.2.2
Extended notation
The following multi-line grammar may be used when interface
definitions, along with any additional input parameter information, are needed
to define a set of interfaces:
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
A.4.11.3 Examples
A.4.11.3.1
Declaration of valid interface type names
|
interfaces: [
mytypes.myinterfaces.myOperationsDefn ]
|
A.4.11.3.2
Declaration of interfaces
|
interfaces:
mytypes.myinterfaces.my_node_interfaces:
my_interface_1:
# Additional details
omitted for brevity
...
my_interface_2:
# Additional details
omitted for brevity
...
|
A.4.12 Properties element
The Properties element describes one or more typed Property definitions that can be
associated with modelable TOSCA entities (e.g., Node Types, Node Templates,
Relationship Types, Artifact Types, etc.). Properties are used by the author
to declare the “desired state” of that entity when initially deployed. 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).
A.4.12.1 Keyname
The following keyname is used to declare a list of properties
within the TOSCA Simple Profile specification:
A.4.12.2 Grammar
The properties element is described as a YAML block
collection that contains a list of property definitions:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
some_typed_entity_name:
represents the name of a typed TOSCA entity (e.g., a Node Type, Node Template,
Relationship Type, etc.) that has, as part of its definition, a list of properties.
·
property_defn_*:
represents one or more property
definitions for the associated entity.
A.4.12.3 Example
The following example shows property definitions
being associated to a Node Type:
|
my_app_node_type:
derived_from: tosca.nodes.Root
properties:
stylesheet:
type: string
default: basic.css
max_connections:
type: integer
required: false
|
A.4.13
Attributes element
The Attributes element describes one or more typed Attribute
definitions that can be associated with a modelable TOSCA entity (e.g., Node
Types, Relationship Types, etc.). Attributes are used by the author to provide
access the “actual state” of certain properties of TOSCA entities at any point
in their lifecycle once instantiated (i.e., post deployment). TOSCA
orchestrators automatically create Attribute
definitions for any Property
definitions declared on the same TOSCA entity in order to make accessible
the actual (i.e., the current state) value from the running instance of the
entity.
A.4.13.1 Keyname
The following keyname is used to declare a list of attributes
within the TOSCA Simple Profile specification:
A.4.13.2 Grammar
The attributes element is described as a YAML block
collection that contains a list of attribute definitions:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
some_typed_entity_name:
represents the name of a typed TOSCA entity (e.g., a Node Type, Relationship
Type, etc.) that has, as part of its definition, a list of attributes.
·
attribute_defn_*:
represents one or more attribute definitions
for the associated entity.
A.4.13.3 Example
The following example shows attribute definitions
being associated to a Node Type:
|
my_app_node_type:
derived_from: tosca.nodes.Root
attributes:
instanceId:
type: string
max_connections:
type: integer
|
A.4.14 Schema definition
A schema definition defines the schema for a new named or
anonymous type in TOSCA. The schema can be derived from an existing type and
may provide additional properties or constraints.
A.4.14.1 Keynames
The following is the list of recognized keynames
recognized for a TOSCA schema definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
description
|
no
|
string
|
The optional description for the
schema.
|
|
type
|
no
|
string
|
The optional key used when the
schema is based upon, but not extend, an existing TOSCA type.
|
|
derived_from
|
no
|
string
|
The optional key used when a
schema is derived from an existing TOSCA type and will be extended with
additional properties.
|
|
constraints
|
no
|
constraints
|
The optional list of sequenced
constraints for the schema type.
|
|
properties
|
no
|
properties
|
The required key used when the
schema definition is used to declare a complex type and comprised of a set of
valid property definitions.
|
A.4.14.2 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 for the schema.
· existing_type_name: represents
the optional name of a valid TOSCA type declaration this new schema would be
based or derive from.
·
type_constraints:
represents the optional sequenced list of one or more constraint
clauses that restrict the schema’s declared type.
· property_definitions:
represents one or more property
definitions that (together) comprise the schema for the schema definition.
A.4.14.3 Additional
Requirements
· Schema
definitions MAY have either the type keyname or derived_from
keyname, but not both.
· Any
constraint
clauses SHALL be type-compatible with the type declared by the schema’s type or
derived_from
keynames.
· The
properties
keyname SHALL only be used in conjunction with the derived_from
keyname.
· If
a properties
keyname is provided, it SHALL contain one or more valid property definitions.
A.4.14.4 Examples
A.4.14.4.1
Entry schema based upon a simple type
The following example represents a map entry schema
definition based upon an existing string type:
|
# Example: Entry schema for a list
of emails using an existing string type
<some_entity>:
...
properties:
emails:
type: map
entry_schema:
description: basic email
type: string
constraints:
- max_length: 128
|
A.4.14.4.2
Complex entry schema example
The following example represents a list’s entry
schema definition for contact information:
|
# Example: Contact information
described as a complex entry schema
<some_entity>:
...
properties:
contacts:
type: list
entry_schema:
description: simple
contact information
properties:
contact_name:
type: string
contact_email:
type: string
contact_phone:
type: string
required: false
|
A.4.15 Datatype definition
A datatype definition defines the schema for a new named
datatype in TOSCA.
A.4.15.1 Grammar
Datatype definitions have the following grammar:
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
·
datatype_name: represents
the required symbolic name of the datatype being declared.
·
schema_definition:
represents the required schema definition
for the datatype.
A.4.15.2 Additional
Requirements
· None
A.4.15.3 Examples
The following example represents a datatype definition based
upon an existing string type:
A.4.15.3.1
Defining a complex datatype
|
# define a new complex
datatype
mytypes.phone.number:
properties:
countrycode:
type: int
areacode:
type: int
number:
type: int
|
A.4.15.3.2 Defining a
datatype derived from an existing datatype
|
# define a new datatype
that derives from existing type and extends it
mytypes.phone.entry:
derived from:
phonenumber
properties:
phone_description:
type: string
constraints:
- max_length:
128
|
A.4.16 Capability
definition
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.
A.4.16.1 Keynames
The following is the list of recognized keynames
recognized for a TOSCA capability definition:
|
Keyname
|
Type
|
Description
|
|
type
|
string
|
The required name of the Capability Type the capability
definition is based upon.
|
|
description
|
description
|
The optional description of the Capability Type.
|
|
properties
|
properties
|
An optional list of property definitions for the
capability definition.
|
A.4.16.2 Grammar
Named capability definitions have one of the
following grammars:
A.4.16.2.1
Short notation
The following grammar may be used when only a list
of capability definition names needs to be declared:
A.4.16.2.2
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_defn_name: represents the name of a capability
definition as a string.
·
capability_type:
represents the required capability type
the capability definition is based upon.
·
capability_defn_description:
represents the optional description of
the capability definition.
·
property_definitions:
represents the optional list of property
definitions for the capability definition.
·
attribute_definitions: represents
the optional list of attribute
definitions for the capability definition.
A.4.16.3 Examples
The following examples show capability definitions
in both simple and full forms:
A.4.16.3.1
Simple notation example
|
# Simple notation, no properties
defined or augmented
some_capability:
mytypes.mycapabilities.MyCapabilityTypeName
|
A.4.16.3.2 Full notation example
|
# Full notationnotation,
augmenting properties of the referenced capability type
some_capability:
type: mytypes.mycapabilities.MyCapabilityTypeName
properties:
limit: 100
|
A.4.16.4 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.
A.4.17 Capabilities
element
The Capabilities element is used to associate one or more
typed Capability definitions with a
TOSCA Node Type or Node Template.
A.4.17.1 Keyname
The following keyname is used to declare a list of capabilities
within the TOSCA Simple Profile specification:
A.4.17.2
Grammar
The capabilities element is described by a YAML
block collection that contains a list of capability definitions:
In the above grammar, the
pseudo values that appear in angle brackets have the following meaning:
- some_typed_entity_name:
represents the name of a typed TOSCA entity (e.g., a Node Type,
Node Template) that has, as part of its definition, a list of capabilities.
- capability_definition_*: represents one
or more Capability definitions
for the associated entity.
A.4.17.3 Example
The following examples show capability definitions
in both simple and full forms being associated to Node Types:
|
my_node_type_1:
# Other keys omitted here for
sake of brevity
capabilities:
app_container:
mytypes.mycapabilities.AppContainer
app_endpoint:
type:
mytypes.mycapabilities.Endpoint
properties:
timeout: 300
|
A.4.17.4 Notes
- This element directly maps to the Capabilities element defined as part of
the schema for the Node Template entity as defined in the TOSCA v1.0 specification.
A.4.18
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
fulfil the capability at runtime (implicitly).
A.4.18.1 Keynames
The following is the list of recognized keynames for
a TOSCA requirement definition:
|
Keyname
|
Type
|
Required
|
Description
|
|
node
|
string
|
no
|
The optional reserved keyname used to provide the name of
a Node Type or Node Template that can fulfil the target node requirement.
|
|
capability
|
string
|
no
|
The optional reserved keyname used to provide the name of
the capability within target node of the relationship that the associated
requirement fulfills.
|
|
relationship
|
string
|
no
|
The optional reserved keyname used to provide a named
Relationship Type to use when fulfilling the associated named requirement.
Please note that this is the “simple form” for the
relationship portion of the requirement. If the relationship needs to be
further described or augmented, then the extended form of relationship
(described below) MUST be used.
|
|
target_filter
|
node filter
|
no
|
The optional filter definition that TOSCA orchestrators
would use to select the correct target node to fulfill the associated
requirement.
|
A.4.18.2 Extended
relationship grammar for the requirement definition
The following are recognized keynames that may be
used when the relationship keyname of the requirement definition needs to
provide extended information (i.e., it cannot be expressed in a simple,
one-line grammar):
|
Keyname
|
Type
|
Required
|
Description
|
|
type
|
string
|
no
|
The optional reserved keyname used to provide the name of
a Relationship Type that should be used to fulfil the target node
requirement.
|
|
interfaces
|
N/A
|
no
|
The optional reserved keyname used to declare or augment
relationship interfaces, their operations, implementations and properties.
|
A.4.18.3 Grammar
Named requirement definitions have one of the
following grammars:
A.4.18.3.1
Short notation (node only):
The following single-line grammar may be used when
only a target node is needed to describe the requirement:
A.4.18.3.2
Short notation (with relationship or capability):
The following grammar would be used if either a
relationship or capability is needed to describe the requirement:
A.4.18.3.3
Extended notation:
The following grammar would be used if additional
target node filtering would be needed to further clarify the requirement or if
additional information would need to be provided to the relationship.
In the above grammars, the pseudo values that appear
in angle brackets have the following meaning:
- requirement_name:
represents the name of a requirement
definition as a string.
- node_type_or_template_name:
represents the name (a string) of a
TOSCA Node Type or Node Template that either, by its definition, has an
implicit set of capabilities or contains an explicit Capability Type definition that
the associated named requirement can be fulfilled by.
- relationship_type_or_template_name:
represents the optional name of an explicit, Relationship Type or Relationship Template definition to be used when relating the node
the requirement appears in to another node.
- interface_settings:
represents any optional property (input) settings that would be provided
to the interfaces on the relationship when it is realized by the orchestrator.
- capability_type_or_template_name:
represents the optional name of a specific capability type or template
within the target Node Type or Template identified by node_type_or_template_name value to be
used when relating it to the source node the requirement appears in.
- Note: This key can be used
to assure that when the target node exports more than one capability that
could fulfill the requirement the correct capability will be selected by
the orchestrator using this name.
- target_filter_definition:
represents the optional node
filter TOSCA orchestrators would use to fulfill the requirement for
selecting a target node.
A.4.18.4 Requirement
definition is a tuple
A requirement definition allows fulfillment to be described
using three levels of specificity.
- Node Type or Node Template
- Capability Type
- Relationship Type or Template
The first level allows selection, as shown in both
the simple or complex grammar, simply providing the node’s type or template
name using the node keyname. The second level provides the
ability to name the specific capability on the target node that the requirement
is seeking using the capability keyname. Finally, the third
level is specification of the relationship (type or template) to use when
connecting the requirement to the capability using the relationship
keyname.
In addition, a filter, with the keyname target_filter, may be provided to allow a
flexible description of matching criteria against potential target nodes’
properties, capabilities and capabilities’ properties. This allows TOSCA
orchestrators to help find the “best fit” when selecting among multiple
potential target nodes for the expressed requirements.
A.4.18.5 Examples
A.4.18.5.1
Example 1 – Explicit hosting requirement on a Node Template
A web application node template named ‘my_webapp_node_template’
declares a requirement named ‘host’ that needs to be
fulfilled by the same named capability on a web server node template named ‘my_webserver_node_template’
in the same TOSCA Service Template.
|
# Example of a requirement
fulfilled by a specific named node template
node_templates:
my_webapp_node_template:
...
requirements:
- host:
my_webserver_node_template
my_webserver_node_template:
...
capabilities:
host:
type: tosca.capabilities.Container
|
Please note that in this example, TOSCA
orchestrators would relate these two nodes using an implied HostedOn relationship.
A.4.18.5.2
Example 2 – Abstract hosting requirement on a Node Type
A web application node template named ‘my_webapp_node_template’
declares a requirement named ‘host’ that needs to be
fulfilled by any node that derives from the node type WebServer.
|
# Example of a requirement
fulfilled by a specific web server node template
node_templates:
my_webapp_node_template:
...
requirements:
- host:
tosca.nodes.WebServer
|
A.4.18.5.3
Example 3 - Requirement on a Capability Type from any node
A web application node template named ‘my_webapp_node_template’
declares a requirement named ‘database’ that needs to be fulfilled by any node
that declares a capability of (or derives from) type DatabaseEndpoint.
|
node_templates:
my_webapp_node_template:
requirements:
- database:
capability:
tosca.capabilities.DatabaseEndpoint
|
Please note that in this example, TOSCA
orchestrators would relate the two nodes with an implied ConnectsTo relationship type
which supports any connections what derive from the Endpoint capability type such
as DatabaseEndpoint.
