Comment 29 for bug 1781286

Reviewed: https://review.opendev.org/685998
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=8c332c4dd79f8bb5fdc5f6722a80c9a117ff52c4
Submitter: Zuul
Branch: master

commit 8c332c4dd79f8bb5fdc5f6722a80c9a117ff52c4
Author: Matt Riedemann <email address hidden>
Date: Tue Oct 1 12:08:18 2019 -0400

    Add functional regression test for build part of bug 1781286

    This adds a functional regression test to recreate bug 1781286
    where rescheduling from a build failure where the cell conductor
    does not have access to the API DB fails when trying to get
    availability zone information about a selected alternate host.
    The test is a bit tricky in that it has to stub out the AZ query
    to fail but only after we hit the compute service and then remove
    that stub so we can use the API again.

    Note that change I6bfa6fa767403fb936a6ae340b8687eb161732fc handles
    the error in conductor and puts the instance into ERROR state. The
    bug is not yet resolved though since we should be able to avoid
    the up-call by stashing the alternate host availability zone on the
    Selection object during scheduling and use that later during the
    reschedule. Once that is working the functional test will be updated.

    Change-Id: I62179d6b93ea1a23c4906477ee19b422bfcb72a2
    Related-Bug: #1781286