Comment 4 for bug 1892570

Reviewed: https://review.opendev.org/748130
Committed: https://git.openstack.org/cgit/openstack/tripleo-heat-templates/commit/?id=cc17467c5018d4f05b53af0a0046def5c5a8633e
Submitter: Zuul
Branch: stable/ussuri

commit cc17467c5018d4f05b53af0a0046def5c5a8633e
Author: Damien Ciabrini <email address hidden>
Date: Wed Aug 19 15:40:00 2020 +0200

    minor update: only migrate HA VIP away when needed

    When update tasks runs in a HA controller node, pacemaker is
    stopped, along with all HA resources hosted on the node. If
    any VIP is hosted on that node, it is moved to another node
    prior to stopping pacemaker to limit service downtime.

    If the HA controller node doesn't manage VIP (no HAProxy) or
    the control plane only has 1 node, there is no need to try and
    move VIP away before stopping pacemaker.

    Tested on a 1-node HA control plane, and also on a control
    plane with external balancer (no HAproxy service, thus no VIP
    managed in pacemaker). The dedicated ansible task no longer
    tries to move VIP if it doesn't need to.

    Closes-Bug: #1892570
    Change-Id: Id9b9c413ee37dcda422e69ebef4aca81e4877156
    (cherry picked from commit 164fac75a0fbff2130f39a5f4d7c5931f5ea3b08)