Post-deployment core tasks don't work with plugins

[Andrey Grebennikov]

MOS8

I deploy the environment with Contrail and set of StackLight plugins.
Both plugins should include dns-client and ntp-client as post-deployment steps.

From current Contrail plugin:
# Group for post-deployment tasks
- id: contrail-post-deploy
  type: group
  role: [primary-contrail-db, contrail-db,
    primary-contrail-config,contrail-config,
    primary-contrail-control,contrail-control]
  tasks: [configure_default_route, dns-client, ntp-client]
  required_for: [post_deployment_end]
  requires: [post_deployment_start]
  parameters:
    strategy:
      type: parallel

But the tasks were not executed.

Current version of StackLight plugins don't have such tasks.
I manually create the task for influxdb-grafana plugin, sync plugins, then do

[<email address hidden>]# fuel node --node 114,115,116 --start dns-client
Started tasks [u'ntp-client', u'ntp-server', u'ntp-check', u'dns-client'] for nodes nodes [114, 115, 116].

Nailgun registers the API call, but in Astute log there is no mentioning that these tasks are going to be executed. The nodes in fact start executing All tasks in general.

[Georgy Kibardin (gkibardin)]

On fresh mitaka with the following added to the plugin example:

- id: post-deploy-doesnt-work
  type: group
  role: [compute]
  tasks: [apache]
  required_for: [post_deployment_end]
  requires: [post_deployment_start]
  parameters:
    strategy:
      type: parallel

apache core task works. Checking on 8.0

[Georgy Kibardin (gkibardin)]

The problem is in the way deployment graphs work in 8.0. For the deployment single graph is created and tasks are ordered and spread by the deployment stages and only after that filtering by roles happens. This produces interesting side effects. In most cases core tasks are run on deployment stage and, therefore not included into post deployment stage. However, later, these core tasks may be stripped from deployment stage depending on node role causing the problem described by the bug.

In 9.0 this problem is solved. To solve the problem in 8.0 we need to backport quite a major refactoring.