Example #1
0
class ScriptLock():
    config = None
    flock = None

    def __init__(self, config):
        '''
        Parse machine-local configuration file.
        '''
        self.config = config

    def __enter__(self):
        '''
        Be a context manager.
        '''
        fname = self.config.get("Execution", "pidfile")
        self.flock = FilesystemLock(fname)
        logger.debug("Obtaining script lock")
        self.flock.lock()

    def __exit__(self, exc_type, exc_value, traceback):
        '''
        Be a context manager.
        '''
        logger.debug("Releasing script lock")
        self.flock.unlock()
Example #2
0
    def test_runUsedDirectory(self):
        """
        L{DistTrialRunner} checks if the test directory is already locked, and
        if it is generates a name based on it.
        """

        class FakeReactorWithLock(FakeReactor):

            def spawnProcess(oself, worker, *args, **kwargs):
                self.assertEqual(os.path.abspath(worker._logDirectory),
                                 os.path.abspath(
                                     os.path.join(workingDirectory + "-1",
                                                  str(oself.spawnCount))))
                localLock = FilesystemLock(workingDirectory + "-1.lock")
                self.assertFalse(localLock.lock())
                oself.spawnCount += 1
                worker.makeConnection(FakeTransport())
                worker._ampProtocol.run = lambda *args: succeed(None)

        newDirectory = self.mktemp()
        os.mkdir(newDirectory)
        workingDirectory = os.path.join(newDirectory, "_trial_temp")
        lock = FilesystemLock(workingDirectory + ".lock")
        lock.lock()
        self.addCleanup(lock.unlock)
        self.runner._workingDirectory = workingDirectory

        fakeReactor = FakeReactorWithLock()
        suite = TrialSuite()
        for i in xrange(10):
            suite.addTest(TestCase())
        self.runner.run(suite, fakeReactor)
Example #3
0
    def copyPackage(title):
        """
        Copy package directory to db path using a file lock to avoid potential
        concurrency race conditions.

        @param title: string to use in log entry
        @type title: C{str}
        """
        dbpath = FilePath(TimezoneCache.getDBPath())
        pkgpath = TimezoneCache.FilteredFilePath(TimezoneCache._getPackageDBPath())

        lockfile = FilesystemLock(dbpath.path + ".lock")
        result = lockfile.lock()
        try:
            if result and not dbpath.exists():
                log.info(
                    "{title} timezones from {pkg} to {to}",
                    title=title,
                    pkg=pkgpath.path,
                    to=dbpath.path
                )

                # Copy over the entire package
                pkgpath.copyFilteredDirectoryTo(dbpath)
        finally:
            if result:
                lockfile.unlock()
Example #4
0
 def check():
     localLock = FilesystemLock(workingDirectory + ".lock")
     self.assertTrue(localLock.lock())
     self.assertEqual(1, fakeReactor.stopCount)
     # We don't wait for the process deferreds here, so nothign is
     # returned by the function before shutdown
     self.assertIdentical(None, functions[0]())
    def test_runUsedDirectory(self):
        """
        L{DistTrialRunner} checks if the test directory is already locked, and
        if it is generates a name based on it.
        """

        class FakeReactorWithLock(FakeReactor):

            def spawnProcess(oself, worker, *args, **kwargs):
                self.assertEqual(os.path.abspath(worker._logDirectory),
                                 os.path.abspath(
                                     os.path.join(workingDirectory + "-1",
                                                  str(oself.spawnCount))))
                localLock = FilesystemLock(workingDirectory + "-1.lock")
                self.assertFalse(localLock.lock())
                oself.spawnCount += 1
                worker.makeConnection(FakeTransport())
                worker._ampProtocol.run = lambda *args: succeed(None)

        newDirectory = self.mktemp()
        os.mkdir(newDirectory)
        workingDirectory = os.path.join(newDirectory, "_trial_temp")
        lock = FilesystemLock(workingDirectory + ".lock")
        lock.lock()
        self.addCleanup(lock.unlock)
        self.runner._workingDirectory = workingDirectory

        fakeReactor = FakeReactorWithLock()
        suite = TrialSuite()
        for i in range(10):
            suite.addTest(TestCase())
        self.runner.run(suite, fakeReactor)
 def check():
     localLock = FilesystemLock(workingDirectory + ".lock")
     self.assertTrue(localLock.lock())
     self.assertEqual(1, fakeReactor.stopCount)
     # We don't wait for the process deferreds here, so nothing is
     # returned by the function before shutdown
     self.assertIdentical(None, functions[0]())
Example #7
0
    def is_locked(self):
        """Is this lock already taken?

