Short Template Format

StoryBoard link: https://storyboard.openstack.org/#!/story/2004871

This spec suggests a shorter format for Vitrage template files. The new format should be shorter, read faster and written more easily.

Problem description

Vitrage template language is powerful, yet a bit verbose and it’s quite easy to make syntax mistakes when creating a new template from scratch. We would like to make it easier to generate any template.

For more information on the current format, see Template_format.

Proposed change

Several simplifications that will result in a shorter template file while preserving it’s capabilities.

1. Remove definitions level nesting, entities will directly replace it

2. Remove relationships, these will be represented inline in the condition, example usage condition: host_ssh_alarm [ on ] host

3. entities will be changed from a list to a dictionary, template_id is removed and the entity key will be used instead.

4. In actions the field action_type is removed and the action key will be used instead

5. In each action action_target nesting level is removed

6. In scenarios removed the scenario nesting level

7. Action set_state will be replaced with set_suboptimal, set_error and set_ok.

8. raise_alarm action will have a new optional field causing_alarm this will add a causal relationship between the new alarm and the causing alarm, de-necessitating the use of add_causal_relationship

Example for a short format template

metadata:
 version: 3
 name: zabbix alarm for network interface and ssh affects host instances
 description: zabbix alarm for network interface and ssh affects host instances
entities:
 host_network_alarm:
  type: zabbix
  rawtext: host network interface is down
 host_ssh_alarm:
  type: zabbix
  rawtext: host ssh is down
 instance:
  type: nova.instance
 host:
  type: nova.host
scenarios:
 - condition: host_ssh_alarm [ on ] host
   actions:
     - set_suboptimal:
        target: host
 - condition: host_network_alarm [ on ] host AND host_ssh_alarm [ on ] host
   actions:
     - add_causal_relationship:
        source: host_network_alarm
        target: host_ssh_alarm
 - condition: host_ssh_alarm [ on ] host AND host [ contains ] instance
   actions:
     - raise_alarm:
        target: instance
        alarm_name: instance is down
        severity: WARNING
        causing_alarm: host_ssh_alarm
     - set_error:
        target: instance

Example for an equivalent template in the previous format

metadata:
 version: 2
 type: standard
 name: zabbix alarm for network interface and ssh affects host instances
 description: zabbix alarm for network interface and ssh affects host instances
definitions:
 entities:
  - entity:
   category: ALARM
   type: zabbix
   rawtext: host network interface is down
   template_id: host_network_alarm
  - entity:
   category: ALARM
   type: zabbix
   rawtext: host ssh is down
   template_id: host_ssh_alarm
  - entity:
   category: ALARM
   type: vitrage
   name: instance is down
   template_id: instance_alarm
  - entity:
   category: RESOURCE
   type: nova.instance
   template_id: instance
  - entity:
   category: RESOURCE
   type: nova.host
   template_id: host
 relationships:
  - relationship:
   source: host_network_alarm
   relationship_type: on
   target: host
   template_id : network_alarm_on_host
  - relationship:
   source: host_ssh_alarm
   relationship_type: on
   target: host
   template_id : ssh_alarm_on_host
  - relationship:
   source: host
   relationship_type: contains
   target: instance
   template_id : host_contains_instance
  - relationship:
   source: instance_alarm
   relationship_type: on
   target: instance
   template_id : alarm_on_instance
scenarios:
 - scenario:
     condition: ssh_alarm_on_host
     actions:
      - action:
          action_type: set_state
          action_target:
            target: host
          properties:
            state: SUBOPTIMAL
 - scenario:
     condition: network_alarm_on_host AND ssh_alarm_on_host
     actions:
      - action:
          action_type: add_causal_relationship
          action_target:
            source: host_network_alarm
            target: host_ssh_alarm
 - scenario:
     condition: ssh_alarm_on_host AND host_contains_instance
     actions:
      - action:
          action_type: raise_alarm
          action_target:
            target: instance
          properties:
            alarm_name: instance is down
            severity: WARNING
      - action:
          action_type: set_state
          action_target:
            target: instance
          properties:
            state: ERROR
 - scenario:
     condition: ssh_alarm_on_host AND host_contains_instance AND alarm_on_instance
     actions:
      - action:
          action_type: add_causal_relationship
          action_target:
            source: host_ssh_alarm
            target: instance_alarm

Alternatives

None.

Data model impact

None. Templates will be stored in the same data model.

REST API impact

None

Versioning impact

These changes will be part of Vitrage template version 3.

Other end user impact

None

Deployer impact

None

Developer impact

None

Horizon impact

None.

Implementation

Assignee(s)

Primary assignee:

idan_hefetz

Work Items

• Introduce Vitrage template version 3

• Support template validation and loading

• Documentation and tests

Dependencies

None

Testing

Unit tests, functional tests and tempest tests

Documentation Impact

The new template format will be documented

References

None