Comment 2 for bug 1757235

Reviewed: https://review.openstack.org/555379
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=341dd44ba796e933920da6718a2891e35ed88506
Submitter: Zuul
Branch: master

commit 341dd44ba796e933920da6718a2891e35ed88506
Author: Alan Bishop <email address hidden>
Date: Tue Mar 20 15:10:28 2018 -0400

    Handle migrating encryption key IDs in Backup table

    Enhance the code that migrates the ConfKeyManager's fixed_key to
    Barbican to also consider the Backup table. When the original key
    migration feature was added, the encryption key ID was not stored in
    the Backup table. But now the Backup table contains that field, so
    the migration code needs to handle that table as well.

    Whereas the cinder-volume service is responsible for migrating keys
    in the Volume and Snapshot tables, the cinder-backup service handles
    migrating keys in the Backup table. Each instance of the service
    migrates its own entries by matching the "host" field in the
    corresponding tables.

    The Backup OVO now inherits from base.CinderComparableObject. This does
    not affect the object's hash signature, and so the version number does
    need to be incremented.

    Closes-Bug: #1757235
    Change-Id: Id4581eec80f82925c20c424847bff1baceda2349