def request_uplink_info(self, context, agent):
        """Process uplink message from an agent."""

        LOG.debug('request_uplink_info from %(agent)s', {'agent': agent})

        # Add the request into queue for processing.
        event_type = 'agent.request.uplink'
        payload = {'agent': agent}
        timestamp = time.ctime()
        data = (event_type, payload)
        pri = self.obj.PRI_LOW_START + 1
        self.obj.pqueue.put((pri, timestamp, data))
        LOG.debug('Added request uplink info into queue.')

        return 0
Process uplink message from an agent.