Comment 55 for bug 1404867

Reviewed: https://review.openstack.org/546203
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=26e32ce85823bf1d87ec5c729aa408b92f526e38
Submitter: Zuul
Branch: stable/queens

commit 26e32ce85823bf1d87ec5c729aa408b92f526e38
Author: ankitagrawal <email address hidden>
Date: Wed Sep 23 03:58:19 2015 -0700

    Clean up ports and volumes when deleting ERROR instance

    Usually, when instance.host = None, it means the instance was never
    scheduled. However, the exception handling routine in compute manager
    [1] will set instance.host = None and set instance.vm_state = ERROR
    if the instance fails to build on the compute host. If that happens, we
    end up with an instance with host = None and vm_state = ERROR which may
    have ports and volumes still allocated.

    This adds some logic around deleting the instance when it may have
    ports or volumes allocated.

      1. If the instance is not in ERROR or SHELVED_OFFLOADED state, we
         expect instance.host to be set to a compute host. So, if we find
         instance.host = None in states other than ERROR or
         SHELVED_OFFLOADED, we consider the instance to have failed
         scheduling and not require ports or volumes to be freed, and we
         simply destroy the instance database record and return. This is
         the "delete while booting" scenario.

      2. If the instance is in ERROR because of a failed build or is
         SHELVED_OFFLOADED, we expect instance.host to be None even though
         there could be ports or volumes allocated. In this case, run the
         _local_delete routine to clean up ports and volumes and delete the
         instance database record.

    Co-Authored-By: Ankit Agrawal <email address hidden>
    Co-Authored-By: Samuel Matzek <email address hidden>
    Co-Authored-By: melanie witt <email address hidden>

    Closes-Bug: 1404867
    Closes-Bug: 1408527

    Conflicts:
          nova/tests/unit/compute/test_compute_api.py

    [1] https://github.com/openstack/nova/blob/55ea961/nova/compute/manager.py#L1927-L1929

    Change-Id: I4dc6c8bd3bb6c135f8a698af41f5d0e026c39117
    (cherry picked from commit b3f39244a3eacd6fb141de61850cbd84fecdb544)