        Use this for informational purposes only.

        The way this works is as follows:

        1. Create a new `FilesystemLock` with the same path.

        2. Use the global process lock to ensure no other processes are also
           trying to access the lock.

        3. Attempt to lock the file-system lock:

           3a. Upon success, we know that the lock must have been unlocked;
               return ``True``.

           3b. Upon failure, no action is required because the lock failed. We
               know that the lock must have been locked; return ``False``.

        """
        fslock = FilesystemLock(self._fslock.name)
        with self.PROCESS_LOCK:
            if fslock.lock():
                fslock.unlock()
                return False
            else:
                return True
Example #8
0
    def copyPackage(title):
        """
        Copy package directory to db path using a file lock to avoid potential
        concurrency race conditions.

        @param title: string to use in log entry
        @type title: C{str}
        """
        dbpath = FilePath(TimezoneCache.getDBPath())
        pkgpath = TimezoneCache.FilteredFilePath(TimezoneCache._getPackageDBPath())

        lockfile = FilesystemLock(dbpath.path + ".lock")
        result = lockfile.lock()
        try:
            if result and not dbpath.exists():
                log.info(
                    "{title} timezones from {pkg} to {to}",
                    title=title,
                    pkg=pkgpath.path,
                    to=dbpath.path
                )

                # Copy over the entire package
                pkgpath.copyFilteredDirectoryTo(dbpath)
        finally:
            if result:
                lockfile.unlock()
Example #9
0
 def __init__(self, path, reactor=None):
     super(SystemLock, self).__init__()
     self._fslock = FilesystemLock(path)
     self.reactor = reactor
     if self.reactor is None:
         from twisted.internet import reactor
         self.reactor = reactor
Example #10
0
 def __enter__(self):
     '''
     Be a context manager.
     '''
     fname = self.config.get("Execution", "pidfile")
     self.flock = FilesystemLock(fname)
     logger.debug("Obtaining script lock")
     self.flock.lock()
def do_restore():
    lock = FilesystemLock("/var/run/jolicloud_restore_utility.lock")
    if lock.lock():
        if os.environ.get('DISPLAY', False):
            JolicloudRestoreUtilityGtk()
        else:
            JolicloudRestoreUtilityText()
        reactor.run()
        lock.unlock()
Example #12
0
 def spawnProcess(oself, worker, *args, **kwargs):
     self.assertEqual(os.path.abspath(worker._logDirectory),
                      os.path.abspath(
                          os.path.join(workingDirectory + "-1",
                                       str(oself.spawnCount))))
     localLock = FilesystemLock(workingDirectory + "-1.lock")
     self.assertFalse(localLock.lock())
     oself.spawnCount += 1
     worker.makeConnection(FakeTransport())
     worker._ampProtocol.run = lambda *args: succeed(None)
 def spawnProcess(oself, worker, *args, **kwargs):
     self.assertEqual(os.path.abspath(worker._logDirectory),
                      os.path.abspath(
                          os.path.join(workingDirectory + "-1",
                                       str(oself.spawnCount))))
     localLock = FilesystemLock(workingDirectory + "-1.lock")
     self.assertFalse(localLock.lock())
     oself.spawnCount += 1
     worker.makeConnection(FakeTransport())
     worker._ampProtocol.run = lambda *args: succeed(None)
Example #14
0
def _unusedTestDirectory(base):
    """
    Find an unused directory named similarly to C{base}.

    Once a directory is found, it will be locked and a marker dropped into it to
    identify it as a trial temporary directory.