A.4.18.5.4
Example 4:Requirement with Node Template and a custom Relationship Type
This example is similar to the previous example; however,
the connection between the web application and a named database node template (my_database)
and further requires a custom relationship designated by the keyword ‘relationship’
and having the custom relationship type definition name of ‘my.types.CustomDbConnection’.
|
# Example of a (database)
requirement that is fulfilled by a node template named
# “my_database”, but also requires
a custom database connection relationship
my_webapp_node_template:
requirements:
- database:
node: my_database
capability:
DatabaseEndpoint
relationship:
my.types.CustomDbConnection
|
A.4.18.5.5
Example 5: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.4.18.6 Additional
Requirements
A.4.18.7 Notes
- This element directly maps to the RequirementsDefinition of the Node Type
entity as defined in the TOSCA v1.0
specification.
A.4.19 Requirements element
The Requirements element is used to associate one or more
named Requirement definitions with
a TOSCA Node Type or Node Template.
A.4.19.1 Keynames
The following keyname is used to declare a list of requirements
within the TOSCA Simple Profile specification:
A.4.19.2
Grammar
The requirements element is described by a YAML
block collection that contains a sequenced list of requirement
definitions:
A.4.19.3
Example
|
# Example a node template with two
named requirements
node_templates:
my_software_node:
requirements:
# Short notation used here
for brevity
- host: tosca.nodes.Compute
- database:
tosca.nodes.Database
- ...
|
A.4.19.4
Additional Requirements
- Requirements are intentionally
expressed as a sequenced list of TOSCA Requirement definitions which
SHOULD be resolved (processed) in sequence order by TOSCA Orchestrators.
- Note: TOSCA Orchestrators, having
a full view of the complete application 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.
A.4.19.5 Notes
- This element directly maps to the Requirements element defined as part of
the schema for the Node Templates entity (as part of a Service Template’s
Topology Template as defined in the TOSCA v1.0
specification.
A.4.20 Property Filter definition
A property filter definition defines criteria, using
constraint clauses, for selection of a TOSCA entity based upon it property
values.
A.4.20.1 Grammar
Property filter definitions have the following
grammar:
A.4.20.1.1
Short notation:
The following single-line grammar may be used when
only a single constraint is needed on a property:
A.4.20.1.2
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).
A.4.20.2 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.4.21 Node Filter definition
A node filter definition defines criteria for selection of a
TOSCA Node Template based upon the template’s property values, capabilities and
capability properties.
A.4.21.1 Keynames
The following is the list of recognized keynames
recognized for a TOSCA node filter definition:
|
Keyname
|
Required
|
Type
|
Description
|
|
properties
|
no
|
list of property filter definitions
|
An optional sequenced 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 sequenced list of
capability names or types that would be used to select (filter) matching
TOSCA entities based upon their existence.
|
|
<capability name_or_type>
properties
|
no
|
list of property filter definitions
|
An optional sequenced 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.
|
A.4.21.2 Grammar
Node filter definitions have the 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.
· property_constraint_clause_*:
represents constraint clause(s) that would be used to filter entities based
upon property 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.
A.4.21.3 Additional Requirements
· None
A.4.21.4 Example
The following example is a filter that would be used to
select a TOSCA Compute node based upon
the values of its properties and also values on 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).
In addition, the Compute node must support an encryption capability of type mytypes.capabilities.compute.encryption which has properties that support a specific (aes)
encryption algorithm and keylength (128).
|
target_filter:
properties:
- num_cpus: { in_range: [ 1, 4
] }
- mem_size: {
greater_or_equal: 2 }
capabilities:
-
mytypes.capabilities.compute.encryption:
properties:
- algorithm: { equal:
aes }
- keylength: {
valid_values: [ 128, 256 ] }
|
A.4.22 Artifact
Type
An Artifact Type is a reusable entity that defines the type
of one or more files which Node Types or Node Templates can have dependent
relationships and used during operations such as during installation or
deployment.
A.4.22.1 Keynames
The following is the list of recognized keynames
recognized for a TOSCA Artifact Type definition:
|
Keyname
|
Definition/Type
|
Description
|
|
derived_from
|
string
|
An optional parent Artifact Type name the Artifact Type
derives from.
|
|
description
|
description
|
An optional description for the Artifact Type.
|
|
mime_type
|
string
|
The required mime type property for the Artifact Type.
|
|
file_ext
|
string[]
|
The required file extension property for the Artifact
Type.
|
|
properties
|
properties
|
An optional list of property definitions for the Artifact
Type.
|
A.4.22.2 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).
- artifact_description:
represents the optional description
string for the corresponding artifact_type_name.
- mime_type_string:
represents the Multipurpose Internet Mail Extensions (MIME) standard
string value that describes the file contents for this type of artifact as
a string.
- file_extension_*:
represents one or more recognized file extensions for this type of
artifact as strings.
- property_definitions:
represents the optional list of property
definitions for the artifact type.
A.4.22.3 Examples
|
my_artifact_type:
description: Java Archive
artifact type
derived_from:
tosca.artifact.Root
mime_type: application/java-archive
file_ext: [ jar ]
|
A.4.23 Requirement Type
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.4.24 Capability Type
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 other node.
The following is the list of recognized keynames
recognized for a TOSCA Capability Type definition:
|
Keyname
|
Definition/Type
|
Description
|
|
derived_from
|
string
|
An optional parent capability type name this new capability
type derives from.
|
|
description
|
description
|
An optional description for the capability type.
|
|
properties
|
properties
|
An optional list of property definitions for the
capability type.
|
A.4.24.1 Grammar
In the above grammar, the pseudo values that appear
in angle brackets have the following meaning:
- capability_type_name:
represents the required symbolic 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).
- capability_description:
represents the optional description
string for the corresponding capability_type_name.
- property_definitions:
represents an optional list of property
definitions that the capability type exports.
A.4.24.2 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.4.25 Relationship Type
A Relationship Type is a reusable entity that defines the
type of one or more relationships between Node Types or Node Templates.
A.4.25.1 Keynames
The following is the list of recognized keynames
recognized for a TOSCA Relationship Type definition:
|
Keyname
|
Definition/Type
|
Description
|
|
derived_from
|
string
|
An optional parent Relationship Type name the Relationship
Type derives from.
|
|
description
|
description
|
An optional description for the Relationship Type.
|
|
properties
|
properties
|
An optional list of property definitions for the
Relationship Type.
|
|
attributes
|
attributes
|
An optional list of attribute definitions for the
Relationship Type.
|
|
interfaces
|
interfaces
|
An optional list of named interfaces for the Relationship
Type.
|
|
valid_targets
|
string[]
|
A required list of one or more valid target entities or
entity types (i.e., a Node Types or Capability Types)
|
A.4.25.2 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.
- property_definitions:
represents the optional list of property
definitions for the Relationship Type.
- attribute_definitions:
represents the optional list of attribute
definitions for the Relationship Type.
- interface_definitions:
represents the optional list of one or more named interface definitions supported by the
Relationship Type.
- entity_name_or_type_*:
represents one or more valid target (types) for the relationship (e.g.,
Node Types, Capability Types, etc.).
A.4.25.3 Best Practices
- The TOSCA Root relationship type
(tosca.relationships.Root) provides a standard configuration interface
(tosca.interfaces.relationship.Configure) that SHOULD be used where
possible when defining new relationships types.
A.4.25.4 Examples
|
mycompanytypes.myrelationships.AppDependency:
derived_from:
tosca.relationships.DependsOn
valid_targets: [
mycompanytypes.mycapabilities.SomeAppCapability ]
|
A.4.26 Relationship
Template definition
A Relationship Template specifies the occurrence of a
manageable relationship between node templates as part of an application’s
topology model which 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.
The following is the list of keynames recognized for
a TOSCA Relationship Template definition:
|
Keyname
|
Definition/Type
|
Description
|
|
type
|
string
|
The required name of the Relationship Type the
Relationship Template is based upon.
|
|
alias
|
string
|
The optional name of a different Relationship Template
definition whose values are (effectively) copied into the definition for this
Relationship Template (prior to any other overrides).
|
|
description
|
description
|
An optional description for the Relationship Template.
|
|
properties
|
properties
|
An optional list of property definitions for the
Relationship Template.
|
|
interfaces
|
interfaces
|
An optional list of named interfaces for the Node
Template.
|
A.4.26.1 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_definitions:
represents the optional list of property
definitions for the Relationship Template that augment those provided
by its declared Relationship Type.
- interface_definitions:
represents the optional list of interface
definitions for the Relationship Template that augment those provided
by its declared Relationship Type.
A.4.26.2 Example
A.4.27 Node Type
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.
The following is the list of recognized keynames
recognized for a TOSCA Node Type definition:
|
Keyname
|
Definition/Type
|
Description
|
|
derived_from
|
string
|
An optional parent Node Type name this new Node Type
derives from.
|
|
description
|
description
|
An optional description for the Node Type.
|
|
properties
|
properties
|
An optional list of property definitions for the Node
Type.
|
|
attributes
|
attributes
|
An optional list of attribute definitions for the Node
Type.
|
|
requirements
|
requirements
|
An optional sequenced list of requirement
definitions for the Node Type.
|
|
capabilities
|
capabilities
|
An optional list of capability definitions for the Node
Type.
|
|
interfaces
|
interfaces
|
An optional list of named interfaces for the Node Type.
|
|
artifacts
|
artifacts
|
An optional sequenced list of named artifact
definitions for the Node Type.
|
A.4.27.1
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).
- node_type_description:
represents the optional description
string for the corresponding node_type_name.
- property_definitions:
represents the optional list of property
definitions for the Node Type.
- attribute_definitions:
represents the optional list of attribute
definitions for the Node Type.
- requirement_definitions:
represents the optional sequenced list of requirement definitions for the Node
Type.
- capability_definitions:
represents the optional list of capability
definitions for the Node Type.
- interface_definitions:
represents the optional list of one or more named interface definitions supported by the
Node Type.
- artifact_definitions:
represents the optional list of artifact
definitions for the Node Template that augment those provided by its
declared Node Type.
A.4.27.2 Best Practices
·
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.
A.4.27.3
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
my_app_port:
type: integer
description: application
port number
requirements:
- host: tosca.nodes.Compute
interfaces: [ Standard ]
|
A.4.28 Node Template
definition
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.
The following is the list of recognized keynames
recognized for a TOSCA Node Template definition:
|
Keyname
|
Definition/Type
|
Description
|
|
type
|
string
|
The required name of the Node Type the Node Template is
based upon.
|
|
description
|
description
|
An optional description for the Node Template.
|
|
properties
|
properties
|
An optional list of property definitions for the Node
Template.
|
|
attributes
|
attributes
|
An optional list of attribute definitions for the Node
Template.
|
|
requirements
|
requirements
|
An optional sequenced list of requirement
definitions for the Node Template.
|
|
capabilities
|
capabilities
|
An optional list of capability definitions for the Node
Template.
|
|
interfaces
|
interfaces
|
An optional list of named interfaces for the Node
Template.
|
|
artifacts
|
artifacts
|
An optional sequenced list of named artifact
definitions for the Node Template.
|
A.4.28.1 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.
- property_definitions:
represents the optional list of property
definitions for the Node Template that augment those provided by its
declared Node Type.
- requirement_definitions:
represents the optional sequenced list of requirement definitions for the Node
Template that augment those provided by its declared Node Type.
- capability_definitions:
represents the optional list of capability
definitions for the Node Template that augment those provided by its
declared Node Type.
- interface_definitions:
represents the optional list of interface
definitions for the Node Template that augment those provided by its
declared Node Type.
- artifact_definitions:
represents the optional list of artifact
definitions for the Node Template that augment those provided by its
declared Node Type.
A.4.28.2 Example
|
node_templates:
mysql:
type: tosca.nodes.DBMS.MySQL
properties:
dbms_password: { get_input:
my_mysql_rootpw }
dbms_port: { get_input:
my_mysql_port }
requirements:
- host: db_server
interfaces:
Standard:
configure:
scripts/my_own_configure.sh
|
A.5
Service Template
A TOSCA Definitions 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
(i.e., YAML keys), which are allowed to appear in a TOSCA Definitions YAML
document.
A.5.1 Keynames
A TOSCA Definitions file contains the following element
keynames:
|
Keyname
|
Required
|
Description
|
|
tosca_definitions_version
|
yes
|
Defines the version of the TOSCA Simple Profile
specification the template (grammar) complies with.
|
|
tosca_default_namespace
|
no
|
Defines the namespace of the TOSCA schema to use for
validation.
|
|
template_name
|
no
|
Declares the name of the template.
|
|
template_author
|
no
|
Declares the author(s) of the template.
|
|
template_version
|
no
|
Declares the version string for the template.
|
|
description
|
no
|
Declares a description for this Service Template and its
contents.
|
|
imports
|
no
|
Declares import statements external TOSCA Definitions documents
(files).
|
|
dsl_defintions
|
no
|
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.
|
|
datatype_definitions
|
no
|
Declares a list of optional TOSCA datatype definitions.
|
|
topology_template
|
no
|
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.
|
|
node_types
|
no
|
This section contains a set of node type definitions for
use in service templates. Such type definitions may be used within the
node_templates section of the same file, or a TOSCA Definitions file may also
just contain node type definitions for use in other files.
|
|
relationship_types
|
no
|
This section contains a set of relationship type
definitions for use in service templates. Such type definitions may be used
within the same file, or a TOSCA Definitions file may also just contain
relationship type definitions for use in other files.
|
|
capability_types
|
no
|
This section contains an optional list of capability type
definitions for use in service templates. Such type definitions may be used
within the same file, or a TOSCA Definitions file may also just contain
capability type definitions for use in other files.
|
|
artifact_types
|
no
|
This section contains an optional list of artifact type
definitions for use in service templates. Such type definitions may be used
within the same file, or a TOSCA Definitions file may also just contain
capability type definitions for use in other files.
|
A.5.2 Grammar
The overall structure of a TOSCA
Service Template and its top-level key collations using the TOSCA Simple Profile
is shown below:
|
tosca_definitions_version: #
Required TOSCA Definitions version string
tosca_default_namespace: #
Optional. default namespace (schema, types version)
template_name: #
Optional name of this service template
template_author: #
Optional author of this service template
template_version: #
Optional version of this service template
description: A short description
of the definitions inside the file.
imports:
# list of import statements for
importing other definitions files
dsl_definitions:
# list of YAML alias anchors (or
macros)
datatype_definitions:
# list of TOSCA datatype
definitions
topology_template:
# topology template definition
of the cloud application or service
node_types:
# list of node type definitions
capability_types:
# list of capability type
definitions
relationship_types:
# list of relationship type
definitions
artifact_types:
# list of artifact type
definitions
|
A.5.2.1
Notes
A.5.3 Top-level key definitions
A.5.3.1
tosca_definitions_version
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.
