Long-running ssh commands in python paramiko module (and how to end them)

Question

I want to run a tail -f logfile command on a remote machine using python\'s paramiko module. I\'ve been attempting it so far in the following fashion:

Answer 1

Instead of calling exec_command on the client, get hold of the transport and generate your own channel. The channel can be used to execute a command, and you can use it in a select statement to find out when data can be read:

#!/usr/bin/env python
import paramiko
import select
client = paramiko.SSHClient()
client.load_system_host_keys()
client.connect('host.example.com')
transport = client.get_transport()
channel = transport.open_session()
channel.exec_command("tail -f /var/log/everything/current")
while True:
  rl, wl, xl = select.select([channel],[],[],0.0)
  if len(rl) > 0:
      # Must be stdout
      print channel.recv(1024)

The channel object can be read from and written to, connecting with stdout and stdin of the remote command. You can get at stderr by calling channel.makefile_stderr(...).

I've set the timeout to 0.0 seconds because a non-blocking solution was requested. Depending on your needs, you might want to block with a non-zero timeout.