    @param base: A template path for the discovery process.  If this path
        exactly cannot be used, a path which varies only in a suffix of the
        basename will be used instead.
    @type base: L{FilePath}

    @return: A two-tuple.  The first element is a L{FilePath} representing the
        directory which was found and created.  The second element is a locked
        L{FilesystemLock<twisted.python.lockfile.FilesystemLock>}.  Another
        call to C{_unusedTestDirectory} will not be able to reused the the
        same name until the lock is released, either explicitly or by this
        process exiting.
    """
    from twisted.python.lockfile import FilesystemLock
    counter = 0
    while True:
        if counter:
            testdir = base.sibling('%s-%d' % (base.basename(), counter))
        else:
            testdir = base

        testDirLock = FilesystemLock(testdir.path + '.lock')
        if testDirLock.lock():
            # It is not in use
            if testdir.exists():
                # It exists though - delete it
                _removeSafely(testdir)

            # Create it anew and mark it as ours so the next _removeSafely on it
            # succeeds.
            testdir.makedirs()
            testdir.child('_trial_marker').setContent('')
            return testdir, testDirLock
        else:
            # It is in use
            if base.basename() == '_trial_temp':
                counter += 1
            else:
                raise _WorkingDirectoryBusy()
Example #15
0
    def __init__(self, uuid, state, responder):
        """
        Initialize the lock resource. Parameters to this constructor are
        automatically passed by u1db.

        :param uuid: The user unique id.
        :type uuid: str
        :param state: The backend database state.
        :type state: u1db.remote.ServerState
        :param responder: The infrastructure to send responses to client.
        :type responder: u1db.remote.HTTPResponder
        """
        self._shared_db = state.open_database(SHARED_DB_NAME)
        self._lock_doc_id = '%s%s' % (SHARED_DB_LOCK_DOC_ID_PREFIX, uuid)
        self._lock = FilesystemLock(
            os.path.join(tempfile.gettempdir(),
                         hashlib.sha512(self._lock_doc_id).hexdigest()))
        self._state = state
        self._responder = responder
Example #16
0
    def __init__(self, uuid, state, responder):
        """
        Initialize the lock resource. Parameters to this constructor are
        automatically passed by u1db.

        :param uuid: The user unique id.
        :type uuid: str
        :param state: The backend database state.
        :type state: u1db.remote.ServerState
        :param responder: The infrastructure to send responses to client.
        :type responder: u1db.remote.HTTPResponder
        """
        self._shared_db = state.open_database(SoledadApp.SHARED_DB_NAME)
        self._lock_doc_id = '%s%s' % (SHARED_DB_LOCK_DOC_ID_PREFIX, uuid)
        self._lock = FilesystemLock(
            hashlib.sha512(self._lock_doc_id).hexdigest())
        self._state = state
        self._responder = responder
Example #17
0
 def check():
     localLock = FilesystemLock(workingDirectory + ".lock")
     self.assertTrue(localLock.lock())
     self.assertEqual(1, fakeReactor.stopCount)
Example #18
0
def obtain_lock():
    scriptname = os.path.basename(__file__)
    lockfile = os.path.join(tempfile.gettempdir(), scriptname + '.lock')
    lock = FilesystemLock(lockfile)
    return lock.lock()
Example #19
0
if __name__ == '__main__':
    parser = OptionParser(__doc__)
    parser.add_option('-l',
                      '--lockfile',
                      dest='lockfile',
                      default=path.join(os.getcwd(), ".release-runner.lock"))
    parser.add_option('-c',
                      '--config',
                      dest='config',
                      help='Configuration file')

    options = parser.parse_args()[0]

    if not options.config:
        parser.error('Need to pass a config')

    lockfile = options.lockfile
    log.debug("Using lock file %s", lockfile)
    lock = FilesystemLock(lockfile)
    if not lock.lock():
        raise Exception("Cannot acquire lock: %s" % lockfile)
    log.debug("Lock acquired: %s", lockfile)
    if not lock.clean:
        log.warning("Previous run did not properly exit")
    try:
        main(options)
    finally:
        log.debug("Releasing lock: %s", lockfile)
        lock.unlock()
Example #20
0
            log.error('Sendchange failed for %s: ' % release, exc_info=True)

