Comment 10 for bug 1801316

Reviewed: https://review.opendev.org/656010
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=66133741602924c4a6509277bcb33a2f2aa042d1
Submitter: Zuul
Branch: stable/queens

commit 66133741602924c4a6509277bcb33a2f2aa042d1
Author: zhangbailin <email address hidden>
Date: Sun Nov 4 19:25:59 2018 -0500

    Change the matching method of the backup driver

    The backup driver name is configured uniformly from the Stein version.
    For example, support for
    'cinder.backup.drivers.service.ServiceBackupDriver' does not support
    'cinder.backup.drivers.service'.

    However, the above two backup drivers are supported in a stable version
    before Rocky (including Rocky).

    For the same storage backend, if the backup driver used to create the
    backup file is 'cinder.backup.drivers.service.ServiceBackupDriver',
    the backup driver configured when restoring the backup is
    'cinder.backup.drivers.service'. The recovery of the backup file will
    fail because the drivers do not match.

    Therefore, the processing of this method needs to be compatible with the
    backup driver for different configurations of the same backend.

    The above 'service' is a proxy, it can be one of {'swift', 'nfs',
    'ceph', 'glusterfs', 'google', 'tsm', 'posix'}

    Closes-Bug: #1801316
    Part of this backup comes from Change-Id:
    If1e34ea112b0cff328a58ec2fc9c3f5a5005f1c6
    Change-Id: I1d7ee395c89beda0e50cbe26b4abb4fc7749e15e
    (cherry picked from commit b90a13d07dcf230a509cc93a4c864a20494cf5e7)
    Conflicts:
        cinder/backup/manager.py