A.5.3.1.1
Keyword
|
tosca_definitions_version
|
A.5.3.1.2
Grammar
Single-line form:
|
tosca_definitions_version:
<tosca_simple_profile_version>
|
A.5.3.1.3
Examples:
TOSCA Simple Profile version 1.0 specification using
the defined namespace alias (see Section A.1):
|
tosca_definitions_version:
tosca_simple_yaml_1_0_0
|
TOSCA Simple Profile version 1.0 specification using
the fully defined (target) namespace (see Section A.1):
A.5.3.2 template_name
This optional element declares the optional name of service
template as a single-line string value.
A.5.3.2.1
Keyword
A.5.3.2.2
Grammar
|
template_name: <name string>
|
A.5.3.2.3
Example
|
template_name: My service template
|
A.5.3.2.4
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.
A.5.3.3
template_author
This optional element declares the optional author(s) of the
service template as a single-line string value.
A.5.3.3.1
Keyword
A.5.3.3.2
Grammar
|
template_author: <author
string>
|
A.5.3.3.3
Example
|
template_author: My service
template
|
A.5.3.4
template_version
This element declares the optional version of the service
template as a single-line string value.
A.5.3.4.1
Keyword
A.5.3.4.2
Grammar
A.5.3.4.3
Example
A.5.3.4.4
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.
A.5.3.5 description
This optional element provides a means to include single or
multiline descriptions within a TOSCA Simple Profile template as a scalar
string value.
A.5.3.5.1
Keyword
A.5.3.6 imports
This optional element 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.
A.5.3.6.1
Keyword
A.5.3.6.2
Grammar
A.5.3.6.3
Example
|
# An example import of definitions
files from a location relative to the
# file location of the service
template declaring the import.
imports:
-
relative_path/my_defns/my_typesdefs_1.yaml
- ...
-
relative_path/my_defns/my_typesdefs_n.yaml
|
A.5.3.7
dsl_definitions
This optional element provides a section to define macros
(e.g., YAML-style macros when using the TOSCA Simple Profile in YAML
specification).
A.5.3.7.1
Keyword
A.5.3.7.2
Grammar
A.5.3.7.3
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
|
A.5.3.8 datatype_definitions
This optional element provides a section to define new
datatypes in TOSCA.
A.5.3.8.1
Keyword
A.5.3.8.2
Grammar
|
datatype_definitions:
<tosca_datatype_def_1>
...
<tosca_datatype_def_n>
|
A.5.3.8.3
Example
|
datatype_definitions:
# 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
|
A.5.3.9
node_types
This element lists the Node Types that provide the reusable
type definitions for software components that Node Templates can be based upon.
A.5.3.9.1
Keyword
A.5.3.9.2
Grammar
A.5.3.9.3
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
|
A.5.3.9.4
Notes
- The node types listed as part of the node_types block can be mapped to the
list of NodeType definitions as
described by the TOSCA v1.0 specification.
A.5.3.10
relationship_types
This element lists the Relationship Types that provide the reusable
type definitions that can be used to describe dependent relationships between
Node Templates or Node Types.
A.5.3.10.1
Keyword
A.5.3.10.2
Grammar
A.5.3.10.3
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 ...
|
A.5.3.11 capability_types
This element 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.
A.5.3.11.1
Keyword
A.5.3.11.2
Grammar
A.5.3.11.3
Example
|
capability_types:
mycompany.mytypes.myCustomEndpoint:
derived_from:
tosca.capabilities.Endpoint
properties:
# more details ...
mycompany.mytypes.myCustomFeature:
derived_from:
tosca.capabilites.Feature
properties:
# more details ...
|
A.6 topology_template
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 elements.
A.6.1 Grammar
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:
# a description of the
topology template
inputs:
# definition of input
parameters for the topology template
node_templates:
# definition of the node
templates of the topology
relationship_templates:
# definition of the
relationship templates of the topology
outputs:
# definition of output
parameters for the topology template
|
A.6.1.1 inputs
The inputs section
provides a means to define parameters, 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)
A.6.1.1.1
Grammar
The grammar of the inputs section is as
follows:
A.6.1.1.2
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
|
A.6.1.2 node_templates
The node_templates
section lists the Node Templates that describe the (software) components that
are used to compose cloud applications.
A.6.1.2.1
grammar
The grammar of the node_templates section
is a follows:
A.6.1.2.2
Example
Example of node_templates section:
|
node_templates:
my_webapp_node_template:
type: WebApplication
my_database_node_template:
type: Database
|
A.6.1.3 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.
A.6.1.3.1
Grammar
The grammar of the relationship_templates
section is as follows:
A.6.1.3.2
Example
Example of relationship_templates
section:
A.6.1.4 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.
A.6.1.4.1
Grammar
The grammar of the outputs section is as
follows:
|
outputs:
<property_definitions>
|
A.6.1.4.2
Example
Example of ouputs section:
|
outputs:
server_ip:
description: The IP address of
the provisioned server.
value: { get_attribute: [
my_server, ip_address ] }
|
A.6.1.5 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.
A.6.1.5.1
Grammar
The grammar of the groups section is as
follows:
|
groups:
<group_name_A>:
<node_template_defn_A_1>
...
<node_template_defn_A_n>
<group_name_B>
<node_template_defn_B_1>
...
<node_template_defn_B_n>
|
A.6.1.5.2
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:
server_group_1:
members: [ server1, server2 ]
policies:
- anti_collocation_policy:
# specific policy
declarations omitted, as this is not yet specified
|
A.6.2 Notes
- The parameters (properties) that
are listed as 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 listed as part
of the node_templates block can be
mapped to the list of NodeTemplate
definitions provided as part of TopologyTemplate
of a ServiceTemplate as described
by the TOSCA v1.0 specification.
- The relationship templates listed
as part of the relationship_templates
block can be mapped to the list of RelationshipTemplate
definitions provided as part of TopologyTemplate
of a ServiceTemplate as described
by the TOSCA v1.0 specification.
- The output parameters that are
listed as 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.
- 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.
This section includes functions that are supported for use
within a TOSCA Service Template.
B.1 Reserved Function Keywords
The following keywords MAY be used in some TOSCA function in
place of a TOSCA Node or Relationship Template name. They will be interpreted
by a TOSCA orchestrator 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.
|
B.2
Environment Variable Conventions
B.2.1 Reserved Environment Variable Names and Usage
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
evaluationl 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.
|
|
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.
|
|
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.
|
|
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.
|
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:
tosca.interfaces.relationships.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
...
|
B.2.2 Prefixed vs. Unprefixed TARGET names
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.
B.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).
B.3
Property functions
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).
B.3.1 get_input
The get_input function
is used to retrieve the values of properties declared within the inputs section of a TOSCA Service Template.
B.3.1.1 Grammar
|
get_input:
<input_property_name>
|
B.3.1.2 Parameters
|
Parameter
|
Required
|
Type
|
Description
|
|
<input_property_name>
|
yes
|
string
|
The name of the property as defined in the inputs section of the service template.
|
B.3.1.3 Examples
|
inputs:
cpus:
type: integer
node_templates:
my_server:
type: tosca.nodes.Compute
properties:
num_cpus: { get_input: cpus }
|
B.3.2 get_property
The get_property function
is used to retrieve property values between modelable entities defined in the
same service template.
B.3.2.1 Grammar
|
get_property:
<modelable_entity_name>, [<req_or_cap_name>], <property_name>
[, <nested_property_name_1>, ..., <nested_property_name_*> ]
|
B.3.2.2 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.
|
|
<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_1>
| nested_property_index_1,, ..., <nested_property_name_m> |
nested_property_index_n,
|
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.
|
B.3.2.3 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:
db_name: sql_database1
wordpress:
type:
tosca.nodes.WebApplication.WordPress
...
interfaces:
Standard:
configure:
inputs:
wp_db_name: { get_property: [
mysql_database, db_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:
B.4
Attribute functions
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.
B.4.1 get_attribute
The get_attribute
function is used to retrieve the values of named attributes declared by the
referenced node or relationship template name.
B.4.1.1 Grammar
|
get_attribute:
<modelable_entity_name>, [<req_or_cap_name>],
<attribute_name> [, <nested_attribute_name_1>, ...,
<nested_attribute_name_x> ]
|
B.4.1.2 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.
|
|
<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_1>
| nested_attribute_index_1, ..., <nested_attribute_name_x> |
<nested_attribute_index_x>
|
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.
|
B.4.1.3 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.
B.4.2 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).
Notes:
- 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).
B.5 Operation functions
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.
B.5.1 get_operation_output
The get_operation_output
function is used to retrieve the values of variables exposed / exported from an
interface operation.
B.5.1.1 Grammar
|
get_operation_output:
<modelable_entity_name>, <interface_name>,
<operation_name>, <output_variable_name>
|
B.5.1.2 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.
|
B.5.1.3 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.
B.6
Navigation functions
- This version of the TOSCA Simple Profile does
not define any model navigation functions.
B.6.1 get_nodes_of_type
The get_nodes_of_type
function can be used to retrieve a list of all known instances of nodes of the declared
Node Type.
B.6.1.1 Grammar
|
get_nodes_of_type:
<node_type_name>
|
B.6.1.2 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.
|
B.6.1.3 Returns
B.6.1.4
|
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.
|
B.7
Context-based Entity name (global)
TBD
Goal:
- 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>)
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.
C.1 Assumptions
- 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.
C.2 Data Types
C.2.1 tosca.datatypes.network.NetworkInfo
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
|
C.2.1.1 Properties
|
Name
|
Type
|
Constraints
|
Description
|
|
network_name
|
string
|
None
|
The name of the logical network.
e.g., public private admin
|
|
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.
|
C.2.1.2 Definition
The TOSCA NetworkInfo data type is defined as
follows:
|
tosca.datatypes.network.NetworkInfo:
properties:
network_name:
type: string
network_id:
type: string
addresses:
type: list
entry_schema:
type: string
|
C.2.1.3 Examples
Example usage of the NetworkInfo data type:
|
private_network:
network_name: private
network_id: 3e54214f-5c09-1bc9-9999-44100326da1b
addresses: [ 10.111.128.10 ]
|
C.2.1.4 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.
C.2.2 tosca.datatypes.network.PortInfo
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
|
C.2.2.1 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.
|
C.2.2.2 Definition
The TOSCA Port type is defined as follows:
|
tosca.datatypes.network.PortInfo:
properties:
port_name:
type: string
port_id:
type: string
network_id:
type: string
network_id:
type: string
mac_address:
type: string
addresses:
type: list
entry_schema:
type: string
|
C.2.2.3 Examples
Example usage of the PortInfo data type:
|
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 ]
|
C.2.2.4 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
NetworkInfo may or may not be required depending on usage context.
C.2.3 tosca.datatypes.network.PortDef
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
|
C.2.3.1 Definition
The TOSCA PortDef type is defined as follows:
|
tosca.datatypes.network.PortDef:
type: integer
constraints:
- in_range: [ 1, 65535 ]
|
C.2.3.2 Examples
Example use of a PortDef property type:
|
listen_port:
type: PortDef
default: 9000
constraints:
- in_range [ 9000, 9090 ]
|
C.2.4 tosca.datatypes.network.PortSpec
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
|
C.2.4.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
protocol
|
yes
|
string
|
default: tcp
|
The required protocol used on the port.
|
|
source
|
no
|
list of integer
|
integer entries
in_range: [ 1, 65536 ]
|
The optional list of source ports.
|
|
source_range
|
no
|
range
|
in_range: [ 1, 65536 ]
|
The optional range for source ports.
|
|
target
|
no
|
list of integer
|
integer entries
in_range: [ 1, 65536 ]
|
The optional list of target ports.
|
|
target_range
|
no
|
range
|
in_range: [ 1, 65536 ]
|
The optional range for target ports.
|
C.2.4.2 Definition
The TOSCA PortSpec type is defined as follows:
|
tosca.datatypes.network.PortSpec:
properties:
protocol:
type: string
required: true
default: tcp
constraints:
- valid_values: [ udp,
tcp, igmp ]
target:
type: list
entry_schema:
type: PortDef
target_range:
type: range
constraints:
- in_range: [ 1, 65535 ]
source:
type: list
entry_schema:
type: PortDef
source_range:
type: range
constraints:
- in_range: [ 1, 65535 ]
|
C.2.4.3 Additional
requirements
- A valid PortSpec must have at least one of the
following properties: target, target_range, source or source_range.
C.2.4.4 Examples
Example usage of the PortSpec data type:
|
# example properties in a node
template
some_endpoint:
properties:
ports:
user_port:
ip_proto: tcp
target: 50000
target_range: [ 20000,
60000 ]
source: 9000
source_range: [ 1000,
10000 ]
|
C.2.5 tosca.datatypes.network.Credential
The PortSpec 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.network.Credential
|
C.2.5.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
protocol
|
yes
|
string
|
None
|
The required protocol name.
|
|
token_type
|
yes
|
string
|
None
|
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 list of protocol-specific keys or assertions.
|
C.2.5.2 Definition
The TOSCA Credential type is defined as follows:
|
tosca.datatypes.network.Credential:
properties:
protocol:
type: string
token_type:
type: string
token:
type: string
keys:
type: map
entry_schema:
type: string
|
C.2.5.3 Notes
- Specific token types and encoding them using
network protocols are not defined or covered in this specification.