    if rc != 0:
        sys.exit(rc)

if __name__ == '__main__':
    parser = OptionParser(__doc__)
    parser.add_option('-l', '--lockfile', dest='lockfile',
                      default=path.join(os.getcwd(), ".release-runner.lock"))
    parser.add_option('-c', '--config', dest='config',
                      help='Configuration file')

    options = parser.parse_args()[0]

    if not options.config:
        parser.error('Need to pass a config')

    lockfile = options.lockfile
    log.debug("Using lock file %s", lockfile)
    lock = FilesystemLock(lockfile)
    if not lock.lock():
        raise Exception("Cannot acquire lock: %s" % lockfile)
    log.debug("Lock acquired: %s", lockfile)
    if not lock.clean:
        log.warning("Previous run did not properly exit")
    try:
        main(options)
    finally:
        log.debug("Releasing lock: %s", lockfile)
        lock.unlock()
Example #21
0
    def getContext(self):
        self.method = SSL.TLSv1_METHOD
        ctx = ssl.ClientContextFactory.getContext(self)
        ctx.set_verify(
            SSL.VERIFY_PEER | SSL.VERIFY_FAIL_IF_NO_PEER_CERT,
            verifyCallback
        )
        #print dir(ctx)
        #raise SystemExit
        return ctx


from os import path

if __name__ == '__main__':
    lock = FilesystemLock("treestatusbot.lock")
    if isLocked("treestatusbot.lock"):
        raise SystemExit("There's already a bot running. If this is not the "
                         "case, please remove treestatusbot.lock manually")
    else:
        lock.lock()
    def unlock():
        lock.unlock()

    f = GaiaBotFactory()
    reactor.connectSSL(SERVER, int(PORT), f, CtxFactory())
    print "Connecting to", SERVER, PORT
    # run bot
    reactor.addSystemEventTrigger('before', 'shutdown', unlock)
    reactor.run()
Example #22
0
 def __init__(self, path):
     super(SystemLock, self).__init__()
     self._fslock = FilesystemLock(path)
Example #23
0
class SystemLock:
    """A file-system lock.

    It is also not reentrant, deliberately so, for good reason: if you use
    this to guard against concurrent writing to a file, say, then opening it
    twice in any circumstance is bad news.

    This behaviour comes about by:

    * Taking a process-global lock before performing any file-system
      operations.

    * Using :class:`twisted.python.lockfile.FilesystemLock` under the hood.
      This does not permit double-locking of a file by the name process (or by
      any other process, naturally).

    There are options too:

    * `SystemLock` uses the given path as its lock file. This is the most
      general lock.

    * `FileLock` adds a suffix of ".lock" to the given path and uses that as
      its lock file. Use this when updating a file in a writable directory,
      for example.

    * `RunLock` puts its lock file in ``/run/lock`` with a distinctive name
      based on the given path. Use this when updating a file in a non-writable
      directory, for example.

    * `NamedLock` also puts its lock file in ``/run/lock`` but with a name
      based on the given _name_. `NamedLock`'s lock file are named in such a
      way that they will never conflict with a `RunLock`'s. Use this to
      synchronise between processes on a single host, for example, where
      synchronisation does not naturally revolve around access to a specific
      file.

    """
    class NotAvailable(Exception):
        """Something has prevented acquisition of this lock.

        For example, the lock has already been acquired.
        """

    # File-system locks typically claim a lock for the sake of a *process*
    # rather than a *thread within a process*. We use a process-global lock to
    # serialise all file-system lock operations so that only one thread can
    # claim a file-system lock at a time.
    PROCESS_LOCK = threading.Lock()

    def __init__(self, path):
        super(SystemLock, self).__init__()
        self._fslock = FilesystemLock(path)

    def __enter__(self):
        self.acquire()

    def __exit__(self, *exc_info):
        self.release()

    def acquire(self):
        """Acquire the lock.

