Comment 7 for bug 1748544

Reviewed: https://review.openstack.org/550489
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=6ed7fc11459eb5a69088630e5ea4d12e441f80f2
Submitter: Zuul
Branch: stable/queens

commit 6ed7fc11459eb5a69088630e5ea4d12e441f80f2
Author: melanie witt <email address hidden>
Date: Fri Feb 9 19:43:30 2018 +0000

    Save admin password to sysmeta in libvirt driver

    We have an API for setting the admin password for an already created
    instance and we have a metadata API for retrieving the encrypted
    password. In the libvirt driver, when a request to set the admin
    password is received, it is indeed set in the guest but the instance
    system metadata is never updated with the encrypted password, so
    attempts to retrieve the password via the metadata service API result
    in an empty string returned instead of the encrypted password.

    This has been broken in the libvirt driver since the set admin password
    password feature was added, as far as I can tell. The xen api driver,
    however, handles the same thing correctly and this adds similar logic
    to the libvirt driver to fix the problem.

    Closes-Bug: #1748544

    Change-Id: Icf44c4c94529cb75232abe1f3ecc5a4d3646b0cc
    (cherry picked from commit 715a3cadb07fb92cc11542cfb5001844122b6f60)