Script mit dem man sich auf einem Cisco-Switch einloggen kann oder mal schnell ein Kommando absetzen kann.

Voraussetzung: Eine Passwort-Datei im YAML-Format, die man natürlich auf einem verschlüsseltem Datenträger lagert denn man nur dafür öffnet:

$HOME/.config/encrypt/switch.yaml

--- # config / password file for switch scripts in yaml format

  userpw: "1totalSCHWERESundLANGESpasswort!!1elf"
  user: "annabeispiel"

$HOME/bin/switch

#!/usr/bin/env python3
 
""" python script for
- opening a interactive session with a cisco switch or
- set commands to a cisco switch
"""
 
# pylint: disable=no-member
 
import sys
import os
import socket
import yaml
 
import pexpect
 
# where the password file is stored (encrypted disk!)
CONFIGFILE = os.path.expanduser("~")+"/.config/encrypt/switch.yaml"
 
def do_telnet(geraet, user, command):
    """do something via telnet"""
    print("### telnet to %s as user %s ..." % (geraet, user))
 
    ## with pexpect instead of telnet lib
    child = pexpect.spawn('telnet ' + geraet)
    child.expect('.*sername:.*')
    child.sendline(user)
    child.expect('.*assword:.*')
    child.sendline(PASSWORD)
 
    child.expect('.*#')
    child.sendline('terminal length 0')
    if command:
        child.sendline(command)
        child.expect('.*#')
        child.expect('.*#')
        output1 = child.before
        output2 = child.after
        # decode, because the return is byte and not string
        print(output1.decode("UTF-8"))
        print(output2.decode("UTF-8"))
    else:
        child.interact()
    child.sendline('exit')
    child.close()
 
     print("### end of telnet session with %s" % geraet)
 
def do_ssh(geraet, user, command):
    """do something via ssh"""
    print("### ssh to %s as user %s ..." % (geraet, user))
 
    child = pexpect.spawn('ssh %s@%s' % (user, geraet))
 
    child.expect('.*assword:.*')
    child.sendline(PASSWORD)
    child.expect('.*#')
    child.sendline('terminal length 0')
 
    if command:
        child.sendline(command)
        child.expect('.*#')
        child.expect('.*#')
        output1 = child.before
        output2 = child.after     
        print(output1.decode("UTF-8"))
        print(output2.decode("UTF-8"))       
    else:
        child.interact()        
    child.sendline('exit')
    child.close()
    print("### end of ssh session with %s" % geraet)
 
# read config
CFG = yaml.load(open(CONFIGFILE))    
 
PASSWORD = CFG['userpw']
USER = CFG['user']
 
GERAET = sys.argv[1]
 
COMMAND = ""  
try:
    COMMAND = sys.argv[2]
except IndexError:
    pass
 
# check for ssh (port 22)
SOCK1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
I_DO_SSH = not SOCK1.connect_ex((GERAET, 22))
 
# check for telnet (port 23)
SOCK2 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
I_DO_TELNET = not SOCK2.connect_ex((GERAET, 23))
 
if I_DO_SSH:
    #print "ssh works on %s " % GERAET
    do_ssh(GERAET, USER, COMMAND)
elif I_DO_TELNET:
    #print "telnet works on %s" % GERAET
    do_telnet(GERAET, USER, COMMAND)
    sys.exit(0)
else:
    print("neither ssh nor telnet port open on %s" % GERAET)
 
## FINI

• Cisco Spickzettel
• Die alte Python2-Version dieses Scripts:CISCO + Pexpect (Python2)
• pexepct auf github
• pexpect dokumentation