diff options
Diffstat (limited to 'file_lock_machine.py')
| -rwxr-xr-x | file_lock_machine.py | 372 |
1 files changed, 372 insertions, 0 deletions
diff --git a/file_lock_machine.py b/file_lock_machine.py new file mode 100755 index 00000000..9b1d3367 --- /dev/null +++ b/file_lock_machine.py @@ -0,0 +1,372 @@ +#!/usr/bin/python2 +# +# Copyright 2010 Google Inc. All Rights Reserved. +"""Script to lock/unlock machines.""" + +from __future__ import print_function + +__author__ = 'asharif@google.com (Ahmad Sharif)' + +import argparse +import datetime +import fcntl +import getpass +import glob +import json +import os +import socket +import sys +import time + +from cros_utils import logger + +LOCK_SUFFIX = '_check_lock_liveness' + +# The locks file directory REQUIRES that 'group' only has read/write +# privileges and 'world' has no privileges. So the mask must be +# '0027': 0777 - 0027 = 0750. +LOCK_MASK = 0027 + + +def FileCheckName(name): + return name + LOCK_SUFFIX + + +def OpenLiveCheck(file_name): + with FileCreationMask(LOCK_MASK): + fd = open(file_name, 'a') + try: + fcntl.lockf(fd, fcntl.LOCK_EX | fcntl.LOCK_NB) + except IOError: + raise + return fd + + +class FileCreationMask(object): + """Class for the file creation mask.""" + + def __init__(self, mask): + self._mask = mask + self._old_mask = None + + def __enter__(self): + self._old_mask = os.umask(self._mask) + + def __exit__(self, typ, value, traceback): + os.umask(self._old_mask) + + +class LockDescription(object): + """The description of the lock.""" + + def __init__(self, desc=None): + try: + self.owner = desc['owner'] + self.exclusive = desc['exclusive'] + self.counter = desc['counter'] + self.time = desc['time'] + self.reason = desc['reason'] + self.auto = desc['auto'] + except (KeyError, TypeError): + self.owner = '' + self.exclusive = False + self.counter = 0 + self.time = 0 + self.reason = '' + self.auto = False + + def IsLocked(self): + return self.counter or self.exclusive + + def __str__(self): + return ' '.join(['Owner: %s' % self.owner, 'Exclusive: %s' % self.exclusive, + 'Counter: %s' % self.counter, 'Time: %s' % self.time, + 'Reason: %s' % self.reason, 'Auto: %s' % self.auto]) + + +class FileLock(object): + """File lock operation class.""" + FILE_OPS = [] + + def __init__(self, lock_filename): + self._filepath = lock_filename + lock_dir = os.path.dirname(lock_filename) + assert os.path.isdir(lock_dir), ("Locks dir: %s doesn't exist!" % lock_dir) + self._file = None + self._description = None + + def getDescription(self): + return self._description + + def getFilePath(self): + return self._filepath + + def setDescription(self, desc): + self._description = desc + + @classmethod + def AsString(cls, file_locks): + stringify_fmt = '%-30s %-15s %-4s %-4s %-15s %-40s %-4s' + header = stringify_fmt % ('machine', 'owner', 'excl', 'ctr', 'elapsed', + 'reason', 'auto') + lock_strings = [] + for file_lock in file_locks: + + elapsed_time = datetime.timedelta( + seconds=int(time.time() - file_lock.getDescription().time)) + elapsed_time = '%s ago' % elapsed_time + lock_strings.append( + stringify_fmt % + (os.path.basename(file_lock.getFilePath), + file_lock.getDescription().owner, + file_lock.getDescription().exclusive, + file_lock.getDescription().counter, + elapsed_time, file_lock.getDescription().reason, + file_lock.getDescription().auto)) + table = '\n'.join(lock_strings) + return '\n'.join([header, table]) + + @classmethod + def ListLock(cls, pattern, locks_dir): + if not locks_dir: + locks_dir = Machine.LOCKS_DIR + full_pattern = os.path.join(locks_dir, pattern) + file_locks = [] + for lock_filename in glob.glob(full_pattern): + if LOCK_SUFFIX in lock_filename: + continue + file_lock = FileLock(lock_filename) + with file_lock as lock: + if lock.IsLocked(): + file_locks.append(file_lock) + logger.GetLogger().LogOutput('\n%s' % cls.AsString(file_locks)) + + def __enter__(self): + with FileCreationMask(LOCK_MASK): + try: + self._file = open(self._filepath, 'a+') + self._file.seek(0, os.SEEK_SET) + + if fcntl.flock(self._file.fileno(), fcntl.LOCK_EX) == -1: + raise IOError('flock(%s, LOCK_EX) failed!' % self._filepath) + + try: + desc = json.load(self._file) + except (EOFError, ValueError): + desc = None + self._description = LockDescription(desc) + + if self._description.exclusive and self._description.auto: + locked_byself = False + for fd in self.FILE_OPS: + if fd.name == FileCheckName(self._filepath): + locked_byself = True + break + if not locked_byself: + try: + fp = OpenLiveCheck(FileCheckName(self._filepath)) + except IOError: + pass + else: + self._description = LockDescription() + fcntl.lockf(fp, fcntl.LOCK_UN) + fp.close() + return self._description + # Check this differently? + except IOError as ex: + logger.GetLogger().LogError(ex) + return None + + def __exit__(self, typ, value, traceback): + self._file.truncate(0) + self._file.write(json.dumps(self._description.