Comment 4 for bug 1876396

Reviewed: https://review.opendev.org/725709
Committed: https://git.openstack.org/cgit/starlingx/config/commit/?id=09dc3cbcded99900feb0fca5f65542c3fa673231
Submitter: Zuul
Branch: master

commit 09dc3cbcded99900feb0fca5f65542c3fa673231
Author: Robert Church <email address hidden>
Date: Tue May 5 15:29:33 2020 -0400

    Provide an update strategy for Tiller deployment

    In the case of a simplex controller configuration the current patching
    strategy for the Tiller environment will fail as the tiller ports will
    be in use when the new deployment is attempted to be applied. The
    resulting tiller pod will be stuck in a Pending state.

    The deployment strategy provided by 'helm init' is unspecified. This
    change will allow one additional pod (current + new) and one unavailable
    pod (current) during an update. The maxUnavailable setting allows the
    tiller pod to be deleted which will release its ports, thus allowing the
    patch deployment to spin up an new pod to a Running state.

    This patching ensures that on an installed system where tiller has been
    manually removed and re-applied via 'helm init', it is patched
    appropriately.

    Change-Id: I356545d05a585f7cbbbd5ca5071aa834fb086c31
    Depends-On: https://review.opendev.org/#/c/725705/
    Closes-Bug: #1876396
    Signed-off-by: Robert Church <email address hidden>