C.2.5.4 Examples
Example usage of the Credential data type:
C.2.5.4.1
HTTP Basic access authentication credential
|
<some_tosca_entity>:
properties:
my_credential:
type: Credential
properties:
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
|
C.2.5.4.2
X-Auth-Token credential
|
<some_tosca_entity>:
properties:
my_credential:
type: Credential
properties:
protocol: xauth
token_type: X-Auth-Token
# token encoded in
Base64
token:
604bbe45ac7143a79e14f3158df67091
|
C.2.5.4.3
OAuth bearer token credential
|
<some_tosca_entity>:
properties:
my_credential:
type: Credential
properties:
protocol: oauth2
token_type: bearer
# token encoded in
Base64
token: 8ao9nE2DEjr1zCsicWMpBC |
C.3 Capabilities Types
C.3.1 tosca.capabilities.Root
This is the default (root) TOSCA Capability Type definition
that all other TOSCA Capability Types derive from.
C.3.1.1 Definition
C.3.2 tosca.capabilities.Container
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
|
C.3.2.1 Properties
|
Name
|
Type
|
Constraints
|
Description
|
|
valid_node_types
|
NodeType[]
|
None
|
A list of one or more names of Node Types that are
supported as containees that declare the Container type as a Capability.
|
C.3.2.2 Definition
|
tosca.capabilities.Container:
derived_from: tosca.capabilities.Root
properties:
valid_node_types: [
<node_type_name_1>,..., <node_type_name_n> ]
|
In the above definition, the pseudo
values that appear in angle brackets have the following meaning:
·
node_type_name_*: represents the name of a Node Type
definition as a string.
C.3.3 tosca.capabilities.Endpoint
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.
|
Shorthand Name
|
Endpoint
|
|
Type Qualified Name
|
tosca:Endpoint
|
|
Type URI
|
tosca.capabilities.Endpoint
|
C.3.3.1 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
|
yes
|
integer
|
greater_or_equal: 1
less_or_equal: 65535
|
The port of the endpoint.
|
|
secure
|
no
|
boolean
|
default: false
|
Indicates if the endpoint is a secure endpoint.
|
|
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
|
None
|
The optional name (or ID) of the network this endpoint
should be bound to.
|
|
initiator
|
no
|
string
|
one of:
·
source
·
target
·
peer
default: source
|
Indicates the direction of the connection.
|
|
ports
|
yes
|
map of PortSpec
|
TBD
|
TBD look to change to “virtual network interface” (vnic)
or something else.
|
C.3.3.2 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.
|
C.3.3.3 Definition
|
tosca.capabilities.Endpoint:
derived_from:
tosca.capabilities.Root
properties:
protocol:
type: string
default: tcp
port:
type: integer
constraints:
- greater_or_equal: 1
- less_or_equal: 65535
secure:
type: boolean
default: false
url_path:
type: string
required: false
port_name:
type: string
required: false
network_name
type: string
required: false
initiator:
type: string
default: source
constraints:
- valid_values: [ source,
target, peer ]
ports:
type: map
required: true
constraints:
- min_length: 1
entry_schema:
type: PortSpec
attributes:
ip_address:
type: string
|
C.3.4 tosca.capabilities.DatabaseEndpoint
This is the default TOSCA type that should be used
or extended to define a specialized database endpoint capability.
|
Shorthand Name
|
DatabaseEndpoint
|
|
Type Qualified Name
|
tosca:DatabaseEndpoint
|
|
Type URI
|
tosca.capabilities.DatabaseEndpoint
|
C.3.4.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
None
|
N/A
|
N/A
|
N/A
|
N/A
|
C.3.4.2 Definition
C.3.5 tosca.capabilities.Attachment
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
|
C.3.5.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
C.3.5.2 Definition
C.3.6 tosca.capabilities.OperatingSystem
This is the default TOSCA type that should be used
to express a scalability capability for a node.
|
Shorthand Name
|
OperatingSystem
|
|
Type Qualified Name
|
tosca:OperatingSystem
|
|
Type URI
|
tosca.capabilities.OperatingSystem
|
C.3.6.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
architecture
|
yes
|
string
|
None
|
The Operating System (OS) architecture.
Examples of valid values include:
x86_32, x86_64, etc.
|
|
type
|
yes
|
string
|
None
|
The Operating System (OS) type.
Examples of valid values include:
linux, aix, mac, windows, etc.
|
|
distribution
|
no
|
string
|
None
|
TheOperating System (OS) distribution.
Examples of valid values for an “type” of “Linux” would
include: debian, fedora, rhel and ubuntu.
|
|
version
|
no
|
string
|
None
|
The Operating System version.
|
C.3.6.2 Definition
|
tosca.capabilities.OperatingSystem:
derived_from: tosca.capabilities.Root
properties:
min_intances:
type: integer
default: 1
max_intances:
type: integer
default: 1
default_instances:
type: integer
|
C.3.6.3 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.
C.3.6.4 Notes
C.3.7 tosca.capabilities.Scalable
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
|
C.3.7.1 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.
|
C.3.7.2 Definition
|
tosca.capabilities.Scalable:
derived_from: tosca.capabilities.Root
properties:
min_intances:
type: integer
default: 1
max_intances:
type: integer
default: 1
default_instances:
type: integer
|
C.3.7.3 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.
C.3.8
tosca.capabilities.network.Bindable
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
|
C.3.8.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
C.3.8.2 Definition
C.4
Requirement Types
There are no normative Requirement Types currently
defined in this working draft. Typically, Requirements are described against a
known Capability Type
C.5 Relationship Types
C.5.1 tosca.relationships.Root
This is the default (root) TOSCA Relationship Type
definition that all other TOSCA Relationship Types derive from.
C.5.1.1 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.
|
C.5.1.2 Definition
C.5.2 tosca.relationships.DependsOn
This type represents a general dependency
relationship between two nodes.
|
Shorthand Name
|
DependsOn
|
|
Type Qualified Name
|
tosca:DependsOn
|
|
Type URI
|
tosca.relationships.DependsOn
|
C.5.2.1 Definition
C.5.3 tosca.relationships.HostedOn
This type represents a hosting relationship between
two nodes.
|
Shorthand Name
|
HostedOn
|
|
Type Qualified Name
|
tosca:HostedOn
|
|
Type URI
|
tosca.relationships.HostedOn
|
C.5.3.1 Definition
C.5.4 tosca.relationships.ConnectsTo
This type represents a network connection
relationship between two nodes.
|
Shorthand Name
|
ConnectsTo
|
|
Type Qualified Name
|
tosca:ConnectsTo
|
|
Type URI
|
tosca.relationships.ConnectsTo
|
C.5.4.1 Definition
C.5.4.2 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
username
|
no
|
string
|
|
|
|
password
|
no
|
string
|
|
|
C.5.5 tosca.relationships.AttachTo
This type represents an attachment relationship
between two nodes. For example, an AttachTo relationship type would be used
for attaching a storage node to a Compute node.
|
Shorthand Name
|
AttachTo
|
|
Type Qualified Name
|
tosca:AttachTo
|
|
Type URI
|
tosca.relationships.AttachTo
|
C.5.5.1 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.
|
|
device
|
no
|
string
|
None
|
The logical device name which for the attached device
(which is represented by the target node in the model).
|
C.5.5.2 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.
|
C.5.5.3 Definition
C.6 Interface Types
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.
C.6.1 Requirements
- 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”.
- Template designers MAY provide or override code or
scripts provided by a type for a specified interface defined for the type
(even if the type itself does not provide a script for that operation).
C.6.2 tosca.interfaces.node.lifecycle.Standard
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
|
C.6.2.1 Definition
|
tosca.interfaces.node.lifecycle.Standard:
create:
description: Standard
lifecycle create operation.
configure:
description: Standard
lifecycle configure operation (pre-start).
start:
description: Standard
lifecycle start operation.
stop:
description: Standard
lifecycle stop operation.
delete:
description: Standard
lifecycle delete operation.
|
C.6.2.2 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:
C.6.2.2.1 Normal node startup sequence diagram
The following diagram shows how the TOSCA orchestrator would invoke operations
on the Standard lifecycle to shut down a node.
C.6.2.2.2 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.
C.6.3 tosca.interfaces.node.lifecycle.Simple
This interface defines the simplest, normative
lifecycle operations that TOSCA nodes may support. It can be used when nodes
are able to perform create, configure,
start and postconfigure
operations as defined in the Standard lifecycle as a single deploy
operation.
|
Shorthand Name
|
Simple
|
|
Type Qualified Name
|
tosca:Simple
|
|
Type URI
|
tosca.interfaces.node.lifecycle.Simple
|
C.6.3.1 Definition
|
tosca.interfaces.node.lifecycle.Simple:
deploy:
description: Simple lifecycle
deploy operation. This single operation would be used to implement the
Standard lifecycle operations of create, configure, start and postconfigure.
start:
description: Simple lifecycle
start operation.
stop:
description: Simple lifecycle
stop operation.
delete:
description: Simple lifecycle
delete operation.
|
C.6.3.2 Requirements
- Following the execution of the deploy operation; the node MUST be in an
active node instance state.
- Implementers of the Simple
lifecycle interfaces SHALL code valid start
and stop operation
implementations.
C.6.4
tosca.interfaces.relationship.Configure
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
|
C.6.4.1 Definition
|
tosca.interfaces.relationship.Configure:
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.
description:
target_changed:
description: Operation to
notify source some property or attribute of the target changed
remove_target:
description: Operation to
remove a target node.
|
C.6.4.2 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:
C.6.4.3 
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.
C.6.4.3.1
Node-Relationship configuration sequence
Depending on which side (i.e., source or target) of
a relationship a node is on, the orchestrator will:
1.
Invoke either the pre_configure_source or
pre-configure_target operation as supplied by the
relationship on the node.
2.
Invoke the node’s configure operation.
3.
Invoke either the post_configure_source
or post_configure_target as supplied by the relationship on
the node.
Note that the The pre_configure_xxx and post_configure_xxx
are invoked only once per node instance.
C.6.4.3.2
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.
C.6.4.4 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 a failure code
when possible.
C.7
Node Types
C.7.1 tosca.nodes.Root
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).
C.7.1.1
Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
The TOSCA Root Node type has no specified properties.
|
C.7.1.2
Attributes
|
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 xxx for
allowed values.
|
C.7.1.3 Definition
C.7.1.4
Additional Requirements
·
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.
·
Valid Nodes Types or Node Templates MUST implement either the
Standard or Simple lifecycle interfaces, but not both.
C.7.2 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
|
C.7.2.1
Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
num_cpus
|
no
|
integer
|
greater_or_equal: 1
|
Number of (actual or virtual) CPUs associated with the
Compute node.
|
|
disk_size
|
no
|
scalar-unit
|
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
|
greater_or_equal: 0 MB
|
Size of memory available to applications running on the
Compute node (default unit is MB).
|
C.7.2.2
Attributes
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
ip_address
|
no
|
string
|
status:
deprecated
|
The primary IP address assigned by the cloud provider that
applications may use to access the Compute node.
Note: This is used by the platform provider to
convey the primary address used to access the compute node. Future working
drafts will address implementations that support floating or multiple IP
addresses.
|
|
networks
|
no
|
map(string) of NetworkInfo
|
None
|
The list of logical networks assigned to the compute host
instance and information about them.
|
|
ports
|
no
|
map(string) of PortInfo
|
None
|
The list of logical ports assigned to the compute host
instance and information about them.
|
C.7.2.3 Definition
C.7.3 tosca.nodes.SoftwareComponent
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
|
C.7.3.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
component_version
|
no
|
version
|
None
|
The software component’s version.
|
C.7.3.2 Attributes
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
ip_address
|
no
|
string
|
status: deprecated
|
The first public IP address assigned to the host Compute node.
Default: get_attribute ( SELF, host, ip_address)
|
C.7.3.3 Definition
|
tosca.nodes.SoftwareComponent:
derived_from: tosca.nodes.Root
properties:
# domain-specific software
component version
component_version:
type: version
required: false
attributes:
# Deprecated
ip_address:
type: string
status: deprecated
default: {
get_attribute: [ SELF, host, ip_address ] }
requirements:
- host:
node: tosca.nodes.Compute
relationship: tosca.relationships.HostedOn
|
C.7.3.4 Additional
Requirements
·
Nodes that can directly be managed and run by a TOSCA Compute Node Type SHOULD extend from this
type.
C.7.4 tosca.nodes.WebServer
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
|
C.7.4.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
None
|
N/A
|
N/A
|
N/A
|
N/A
|
C.7.4.2 Definition
C.7.4.3 Notes and
Additional Requirements
·
This node exports both a secure endpoint capability (i.e., secure_endpoint), typically for
administration, as well as a regular endpoint (i.e., app_endpoint)
C.7.5 tosca.nodes.WebApplication
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
|
C.7.5.1 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.
|
C.7.5.2 Definition
C.7.5.3 Additional
Requirements
·
None
C.7.6 tosca.nodes.DBMS
The TOSCA DBMS node
represents a typical relational, SQL Database Management System software
component or service.
C.7.6.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
dbms_root_password
|
yes
|
string
|
None
|
The DBMS server’s root password.
|
|
dbms_port
|
no
|
integer
|
None
|
The DBMS server’s port.
|
C.7.6.2 Definition
C.7.6.3 Additional
Requirements
·
None
C.7.7 tosca.nodes.Database
Base type for the schema and content associated with
a DBMS.
