[Twisted-Python] twisted python conch SSH shell?

[Eli Criffield]

conchClient.py is libarary. Running it from the command line was an
afterthought just for testing.
To run multiple commands in the same session you just give sshCmds a
list of commands to run and it will return the output of all of them.
Here is an example script that creates a function to up a port and
another to return the wwn (this is from a SAN switch) of a port.

#!/usr/bin/env python
# Eli Criffield

__version__ = 0.1186070837
__author__ = 'Eli Criffield <python AT zendo.net>'

import sys
import re
import time
import os
from conchClient import sshCmds

dryRun = False
Confirm = True
echo = False

class reError(Exception):
    pass

def execList(switch,cmds,change=False):
    global echo, dryRun, Confirm
    # if change is False, the commands arn't suppose to do any damage
    # always exec them, they need the info
    if not change:
        return sshCmds(switch,cmds,echo=echo)

    if dryRun:
        print 'DRY RUN'
        print 'ssh %s'%switch
        for cmd in cmds:
            print cmd
        print 'ENTER to continue:',
        sys.stdin.readline()
        return ('dryrun','')


    if Confirm:
        print "I'm going to run:"
        print '\nssh %s'%switch
        for cmd in cmds:
            print cmd
        ans = raw_input('Does that look ok (yes/no)? ')
        while ans.lower() not in ('yes', 'no'):
            ans = raw_input("Please type 'yes' or 'no': ")
        if ans == 'no':
            print 'exiting out'
            sys.exit(1)
        else:
            return sshCmds(switch,cmds,echo=echo)

    # No dryRun or Confirm just execute it
    return sshCmds(switch,cmds,echo=echo)

def upPort(switch,port):
    cmds=[ 'config term', 'interface fc%s'%port, 'no shutdown' ,'end'
    ,'exit' ]
    execList(switch,cmds,change=True)

def wwnFromPort(switch,port):
    portre = re.compile(r'%s '%port)
    linere = re.compile(r'(\S*)\s*(\S*)\s*(\S*)\s*(\S*)\s*(\S*)')
    (out,err) = execList(switch,['show flogi database'])
    for line in out.split('fc'):
        if portre.match(line):
            #print 'line:',line #DEBUG
            wwn = linere.match(line).groups()[3]
            #print wwn #DEBUG
            return wwn


On Thu, Aug 21, 2008 at 2:07 AM, The Noob <thenoob06 at gmail.com> wrote:
> Hello,
>
> If I understand your code, you can't find a way to run a real shell on Cisco
> ?
> For example if I connect to a router, I send a "sh log" , " conf t "
> commands but I do not know them before. With the actual script:
> conchClient.py 192.168.0.254 sh log
> The script disconnects us from the router
> conchClient.py 192.168.0.254 conf t
> The script disconnects us  disconnect from the router
> I think the problem with your script it is for each command you are
> disconnected The best will be to find a solution to do this:
> conchClient.py 192.168.0.254 sh log
> conchClient.py 192.168.0.254 conf t
> conchClient.py 192.168.0.254 exit
> disconnect from server
>
> I try to do this with a custom ssh server which permits to connect to others
> ssh servers and have a shell. But I don't know how to communicate between my
> custom ssh server and my child ( an expect script which launch ssh root at host
> and permits to have a real shell)
>
>
> Best Regards
> TheNoob06
>
>
> 2008/8/21 Eli Criffield <elicriffield at gmail.com>
>>
>> check out
>>
>> http://twistedmatrix.com/pipermail/twisted-python/2007-July/015793.html
>>
>> Eli Criffield
>>
>> On Tue, Aug 12, 2008 at 3:40 PM, Bill Zeller <wzeller at cs.princeton.edu>
>> wrote:
>> > Hi,
>> >
>> > I've been playing around with Twisted's Conch client (which looks
>> > extremely
>> > well done, thanks!). I've been able to connect to a conch server and
>> > also
>> > connect to other ssh servers and execuate various commands. I'd like to
>> > be
>> > able to connect to an arbitrary SSH server and run /bin/bash.
>> >
>> > I'm able to execute a command like so:
>> >
>> > ---------------------
>> > class CommandChannel(channel.SSHChannel):
>> >     ....
>> >     def channelOpen(self, data):
>> >         self.conn.sendRequest(
>> >             self, 'exec', common.NS(self.command),
>> > wantReply=True).addCallback(
>> >             self._gotResponse)
>> > ---------------------
>> >
>> > Looking through the SSH spec (connect protocol, rfc4254), it looks like
>> > shells are opened with this command.
>> >
>> > ---------------------
>> >
>> >       byte      SSH_MSG_CHANNEL_REQUEST
>> >
>> >       uint32    recipient channel
>> >       string    "shell"
>> >       boolean   want reply
>> >
>> > ---------------------
>> >
>> > It doesn't look like Conch supports these requests (here's how
>> > CHANNEL_REQUESTs are currently sent out)
>> >
>> > ---------------------
>> > (Twisted-8.1.0)
>> > twisted/conch/ssh/connection.py (413):
>> >         self.transport.sendPacket(MSG_CHANNEL_REQUEST, struct.pack('>L',
>> >
>> > self.channelsToRemoteChannel[channel])
>> >                                   +
>> > common.NS(requestType)+chr(wantReply)
>> >                                   + data)
>> > ---------------------
>> >
>> > I may be misunderstanding how remote shells are started, so any help
>> > would
>> > be appreciated.
>> >
>> > Again, I'm trying to launch an interactive /bin/bash shell from a Conch
>> > SSH
>> > client on an arbitrary remote SSH server.
>> >
>> > Thanks for your time.
>> >
>> > Best Regards,
>> > Bill Zeller
>> >
>> > _______________________________________________
>> > Twisted-Python mailing list
>> > Twisted-Python at twistedmatrix.com
>> > http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
>> >
>> >
>>
>> _______________________________________________
>> Twisted-Python mailing list
>> Twisted-Python at twistedmatrix.com
>> http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
>
>