Comment 4 for bug 1770599

Reviewed: https://review.openstack.org/569146
Committed: https://git.openstack.org/cgit/openstack/tripleo-heat-templates/commit/?id=815f99a2d9d4ba206e78bbaf5745c5ce1ff7f9b5
Submitter: Zuul
Branch: stable/queens

commit 815f99a2d9d4ba206e78bbaf5745c5ce1ff7f9b5
Author: Jiri Stransky <email address hidden>
Date: Fri May 11 11:13:22 2018 +0200

    Fix cinder-backup image wrangling on update

    The minor update tasks for cinder-backup first pull the new image and
    then delete the old one. If the image hasn't changed, deleting the old
    one means deleting the new one too, and then trying to tag it as
    pcmklatest will fail. The other services under
    services/docker/pacemaker seem to have the order correct.

    All services here could use a performance optimization for cases when
    the image hasn't changed (don't reshuffle images if the hash hasn't
    changed) but let's fix the breakage first and address performance
    later.

    Change-Id: I5e0fcb7467fcff7e549e04789ceeb8eb49ee265a
    Closes-Bug: #1770598
    Related-Bug: #1770599
    (cherry picked from commit b0322730a7b0759526c3e0b876afa514d8ab35dd)