command_client.py

import socket
from subprocess import Popen, PIPE
import uuid
import json

class CommandClient(object):
  def __init__(self, ctlloc):
    if ctlloc == "in":
      print "Using unix socket client for commands"
      self.client = UnixSocketClient()
    else:
      print "Using subprocess client for commands"
      self.client = SubprocessClient()

  def run_command(self, command):
    return self.client.run_command(command)

  def run_commands(self, commands):
    for command in commands:
      _, err = self.run_command(command)
      if err:
        return False
    return True

class SubprocessClient(object):
  def run_command(self, command):
    process = Popen(command, shell=True, executable="/bin/bash", stdout=PIPE, stderr=PIPE)
    stdout, stderr = process.communicate()
    if process.returncode != 0:
      return (stdout, stderr)
    else:
      return (stdout, None)

class UnixSocketClient(object):
  SOCKET = "/var/run/command.sock"

  def _send(self, request):
    unix_socket = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
    unix_socket.connect(UnixSocketClient.SOCKET)
    unix_socket.sendall(json.dumps(request))
    response_string = unix_socket.recv(4096)
    unix_socket.close()
    return json.loads(response_string)

  def run_command(self, command):
    request = {"id": str(uuid.uuid1()), "command": command}
    response = self._send(request)
    exit_code = response["exit_code"]
    if exit_code != 0:
      return (None, "Command failed with exit code %d, stderr: %s" % (exit_code, response["stderr"]))

    return (response["stdout"], None)