Comment 22 for bug 1732428

Reviewed: https://review.opendev.org/749205
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=fe52b6c25bebdd1b459c7a59fbb8d9f6de200c9d
Submitter: Zuul
Branch: master

commit fe52b6c25bebdd1b459c7a59fbb8d9f6de200c9d
Author: Alexandre Arents <email address hidden>
Date: Tue Sep 1 08:26:25 2020 +0000

    Update image_base_image_ref during rebuild.

    In different location we assume system_metadata.image_base_image_ref
    exists, because it is set during instance creation in method
    _populate_instance_for_create

    But once instance is rebuild, all system_metadata image property a dropped
    and replace by new image property and without setting back
    image_base_image_ref.

    This change propose to set image_base_image_ref during rebuild.

    In specific case of shelve/unshelve in Qcow2 backend, image_base_image_ref is
    used to rebase disk image, so we ensure this property is set as instance may
    have been rebuild before the fix was apply.

    Related-Bug: #1732428
    Closes-Bug: #1893618
    Change-Id: Ia3031ea1f7db8b398f02d2080ca603ded8970200