def ssh(host, cmd, user, password, timeout=30, bg_run=False):
    """SSH'es to a host using the supplied credentials and executes a command.                                                                                                 
    Throws an exception if the command doesn't return 0.                                                                                                                       
    bgrun: run command in the background"""
fname = tempfile.mktemp()
fout = open(fname, 'w')
options = (
    '-q -oStrictHostKeyChecking=no -oUserKnownHostsFile=/dev/null -oPubkeyAuthentication=no'
    )
if bg_run:
    options += ' -f'
ssh_cmd = 'ssh %s@%s %s "%s"' % (user, host, options, cmd)
child = pexpect.spawn(ssh_cmd, timeout=timeout)
child.expect(['password: '])
child.sendline(password)
child.logfile = fout
child.expect(pexpect.EOF)
child.close()
fout.close()
fin = open(fname, 'r')
stdout = fin.read()
fin.close()
if 0 != child.exitstatus:
    raise Exception(stdout)
return stdout
Sending a password over SSH or SCP with subprocess.Popen