Comment 2 for bug 1412547

Reviewed: https://review.openstack.org/148346
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=abd6d880bcff18d0a6dcef28121c00d7d172e496
Submitter: Jenkins
Branch: master

commit abd6d880bcff18d0a6dcef28121c00d7d172e496
Author: Davanum Srinivas <email address hidden>
Date: Mon Jan 19 14:36:53 2015 -0500

    Fix py27 gate failure - test_create_instance_both_bdm_formats

    Intermittent failure, depending on how the extensions get loaded.
    The specific check for HTTPBadRequest is for the exception being
    thrown here:
    https://github.com/openstack/nova/blob/master/nova/api/openstack/compute/plugins/v3/block_device_mapping_v1.py#L53

    To be able to reach this piece of code, both the extensions
    'os-block-device-mapping' and 'os-block-device-mapping-v1'
    need to be activated. To be sure this happens all the time
    we create a both_controllers with an empty blacklist and
    use that for this test.

    Closes-Bug: #1412547
    Change-Id: I284cc9f053909359a8de1a0bd85f61fbfbc98af0