Comment 9 for bug 1856313

Reviewed: https://review.opendev.org/698891
Committed: https://git.openstack.org/cgit/openstack/tripleo-heat-templates/commit/?id=14db20baee3529b223a87e9f73279c6034a47427
Submitter: Zuul
Branch: master

commit 14db20baee3529b223a87e9f73279c6034a47427
Author: Jose Luis Franco Arza <email address hidden>
Date: Fri Dec 13 13:39:17 2019 +0100

    Force facts cache refreshing before upgrade.

    When upgrading from Rocky to Stein, an upgrade of the operating system is
    performed. This upgrade from RHEL7 to RHEL8 implies the removal of the
    default /usr/bin/python binary. As the facts cache is enabled, Ansible's
    strategy does not consider to upgrade facts and therefore we try to run the
    ansible playbook using the old python binary when running the upgrade.
    This fails with the error: /usr/bin/python: No such file or directory.

    This patch makes use of the setup task in combination with gather_facts
    false, to ensure that the facts are gathered and refreshed for the
    Overcloud nodes. This way, we make sure that we are using the right
    python binary. As during scale, a similar situation is occuring, this
    patch adds the same logic in scale_playbook.

    Closes-Bug: #1856313
    Change-Id: I87974e88c38b42e90bc3cd801fcf1deaf268720c