context.py 文件源码

def __call__(self):
        ports = config('data-port')
        if ports:
            # Map of {port/mac:bridge}
            portmap = parse_data_port_mappings(ports)
            ports = portmap.keys()
            # Resolve provided ports or mac addresses and filter out those
            # already attached to a bridge.
            resolved = self.resolve_ports(ports)
            # FIXME: is this necessary?
            normalized = {get_nic_hwaddr(port): port for port in resolved
                          if port not in ports}
            normalized.update({port: port for port in resolved
                               if port in ports})
            if resolved:
                return {normalized[port]: bridge for port, bridge in
                        six.iteritems(portmap) if port in normalized.keys()}

        return None