Include template definitions from an external file

https://blueprints.launchpad.net/vitrage/+spec/definition-templates

Define special template files that contain only definitions (entities / relationships and not scenarios), that can then be included within other template files and used there to create new scenarios.

Problem description

A lot of templates were redefining the same entities and relationships for use in their scenarios.

Proposed change

Add a new file (or a set of files) into a “def_templates” directory. These files are the same as templates but do not contain scenarios or an “include” section (only definitions):

metadata:
 name: alarm_on_host_defs
 description: basic def_template example
definitions:
 entities:
  - entity:
     category: ALARM
     type: nagios
     name: host_problem
     template_id: alarm
  - entity:
     category: RESOURCE
     type: nova.host
     template_id: resource
 relationships:
  - relationship:
     source: alarm
     target: resource
     relationship_type: on
     template_id : alarm_on_host

Add an “include” section within templates, which states the name that should be included at it appears in the metadata of the definition template. Multiple definition templates can be added:

metadata:
 name: alarm_on_host_scenario
 description: basic template with an include section example
definitions:
 entities:
  - entity:
    ...
 relationships:
  - relationship:
     ...
include:
 - name: alarm_on_host_defs
 - name: ...
scenarios:
 - scenario:
    condition: alarm_on_host
    actions:
     - action:
        action_type: set_state
        properties:
         state: SUBOPTIMAL
        action_target:
         target: resource11

Alternatives

None

Data model impact

None

REST API impact

None. Should be addressed in a future template CRUD implementation

Versioning impact

None - Old template formats will still be supported. Introduces an alternative version.

Other end user impact

None

Deployer impact

None

Developer impact

None

Horizon impact

Template UI should be changed to show definition template files.

Topology view

No impact

RCA view

No impact

Entity graph

No impact

Summary

No impacts

Implementation

Assignee(s)

Primary assignee:

nivolas

Other contributors:

None

Work Items

In scope:

• Loading definition templates.

• Validating definition templates.

• Tests

• Documentation

The following items are not in scope:

• Definition templates with scenarios.

• Recursive includes (a definition template can not include other definition templates).

Dependencies

None

Testing

The implementation will be covered by additional unit tests and tempest tests.

Documentation Impact

Documentation on how to define definition template files and when to use them

References

None