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
|
C.7.7.1
Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
db_user
|
yes
|
string
|
None
|
The special user account used for database administration.
|
|
db_password
|
yes
|
string
|
None
|
The password associated with the user account provided in
the ‘db_user’ property.
|
|
db_port
|
yes
|
integer
|
None
|
The port the database service will use to listen for
incoming data and requests.
|
|
db_name
|
yes
|
string
|
None
|
The logical database Name
|
C.7.7.2 Definition
|
tosca.nodes.Database:
derived_from: tosca.nodes.Root
properties:
db_user:
type: string
description: user account
name for DB administration
db_password:
type: string
description: the password
for the DB user account
db_port:
type: integer
description: the port the
underlying database service will listen to data
db_name:
type: string
description: the logical
name of the database
requirements:
- host:
node: tosca.nodes.DBMS
relationship: tosca.relationships.HostedOn
capabilities:
database_endpoint: tosca.capabilities.DatabaseEndpoint
|
C.7.7.3
Additional Requirements
·
None
C.7.8 tosca.nodes.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.ObjectStorage
|
C.7.8.1
Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
store_name
|
yes
|
string
|
None
|
The logical name of the object store (or container).
|
|
store_size
|
no
|
scalar-unit
|
greater_or_equal:
0 GB
|
The requested initial storage size (default unit is in
Gigabytes).
|
|
store_maxsize
|
no
|
scalar-unit
|
greater_or_equal:
0 GB
|
The requested maximum storage size (default unit is in
Gigabytes).
|
C.7.8.2
Definition
|
tosca.nodes.ObjectStorage:
derived_from: tosca.nodes.Root
properties:
store_name:
type: string
store_size:
type: scalar-unit
constraints:
- greater_or_equal: 0 GB
store_maxsize:
type: scalar-unit
constraints:
- greater_or_equal: 0 GB
|
C.7.8.3
Additional Requirements
·
None
C.7.8.4 Notes:
- Subclasses of the ObjectStorage node may impose
further constraints on properties such as store_name, such as minimum and maximum
lengths or include regular expressions to constrain allowed characters.
C.7.9 tosca.nodes.BlockStorage
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.BlockStorage
|
C.7.9.1
Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
size
|
yes *
|
scalar-unit
|
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).
|
C.7.9.2
Attributes
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
volumeId
|
no
|
string
|
None
|
ID provided by the orchestrator for newly created volumes
|
C.7.9.3 Definition
|
tosca.nodes.BlockStorage:
derived_from: tosca.nodes.Root
properties:
size:
type: scalar-unit
constraints:
- greater_or_equal: 1 MB
volume_id:
type: string
required: false
snapshot_id:
type: string
required: false
attributes:
volumeId:
type: string
capabilities:
attachment: tosca.capabilities.Attachment
|
C.7.9.4 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.
C.7.9.5 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.
C.7.10 tosca.nodes.Container
The TOSCA Container node represents
operating system-level virtualization technology used to run multiple
application services on a single Compute host.
|
Shorthand Name
|
Container
|
|
Type Qualified Name
|
tosca:Container
|
|
Type URI
|
tosca.nodes.Container
|
C.7.10.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
ContainerPort
|
yes
|
integer
|
TBD
|
The network port the container wishes to be addressed at.
|
|
hostPort
|
yes
|
integer
|
TBD
|
The network port of the host.
|
C.7.10.2 Attributes
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
TBD
|
|
|
|
|
C.7.10.3 Definition
C.7.10.4 Additional
Requirements
·
None
C.8 Artifact Types
TOSCA Artifacts represent the packages and imperative used
by the orchestrator when invoking TOSCA Interfaces on Node or Relationship
Types. 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 and 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.
Note: Normative TOSCA Artifact Types will be
developed in future drafts of this specification.
C.8.1 tosca.artifacts.Root
This is the default (root) TOSCA Artifact Type definition that all other
TOSCA base Artifact Types derive from.
C.8.1.1 Definition
|
tosca.artifacts.Root:
description: The TOSCA Artifact
Type all other TOSCA Artifact Types derive from
|
C.8.2 tosca.artifacts.File
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.
C.8.2.1 Definition
C.8.3 Implementation Types
C.8.3.1 Script Types
C.8.3.1.1 tosca.artifacts.impl.Bash
This artifact type represents a Bash script type
that contains Bash commands that can be executed on the Unix Bash shell.
C.8.3.2 Definition
|
tosca.artifacts.impl.Bash:
derived_from: tosca.artifacts.Root
description: Script artifact
for the Unix Bash shell
properties:
mime_type: application/x-sh
file_ext: [ sh ]
|
|
|
|
This section defines non-normative types used in examples or
use cases within this specification.
D.1
Capability Types
D.1.1 tosca.capabilities.DatabaseEndpoint.MySQL
This type defines a custom MySQL database endpoint
capability.
D.1.1.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
None
|
N/A
|
N/A
|
N/A
|
N/A
|
D.1.1.2 Definition
D.2
Node Types
D.2.1 tosca.nodes.Database.MySQL
D.2.1.1
Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
None
|
N/A
|
N/A
|
N/A
|
N/A
|
D.2.1.2
Definition
D.2.2 tosca.nodes.DBMS.MySQL
D.2.2.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
None
|
N/A
|
N/A
|
N/A
|
N/A
|
D.2.2.2 Definition
|
tosca.nodes.DBMS.MySQL:
derived_from: tosca.nodes.DBMS
properties:
dbms_port:
description: reflect the
default MySQL server port
default: 3306
capabilities:
host:
type: Container
properties:
valid_node_types: [ tosca.nodes.Database.MySQL ]
|
D.2.3 tosca.nodes.WebServer.Apache
D.2.3.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
None
|
N/A
|
N/A
|
N/A
|
N/A
|
D.2.3.2 Definition
D.2.4 tosca.nodes.WebApplication.WordPress
D.2.4.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
None
|
N/A
|
N/A
|
N/A
|
N/A
|
D.2.4.2 Definition
|
tosca.nodes.WebApplication.WordPress:
derived_from: tosca.nodes.WebApplication
properties:
admin_user:
type: string
admin_password:
type: string
db_host:
type: string
requirements:
- database_endpoint: tosca.nodes.Database
interfaces:
Standard:
inputs:
db_host: string
db_port: integer
db_name: string
db_user: string
db_password: string
|
D.2.5 tosca.nodes.WebServer.Nodejs
D.2.5.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
TBD
|
N/A
|
N/A
|
N/A
|
N/A
|
D.2.5.2 Definition
|
tosca.nodes.WebServer.Nodejs:
derived_from: tosca.nodes.WebServer
properties:
github_url:
required: no
type: string
description: location of the
application on the github.
default:
https://github.com/mmm/testnode.git
requirements:
- database_endpoint:
node: tosca.nodes.Database
relationship:
type:
tosca.relationships.ConnectsTo
interfaces:
tosca.interfaces.relationship.Configure:
pre_configure_source:
implementation:
type: string
input:
host:
type: string
port:
type: integer
interfaces:
tosca.interfaces.node.Lifecycle:
input:
github_url:
type: string
|
This describes how to express and control the application
centric network semantics available in TOSCA.
E.1
Networking and Service Template Portability
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.
- 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.
- 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.
- 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.
- 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.
- 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.
E.2
Connectivity Semantics
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.
E.3
Expressing connectivity semantics
This section describes how TOSCA supports the typical
client/server and group communication semantics found in application
architectures.
E.3.1 Connection initiation semantics
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.
E.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.
E.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.
E.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.
E.3.2 Specifying layer 4 ports
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.
E.4
Network provisioning
E.4.1 Declarative network provisioning
TOSCA orchestrators are responsible for the provisioning of
the network connectivity for declarative TOCSA Service Templates (Declarative
TOCSA 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.
E.4.2 Implicit network fulfillment
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.
E.4.3 Controlling network fulfillment
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‑1: Typical 3-Tier Network
E.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:
E.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.
E.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:
E.5 Network Types
E.5.1 tosca.nodes.Network
The TOSCA Network node represents
a simple, logical network service.
|
Shorthand Name
|
Network
|
|
Type Qualified Name
|
tosca:Network
|
|
Type URI
|
tosca.nodes.Network
|
E.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.
|
|
dhcp_enabled
|
no
|
boolean
|
default: true
|
Indicates the TOSCA container to create a virtual network
instance with or without a DHCP service.
|
E.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.
|
E.5.1.3 Definition
|
tosca.nodes.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
capabilities:
connection:
type: tosca.capabilities.network.Connectable
|
E.5.1.4 Additional
Requirements
E.5.2 tosca.nodes.Port
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.Port
|
E.5.2.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
ip_address
|
no
|
string
|
None
|
Allow the user to set a static IP.
|
|
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.
|
E.5.2.2 Attributes
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
ip_address
|
no
|
string
|
None
|
The IP address which is being assigned to the associated
compute instance.
|
E.5.2.3 Definition
|
tosca.nodes.Port:
derived_from: tosca.nodes.Root
properties:
ip_address:
type: string
required: false
order:
type: integer
required: true
default: 0
constraints:
- greater_or_equal: 0
is_default:
type: string
required: false
default: false
ip_range_start:
type: string
required: false
ip_range_end:
type: string
required: false
attributes:
ip_address:
type: string
requirements:
binding:
type: tosca.capabilities.network.Bindable
connection:
type: tosca.capabilities.network.Connectable
|
E.5.2.4 Additional
Requirements
·
None
E.5.3
tosca.capabilities.network.Connectable
A node type that includes the Connectable capability
indicates that it can be pointed by tosca.relationships.network.ConnectsTo
relationship type.
|
Shorthand Name
|
network.Connectable
|
|
Type Qualified Name
|
tosca:network.Connectable
|
|
Type URI
|
tosca.capabilities.network.Connectable
|
E.5.3.1 Properties
|
Name
|
Required
|
Type
|
Constraints
|
Description
|
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
E.5.3.2 Definition
E.5.4
tosca.relationships.network.ConnectsTo
This relationship type represents an association
relationship between Port and Network node types.
|
Shorthand Name
|
network.ConnectsTo
|
|
Type Qualified Name
|
tosca:network.ConnectsTo
|
|
Type URI
|
tosca.relationships.network.ConnectsTo
|
E.5.4.1 Definition
E.5.5
tosca.relationships.network.BindTo
This type represents a network association
relationship between Port and Compute node types.
|
Shorthand Name
|
network.BindTo
|
|
Type Qualified Name
|
tosca:network.BindTo
|
|
Type URI
|
tosca.relationships.network.BindTo
|
E.5.5.1 Definition
E.6
Network modeling approaches
E.6.1 Option 1: Specifying a network outside the
application’s Service Template
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.Connectable
and relationship type called tosca.relationships.network.ConnectsTo.
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‑2: 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‑3: 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‑4: 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
properties: # omitted for
brevity
admin_network:
type: tosca.nodes.Network
properties: # omitted for
brevity
data_network:
type: tosca.nodes.Network
properties: # omitted for
brevity
# ports definition
fe_oam_net_port:
type: tosca.nodes.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:
- binding: frontend
- connection: oam_network
fe_admin_net_port:
type: tosca.nodes.Port
requirements:
- binding: frontend
- connection: admin_network
be_admin_net_port:
type: tosca.nodes.Port
properties:
order: 0
requirements:
- binding: backend
- connection: admin_network
be_data_net_port:
type: tosca.nodes.Port
properties:
order: 1
requirements:
- binding: backend
- connection: data_network
db_data_net_port:
type: tosca.nodes.Port
requirements:
- binding: database
- connection: data_network
|
E.6.2 Option 2: Specifying network requirements
within the application’s Service Template
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
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
properties:
ip_version: { get_input:
admin_network_ip_version }
dhcp_enabled: { get_input:
admin_network_dhcp_enabled }
data_network:
type: tosca.nodes.Network
properties:
ip_version: { get_input:
data_network_ip_version }
cidr: { get_input:
data_network_cidr }
|
F.1.1 Use Case: Establishing a HostedOn relationship
using WebApplication and WebServer
This use case examines the ways TOSCA YAML can be used to
express a simple hosting relationship (i.e., HostedOn) using the normative
WebServer and WebApplication node types defined in this specification.
For convenience, relevant parts of the normative
Node Type for Web Server are shown below:
As can be seen, the WebServer
Node Type declares its capability to “contain” other nodes using the logical
name “host” and providing the Capability Type tosca.capabilities.Container
using its alias Container. It should be noted that the logical
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. It is given the property name of valid_node_types and in
this case it includes only the type WebApplication.
If we wish to establish a HostedOn relationship between a
source WebApplication NodeType to a target WebServer Node Type we need to be
able to declare a requirement from the source WebApplication that either
explicitly declares the relationship or one that allows the relationship to be unambiguously
inferred. We will examine three options for declaring this relationship below.
F.1.1.1 Option A: Inferred
HostedOn relationship via logical name matching
In this option, the target WebApplication
declares a requirement with the logical name “host”
which matches the logical name for the declared capability in the WebServer Node Type, also named “host”. By virtue of the logical names
matching (via the type designers), the HostedOn Relationship Type can be
inferred by an orchestrator.
F.1.1.1.1
Notes
- The logical name “host” is not a keyword and was
selected for us in TOSCA normative types to give the reader an indication
of the type of requirement being referenced.
F.1.1.2
Option B: Explicit HostedOn relationship via ‘relationship’ keyword
In this option, the target WebApplication
declares a requirement with the logical name “host”
(as in Option A), but also uses the relationship
keyword to explicitly declare the Relationship Type HostedOn.
F.1.1.3 Option C: Explicit
HostedOn relationship with capability keyword
In this option, let us instead declare a different
Node Type called CustomWebApplication which declares a
requirement with the logical name “bar” for a WebServer
Node Type and also uses the type keyword to
explicitly declare the Relationship Type HostedOn.
Since there is no implicit logical name match
between “host” capability in the WebServer
and “bar” requirement in CustomWebApplication,
the type designer MUST use the capability keyword on the requirement to
indicate to the orchestrator the exact name (i.e., “host”)
of the capability in WebServer it should use to create the
HostedOn relationship with.
The service template that would reference the hosted on
relationship would appear as follows:
F.1.2 Use Case: Establishing a ConnectsTo
relationship to WebServer
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:
- connection1:
node: WebServer
relationship: ConnectsTo
capability: https_endpoint
node_templates:
my_web_app:
type: MyServiceType
...
requirements:
- connection1: my_web_server
my_web_server:
type: WebServer
|
F.1.2.1 Issues
4.
How do we know that the requirement labeled “host” is a HostedOn
relationship?
