parallel ssh commands. key-based auth *highly* recommended

parallel_ssh.py

#!/usr/bin/env python
#
# Pass any number of short hostnames to run cmd on all
# hosts in parallel and display the results nicely.

import sys
import subprocess
import multiprocessing

PROCESSES = 8
domain = 'site.example.com'

# you can string together multiple commands if you want
cmd = """command -with options; \
simple_command; \
even_more -optiony things"""

def do_ssh_command(host):
    ssh = subprocess.Popen(["ssh", "-oStrictHostKeyChecking=no", str(host), cmd],
                           shell=False,
                           stdout=subprocess.PIPE,
                           stderr=subprocess.PIPE)
    result = ssh.stdout.readlines()
    if result == []:
        error = ssh.stderr.readlines()
        SSH_ERRORS.append("[%s]: %s" % ( host.split('.')[0], error[0].strip()) )
    else:
        results = "[%s]\n%s" % ( host.split('.')[0], ''.join(result) )
        SSH_RESULTS.append(results)


if __name__ == '__main__':
    inputs = sys.argv[1:]
    if len(inputs) < 1:
        print "Please supply at least one short hostname."
    else:
        print "\nNow running commands...\n"
        hosts = [ h + '.' + domain for h in inputs ]

        ssh_manager = multiprocessing.Manager()
        SSH_RESULTS = ssh_manager.list()
        SSH_ERRORS = ssh_manager.list()
        p = multiprocessing.Pool(processes=PROCESSES)
        p.map(do_ssh_command, hosts)
        p.close()

        if len(SSH_RESULTS) > 0:
            print "=======\nRESULTS\n-------"
            for result in SSH_RESULTS: print result

        if len(SSH_ERRORS) > 0:
            print "======\nERRORS\n------"
            for error in SSH_ERRORS: print error