Comment 4 for bug 1596922

Reviewed: https://review.openstack.org/341253
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=0e24e9e2ec254364ffe029226b9ae5956002df54
Submitter: Jenkins
Branch: master

commit 0e24e9e2ec254364ffe029226b9ae5956002df54
Author: Hironori Shiina <email address hidden>
Date: Sun Jul 10 15:32:58 2016 +0900

    ironic: Cleanup instance information when spawn fails

    Instance information such as an instance_uuid set to an ironic node by
    _add_driver_fields() is not cleared when spawning is aborted by an
    exception raised before ironic starts deployment. Then, ironic node
    stays AVAILABLE state with instance_uuid set. This information is not
    cleared even if the instance is deleted. The ironic node cannot be
    removed nor deployed again becuase instance_uuid remains.

    This patch adds a method to remove the information. This method is
    called if ironic doesn't need unprovisioning when an instance is
    destroyed.

    Change-Id: Idf5191aa1c990552ca2340856d5d5b6ac03f7539
    Closes-Bug: 1596922