1.
versus a general “DependsOn” relationship? For example, what if the
WebApplication had a different dependency on a WebServer node in addition to a
hosting (i.e., HostedOn) dependency?
2.
Currently, our normative node uses the same named slot “host” on the
requirement and capabilities side. If this were not the case, an ambiguity
exists.
3.
Should Nodes be restricted to one Container requirement?
5.
What capability does the “http_endpoint” export versus the
“https_endpoint” from the WebServer?
4.
How does a WebApplication provide a Requirement to (one or the other of)
them?
6.
How do we list additional (sub) capabilities on the WebServer node that
are NOT types?
5.
How do we reference them as additional requirements from the
WebApplication?
F.1.3 Use Case: Attaching
(local) BlockStorage to a Compute node
This use case examines the ways TOSCA YAML can be used to
express a simple AttachTo relationship between a Compute node and a locally
attached BlockStorage node.
The service template that would establish an AttachTo relationship follows:
|
node_templates:
my_server:
type: Compute
...
requirements:
# contextually this can
only be a relationship type
- persistant_storage:
node: my_block_storage
relationship: AttachTo
# This maps the local
requirement name ‘persistent_storage’ to the
# target node’s
capability name ‘attachment’
capability: attachment
properties:
location: /path1/path2
my_block_storage:
type: BlockStorage
properties:
size: 10
|
F.1.3.1 Issues
·
TBD
F.1.4 Use
Case: Reusing a BlockStorage Relationship using Relationship Type or
Relationship Template
This builds upon the previous use case (F.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 AttachTo relationship.
Specifically, several notation options are shown (in this
use case) that achieve the same desired result.
F.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.
F.1.4.2 Notation Style #1:
Augment AttachTo Relationship Type directly in each Node Template
This notation extends the methodology used for establishing
a HostedOn relationship (see previous example, F.1.1.2), 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 (following) notation (or aliasing) options being
discussed or adopted.
|
node_templates:
my_block_storage:
type: BlockStorage
properties:
size: 10
my_web_app_tier_1:
type: Compute
requirements:
- attachment:
node: my_block_storage
relationship: MyAttachTo
# use default property
settings in the Relationship Type definition
my_web_app_tier_2:
type: Compute
requirements:
- attachment:
node: my_block_storage
relationship: MyAttachTo
# Override default property
setting for just the ‘location’ property
properties:
location:
/some_other_data_location
relationship_types:
MyAttachTo:
derived_from: AttachTo
properties: #
follows the syntax of property definitions
location:
default:
/default_location
interfaces:
some_interface_name:
some_operation:
implementation: default_script.sh
|
F.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:
- attachment:
node: my_block_storage
relationship:
storage_attachto_1
my_web_app_tier_2:
derived_from: Compute
requirements:
- attachment:
node: my_block_storage
relationship:
storage_attachto_2
relationship_templates:
storage_attachto_1:
type: MyAttachTo
properties:
location: /my_data_location
storage_attachto_2:
type: MyAttachTo
properties:
location: /some_other_data_location
relationship_types:
MyAttachTo:
derived_from: AttachTo
properties: #
follows the syntax of property definitions
location:
default:
/default_location
interfaces:
some_interface_name:
some_operation:
implementation: default_script.sh
|
F.1.4.4 Notation Style #3:
Using an alias which named Relationship Template to use
This option shows a way to alias an existing template from
another template to further simplify the definition of named Relationship
Templates using aliases to effectively “copy” an existing definition in to
avoid repetition.
The example below shows that the Relationship Template named
storage_attachto_1 provides some overrides (conceptually a large set
of overrides) on its Type which the Relationship Template named storage_attachto_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_attachto_1
my_web_app_tier_2:
derived_from: Compute
requirements:
- attachment:
node: my_block_storage
relationship:
storage_attachto_2
relationship_templates:
storage_attachto_1:
type: MyAttachTo
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_attachto_2:
alias:
storage_attachto_1
properties:
location: /some_other_data_location
relationship_types:
MyAttachTo:
derived_from: AttachTo
properties: #
follows the syntax of property definitions
location:
default:
/default_location
interfaces:
some_interface_name:
some_operation:
implementation: default_script.sh
|
For reference, here are is the BlockStorage,
AttachTo and Attachment definitions:
|
tosca.capabilities.Attachment:
derived_from:
tosca.capabilities.Root
tosca.relationships.AttachTo:
derived_from:
tosca.relationships.Root
valid_targets: [
tosca.capabilities.Attachment ]
properties:
location:
type: string
constraints:
- min_length: 1
device:
type: string
required: false
type: tosca.nodes.BlockStorage
derived_from: tosca.nodes.Root
properties:
size:
type: integer
constraints:
- greater_or_equal: 1
volumeId:
type: string
required: false
attributes:
volumeId:
type: string
capabilities:
- attachment:
tosca.capabilities.Attachment
type: tosca.nodes.Compute
derived_from: tosca.nodes.Root
properties:
...
capabilities:
host:
type: Container
properties:
valid_node_types:
[tosca.nodes.SoftwareComponent]
|
F.1.5 Usage of add_target, target_changed,
remove_target
TODO
Notes:
- These examples would apply the
corresponding add_source, remove_source operations as well but in
the reverse direction.
G.1 Application Modeling Use
Cases:
|
Short description
|
Interesting Feature
|
Description
|
|
Virtual Machine (VM), single instance
|
· Introduces the TOSCA
base Node Type for “Compute”.
|
TOSCA simple profile demonstrates how to stand up a single
instance of a Virtual Machine (VM) image using a normative TOSCA Compute
node.
|
|
WordPress + MySQL, single instance
|
· Introduces the
TOSCA base Node Types of: “WebServer”, “WebApplication”, “DBMS” and
“Database” along with their dependent hosting and connection relationships.
|
TOSCA simple profile service showing the WordPress web
application with a MySQL database hosted on a single server (instance).
|
|
WordPress + MySQL + Object Storage, single instance
|
· Introduces the
TOSCA base Node Type for “ObjectStorage”.
|
TOSCA simple profile service showing the WordPress web
application hosted on a single server (instance) with attached (Object)
storage.
|
|
WordPress + MySQL + Block Storage, single instance
|
· Introduces the
TOSCA base Node Type for “BlockStorage” (i.e., for Volume-based storage).
|
TOSCA simple profile service showing the WordPress web
application hosted on a single server (instance) with attached (Block)
storage.
|
|
WordPress + MySQL, each on separate instances
|
· Instantiates 2
tiers, 1 for WordPress, 1 for DBMS and coordinates both.
|
Template installs two instances: one running a WordPress
deployment and the other using a specific (local) MySQL database to store the
data.
|
|
WordPress + MySQL + Network, single instance
|
· Introduces
the TOSCA base Node Type for a simple “Network”.
|
TOSCA simple profile service showing the WordPress web
application and MySQL database hosted on a single server (instance) along
with demonstrating how to define associate the instance to a simple named
network.
|
|
WordPress + MySQL + Floating IPs, single instance
|
· Connects to an
external (relational) DBMS service
|
TOSCA simple profile service showing the WordPress web
application and MySQL database hosted on a single server (instance) along
with demonstrating how to create a network for the application with Floating
IP addresses.
|
G.1.1 Virtual Machine (VM),
single instance
G.1.1.1
Description
This use case demonstrates how the TOSCA Simple Profile
specification can be used to stand up a single instance of a Virtual Machine
(VM) image 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) that are desired by the template author. The cloud provider
would attempt to fulfill these properties (to the best of its abilities) during
orchestration.
G.1.1.2 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 property
named “cpus” (of type integer) is declared.
- Use of a property constraint to
limit the allowed integer values for the “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
- The “instance_ip” output property
is programmatically retrieved from the Compute
node’s “ip_address” property using the TOSCA Service Template-level get_property function.
G.1.1.3
Logical Diagram
TBD
G.1.1.4
Sample YAML
|
tosca_definitions_version:
tosca_simple_yaml_1_0_0
description: >
TOSCA simple profile that just
defines a single compute instance. 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
properties:
# compute properties
disk_size: 10 GB
num_cpus: { get_input: cpus }
mem_size: 4 MB
capabilities:
os:
properties:
architecture: x86_64
type:
Linux
distribution: ubuntu
version: 12.04
outputs:
instance_ip:
description: The IP address
of the deployed instance.
value: { get_attribute:
[my_server, ip_address] }
|
G.1.1.5
Notes
- This use case uses a versioned, Linux Ubuntu
distribution on the Compute node.
G.1.2 WordPress + MySQL,
single instance
G.1.2.1 Description
TOSCA simple profile service showing the WordPress web
application with a MySQL database hosted on a single server (instance).
This use case is built upon the following templates from,
OpenStack Heat’s Cloud Formation (CFN) template and from an OpenStack
Heat-native template:
However, where the CFN template simply connects to
an existing Relational Database Service (RDS) our template below will also
install a MySQL database explicitly and connect to it.
G.1.2.2
Logical Diagram
TBD
G.1.2.3 Sample YAML
|
tosca_definitions_version:
tosca_simple_yaml_1_0_0
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: integer
description: Port for the
MySQL database
node_templates:
wordpress:
type:
tosca.nodes.WebApplication.WordPress
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, db_name ] }
wp_db_user: {
get_property: [ mysql_database, db_user ] }
wp_db_password: {
get_property: [ mysql_database, db_password ] }
# goto requirement,
goto capability, goto port property
wp_db_port: {
get_property: [ SELF, database_endpoint, port ] }
mysql_database:
type: Database
properties:
db_name: { get_input:
db_name }
db_user: { get_input:
db_user }
db_password: { get_input:
db_pwd }
capabilities:
database_endpoint:
properties:
port: { get_input:
db_port }
requirements:
- host: mysql_dbms
interfaces:
Standard:
postconfigure: mysql_database_postconfigure.sh
mysql_dbms:
type: DBMS
properties:
dbms_root_password: {
get_input: db_root_pwd }
dbms_port: { get_input:
db_port }
requirements:
- host: server
interfaces:
Standard:
create: mysql_dbms_install.sh
start: mysql_dbms_start.sh
configure: mysql_dbms_configure.sh
inputs:
db_root_password: {
get_property: [ mysql_dbms, dbms_root_password ] }
webserver:
type: WebServer
requirements:
- host: server
interfaces:
Standard:
create: webserver_install.sh
start: webserver_start.sh
server:
type: Compute
properties:
# compute properties
(flavor)
disk_size: 10
num_cpus: { get_input:
cpus }
mem_size: 4096
capabilities:
os:
properties:
architecture: x86_64
type: linux
distribution: fedora
version: 17
outputs:
website_url:
description: URL for
Wordpress wiki.
value: { get_attribute:
[server, ip_address] }
|
G.1.2.4
Sample scripts
Where the referenced implementation scripts in the
example above would have the following contents
G.1.2.4.1 wordpress_install.sh
G.1.2.4.2 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/db_name/ /etc/wordpress/wp-config.php
sed -i s/username_here/db_user/
/etc/wordpress/wp-config.php
sed -i
s/password_here/db_password/ /etc/wordpress/wp-config.php
systemctl restart httpd.service
|
G.1.2.4.3 mysql_database_postconfigure.sh
|
# Setup MySQL root password and
create user
cat << EOF | mysql -u root
--password=db_rootpassword
CREATE DATABASE db_name;
GRANT ALL PRIVILEGES ON db_name.*
TO "db_user"@"localhost"
IDENTIFIED BY
"db_password";
FLUSH PRIVILEGES;
EXIT
EOF
|
G.1.2.4.4 mysql_dbms_install.sh
|
yum -y install mysql mysql-server
# Use systemd to start MySQL
server at system boot time
systemctl enable mysqld.service
|
G.1.2.4.5 mysql_dbms_start.sh
|
# Start the MySQL service (NOTE:
may already be started at image boot time)
systemctl start mysqld.service
|
G.1.2.4.6 mysql_dbms_configure
|
# Set the MySQL server root
password
mysqladmin -u root password
db_rootpassword
|
G.1.2.4.7
webserver_install.sh
|
yum -y install httpd
systemctl enable httpd.service
|
G.1.2.4.8 webserver_start.sh
|
# Start the httpd service (NOTE:
may already be started at image boot time)
systemctl start httpd.service
|
G.1.3 WordPress + MySQL +
Object Storage, single instance
G.1.3.1
Description
This use case shows a WordPress application that makes use
of an Object Storage service to application artifacts.
Note: Future drafts of this specification
will detail this use case
G.1.3.2
Logical Diagram
TBD
G.1.3.3
Sample YAML
G.1.4 WordPress + MySQL +
Block Storage, single instance
G.1.4.1
Description
This use case is based upon OpenStack Heat’s Cloud Formation
(CFN) template:
Note: Future drafts of this specification will detail
this use case.
