Comment 4 for bug 1831917

Reviewed: https://review.opendev.org/663332
Committed: https://git.openstack.org/cgit/openstack/watcher/commit/?id=966a4dfa5f030d4b88e4902c9f762a2d6213a670
Submitter: Zuul
Branch: master

commit 966a4dfa5f030d4b88e4902c9f762a2d6213a670
Author: Matt Riedemann <email address hidden>
Date: Wed Jun 5 09:33:11 2019 -0400

    Configure nova notification format in non-grenade CI jobs

    Nova used to emit versioned and unversioned notiifcations
    by default but that changed in https://review.opendev.org/603079/
    so now nova emits only unversioned notifications by default.
    Watcher listens for versioned notifications so we need to configure
    nova to emit both versioned (for Watcher) and unversioned
    (for Ceilometer) notifications explicitly.

    This adds an override-defaults file so devstack will load up
    the nova devstack variable to set the notification_format before
    importing and stacking the nova lib script.

    Note that this only fixes the non-grenade CI jobs since grenade
    requires separate handling for overriding defaults which is proving
    hard to do and will be addressed in a separate change.

    Partial-Bug: #1831917

    Change-Id: I7e441608b38338eecd80e663ed3abe66a89e504f