        :raise NotAvailable: When the lock has already been acquired.
        """
        with self.PROCESS_LOCK:
            if not self._fslock.lock():
                raise self.NotAvailable(self._fslock.name)

    def release(self):
        """Release the lock."""
        with self.PROCESS_LOCK:
            self._fslock.unlock()

    @contextmanager
    def wait(self, timeout=86400):
        """Wait for the lock to become available.

        :param timeout: The number of seconds to wait. By default it will wait
            up to 1 day.
        """
        interval = max(0.1, min(1.0, float(timeout) / 10.0))

        for _, _, wait in retries(timeout, interval, reactor):
            with self.PROCESS_LOCK:
                if self._fslock.lock():
                    break
            if wait > 0:
                sleep(wait)
        else:
            raise self.NotAvailable(self._fslock.name)

        try:
            yield
        finally:
            with self.PROCESS_LOCK:
                self._fslock.unlock()

    @property
    def path(self):
        return self._fslock.name

    def is_locked(self):
        """Is this lock already taken?

        Use this for informational purposes only.

        The way this works is as follows:

        1. Create a new `FilesystemLock` with the same path.

        2. Use the global process lock to ensure no other processes are also
           trying to access the lock.

        3. Attempt to lock the file-system lock:

           3a. Upon success, we know that the lock must have been unlocked;
               return ``True``.

           3b. Upon failure, no action is required because the lock failed. We
               know that the lock must have been locked; return ``False``.

        """
        fslock = FilesystemLock(self._fslock.name)
        with self.PROCESS_LOCK:
            if fslock.lock():
                fslock.unlock()
                return False
            else:
                return True
def obtain_lock():
    scriptname = os.path.basename(__file__)
    lockfile = os.path.join(tempfile.gettempdir(), scriptname + '.lock')
    lock = FilesystemLock(lockfile)
    return lock.lock()
Example #25
0
 def realCheck():
     localLock = FilesystemLock(workingDirectory + ".lock")
     self.assertTrue(localLock.lock())
     # Stop is not called, as it ought to have been called before
     self.assertEqual(0, fakeReactor.stopCount)
 def realCheck():
     localLock = FilesystemLock(workingDirectory + ".lock")
     self.assertTrue(localLock.lock())
     # Stop is not called, as it ought to have been called before
     self.assertEqual(0, fakeReactor.stopCount)
Example #27
0
class LockResource(object):
    """
    Handle requests for locking documents.

    This class uses Twisted's Filesystem lock to manage a lock in the shared
    database.
    """

    url_pattern = '/%s/lock/{uuid}' % SHARED_DB_NAME
    """
    """

    TIMEOUT = 300  # XXX is 5 minutes reasonable?
    """
    The timeout after which the lock expires.
    """

    # used for lock doc storage
    TIMESTAMP_KEY = '_timestamp'
    LOCK_TOKEN_KEY = '_token'

    FILESYSTEM_LOCK_TRIES = 5
    FILESYSTEM_LOCK_SLEEP_SECONDS = 1

    def __init__(self, uuid, state, responder):
        """
        Initialize the lock resource. Parameters to this constructor are
        automatically passed by u1db.

        :param uuid: The user unique id.
        :type uuid: str
        :param state: The backend database state.
        :type state: u1db.remote.ServerState
        :param responder: The infrastructure to send responses to client.
        :type responder: u1db.remote.HTTPResponder
        """
        self._shared_db = state.open_database(SHARED_DB_NAME)
        self._lock_doc_id = '%s%s' % (SHARED_DB_LOCK_DOC_ID_PREFIX, uuid)
        self._lock = FilesystemLock(
            os.path.join(tempfile.gettempdir(),
                         hashlib.sha512(self._lock_doc_id).hexdigest()))
        self._state = state
        self._responder = responder

    @http_app.http_method(content=str)
    def put(self, content=None):
        """
        Handle a PUT request to the lock document.

        A lock is a document in the shared db with doc_id equal to
        'lock-<uuid>' and the timestamp of its creation as content. This
        method obtains a threaded-lock and creates a lock document if it does
        not exist or if it has expired.

        It returns '201 Created' and a pair containing a token to unlock and
        the lock timeout, or '403 AlreadyLockedError' and the remaining amount
        of seconds the lock will still be valid.