G.1.4.2
Logical Diagram
TBD
G.1.4.3
Sample YAML: Variant 1: Using the normative AttachTo Relationship Type
|
tosca_definitions_version:
tosca_simple_yaml_1_0_0
description: >
TOSCA simple profile with server
and attached block storage using the normative AttachTo 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: string
description: Size of the
storage to be created.
default: 1 GB
storage_location:
type: string
description: Storage mount
path.
node_templates:
server:
type: Compute
properties:
# compute properties
(flavor)
disk_size: 10
num_cpus: { get_input:
cpus }
mem_size: 4096
# host image properties
capabilities:
os:
properties:
architecture: x86_64
type: linux
distribution: fedora
version: 18
requirements:
- persistant_storage:
node: storage
# Clarify the
requirement as an ‘AttachTo’ Relationship Type
relationship: AttachTo
properties:
location: {
get_input: storage_location }
storage:
type: BlockStorage
properties:
size: { get_input:
storage_size }
outputs:
public_ip:
description: Public IP
address of the newly created compute instance.
value: { get_attribute:
[server, ip_address] }
|
G.1.4.4 Sample YAML: Variant 2: Using a custom AttachTo
Relationship Type
|
tosca_definitions_version:
tosca_simple_yaml_1_0_0
description: >
TOSCA simple profile with server
and attached block storage using a custom AttachTo 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: string
description: Size of the
storage to be created.
default: 1 GB
storage_location:
type: string
description: Storage mount
path.
node_templates:
server:
type: Compute
properties:
# compute properties
(flavor)
disk_size: 10
num_cpus: { get_input:
cpus }
mem_size: 4096
capabilities:
os:
properties:
architecture: x86_64
type: Linux
distribution: Fedora
version: 18
requirements:
- persistant_storage:
node: storage
# Declare custom
AttachTo type using the ‘type’ keyword
relationship: MyCustomAttachToType
storage:
type: BlockStorage
properties:
size: { get_input:
storage_size }
outputs:
public_ip:
description: Public IP address
of the newly created compute instance.
value: { get_attribute: [server,
ip_address] }
|
G.1.4.5 Sample YAML:
Variant 3: using a Relationship Template
|
tosca_definitions_version:
tosca_simple_yaml_1_0_0
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: string
description: Size of the
storage to be created.
default: 1 GB
storage_location:
type: string
description: Storage mount
path.
node_templates:
server:
type: Compute
properties:
# compute properties (flavor)
disk_size: 10
num_cpus: { get_input:
cpus }
mem_size: 4096
capabilities:
os:
properties:
architecture: x86_64
type: Linux
distribution: Fedora
version: 18
requirements:
- persistant_storage:
node: storage
# Declare template to
use with ‘relationship’ keyword
relationship: storage_attachment
storage:
type: BlockStorage
properties:
size: { get_input:
storage_size }
relationship_templates:
storage_attachment:
type: AttachTo
properties:
location: { get_input:
storage_location }
outputs:
public_ip:
description: Public IP
address of the newly created compute instance.
value: { get_attribute:
[server, ip_address] }
relationship_types:
MyCustomAttachToType:
derived_from: AttachTo
properties:
location: { get_input:
storage_location }
|
G.1.5 WordPress + MySQL, each on separate instances
G.1.5.1 Description
TOSCA simple profile service showing the WordPress web
application hosted on one server (instance) and a MySQL database hosted on
another server (instance).
This is based upon OpenStack Heat’s Cloud Formation (CFN)
template:
Note: Future drafts of this specification will detail
this use case.
G.1.5.2 Logical Diagram
TBD
G.1.5.3 Sample YAML
G.1.6 WordPress + MySQL + Network, single instance
G.1.6.1
Description
This use case is based upon OpenStack Heat’s Cloud Formation
(CFN) template:
Note: Future drafts of this specification will detail
this use case.
G.1.6.2
Logical Diagram
TBD
G.1.6.3
Sample YAML
G.1.7
WordPress + MySQL + Floating IPs, single instance
G.1.7.1 Description
This use case is based upon OpenStack Heat’s Cloud Formation
(CFN) template:
Note: Future drafts of this specification
will detail this use case.
G.1.7.2
Logical Diagram
TBD
G.1.7.3
Sample YAML
G.1.7.4 Notes
- The Heat/CFN use case also
introduces the concept of “Elastic IP” (EIP) addresses which is the Amazon
AWS term for floating IPs.
- The Heat/CFN use case provides a
“key_name” as input which we will not attempt to show in this use case as
this is a future security/credential topic.
- The Heat/CFN use case assumes that
the “image” uses the “yum” installer to install Apache, MySQL and
Wordpress and installs, starts and configures them all in one script
(i.e., under Compute). In TOSCA we represent each of these software
components as their own Nodes each with independent scripts.
G.1.8 BlockStorage + Compute
G.1.8.1.1
Description
TOSCA simple profile service showing single BlockStorage
attached to Computer node as well as multiple BlockStorage attached to Compute
node.
This use case is built upon the following templates from,
OpenStack Heat’s Cloud Formation (CFN) template and from an OpenStack
Heat-native template:
- https://github.com/openstack/heat-templates/blob/master/hot/F18/NovaInstanceWithCinderVolume_Native.yaml
G.1.8.2 Logical Diagram
TBD
G.1.8.3 Sample YAML
G.1.8.3.1
G1.8.3.1 Single BlockStorage
|
tosca_definitions_version:
tosca_simple_1.0
description: >
TOSCA simple profile with server
and 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: integer
default: 1 GB
description: Size of the
storage to be created.
storage_snapshot_id:
type: string
description: Some identifier
that represents an existing snapshot that should be used when creating the block
storage.
storage_location:
type: string
description: The relative
location (e.g., path on the file system), which provides the root location to
address an attached node.
node_templates:
my_server:
type: tosca.nodes.Compute
properties:
# compute properties
(flavor)
disk_size: 10
num_cpus: { get_input:
cpus }
mem_size: 4096
# host image properties
capabilities:
os:
properties:
architecture: x86_64
type: linux
distribution: fedora
version: 18
requirements:
- attachment:
node: my_storage
relatonship: AttachTo
properties:
location: {
get_input: storage_location }
my_storage:
type:
tosca.nodes.BlockStorage
properties:
size: { get_input:
storage_size }
snapshot_id: { get_input:
storage_snapshot_id }
outputs:
public_ip:
description: Public IP
address of the newly created compute instance.
value: { get_attribute:
[server, ip_address] }
|
G.1.8.3.2
G1.8.3.2 Multiple BlockStorage
|
tosca_definitions_version:
tosca_simple_1.0
description:
>
TOSCA simple profile with server and 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: integer
default: 1 GB
description: Size of the storage to be created.
storage_snapshot_id:
type: string
description: Some identifier that represents an existing snapshot that should
be used when creating the block storage.
storage_location:
type: string
description: The relative location (e.g., path on the file system), which
provides the root location to address an attached node.
node_templates:
my_server:
type: tosca.nodes.Compute
properties:
# compute properties (flavor)
disk_size: 10
num_cpus:
{ get_input: cpus }
mem_size: 4096
capabilities:
os:
properties:
architecture: x86_64
type: linux
distribution: fedora
version: 18
requirements:
- attachment:
node: my_storage
relationship: AttachTo
properties:
location: { get_input: storage_location }
my_storage:
type: tosca.nodes.BlockStorage
properties:
size: { get_input: storage_size }
snapshot_id: { get_input: storage_snapshot_id }
my_server2:
type: tosca.nodes.Compute
properties:
# compute properties (flavor)
disk_size: 10
num_cpus: { get_input: cpus }
mem_size: 4096
capabilities:
os:
properties:
architecture: x86_64
type: Linux
distribution: Fedora
version: 18
requirements:
- attachment:
node: my_storage2
relationship: AttachTo
properties:
location: { get_input: storage_location }
my_storage2:
type: tosca.nodes.BlockStorage
properties:
size: { get_input: storage_size }
snapshot_id: { get_input: storage_snapshot_id }
outputs:
public_ip:
description: Public IP address of the newly created compute instance.
value: { get_attr: [server, ip_address] }
|
G.1.9 Monitoring use case with multiple instances
G.1.9.1 Description
TOSCA simple profile service showing the nodejs, mongodb,
elaasticsearch, logstash, kibana, rsyslog and collectd installed on a different
server (instance). This use case also demonstrates a use of TOSCA macros or
dsl_definitions. It is a work in progress…
G.1.9.2 Logical Diagram
G.1.9.3 Sample YAML for
application server
|
tosca_definitions_version:
tosca_simple_1.0
description: >
TOSCA simple profile with nodejs
mongodb, elaasticsearch, logstash, kibana, rsyslog and collectd.
imports:
- custom_types/nodejs.yaml
dsl_definitions:
ubuntu_node: &ubuntu_node
# compute properties
(flavor)
disk_size: 10
num_cpus: { get_input:
my_cpus }
mem_size: 4096
# host image properties
capabilities:
os:
properties:
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/mmm/testnode.git
node_templates:
nodejs:
type: tosca.nodes.Nodejs
properties:
github_url: { get_input:
github_url }
requirements:
- host: app_server
- database_endpoint:
node: mongo_db
interfaces:
tosca.interfaces.relationship.Configure:
pre_configure_source:
implementation: nodejs/pre_configure_source.sh
input:
host: {
get_attribute: [ TARGET, ip_address ] }
port: {
get_property: [mongo_dbms, dbms_port] }
interfaces:
tosca.interfaces.node.Lifecycle:
create: nodejs/create.sh
configure:
implementation:
nodejs/config.sh
input:
github_url: {
get_property: [ SELF, github_url ] }
start: nodejs/start.sh
mongo_db:
type: tosca.nodes.Database
requirements:
- host: mongo_dbms
mongo_dbms:
type: tosca.nodes.DBMS
requirements:
- host: mongo_server
properties:
dbms_port: 27017
interfaces:
tosca.interfaces.node.Lifecycle:
create:
mongodb/create.sh
configure:
mongodb/config.sh
start: mongodb/start.sh
mongo_server:
type: tosca.nodes.Compute
properties: *ubuntu_node
app_server:
type: tosca.nodes.Compute
properties: *ubuntu_node
outputs:
nodejs_url:
description: URL for the
nodejs server.
value: { get_attribute:
[app_server, ip_address] }
mongodb_url:
description: URL for the
mongodb server.
value: { get_attribute:
[mongo_server, ip_address] }
mongodb_port:
description: Port for the
mongodb server.
value: { get_property:
[mongo_dbms, dbms_port] }
|
G.1.9.4 Sample scripts
Where the referenced implementation scripts in the
example above would have the following contents
G.1.9.4.1
nodejs_install.sh
|
#!/bin/bash
add-apt-repository ppa:
chris-lea/node.js
apt-get update
apt-get install -y nodejs
build-essential curl git npm
|
G.1.9.4.2
nodejs_configure.sh
|
#!/bin/bash
export app_dir=/opt/app
git clone $github_url /opt/app
if [ -f /opt/app/package.json ]
cd /opt/app/ && npm
install
fi
cat > /etc/init/nodeapp.conf
<<EOS
description "node.js
app"
start on (net-device-up
and local-filesystems
and runlevel [2345])
stop on runlevel [!2345]
expect fork
respawn
script
export HOME=/
export NODE_PATH=/usr/lib/node
exec /usr/bin/node
${app_dir}/server.js >> /var/log/nodeapp.log 2>&1 &
end script
EOS
|
G.1.9.4.3
nodejs_start.sh
|
#!/bin/bash
start nodeapp
|
G.1.9.4.4
nodejs_preconfigure.sh
|
#!/bin/bash
cat >
/opt/node/config.js<<EOF
{
"host":
"${host}"
, "port": ${port}
}
EOF
|
G.1.9.4.5
mongodb_install.sh
|
#!/bin/bash
apt-get install -y mongodb
|
G.1.9.4.6
mongodb_start.sh
|
#!/bin/bash
start mongodb
|
H.1
Known Extensions to TOSCA v1.0
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.
H.1.1 Model Changes
·
The “TOSCA Simple ‘Hello World’” example introduces this concept
in Section 3. 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 3.1.
·
“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).
H.1.2 Normative Types
·
Constraint (addresses TOSCA-117)
·
constraint clauses, regex
·
Types / Property / Parameters
·
list, map, range, scalar-unit
·
anonymous types (entity_schema)
·
Includes YAML intrinsic types
·
NetworkInfo, PortInfo
·
Node
·
Root, Compute, ObjectStorage, BlockStorage, Network,
SoftwareComponent, WebServer, WebApp, DBMS, Database, …
·
Relationship
·
Root, DependsOn, HostedOn, ConnectsTo, AttachTo, …
·
Artifact
·
Deployment: Bash (for WD01)
·
Requirements
·
None
·
Capabilities
·
Container, Endpoint, Attachment, Scalable
·
Lifecycle
·
(node) Standard, Simple
·
(Relationship) Configure
·
Functions
·
get_input, get_attribute, get_property, get_nodes_of_type,
get_operation_output
·
Resource
·
In HEAT they have concept of key pairs (an additional resource
type in the template).
H.2 Terminology
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
|
[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
|
.
H.3 Normative References
|
[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
|
H.4
Non-Normative References
H.5 Glossary
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 special
plan defined for the Service Template, often referred to as build plan.
|
|
Node Template
|
A Relationship Template specifies the occurrence of
a software 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.
|
|
|
|
The following individuals have participated in the creation
of this specification and are gratefully acknowledged:
Contributors:
Avi Vachnis (avi.vachnis@alcatel-lucent.com), Alcatel-Lucent
Chris Lauwers (lauwers@ubicity.com)
Derek Palma (dpalma@vnomic.com), Vnomic
Frank Leymann (Frank.Leymann@informatik.uni-stuttgart.de),
Univ. of Stuttgart
Gerd Breiter (gbreiter@de.ibm.com),
IBM
Hemal Surti (hsurti@cisco.com),
Cisco
Idan Moyal, (idan@gigaspaces.com),
Gigaspaces
Jacques Durand (jdurand@us.fujitsu.com),
Fujitsu
Juergen Meynert (juergen.meynert@ts.fujitsu.com), Fujitsu
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
Matt Rutkowski (mrutkows@us.ibm.com), IBM
Moshe Elisha (moshe.elisha@alcatel-lucent.com),
Alcatel-Lucent
Nikunj Nemani (nnemani@vmware.com), WMware
Richard Probst (richard.probst@sap.com), SAP AG
Sahdev Zala (spzala@us.ibm.com), IBM
Stephane Maes (stephane.maes@hp.com), HP
Thomas Spatzier (thomas.spatzier@de.ibm.com), IBM
Ton Ngo (ton@us.ibm.com), IBM
Travis Tripp (travis.tripp@hp.com), HP
Yaron Parasol (yaronpa@gigaspaces.com), Gigaspaces
|
Revision
|
Date
|
Editor
|
Changes Made
|
|
WD04, Rev. 01
|
2014-10-13
|
Matt Rutkowski, IBM
|
· Initial WD04,
Revision 01 baseline.
· Imported Ch. 13
“Nested templates” from Thomas Spatzier.
|
|
WD04, Rev 02
|
2014-10-20
|
Matt Rutkowski, IBM
|
· Merged updates to
Ch 13 “nested templates” which update the examples/prose to wd03 normative
type definitions.
