Comment 14 for bug 1835070

Reviewed: https://review.opendev.org/676677
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=d89a0d1f96df1cfe4c9e8025b147508315ca239d
Submitter: Zuul
Branch: stable/pike

commit d89a0d1f96df1cfe4c9e8025b147508315ca239d
Author: Balazs Gibizer <email address hidden>
Date: Tue Jul 2 14:56:40 2019 +0200

    Stabilize unshelve notification sample tests

    The notification sample test for unshelve waits for the instance to
    reach ACTIVE state and then asserts if unshelve.end notification is
    emitted properly. However the instance.vm_state is set to ACTIVE earlier[1]
    than emitting the unshelve.end notification[2]. This can cause two
    different test case failure.

    1) _test_unshelve_server() fails with no ushelve.end notification
    received.

    2) _test_shelve_and_shelve_offload_server() also has a unshelve action
    at the end and that test step also only waits for the the ACTIVE state.
    So the unshelve.end notification from the end of
    _test_shelve_and_shelve_offload_server() can bleed into the
    _test_unshelve_server() step causing that it receive one more
    notifications.

    So this patch adds an extra
    self._wait_for_notification('instance.unshelve.end') call to each test
    step to prevent the instability.

    [1] https://github.com/openstack/nova/blob/5c6c1f8f/nova/compute/manager.py#L5322-L5326
    [2] https://github.com/openstack/nova/blob/5c6c1f8f/nova/compute/manager.py#L5329
    [3] https://github.com/openstack/nova/blob/5c6c1f8f/nova/tests/functional/notification_sample_tests/test_instance.py#L836

    Conflicts:
          nova/tests/functional/notification_sample_tests/test_instance.py
    Conflicts due to:
    * Ie7a886f5b389c2f0bb9dc66129e4562cc09ba1b5

    Also in pike there is no _test_shelve_and_shelve_offload_server step but
    two distinct steps _test_shelve_server and _test_shelve_offload_server so
    this patch needed to be extened on pike. In the_test_shelve_server step
    we need to wait for instance.power_on.end instead of instance.unshelve.end
    as unshelve without offload just powers on the instance.

    Closes-Bug: #1835070

    Change-Id: Ie217523a8969326b27930d7f74e50e9b352ab7a1
    (cherry picked from commit 40f1e7c4c22dc6023614b34f28bb7fc416b668a8)
    (cherry picked from commit 3bc6ff029ff24083844db363010988d8d08cff00)
    (cherry picked from commit a85ce04fa39e60e672e4fa2d7912f6880079c6ef)
    (cherry picked from commit 8afc39a2c748a8fde070493dd5633788f782c69a)