Comment 5 for bug 1852458

Reviewed: https://review.opendev.org/701279
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=6484d9ff5b03f7b7d8e9ba296f7f32d2e54fcc11
Submitter: Zuul
Branch: stable/train

commit 6484d9ff5b03f7b7d8e9ba296f7f32d2e54fcc11
Author: Matt Riedemann <email address hidden>
Date: Wed Nov 13 15:03:27 2019 -0500

    Create instance action when burying in cell0

    Change I8742071b55f018f864f5a382de20075a5b444a79 in Ocata
    moved the creation of the instance record from the API to
    conductor. As a result, the "create" instance action was
    only being created in conductor when the instance is created
    in a non-cell0 database. This is a regression because before
    that change when a server create would fail during scheduling
    you could still list instance actions for the server and see
    the "create" action but that was lost once we started burying
    those instances in cell0.

    This fixes the bug by creating the "create" action in the cell0
    database when burying an instance there. It goes a step further
    and also creates and finishes an event so the overall action
    message shows up as "Error" with the details about where the
    failure occurred in the event traceback.

    A short release note is added since a new action event is
    added here (conductor_schedule_and_build_instances) rather than
    re-use some kind of event that we could generate from the
    compute service, e.g. compute__do_build_and_run_instance.

    NOTE(mriedem): A couple of helper method calls in the test had
    to be updated since change I8c96b337f32148f8f5899c9b87af331b1fa41424
    is not in Train.

    Change-Id: I1e9431e739adfbcfc1ca34b87e826a516a4b18e2
    Closes-Bug: #1852458
    (cherry picked from commit f2608c91175411ec7c2604035adb39306d7e607e)