        :param content: The content of the PUT request. It is only here
                        because PUT requests with empty content are considered
                        invalid requests by u1db.
        :type content: str
        """
        # obtain filesystem lock
        if not self._try_obtain_filesystem_lock():
            self._responder.send_response_json(
                LockTimedOutError.status,  # error: request timeout
                error=LockTimedOutError.wire_description)
            return

        created_lock = False
        now = time.time()
        token = hashlib.sha256(os.urandom(10)).hexdigest()  # for releasing
        lock_doc = self._shared_db.get_doc(self._lock_doc_id)
        remaining = self._remaining(lock_doc, now)

        # if there's no lock, create one
        if lock_doc is None:
            lock_doc = self._shared_db.create_doc(
                {
                    self.TIMESTAMP_KEY: now,
                    self.LOCK_TOKEN_KEY: token,
                },
                doc_id=self._lock_doc_id)
            created_lock = True
        else:
            if remaining == 0:
                # lock expired, create new one
                lock_doc.content = {
                    self.TIMESTAMP_KEY: now,
                    self.LOCK_TOKEN_KEY: token,
                }
                self._shared_db.put_doc(lock_doc)
                created_lock = True

        self._try_release_filesystem_lock()

        # send response to client
        if created_lock is True:
            self._responder.send_response_json(201,
                                               timeout=self.TIMEOUT,
                                               token=token)  # success: created
        else:
            self._responder.send_response_json(
                AlreadyLockedError.status,  # error: forbidden
                error=AlreadyLockedError.wire_description,
                remaining=remaining)

    @http_app.http_method(token=str)
    def delete(self, token=None):
        """
        Delete the lock if the C{token} is valid.

        Delete the lock document in case C{token} is equal to the token stored
        in the lock document.

        :param token: The token returned when locking.
        :type token: str

        :raise NotLockedError: Raised in case the lock is not locked.
        :raise InvalidTokenError: Raised in case the token is invalid for
                                  unlocking.
        """
        lock_doc = self._shared_db.get_doc(self._lock_doc_id)
        if lock_doc is None or self._remaining(lock_doc, time.time()) == 0:
            self._responder.send_response_json(
                NotLockedError.status,  # error: not found
                error=NotLockedError.wire_description)
        elif token != lock_doc.content[self.LOCK_TOKEN_KEY]:
            self._responder.send_response_json(
                InvalidTokenError.status,  # error: unauthorized
                error=InvalidTokenError.wire_description)
        else:
            self._shared_db.delete_doc(lock_doc)
            # respond success: should use 204 but u1db does not support it.
            self._responder.send_response_json(200)

    def _remaining(self, lock_doc, now):
        """
        Return the number of seconds the lock contained in C{lock_doc} is
        still valid, when compared to C{now}.

        :param lock_doc: The document containing the lock.
        :type lock_doc: u1db.Document
        :param now: The time to which to compare the lock timestamp.
        :type now: float

        :return: The amount of seconds the lock is still valid.
        :rtype: float
        """
        if lock_doc is not None:
            lock_timestamp = lock_doc.content[self.TIMESTAMP_KEY]
            remaining = lock_timestamp + self.TIMEOUT - now
            return remaining if remaining > 0 else 0.0
        return 0.0

    def _try_obtain_filesystem_lock(self):
        """
        Try to obtain the file system lock.

        @return: Whether the lock was succesfully obtained.
        @rtype: bool
        """
        tries = self.FILESYSTEM_LOCK_TRIES
        while tries > 0:
            try:
                return self._lock.lock()
            except OSError as e:
                tries -= 1
                if tries == 0:
                    raise CouldNotObtainLockError(e.message)
                time.sleep(self.FILESYSTEM_LOCK_SLEEP_SECONDS)
        return False

    def _try_release_filesystem_lock(self):
        """
        Release the filesystem lock.
        """
        try:
            self._lock.unlock()
            return True
        except OSError as e:
            if e.errno == errno.ENOENT:
                return True
            return False
Example #28
0
class LockResource(object):
    """
    Handle requests for locking documents.

