Comment 2 for bug 1704423

Reviewed: https://review.openstack.org/483986
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=da57d17e6c7d5d7e84af3c46a836ee587581bf8d
Submitter: Jenkins
Branch: master

commit da57d17e6c7d5d7e84af3c46a836ee587581bf8d
Author: Balazs Gibizer <email address hidden>
Date: Fri Jul 14 18:18:33 2017 +0200

    fix unshelve notification test instability

    The unshelve notification sample test shelve-offloads an instance, waits for
    it state to change to SHELVED_OFFLOADED then unshelve the instance and matches
    generated the unshelve notification with the stored sample. This test
    intermittently fails as the host paramter of the instance doesn't match
    sometimes. The reason is that the compute manager during shelve offloading
    first sets the state of the instance then later sets the host of the instance.
    So the test can start unshelving the instance before the host is cleaned by
    the shelve offload code.

    The test is updated to not just wait for the state change but also wait for
    the change of the host attribute.

    Change-Id: I459332de407187724fd2962effb7f3a34751f505
    Closes-Bug: #1704423