manage.py 文件源码

def _get_path(self, src_vnf, dst_vnf, src_vnf_intf, dst_vnf_intf):
        """
        Own implementation of the get_path function from DCNetwork, because we just want the path and not set up
        flows on the way.

        :param src_vnf: Name of the source VNF
        :type src_vnf: ``str``
        :param dst_vnf: Name of the destination VNF
        :type dst_vnf: ``str``
        :param src_vnf_intf: Name of the source VNF interface
        :type src_vnf_intf: ``str``
        :param dst_vnf_intf: Name of the destination VNF interface
        :type dst_vnf_intf: ``str``
        :return: path, src_sw, dst_sw
        :rtype: ``list``, ``str``, ``str``
        """
        # modified version of the _chainAddFlow from emuvim.dcemulator.net._chainAddFlow
        src_sw = None
        dst_sw = None
        logging.debug("Find shortest path from vnf %s to %s",
                      src_vnf, dst_vnf)

        for connected_sw in self.net.DCNetwork_graph.neighbors(src_vnf):
            link_dict = self.net.DCNetwork_graph[src_vnf][connected_sw]
            for link in link_dict:
                if (link_dict[link]['src_port_id'] == src_vnf_intf or
                            link_dict[link][
                                'src_port_name'] == src_vnf_intf):
                    # found the right link and connected switch
                    src_sw = connected_sw
                    break

        for connected_sw in self.net.DCNetwork_graph.neighbors(dst_vnf):
            link_dict = self.net.DCNetwork_graph[connected_sw][dst_vnf]
            for link in link_dict:
                if link_dict[link]['dst_port_id'] == dst_vnf_intf or \
                                link_dict[link][
                                    'dst_port_name'] == dst_vnf_intf:
                    # found the right link and connected
                    dst_sw = connected_sw
                    break
        logging.debug("From switch %s to %s " % (src_sw, dst_sw))

        # get shortest path
        try:
            # returns the first found shortest path
            # if all shortest paths are wanted, use: all_shortest_paths
            path = nx.shortest_path(self.net.DCNetwork_graph, src_sw, dst_sw)
        except:
            logging.exception("No path could be found between {0} and {1} using src_sw={2} and dst_sw={3}".format(
                src_vnf, dst_vnf, src_sw, dst_sw))
            logging.debug("Graph nodes: %r" % self.net.DCNetwork_graph.nodes())
            logging.debug("Graph edges: %r" % self.net.DCNetwork_graph.edges())
            for e, v in self.net.DCNetwork_graph.edges():
                logging.debug("%r" % self.net.DCNetwork_graph[e][v])
            return "No path could be found between {0} and {1}".format(src_vnf, dst_vnf)

        logging.info("Shortest path between {0} and {1}: {2}".format(src_vnf, dst_vnf, path))
        return path, src_sw, dst_sw