    This class uses Twisted's Filesystem lock to manage a lock in the shared
    database.
    """

    url_pattern = '/%s/lock/{uuid}' % SHARED_DB_NAME
    """
    """

    TIMEOUT = 300  # XXX is 5 minutes reasonable?
    """
    The timeout after which the lock expires.
    """

    # used for lock doc storage
    TIMESTAMP_KEY = '_timestamp'
    LOCK_TOKEN_KEY = '_token'

    FILESYSTEM_LOCK_TRIES = 5
    FILESYSTEM_LOCK_SLEEP_SECONDS = 1

    def __init__(self, uuid, state, responder):
        """
        Initialize the lock resource. Parameters to this constructor are
        automatically passed by u1db.

        :param uuid: The user unique id.
        :type uuid: str
        :param state: The backend database state.
        :type state: u1db.remote.ServerState
        :param responder: The infrastructure to send responses to client.
        :type responder: u1db.remote.HTTPResponder
        """
        self._shared_db = state.open_database(SHARED_DB_NAME)
        self._lock_doc_id = '%s%s' % (SHARED_DB_LOCK_DOC_ID_PREFIX, uuid)
        self._lock = FilesystemLock(
            os.path.join(
                tempfile.gettempdir(),
                hashlib.sha512(self._lock_doc_id).hexdigest()))
        self._state = state
        self._responder = responder

    @http_app.http_method(content=str)
    def put(self, content=None):
        """
        Handle a PUT request to the lock document.

        A lock is a document in the shared db with doc_id equal to
        'lock-<uuid>' and the timestamp of its creation as content. This
        method obtains a threaded-lock and creates a lock document if it does
        not exist or if it has expired.

        It returns '201 Created' and a pair containing a token to unlock and
        the lock timeout, or '403 AlreadyLockedError' and the remaining amount
        of seconds the lock will still be valid.

        :param content: The content of the PUT request. It is only here
                        because PUT requests with empty content are considered
                        invalid requests by u1db.
        :type content: str
        """
        # obtain filesystem lock
        if not self._try_obtain_filesystem_lock():
            self._responder.send_response_json(
                LockTimedOutError.status,  # error: request timeout
                error=LockTimedOutError.wire_description)
            return

        created_lock = False
        now = time.time()
        token = hashlib.sha256(os.urandom(10)).hexdigest()  # for releasing
        lock_doc = self._shared_db.get_doc(self._lock_doc_id)
        remaining = self._remaining(lock_doc, now)

        # if there's no lock, create one
        if lock_doc is None:
            lock_doc = self._shared_db.create_doc(
                {
                    self.TIMESTAMP_KEY: now,
                    self.LOCK_TOKEN_KEY: token,
                },
                doc_id=self._lock_doc_id)
            created_lock = True
        else:
            if remaining == 0:
                # lock expired, create new one
                lock_doc.content = {
                    self.TIMESTAMP_KEY: now,
                    self.LOCK_TOKEN_KEY: token,
                }
                self._shared_db.put_doc(lock_doc)
                created_lock = True

        self._try_release_filesystem_lock()

        # send response to client
        if created_lock is True:
            self._responder.send_response_json(
                201, timeout=self.TIMEOUT, token=token)  # success: created
        else:
            self._responder.send_response_json(
                AlreadyLockedError.status,  # error: forbidden
                error=AlreadyLockedError.wire_description, remaining=remaining)

    @http_app.http_method(token=str)
    def delete(self, token=None):
        """
        Delete the lock if the C{token} is valid.

        Delete the lock document in case C{token} is equal to the token stored
        in the lock document.

