Nested SSH session with Paramiko

Question

I\'m rewriting a Bash script I wrote into Python. The crux of that script was

ssh -t first.com \"ssh second.com very_remote_command\"

I\'m

Answer 1

Here is a small example using paramiko only (and port forwarding):

import paramiko as ssh

class SSHTool():
    def __init__(self, host, user, auth,
                 via=None, via_user=None, via_auth=None):
        if via:
            t0 = ssh.Transport(via)
            t0.start_client()
            t0.auth_password(via_user, via_auth)
            # setup forwarding from 127.0.0.1: to |host|
            channel = t0.open_channel('direct-tcpip', host, ('127.0.0.1', 0))
            self.transport = ssh.Transport(channel)
        else:
            self.transport = ssh.Transport(host)
        self.transport.start_client()
        self.transport.auth_password(user, auth)

    def run(self, cmd):
        ch = self.transport.open_session()
        ch.set_combine_stderr(True)
        ch.exec_command(cmd)
        retcode = ch.recv_exit_status()
        buf = ''
        while ch.recv_ready():
            buf += ch.recv(1024)
        return (buf, retcode)

# The example below is equivalent to
# $ ssh 10.10.10.10 ssh 192.168.1.1 uname -a
# The code above works as if these 2 commands were executed:
# $ ssh -L :192.168.1.1:22 10.10.10.10
# $ ssh 127.0.0.1: uname -a
host = ('192.168.1.1', 22)
via_host = ('10.10.10.10', 22)

ssht = SSHTool(host, 'user1', 'pass1',
    via=via_host, via_user='user2', via_auth='pass2')

print ssht.run('uname -a')