__dict__, skipkeys=True)) + self._file.close() + + def __str__(self): + return self.AsString([self]) + + +class Lock(object): + """Lock class""" + + def __init__(self, lock_file, auto=True): + self._to_lock = os.path.basename(lock_file) + self._lock_file = lock_file + self._logger = logger.GetLogger() + self._auto = auto + + def NonBlockingLock(self, exclusive, reason=''): + with FileLock(self._lock_file) as lock: + if lock.exclusive: + self._logger.LogError( + 'Exclusive lock already acquired by %s. Reason: %s' % + (lock.owner, lock.reason)) + return False + + if exclusive: + if lock.counter: + self._logger.LogError('Shared lock already acquired') + return False + lock_file_check = FileCheckName(self._lock_file) + fd = OpenLiveCheck(lock_file_check) + FileLock.FILE_OPS.append(fd) + + lock.exclusive = True + lock.reason = reason + lock.owner = getpass.getuser() + lock.time = time.time() + lock.auto = self._auto + else: + lock.counter += 1 + self._logger.LogOutput('Successfully locked: %s' % self._to_lock) + return True + + def Unlock(self, exclusive, force=False): + with FileLock(self._lock_file) as lock: + if not lock.IsLocked(): + self._logger.LogWarning("Can't unlock unlocked machine!") + return True + + if lock.exclusive != exclusive: + self._logger.LogError('shared locks must be unlocked with --shared') + return False + + if lock.exclusive: + if lock.owner != getpass.getuser() and not force: + self._logger.LogError("%s can't unlock lock owned by: %s" % + (getpass.getuser(), lock.owner)) + return False + if lock.auto != self._auto: + self._logger.LogError("Can't unlock lock with different -a" + ' parameter.') + return False + lock.exclusive = False + lock.reason = '' + lock.owner = '' + + if self._auto: + del_list = [i + for i in FileLock.FILE_OPS + if i.name == FileCheckName(self._lock_file)] + for i in del_list: + FileLock.FILE_OPS.remove(i) + for f in del_list: + fcntl.lockf(f, fcntl.LOCK_UN) + f.close() + del del_list + os.remove(FileCheckName(self._lock_file)) + + else: + lock.counter -= 1 + return True + + +class Machine(object): + """Machine class""" + + LOCKS_DIR = '/google/data/rw/users/mo/mobiletc-prebuild/locks' + + def __init__(self, name, locks_dir=LOCKS_DIR, auto=True): + self._name = name + self._auto = auto + try: + self._full_name = socket.gethostbyaddr(name)[0] + except socket.error: + self._full_name = self._name + self._full_name = os.path.join(locks_dir, self._full_name) + + def Lock(self, exclusive=False, reason=''): + lock = Lock(self._full_name, self._auto) + return lock.NonBlockingLock(exclusive, reason) + + def TryLock(self, timeout=300, exclusive=False, reason=''): + locked = False + sleep = timeout / 10 + while True: + locked = self.Lock(exclusive, reason) + if locked or not timeout >= 0: + break + print('Lock not acquired for {0}, wait {1} seconds ...'.format( + self._name, + sleep)) + time.sleep(sleep) + timeout -= sleep + return locked + + def Unlock(self, exclusive=False, ignore_ownership=False): + lock = Lock(self._full_name, self._auto) + return lock.Unlock(exclusive, ignore_ownership) + + +def Main(argv): + """The main function.""" + + parser = argparse.ArgumentParser() + parser.add_argument('-r', + '--reason', + dest='reason', + default='', + help='The lock reason.') + parser.add_argument('-u', + '--unlock', + dest='unlock', + action='store_true', + default=False, + help='Use this to unlock.') + parser.add_argument('-l', + '--list_locks', + dest='list_locks', + action='store_true', + default=False, + help='Use this to list locks.') + parser.add_argument('-f', + '--ignore_ownership', + dest='ignore_ownership', + action='store_true', + default=False, + help="Use this to force unlock on a lock you don't own.") + parser.add_argument('-s', + '--shared', + dest='shared', + action='store_true', + default=False, + help='Use this for a shared (non-exclusive) lock.') + parser.add_argument('-d', + '--dir', + dest='locks_dir', + action='store', + default=Machine.LOCKS_DIR, + help='Use this to set different locks_dir') + parser.add_argument('args', nargs='*', help='Machine arg.') + + options = parser.parse_args(argv) + + options.locks_dir = os.path.abspath(options.locks_dir) + exclusive = not options.shared + + if not options.list_locks and len(options.args) != 2: + logger.GetLogger().LogError( + 'Either --list_locks or a machine arg is needed.') + return 1 + + if len(options.args) > 1: + machine = Machine(options.args[1], options.locks_dir, auto=False) + else: + machine = None + + if options.list_locks: + FileLock.ListLock('*', options.locks_dir) + retval = True + elif options.unlock: + retval = machine.Unlock(exclusive, options.ignore_ownership) + else: + retval = machine.Lock(exclusive, options.reason) + + if retval: + return 0 + else: + return 1 + + +if __name__ == '__main__': + sys.exit(Main(sys.argv[1:])) |