Comment 57 for bug 1750656

Reviewed: https://review.openstack.org/547402
Committed: https://git.openstack.org/cgit/openstack/openstack-ansible-openstack_hosts/commit/?id=b48de36760e789ee6bcaf52bab1c54165de236ef
Submitter: Zuul
Branch: stable/queens

commit b48de36760e789ee6bcaf52bab1c54165de236ef
Author: Jesse Pretorius <email address hidden>
Date: Thu Feb 22 14:29:00 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: Ia0723407a08a84d5a1a59f4cc3b9006e8587d7b3
    Partial-Bug: #1750656
    (cherry picked from commit e647596930fb898e13630a449722f3a75160e0be)