Comment 16 for bug 1806064

Reviewed: https://review.openstack.org/623934
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=3dd42c2cd658fd3f73b11fbf5e81ccccd748b450
Submitter: Zuul
Branch: stable/queens

commit 3dd42c2cd658fd3f73b11fbf5e81ccccd748b450
Author: Matt Riedemann <email address hidden>
Date: Mon Dec 3 15:12:12 2018 -0500

    Create BDMs/tags in cell with instance when over-quota

    If the server create build request fails the quota check
    after the instance record has been created in a cell, we also
    need to create the BDMs and tags in that cell so that users
    can still see the tags on the server and so the API can
    properly cleanup volume attachments when the server is deleted.

    This change updates _cleanup_build_artifacts to create BDMs
    and tags in the same cell as the instance prior to deleting the
    build request and request spec and adjusts the assertions in the
    related functional test to show the bug is fixed.

    As for instances that get buried in cell0 due to scheduling
    failures, the tags are not created there so comments are left
    in those code paths to fix that issue as well, but that can be
    done separately from this patch.

    Change-Id: I1a9bdb596f74605ab4613c9cb2574e976aebbd8c
    Closes-Bug: #1806064
    (cherry picked from commit 6d0386058b9628bbfcf64abdd707ad87ee19353c)
    (cherry picked from commit 3028d25705bbd54cdf0b7ba13859a809d401fc70)