'Retrieve instance uuids associated with the given IP address.
:returns: A list of dicts containing the uuids keyed by \'instance_uuid\'
e.g. [{\'instance_uuid\': uuid}, ...]'

def _get_instance_uuids_by_ip(self, context, address):

    search_opts = {'fixed_ips': ('ip_address=%s' % address)}
    data = get_client(context).list_ports(**search_opts)
    ports = data.get('ports', [])
    return [{'instance_uuid': port['device_id']} for port in ports if port['device_id']]
