Comment 4 for bug 1368445

Reviewed: https://review.openstack.org/132549
Committed: https://git.openstack.org/cgit/stackforge/fuel-web/commit/?id=1d3982f606b5d0d0cba78b52a5806abee6a97918
Submitter: Jenkins
Branch: master

commit 1d3982f606b5d0d0cba78b52a5806abee6a97918
Author: Dima Shulyak <email address hidden>
Date: Mon Nov 3 13:37:37 2014 +0200

    Redeploy cinder/compute nodes if new controller added

    Addition of new controller affects cluster messaging,
    particularly cinder/computes nodes which is reliant on
    rabbitmq_hosts settings

    In current orchestration model - the only way to
    fix configuration on nodes is to redeploy them.
    Configuration will be applied from /etc/astute.yaml and
    it is not enough to simply add additional PostDeployment
    method in astute

    Introduced additional setting for roles_metadata:
    - update_required
      should store list of roles that dependends on this role

    On deployment stage:
    - make update_required list for the whole cluster
    - select ready nodes without pending_roles and deploy them

    No migration added to keep behaviour on old clusters as it is

    DocImpact
    Closes-Bug: 1368445

    Change-Id: I1735a8b06531018b1240726f5faa4f7ce6e6a631