Comment 20 for bug 1750656

Reviewed: https://review.openstack.org/547048
Committed: https://git.openstack.org/cgit/openstack/openstack-ansible-galera_client/commit/?id=3a01c65e3d09d2fe23cbb8c2a6c6a75d73791c4b
Submitter: Zuul
Branch: stable/ocata

commit 3a01c65e3d09d2fe23cbb8c2a6c6a75d73791c4b
Author: git-harry <email address hidden>
Date: Wed Feb 21 10:35:06 2018 +0000

    Fix cache update after initial apt_repository fail

    If apt_repository fails to update the apt cache after updating the
    configuration, retries don't register there was a change and so no
    attempt is made to update the cache by the module on the second attempt.
    This failure can result in a failure to install packages.

    This change adds an apt module task to update the cache if the
    apt_repository task registers a change. This means updating the cache
    will get retried on failure and no longer fail silently.

    Change-Id: I41de2b9a98977bb89de812a9fbc85a9f99d62942
    Partial-bug: 1750656
    (cherry picked from commit 69729be3d1a24f639a9526e09ed027801442ed8c)