Comment 3 for bug 1801969

Reviewed: https://review.openstack.org/616022
Committed: https://git.openstack.org/cgit/openstack/tripleo-common/commit/?id=8abbdeb42300ed64f15f1041492ebc895e49dee9
Submitter: Zuul
Branch: master

commit 8abbdeb42300ed64f15f1041492ebc895e49dee9
Author: Alex Schultz <email address hidden>
Date: Tue Nov 6 15:39:53 2018 -0700

    Add image_source to containers

    Previously when containers were added to the upstream kolla project or
    added to our container list, the container build process might try and
    build them when we execute kolla-build. This change adds a image_source
    parameter that is used to understand when we should and should not
    attempt to build the container with kolla witht he 'overcloud container
    image build' command.

    Change-Id: I82d6e09c856f78c0b29d7324c59b5e00bf5ae04d
    Closes-BUg: #1801969