· Merged in Block
Storage and Monitoring use cases from Sahdev Zala
|
|
WD04, Rev03
|
2014-10-21
|
Matt Rutkowski, IBM
|
· Broke out
Requirement definition grammar from requirements element
· Split up 4
different examples of requirement definition usage
· Added target_filter
keyword on requirement defn. and added an example for it.
|
|
WD04, Rev04
|
2014-10-22
|
Matt Rutkowski, IBM
|
· More work
clarifying requirements and grammar for the Schema definition.
· Re-authored
requirement definition grammar and section (and examples).
· Added datatype
definitions
· Added
dsl_definitions, datatype_definitions and implements keywords for service
template
· Added placeholder
for filter definition.
|
|
WD04, Rev05
|
2014-10-29
|
Matt Rutkowski, IBM
|
· Requirement
definitions grammar chance and cascade change to ALL examples in document
· Addition of
property and node filter grammar, also cascaded to ALL examples in document
|
|
WD04, Rev06
|
2014-11-08
|
Matt Rutkowski, IBM
|
·
Added the OperatingSystem Capability Type. changed Compute node
to use it and fixed all examples in document.
·
Assured all references to target_filter on Requirement
definitions where correct in all examples
·
Added text to property and attribute (definitions and elements)
to better explain usage to retrieve desire or actual state of a Tosca
entity’s transparent properties using get_xxx functions.
·
Better explained how scalar-unit type is used with constraints,
updated properties in Compute, ObjectStorage, etc. to change some
memory/storage size values to this type instead of integer and updated their
definitions.
·
Added a status flag to Property definition with allowed values.
|
|
WD04, Rev07
|
2014-11-11
|
Matt Rutkowski, IBM
|
·
Fixed one case where type “number” appeared
·
Added clarification to HOST function keyword to indicate entity
hosted on chain is to be searched. Updated get_xxx grammars to include HOST.
·
Added Credential datatype
·
changed namespace for datatypes, to say “datatypes” instead of
just “type”
|
|
WD04,
Rev08
|
2014-11-17
|
Matt Rutkowski, IBM
|
·
Updated issues lost based upon half-day work group review on
2014-11-13
·
Fixed a few examples that used old namespaces.
·
Fixed prose of one example that used an old keyname “type” for
a requirement definition.
·
Merged properties from MultiportEndpoint capability to Endpoint
capability.
|
|
WD04,
Rev09
|
2014-11-17
|
Thomas Spatzier, IBM
|
·
Initial draft for nested template changes (TOSCA-186) in
section 13; just edited sample snippets as base for discussion; overall text
changes still to be done once discussions settle
|
|
WD04, Rev10
|
2014-12-03
|
Matt Rutkowski, IBM
|
·
Fixed type defn. typos in some examples.
·
Cleaned up closed and deferred Mantis issue references
·
Fixed Port Node Type to have proper Requirements for “link” and
“connection” otherwise they could not be wired together.
·
Showed simplified Req. Def. grammar versus full (i.e., no need
to use “type” keyname in simple cases).
o
Opened issue TOSCA-217 for simplified grammar
|
|
WD04, Rev11
|
2014-12-05
|
Matt Rutkowski, IBM
|
·
Fixed type defn. typos in some examples.
·
Added additional transitional states, removed unnecessary
states (stopped, deleted).
·
Added diagrams to show normal startup/shutdown sequencing of
Standard Lifecycle operations and resulting Node States.
·
Created TOSCA-218 to address agreements on how to handle
valid_node_types as a part of Capability metamodel and tagged all relevant
code/comments with this issue number.
|
|
WD04, Rev12
|
2014-12-08
|
Thomas Spatzier, IBM
|
·
Introduction of topology_template throughout the document
(except appendixes F and G).
·
Rewrite of “nested templates” use case in section 13.
·
Introduction of substitution_mapping section for
topology_template.
|
|
WD04, Rev13
|
2014-12-10
|
Matt Rutkowski, IBM
|
·
Added topology template key for all use cases in Appendix G.
Fixed indentation on all use cases.
·
Fixed some errors in examples in section 13 as identified
during YAML WG review.
·
Removed post_configure operation from Standard lifecycle and
adjusted diagrams
·
Added diagrams showing typical startup and shutdown sequence
for Standard lifecycle
·
Added illustration to show interleaving of relationship Configure
lifecycle and Standard node lifecycle.
·
Added diagram to show how Compute-Port-Network relationship is
established using new network caps., reqs. and relationship types. Added
prose to explain diagram
·
After consulting Network WG co-chairs changed network
node/Cap/Rel. type names as follows:
o
Capabilities.Linkable -> tosca.capabilities.network.Bindable
o
Relationships.LinkedTo ->
tosca.relationships.network.BindsTo
o
Relationships.NetworkTo ->
tosca.relationships.network.ConnectsTo
o
Capabilities.Connectivity ->
tosca.capabilities.network.Connectable
o
This allows more app-centric naming for “network binding” and
follows the naming paradigms established for Caps and Rels.
o
Updated all examples and grammar to reflect these name changes.
|
|
Issue #
|
Target
|
Status
|
Owner
|
Title
|
Notes
|
|
TOSCA-132
|
CSD03
|
Open
|
Palma
|
Use "set_property" methods to "push"
values from template inputs to nodes
|
Feature. Needs new owner.
|
|
TOSCA-135
|
CSD02
|
Open
|
Rutkowski
|
Define/reference a Regex language (or subset) we wish to
support for constraints
|
Feature, Reference a Perl subset.
|
|
TOSCA-136
|
CSD03
|
Open
|
Spatzier
|
Need rules to assure non-collision (uniqueness) of
requirement or capability names
|
None
|
|
TOSCA-137
|
CSD03
|
Defer
|
Palma
|
Need to address "optional" and "best
can" on node requirements (constraints) for matching/resolution
|
None
|
|
TOSCA-138
|
CSD02
|
Review/ Action
|
Palma
|
Define a Network topology for L2 Networks along with
support for Gateways, Subnets, Floating IPs and Routers
|
Luc Boutier has rough proposal in MS Word format.
|
|
TOSCA-140
|
CSD03
|
Review
|
Palma
|
Constraining
the capabilities of multiple node templates
|
|
|
TOSCA-141
|
CSD03
|
Review
|
Palma
|
Specifying
Environment Constraints for Node Templates (Policy related)
|
|
|
TOSCA-142
|
CSD02
|
Review
|
Spatzier / Rutkowski
|
Define normative Artifact Types (including
deployment/packages, impls., and runtime types)
|
|
|
TOSCA-143
|
CSD02
|
Review
|
Rutkowski
|
Define normative tosca.nodes.Network Node Type (for simple
networks)
|
Separate use case as what Luc proposes in TOSCA-138.
|
|
TOSCA-148
|
CSD03
|
Open
|
Palma
|
Need a means to express cardinality on relationships
(e.g., number of connections allowed)
|
|
|
TOSCA-151
|
CSD03
|
Defer
|
Rutkowski
|
Resolve spec. behavior if name collisions occur on named
Requirements
|
subtask of TOSCA-148
|
|
TOSCA-152
|
CSD03
|
Open
|
Palma
|
Extend Requirement grammar to support "Optional/Best
Can" Capability Type matching
|
subtask of TOSCA-137
|
|
TOSCA-153
|
CSD03
|
Open
|
Rutkowski
|
Define grammar and usage of Service Template keyname
(schema namespace) "tosca_default_namespace"
|
|
|
TOSCA-154
|
CSD03
|
Defer
|
Palma
|
Decide how security/access control work with Nodes, update
grammar, author descriptive text/examples
|
|
|
TOSCA-155
|
CSD03
|
Open
|
Rutkowski
|
How do we provide constraints on properties declared as
simple YAML lists (sets)
|
Need to define constraints for “set” types
|
|
TOSCA-156
|
CSD03
|
Defer
|
Palma
|
Are there IPv6 considerations (e.g., new properties) for
tosca.capabilities.Endpoint
|
|
|
TOSCA-158
|
CSD03
|
Defer
|
|
Provide prose describing how Feature matching is done by
orchestrators
|
Subtask of TOSCA-137
|
|
TOSCA-161
|
CSD03
|
Defer
|
Spatzier
|
Need examples of using the built-in feature (Capability)
and dependency (Requirement) of tosca.nodes.Root
|
|
|
TOSCA-162
|
CSD03
|
Defer
|
Rutkowski
|
Provide recognized values for tosca.nodes.compute
properties: os_arch
|
|
|
TOSCA-163
|
CSD03
|
Defer
|
Vachnis
|
Provide recognized values for tosca.nodes.BlockStorage:
store_fs_type
|
|
|
TOSCA-165
|
CSD03
|
Defer
|
Need new owner
|
New use case / example: Selection/Replacement of web
server type (e.g. Apache, NGinx, Lighttpd, etc.)
|
|
|
TOSCA-166
|
CSD03
|
Defer
|
Unassigned
|
New use case / example: Web Server with (one or more)
runtimes environments (e.g., PHP, Java, etc.)
|
|
|
TOSCA-167
|
CSD03
|
Defer
|
Unassigned
|
New use case / example: Show abstract substitution of
Compute node OS with different Node Type Impls.
|
|
|
TOSCA-168
|
CSD03
|
Defer
|
Unassigned
|
New use case / example: Show how substitution of IaaS can
be accomplished.
|
|
|
TOSCA-170
|
CSD02
|
Open
|
Elisha
|
WD02 - Explicit textual mention, and grammar support, for
adding (extending) node operations
|
|
|
TOSCA-172
|
CSD02
|
Review
|
Lipton
|
2014 March - Public Comment Questions (Plans, Instance
Counts, and linking SW Nodes)
|
|
|
TOSCA-176
|
CSD03
|
Defer
|
Elisha
|
Add connectivity ability to Compute
|
|
|
TOSCA-179
|
CSD03
|
Defer
|
Elisha
|
Add "timeout" and "retry" keynames to
an operation
|
|
|
TOSCA-180
|
CSD02
|
Open / In-progress
|
Elisha / Rutkowski
|
Support of secured repositories for artifacts
|
|
|
TOSCA-181
|
CSD03
|
Open
|
Boutier
|
Dependency requirement type should match any target node.
|
Subtask of TOSCA-161
|
|
TOSCA-182
|
CSD02
|
Open
|
Palma
|
Document
parsing conventions
|
|
|
TOSCA-183
|
CSD02
|
Open
|
Palma
|
Composition
across multiple yaml documents
|
|
|
TOSCA-184
|
CSD02
|
Open
|
Palma
|
Pushing
(vs pulling) inputs to templates
|
Subtask of TOSCA-132
|
|
TOSCA-185
|
CSD03
|
Review / Defer
|
Durand
|
Instance
model
|
|
|
TOSCA-186
|
CSD03
|
Defer
|
Spatzier
|
model
composition
|
|
|
TOSCA-189
|
CSD03
|
Defer
|
Shtilman
|
Application
Monitoring - Proposal
|
Fixed
|
|
TOSCA-191
|
CSD02
|
Open
In-Progress
|
Rutkowski
|
Document
the “augmentation” behavior after relationship is selected in a requirement
|
|
|
TOSCA-193
|
CSD02
|
Open
|
Spatzier
|
“implements” keyword needs its own section/grammar/example
in A.5.2
|
Subtask of TOSCA-186
|
|
TOSCA-194
|
CSD02
|
Open
|
Lauwers
|
Nested Service Templates should be able to define
additional operations
|
Subtask of TOSCA-186
|
|
TOSCA-196
|
CSD02
|
Open
|
Lauwers
|
Enhance "capabilities" section in nested
templates
|
Subtask of TOSCA-186
|
|
TOSCA-197
|
CSD02
|
Open
|
Lauwers
|
Add "requirements" section in nested templates
|
Subtask of TOSCA-186
|
|
TOSCA-198
|
CSD02
|
Open
|
Lauwers / Rutkowski
|
Simplify “schema” specification
|
|
|
TOSCA-200
|
CSD03
|
Open
|
Parasol
|
Query based upon capability
|
|
|
TOSCA-201
|
CSD03
|
Open
|
Lauwers
|
Harmonize Properties and Capabilities in Node Types
|
|
|
TOSCA-202
|
CSD03
|
Open
|
Boutier
|
Cardinalities for capabilities and requirements
|
Subtask of TOSCA-148
|
|
TOSCA-204
|
CSD03
|
Open
|
Boutier
|
Parameter
definitions on operations should be closer to property definitions
|
|
|
TOSCA-205
|
CSD03
|
Open
|
Boutier
|
Add
interface type.
|
|
|
TOSCA-206
|
CSD03
|
Open
|
Boutier
|
lifecycle.Simple
interface and plan/workflow management...
|
|
|
TOSCA-207
|
CSD02
|
Open
|
Boutier
|
postconfigure
operation on Standard operation should be renamed in poststart
|
|
|
TOSCA-208
|
CSD03
|
Open
|
Boutier
|
Add
conditional capabilities (enable/disable capabilities on a node)
|
|
|
TOSCA-209
|
CSD02
|
Open
|
Rutkowski
|
Fix Grouping example to use correct parameter for
WebServer
|
|
|
TOSCA-210
|
CSD02
|
Open
|
Rutkowski
|
Need example on get_xxx functions using HOST keyword
|
|
|
TOSCA-211
|
CSD02
|
Open
|
Rutkowski
|
Need version on TOSCA Types (Node, Relationship, etc.)
|
|
|
TOSCA-212
|
CSD03
|
Open
|
Boutier
|
Allow
String concatenation for get_attributes/ properties to create aggregated
props/outputs
|
|
|
TOSCA-213
|
CSD03
|
Open
|
Lauwers
|
Clarify
distinction between declaring properties and assigning property values
|
|
|
TOSCA-214
|
CSD02
|
Open
|
Vachnis / Rutkowski
|
New
functions for accessing the instance model
|
|
|
TOSCA-217
|
CSD02
|
Open
|
Spatzier / Rutkowski
|
Add new simplified, single-line list notation / grammar
for Requirement Def.
|
|
