Comment 19 for bug 1768876

Reviewed: https://review.openstack.org/643173
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=133763d3582c2e85e4e5962b542294135d1a7f4c
Submitter: Zuul
Branch: stable/rocky

commit 133763d3582c2e85e4e5962b542294135d1a7f4c
Author: Matt Riedemann <email address hidden>
Date: Thu May 10 19:27:36 2018 -0400

    Update instance.availability_zone during live migration

    While triaging bug 1768876 there was some concern
    that change I8d426f2635232ffc4b510548a905794ca88d7f99
    in Pike had regressed some behavior where a user that
    does not explicitly request a specific AZ during server
    create is then later restricted to only move operations
    within that same AZ.

    This test shows that is not a regression because the
    AvailabilityZoneFilter looks at RequestSpec.availability_zone
    rather than instance.availabililty_zone, so the instance
    is free to be moved across zones.

    As a result of the test, however, it was noticed that
    the instance.availability_zone isn't updated during live
    migration once the destination host is selected. The other
    move operations like unshelve, evacuate and cold migrate
    all update the instance.availabiltiy_zone, so this copies
    the same logic.

    Conflicts:
          nova/tests/unit/conductor/tasks/test_live_migrate.py

    NOTE(mriedem): The conflict is due to not having change
    I8e47cac8bab50a086b98f37c2f9f659b10009cf1 in Rocky.
    Also note that the func_fixtures import in the functional
    test was changed since it was added in Stein with change
    Idaed39629095f86d24a54334c699a26c218c6593.

    Change-Id: I9f73c237923fdcbf4096edc5aedd2c968d4b893e
    Closes-Bug: #1771860
    Related-Bug: #1768876
    (cherry picked from commit 0ed68c76fa8a84d1d5f0ab945e34c8e16341d627)