python - 被 Python 中的 read_all() 函数困住了吗？

Question

我用 python 编写了一段小代码，使用 telnet 库在多个 Cisco 路由器上自动执行配置任务。在第一次迭代中，一切正常，问题是我在函数 read_all() 的第二次迭代中超时。如果我从 telnetlib.Telnet() 函数中删除超时参数，我将永远陷入同一个迭代中。

from telnet import telnet

import xlrd

class handler:
 excel_sheet=None
 ipv4_devices=None
 ipv6_devices=None
 config=None
 telnet=None

def __init__(self):
 self.excel_sheet = xlrd.open_workbook("ipv4_devices.xlsx")
 self.config=open("config.txt","r")
 output_init = open("output.txt","w+")
 output_init.write("")
 output_init.close()  

def execute(self):
 row = None
 column = None
 self.ipv4_devices = self.excel_sheet.sheet_by_index(0)
 for row in range(self.ipv4_devices.nrows-1):
  self.telnet = telnet(self.ipv4_devices.cell_value(row+1,0),self.ipv4_devices.cell_value(row+1,1), self.ipv4_devices.cell_value(row+1,2), self.ipv4_devices.cell_value(row+1,3), self.config)
 self.telnet.do_telnet()
 self.telnet=None
self.config.close()

上面是我的 Handler.py 文件，它依次调用包含实际 telnet 代码的 telnet.py 文件。

import sys
import telnetlib

class telnet:
 ipv4_address=None
 port=0
 username=None 
 passphrase=None
 config=None

 def __init__(self, ipv4_address=None, port=23, username=None, passphrase=None, config=None):
  if (ipv4_address is not None) and (username is not None) and (passphrase is not None) and (config is not None) : 
   self.ipv4_address = ipv4_address
   self.port = port
   self.username = username
   self.passphrase = passphrase
   self.config = config
  else:
   exit()  

 def do_telnet(self):
  output = open("output.txt","a")
  remote= telnetlib.Telnet(self.ipv4_address,int(self.port))
  remote.read_until("Username: ")
  remote.write(self.username.encode('ascii')+"\n")
  remote.read_until("Password: ")
  remote.write(self.passphrase.encode('ascii')+"\n")
  remote.write(self.config.read().encode('ascii')+"\n")
  output.write(remote.read_all()+"\n"+"  -------  "+"\n")
  remote.close()
  output.close()

下面是我超时时收到的错误

Traceback (most recent call last):
  File "Automate.py", line 5, in <module>
    automate_it.execute()
  File "/home/abdultayyeb/Desktop/Automation/handler.py", line 30, in execute
    self.telnet.do_telnet()
  File "/home/abdultayyeb/Desktop/Automation/telnet.py", line 31, in do_telnet
    output.write(remote.read_all()+"\n"+"  -------  "+"\n")
  File "/usr/lib/python2.7/telnetlib.py", line 385, in read_all
    self.fill_rawq()
  File "/usr/lib/python2.7/telnetlib.py", line 576, in fill_rawq
    buf = self.sock.recv(50)
  socket.timeout: timed out

Answer 1

我建议重写它以使用 netmiko，因为它将处理处理 Cisco IOS 的特性。

关键是将您的设备类型指定为 cisco_ios_telnet。

这还有一个额外的好处，即当您将系统转换为 SSH 时无需重新编写代码。您只需将设备类型从 cisco_ios_telnet 更改为 cisco_ios

https://pynet.twb-tech.com/blog/automation/netmiko.html