'Setup the reserved DHCP port, if there is one.'

def _setup_reserved_dhcp_port(self, network, device_id, dhcp_subnets):

    LOG.debug('DHCP    port    %(device_id)s    on    network    %(network_id)s    does    not    yet    exist.    Checking    for    a    reserved    port.', {'device_id': device_id, 'network_id': network.id})
    for port in network.ports:
        port_device_id = getattr(port, 'device_id', None)
        if (port_device_id == n_const.DEVICE_ID_RESERVED_DHCP_PORT):
            try:
                port = self.plugin.update_dhcp_port(port.id, {'port': {'network_id': network.id, 'device_id': device_id}})
            except oslo_messaging.RemoteError as e:
                if (e.exc_type == 'DhcpPortInUse'):
                    LOG.info(_LI('Skipping    DHCP    port    %s    as    it    is    already    in    use'), port.id)
                    continue
                raise
            if port:
                return port
