import errno import fcntl import getpass import os import re import select import subprocess import sys from django.core.management.base import CommandError def check_root(func): """ Function decorator that checks if user has root permissions """ def wrapped(*args, **kwargs): if getpass.getuser() != 'root': cmd_name = func.__module__.split('.')[-1] msg = "Sorry, '%s' must be executed as a superuser (root)" raise CommandError(msg % cmd_name) return func(*args, **kwargs) return wrapped class _AttributeString(str): """ Simple string subclass to allow arbitrary attribute access. """ @property def stdout(self): return str(self) def make_async(fd): """ Helper function to add the O_NONBLOCK flag to a file descriptor """ fcntl.fcntl(fd, fcntl.F_SETFL, fcntl.fcntl(fd, fcntl.F_GETFL) | os.O_NONBLOCK) def read_async(fd): """ Helper function to read some data from a file descriptor, ignoring EAGAIN errors """ try: return fd.read() except IOError, e: if e.errno != errno.EAGAIN: raise e else: return '' def run(command, display=True, error_codes=[0], silent=True): """ Subprocess wrapper for running commands """ if display: sys.stderr.write("\n\033[1m $ %s\033[0m\n" % command) out_stream = subprocess.PIPE err_stream = subprocess.PIPE p = subprocess.Popen(command, shell=True, executable='/bin/bash', stdout=out_stream, stderr=err_stream) make_async(p.stdout) make_async(p.stderr) stdout = str() stderr = str() # Async reading of stdout and sterr while True: # Wait for data to become available select.select([p.stdout, p.stderr], [], []) # Try reading some data from each stdoutPiece = read_async(p.stdout) stderrPiece = read_async(p.stderr) if display and stdoutPiece: sys.stdout.write(stdoutPiece) if display and stderrPiece: sys.stderr.write(stderrPiece) stdout += stdoutPiece stderr += stderrPiece returnCode = p.poll() if returnCode != None: break out = _AttributeString(stdout.strip()) err = _AttributeString(stderr.strip()) p.stdout.close() p.stderr.close() out.failed = False out.return_code = returnCode out.stderr = err if p.returncode not in error_codes: out.failed = True msg = "\nrun() encountered an error (return code %s) while executing '%s'\n" msg = msg % (p.returncode, command) sys.stderr.write("\n\033[1;31mCommandError: %s %s\033[m\n" % (msg, err)) if not silent: raise CommandError("\n%s\n %s\n" % (msg, err)) out.succeeded = not out.failed return out def get_default_celeryd_username(): """ Introspect celeryd defaults file in order to get its username """ user = None try: with open('/etc/default/celeryd') as celeryd_defaults: for line in celeryd_defaults.readlines(): if 'CELERYD_USER=' in line: user = re.findall('"([^"]*)"', line)[0] finally: if user is None: raise CommandError("Can not find the default celeryd username") return user