'Return capabilities list of given backend.'

def show(self, req, id):

    context = req.environ['cinder.context']
    authorize(context, 'capabilities')
    filters = {'host_or_cluster': id, 'binary': 'cinder-volume'}
    services = objects.ServiceList.get_all(context, filters)
    if (not services):
        msg = (_("Can't    find    service:    %s") % id)
        raise exception.NotFound(msg)
    topic = services[0].service_topic_queue
    try:
        capabilities = self.volume_api.get_capabilities(context, topic, False)
    except oslo_messaging.MessagingTimeout:
        raise exception.RPCTimeout(service=topic)
    return self._view_builder.summary(req, capabilities, topic)
