Comment 18 for bug 1820007

Reviewed: https://review.opendev.org/697118
Committed: https://git.openstack.org/cgit/openstack/os-brick/commit/?id=8972aa4add00e8c27642e5a39ee5dd3aedb39d9f
Submitter: Zuul
Branch: stable/queens

commit 8972aa4add00e8c27642e5a39ee5dd3aedb39d9f
Author: Lee Yarwood <email address hidden>
Date: Thu Nov 21 20:01:50 2019 +0000

    iscsi: Add _get_device_link retry when waiting for /dev/disk/by-id/ to populate

    Bug #1820007 documents failures to find /dev/disk/by-id/ symlinks
    associated with encrypted volumes both in real world and CI
    environments. These failures appear to be due to udev on these slow or
    overloaded hosts failing to populate the required /dev/disk/by-id/
    symlinks in time after the iSCSI volume has been connected.

    This change seeks to avoid such failures by simply decorating
    _get_device_link with the @utils.retry to hopefully allow udev time to
    create the required symlinks under /dev/disk/by-id/.

    Closes-Bug: #1820007
    Change-Id: Ib9c8ebae7a6051e18538920139fecd123682a474
    (cherry picked from commit 331316827a60aa50ee26be08a06027525f5194ef)
    (cherry picked from commit d8ed21e7d25f67c6d2bfe71515723f68ce15b887)
    (cherry picked from commit 7ffa3fb7d9d497fd3848ab0313ba8aa84136a06e)
    (cherry picked from commit ed9feedfa3f9a434a0bbd48953262fbb2999465b)