回忆--RYU流量监控

RYU流量监控

前言

Ryu book上的一个流量监控的应用,相对比较好看懂

实验代码

github源码

from ryu.app import simple_switch_13
from ryu.controller import ofp_event
from ryu.controller.handler import MAIN_DISPATCHER, DEAD_DISPATCHER
from ryu.controller.handler import set_ev_cls
from ryu.lib import hub
from operator import attrgetter

class SimpleMonitor13(simple_switch_13.SimpleSwitch13):

    def __init__(self, *args, **kwargs):
        super(SimpleMonitor13, self).__init__(*args, **kwargs)
        self.datapaths = {}
        self.monitor_thread = hub.spawn(self._monitor)

    """
    EventOFPStateChange

    An event class for negotiation phase change notification.

    An instance of this class is sent to observer after changing the negotiation phase. An instance has at least the following attributes.
    """
    @set_ev_cls(ofp_event.EventOFPStateChange, [MAIN_DISPATCHER, DEAD_DISPATCHER])
    def _state_change_handler(self, ev):
        datapath = ev.datapath
        if ev.state == MAIN_DISPATCHER:
            if datapath.id not in self.datapaths:
                self.logger.debug('register datapath: %016x', datapath.id)
                self.datapaths[datapath.id] = datapath
        elif ev.state == DEAD_DISPATCHER:
            if datapath.id in self.datapaths:
                self.logger.debug('unregister datapath: %016x', datapath.id)
                del self.datapaths[datapath.id]

    def _monitor(self):
        while True:
            for dp in self.datapaths.values():
                self._request_stats(dp)
            hub.sleep(10)

    """
    OFPFlowStatsRequest

    Individual flow statistics request message

    The controller uses this message to query individual flow statistics.
    """

    def _request_stats(self, datapath):
        self.logger.debug('send stats request: %016x', datapath.id)
        ofproto = datapath.ofproto
        parser = datapath.ofproto_parser

        req = parser.OFPFlowStatsRequest(datapath)
        datapath.send_msg(req)

        req = parser.OFPPortStatsRequest(datapath, 0, ofproto.OFPP_ANY)
        datapath.send_msg(req)

    """
    OFPFlowStatsReply

    Individual flow statistics reply message

    The switch responds with this message to an individual flow statistics request.
    """

    @set_ev_cls(ofp_event.EventOFPFlowStatsReply, MAIN_DISPATCHER)
    def _flow_stats_reply_handler(self, ev):
        body = ev.msg.body

        print body

        self.logger.info('datapath         '
                         'in-port  eth-dst           '
                         'out-port packets  bytes')
        self.logger.info('---------------- '
                         '-------- ----------------- '
                         '-------- -------- --------')
        for stat in sorted([flow for flow in body if flow.priority == 1],
                           key=lambda flow: (flow.match['out_port'],
                                             flow.match['eth_dst'])):
            self.logger.info('%016x %8x %17s %8x %8d %8d',
                             ev.msg.datapath.id,
                             stat.match['in_port'], stat.match['eth_dst'],
                             stat.instructions[0].actions[0].port,
                             stat.packet_count, stat.byte_count)

    """
    OFPPortStatsReply

    Port statistics reply message

    The switch responds with this message to a port statistics request.
    """
    @set_ev_cls(ofp_event.EventOFPPortStatsReply, MAIN_DISPATCHER)
    def _port_stats_reply_handler(self, ev):
        body = ev.msg.body
        # print body
        # print type(body)
        self.logger.info('datapath         port     '
                         'rx-pkts  rx-bytes rx-error '
                         'tx-pkts  tx-bytes tx-error')
        self.logger.info('---------------- -------- '
                         '-------- -------- -------- '
                         '-------- -------- --------')
        for stat in sorted(body, key=attrgetter('port_no')):
            # print type(stat)
            self.logger.info('%016x %8x %8d %8d %8d %8d %8d %8d',
                             ev.msg.datapath.id, stat.port_no,
                             stat.rx_packets, stat.rx_bytes, stat.rx_errors,
                             stat.tx_packets, stat.tx_bytes, stat.tx_errors)

代码细节

这次实验细节主要是关于 sorted, lambda, attrgetter

• sorted

  python sorted

  比较好理解的一个排序函数

  lambda, attrgetter在这里主要是为了sorted服务,根据关键字排序而用

• lambda

  lambda还有很多作用,详情请参照: Python中的lambda表达式小析

• attrgetter

  python中的attrgetter()