import errno import fcntl import getpass import os import re import select import subprocess import sys import time 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 def check_non_root(func): """ Function decorator that checks if user not has root permissions """ def wrapped(*args, **kwargs): if getpass.getuser() == 'root': cmd_name = func.__module__.split('.')[-1] raise CommandError("Sorry, you don't want to execute '%s' as superuser (root)." % cmd_name) return func(*args, **kwargs) return wrapped class _Attribute(object): """ Simple string subclass to allow arbitrary attribute access. """ def __init__(self, stdout): self.stdout = stdout 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 as e: if e.errno != errno.EAGAIN: raise e else: return '' def runiterator(command, display=False, stdin=b''): """ Subprocess wrapper for running commands concurrently """ if display: sys.stderr.write("\n\033[1m $ %s\033[0m\n" % command) p = subprocess.Popen(command, shell=True, executable='/bin/bash', stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE) p.stdin.write(stdin) p.stdin.close() yield make_async(p.stdout) make_async(p.stderr) # Async reading of stdout and sterr while True: stdout = b'' stderr = b'' # Get complete unicode chunks select.select([p.stdout, p.stderr], [], []) stdoutPiece = read_async(p.stdout) stderrPiece = read_async(p.stderr) stdout += (stdoutPiece or b'') #.decode('ascii'), errors='replace') stderr += (stderrPiece or b'') #.decode('ascii'), errors='replace') if display and stdout: sys.stdout.write(stdout.decode('utf8')) if display and stderr: sys.stderr.write(stderr.decode('utf8')) state = _Attribute(stdout) state.stderr = stderr state.exit_code = p.poll() state.command = command yield state if state.exit_code != None: p.stdout.close() p.stderr.close() raise StopIteration def join(iterator, display=False, silent=False, valid_codes=(0,)): """ joins the iterator process """ stdout = b'' stderr = b'' for state in iterator: stdout += state.stdout stderr += state.stderr exit_code = state.exit_code out = _Attribute(stdout.strip()) err = stderr.strip() out.failed = False out.exit_code = exit_code out.stderr = err if exit_code not in valid_codes: out.failed = True msg = "\nrun() encountered an error (return code %s) while executing '%s'\n" msg = msg % (exit_code, state.command) if display: sys.stderr.write("\n\033[1;31mCommandError: %s %s\033[m\n" % (msg, err)) if not silent: raise CommandError("%s %s" % (msg, err)) out.succeeded = not out.failed return out def run(command, display=False, valid_codes=(0,), silent=False, stdin=b'', async=False): iterator = runiterator(command, display, stdin) next(iterator) if async: return iterator return join(iterator, display=display, silent=silent, valid_codes=valid_codes) def sshrun(addr, command, *args, executable='bash', persist=False, **kwargs): options = ['stricthostkeychecking=no'] if persist: options.extend(( 'ControlMaster=auto', 'ControlPersist=yes', 'ControlPath=~/.ssh/orchestra-%r-%h-%p', )) options = ' -o '.join(options) cmd = 'ssh -o {options} -C root@{addr} {executable}'.format(options=options, addr=addr, executable=executable) return run(cmd, *args, stdin=command.encode('utf8'), **kwargs) 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 def touch(fname, mode=0o666, dir_fd=None, **kwargs): flags = os.O_CREAT | os.O_APPEND with os.fdopen(os.open(fname, flags=flags, mode=mode, dir_fd=dir_fd)) as f: os.utime(f.fileno() if os.utime in os.supports_fd else fname, dir_fd=None if os.supports_fd else dir_fd, **kwargs) class OperationLocked(Exception): pass class LockFile(object): """ File-based lock mechanism used for preventing concurrency problems """ def __init__(self, lockfile, expire=5*60, unlocked=False): # /dev/shm/ can be a good place for storing locks self.lockfile = lockfile self.expire = expire self.unlocked = unlocked def acquire(self): if os.path.exists(self.lockfile): lock_time = os.path.getmtime(self.lockfile) # lock expires to avoid starvation if time.time()-lock_time < self.expire: return False touch(self.lockfile) return True def release(self): os.remove(self.lockfile) def __enter__(self): if not self.unlocked: if not self.acquire(): raise OperationLocked("%s lock file exists and its mtime is less than %s seconds" % (self.lockfile, self.expire)) return True def __exit__(self, type, value, traceback): if not self.unlocked: self.release() def touch_wsgi(delay=5): from . import paths run('{ sleep %i && touch %s/wsgi.py; } &' % (delay, paths.get_project_dir()), async=True)