使用pyroute2 IPDB功能监视以太网接口内核事件时出现异常

Question

我正在尝试使用pyroute2ipdb功能监视内核网络接口（链接）向上或向下事件。从回调函数获取接口索引信息时会出现异常。但是在“msg”中有一个索引字段。我是根据这个参考来编码的。任何解决例外的方法。你知道吗

#!/usr/bin/python

import pyroute2

# Create Instance of IPDB
ipdb = pyroute2.IPDB()

action = 'RTM_NEWLINK'

def my_call_back(ipdb, msg, action):
   index = msg['index']
   print msg
   print index


ipdb.register_callback(my_call_back, mode='post')

while(True):
  pass

期望值： 根@VirtualBox：/home/#Python通知.py你知道吗

{'index': 2, 'family': 0, '__align': (), 'header': {'pid': 0, 'length': 1276, 'flags': 0, 'error': None, 'type': 16, 'sequence_number': 0}, 'flags': 4098, 'ifi_type': 1, 'event': 'RTM_NEWLINK', 'change': 1, 'attrs': [('IFLA_IFNAME', 'eth0'), ('IFLA_TXQLEN', 1000), ('IFLA_OPERSTATE', 'DOWN'), ('IFLA_LINKMODE', 0), ('IFLA_MTU', 1500), ('IFLA_GROUP', 0), ('IFLA_PROMISCUITY', 0), ('IFLA_NUM_TX_QUEUES', 1), ('IFLA_GSO_MAX_SEGS', 65535), ('IFLA_GSO_MAX_SIZE', 65536), ('IFLA_NUM_RX_QUEUES', 1), ('IFLA_CARRIER', 0), ('IFLA_QDISC', 'pfifo_fast'), ('IFLA_CARRIER_CHANGES', 21), ('IFLA_PROTO_DOWN', 0), ('IFLA_MAP', {'dma': 0, 'base_addr': 0, 'irq': 0, 'mem_end': 0, 'port': 0, 'mem_start': 0}), ('IFLA_ADDRESS', '08:00:27:5f:7d:3e'), ('IFLA_BROADCAST', 'ff:ff:ff:ff:ff:ff'))
2
Exception in thread IPDB callback 140583224088768:
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 801, in __bootstrap_inner
    self.run()
  File "/usr/lib/python2.7/threading.py", line 754, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/usr/local/lib/python2.7/dist-packages/pyroute2/ipdb/main.py", line 968, in safe
    callback(*argv, **kwarg)
  File "notification.py", line 11, in my_call_back
    index = msg['index']
KeyError: 'index'

Exception in thread IPDB callback 140583224088768:
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 801, in __bootstrap_inner
    self.run()
  File "/usr/lib/python2.7/threading.py", line 754, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/usr/local/lib/python2.7/dist-packages/pyroute2/ipdb/main.py", line 968, in safe
    callback(*argv, **kwarg)
  File "notification.py", line 11, in my_call_back
    index = msg['index']
KeyError: 'index'

测试：

 ifconfig <interface name> up/down
 ifconfig eth0 down
 ifconfig eth0 up

Answer 1

当链接建立或关闭时，从内核到回调函数有多条内核消息。有些消息没有“index”字段，因此可以看到键错误。下面修改的函数应解决

def my_call_back(ipdb, msg, action):
   if 'index' in msg:
      index = msg['index']
      interface = ipdb.interfaces[index]
      print interface