Comment 28 for bug 1831690

Reviewed: https://review.opendev.org/670062
Committed: https://git.openstack.org/cgit/openstack/tripleo-heat-templates/commit/?id=2b427970a36a63cc2b9afbd61f10fe033287aca5
Submitter: Zuul
Branch: master

commit 2b427970a36a63cc2b9afbd61f10fe033287aca5
Author: Jiri Stransky <email address hidden>
Date: Wed Jul 10 15:24:13 2019 +0200

    Handle edge cases in staged upgrade hiera data

    We make sure the hiera is set in an either-or branches so that we
    prevent from executing both at the same time or none at all.

    Edge case 1 which is not that much of an edge case --
    single-controller environment with Pacemaker. Previously we ran both
    branches resulting in duplicate entries.

    Edge case 2 -- having the service in roles data but having no node
    assigned to that role. In that case previously we wouldn't set the
    variables and the upgrade would fail.

    Change-Id: I1681a5e5ac7842500fc5e9dd0900ee6121773537
    Partial-Bug: #1831690