Comment 9 for bug 1837082

Reviewed: https://review.opendev.org/672049
Committed: https://git.openstack.org/cgit/openstack/tripleo-heat-templates/commit/?id=ef01df9b8df79f7faf21791e9d9ddcd85e706bd4
Submitter: Zuul
Branch: stable/queens

commit ef01df9b8df79f7faf21791e9d9ddcd85e706bd4
Author: Alex Schultz <email address hidden>
Date: Thu Jul 18 10:36:05 2019 -0600

    Re-Add facter cache for container configurations

    Rather than running all the facts for every invocation of
    container-puppet.py, let's cache the facts for the entire container
    config step. This is similar to what used to happen when we ran puppet
    in a single instance for a given step. This improves the time it takes
    puppet tp execute within the containers. When systems have large number
    of interfaces, the fact generation for puppet can come to a crawl given
    that puppet is not supposed to be invoked multiple times in parallel. By
    pre-caching the facts, we eliminate the need for puppet to do the
    network (and other fact) related lookups when running container
    configuration generation.

    This patch includes logic to exclude the puppet caching dirs that we
    mount as read only in the config containers.

    Conflicts:
     common/container-puppet.py

    Change-Id: I94002572ec7ac1767fbfbfdf4c6fa6fbf0cd58d5
    Closes-Bug: #1837082
    Closes-Bug: #1835959
    (cherry picked from commit 08e34dbcaebb0608df61d6540d4919cab71632f5)