        :param token: The token returned when locking.
        :type token: str

        :raise NotLockedError: Raised in case the lock is not locked.
        :raise InvalidTokenError: Raised in case the token is invalid for
                                  unlocking.
        """
        lock_doc = self._shared_db.get_doc(self._lock_doc_id)
        if lock_doc is None or self._remaining(lock_doc, time.time()) == 0:
            self._responder.send_response_json(
                NotLockedError.status,  # error: not found
                error=NotLockedError.wire_description)
        elif token != lock_doc.content[self.LOCK_TOKEN_KEY]:
            self._responder.send_response_json(
                InvalidTokenError.status,  # error: unauthorized
                error=InvalidTokenError.wire_description)
        else:
            self._shared_db.delete_doc(lock_doc)
            # respond success: should use 204 but u1db does not support it.
            self._responder.send_response_json(200)

    def _remaining(self, lock_doc, now):
        """
        Return the number of seconds the lock contained in C{lock_doc} is
        still valid, when compared to C{now}.

        :param lock_doc: The document containing the lock.
        :type lock_doc: u1db.Document
        :param now: The time to which to compare the lock timestamp.
        :type now: float

        :return: The amount of seconds the lock is still valid.
        :rtype: float
        """
        if lock_doc is not None:
            lock_timestamp = lock_doc.content[self.TIMESTAMP_KEY]
            remaining = lock_timestamp + self.TIMEOUT - now
            return remaining if remaining > 0 else 0.0
        return 0.0

    def _try_obtain_filesystem_lock(self):
        """
        Try to obtain the file system lock.

        @return: Whether the lock was succesfully obtained.
        @rtype: bool
        """
        tries = self.FILESYSTEM_LOCK_TRIES
        while tries > 0:
            try:
                return self._lock.lock()
            except OSError as e:
                tries -= 1
                if tries == 0:
                    raise CouldNotObtainLockError(e.message)
                time.sleep(self.FILESYSTEM_LOCK_SLEEP_SECONDS)
        return False

    def _try_release_filesystem_lock(self):
        """
        Release the filesystem lock.
        """
        try:
            self._lock.unlock()
            return True
        except OSError as e:
            if e.errno == errno.ENOENT:
                return True
            return False
Example #29
0
class CtxFactory(ssl.ClientContextFactory):
    def getContext(self):
        self.method = SSL.TLSv1_METHOD
        ctx = ssl.ClientContextFactory.getContext(self)
        ctx.set_verify(SSL.VERIFY_PEER | SSL.VERIFY_FAIL_IF_NO_PEER_CERT,
                       verifyCallback)
        #print dir(ctx)
        #raise SystemExit
        return ctx


from os import path

if __name__ == '__main__':
    lock = FilesystemLock("treestatusbot.lock")
    if isLocked("treestatusbot.lock"):
        raise SystemExit("There's already a bot running. If this is not the "
                         "case, please remove treestatusbot.lock manually")
    else:
        lock.lock()

    def unlock():
        lock.unlock()

    f = GaiaBotFactory()
    reactor.connectSSL(SERVER, int(PORT), f, CtxFactory())
    print "Connecting to", SERVER, PORT
    # run bot
    reactor.addSystemEventTrigger('before', 'shutdown', unlock)
    reactor.run()
Example #30
0
 tempdir = path = tempfile.mkdtemp()
 
 _home = os.environ.get('HOME', '/')
 if platform.system() == 'Windows':
     novatool_config_home = os.path.join(os.environ['APPDATA'], 'Novatool')
 elif platform.system() == 'Linux':
     novatool_config_home = os.path.join(os.environ.get('XDG_CONFIG_HOME', os.path.join(_home, '.config')), 'novatool')
 elif platform.system() == 'Darwin':
     novatool_config_home = os.path.join(_home, 'Library', 'Application Support', 'Novatool')
 else:
     novatool_config_home = os.path.join(_home, '.novatool')
 if not os.path.exists(novatool_config_home):
     os.makedirs(novatool_config_home)
     
 ipc_file = os.path.join(novatool_config_home,'ipc')
 
 lock = FilesystemLock(os.path.join(novatool_config_home,"lock"))
 if lock.lock():
     mainWin = MainWindow(novatool_config_home, tempdir, githash)
     reactor.run()
     lock.unlock()
     QApplication.quit()
 else:
     if os.path.isfile(ipc_file):
         f = open(ipc_file,'r')
         ipc_port = int(f.read())
         f.close()
         s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         s.connect(('localhost', ipc_port))
     else:
         print lock.name, 'is locked.'