code: def get_host_port(self, container_port, proto='tcp', index=0):
          
          port_spec = '{}/{}'.format(container_port, proto)
          return self._host_port(port_spec, index)
docs: :param container_port: The container port.
          :param proto: The protocol ('tcp' or 'udp').
          :param index: The index of the mapping entry to return.
          :returns: A tuple of the interface IP and port on the host.