Comment 1 for bug 1523336

Reviewed: https://review.openstack.org/251594
Committed: https://git.openstack.org/cgit/openstack/kolla/commit/?id=c7297e04c15eb3dd7fbf0825c51932452c8c1275
Submitter: Jenkins
Branch: master

commit c7297e04c15eb3dd7fbf0825c51932452c8c1275
Author: Diogo Monteiro <email address hidden>
Date: Mon Nov 30 19:23:16 2015 -0500

    Update Vagrant's Ubuntu box provisioning script

    Starting from Vivid Ubuntu uses systemd as the
    default boot manager instead of upstart. Updating
    the way the docker daemon is configured to follow
    the systemd way.
    Setting env variable GUNICORN_OPTS=[--preload]
    to fix race condition and avoid IntegrityError
    when pushing images to local registry

    Change-Id: I841f85015c2c3683ef7e1e454ec1369263063c45
    Related-bug: https://github.com/docker/docker-registry/issues/518
    Closes-Bug: #1523336