Steps to reproduce:
1. Enable barbican in devstack
2. Create a k8s bay
3. Delete the bay
I saw the following error in conductor:
2015-10-08 16:02:47.365 ERROR barbicanclient.client [req-9557907e-d313-4157-bbdb-2cc2a89e2447 None None] 5xx Server error: Internal Server Error
2015-10-08 16:02:47.366 ERROR magnum.common.cert_manager.barbican_cert_manager [req-9557907e-d313-4157-bbdb-2cc2a89e2447 None None] Error deregistering as a consumer of http://192.168.10.100:9311/v1/containers/25c11763-6d63-4b79-802f-1fb944debc8e
2015-10-08 16:02:47.366 TRACE magnum.common.cert_manager.barbican_cert_manager Traceback (most recent call last):
2015-10-08 16:02:47.366 TRACE magnum.common.cert_manager.barbican_cert_manager File "/opt/stack/magnum/magnum/common/cert_manager/barbican_cert_manager.py", line 210, in delete_cert
2015-10-08 16:02:47.366 TRACE magnum.common.cert_manager.barbican_cert_manager url=resource_ref
2015-10-08 16:02:47.366 TRACE magnum.common.cert_manager.barbican_cert_manager File "/opt/stack/python-barbicanclient/barbicanclient/containers.py", line 775, in remove_consumer
2015-10-08 16:02:47.366 TRACE magnum.common.cert_manager.barbican_cert_manager self._api.delete(href, json=consumer_dict)
2015-10-08 16:02:47.366 TRACE magnum.common.cert_manager.barbican_cert_manager File "/usr/local/lib/python2.7/dist-packages/keystoneclient/adapter.py", line 185, in delete
2015-10-08 16:02:47.366 TRACE magnum.common.cert_manager.barbican_cert_manager return self.request(url, 'DELETE', **kwargs)
2015-10-08 16:02:47.366 TRACE magnum.common.cert_manager.barbican_cert_manager File "/opt/stack/python-barbicanclient/barbicanclient/client.py", line 65, in request
2015-10-08 16:02:47.366 TRACE magnum.common.cert_manager.barbican_cert_manager self._check_status_code(resp)
2015-10-08 16:02:47.366 TRACE magnum.common.cert_manager.barbican_cert_manager File "/opt/stack/python-barbicanclient/barbicanclient/client.py", line 101, in _check_status_code
2015-10-08 16:02:47.366 TRACE magnum.common.cert_manager.barbican_cert_manager status
2015-10-08 16:02:47.366 TRACE magnum.common.cert_manager.barbican_cert_manager HTTPServerError: Internal Server Error
2015-10-08 16:02:47.366 TRACE magnum.common.cert_manager.barbican_cert_manager
2015-10-08 16:02:47.367 WARNING magnum.conductor.handlers.common.cert_manager [req-9557907e-d313-4157-bbdb-2cc2a89e2447 None None] Deleting cert is failed: http://192.168.10.100:9311/v1/containers/25c11763-6d63-4b79-802f-1fb944debc8e
