from .common import to_utf8
-__version__ = '0.1.1'
+__version__ = '0.2.2'
LOG = logging.getLogger(__name__)
return msg
+# =============================================================================
+class PidFile(PpBaseObject):
+ """
+ Base class for a pidfile object.
+ """
+
+ open_args = {}
+ if six.PY3:
+ open_args = {
+ 'encoding': 'utf-8',
+ 'errors': 'surrogateescape',
+ }
+
+ # -------------------------------------------------------------------------
+ def __init__(
+ self, filename, auto_remove=True, appname=None, verbose=0,
+ version=__version__, base_dir=None,
+ initialized=False, simulate=False, timeout=10):
+ """
+ Initialisation of the pidfile object.
+
+ @raise ValueError: no filename was given
+ @raise PidFileError: on some errors.
+
+ @param filename: the filename of the pidfile
+ @type filename: str
+ @param auto_remove: Remove the self created pidfile on destroying
+ the current object
+ @type auto_remove: bool
+ @param appname: name of the current running application
+ @type appname: str
+ @param verbose: verbose level
+ @type verbose: int
+ @param version: the version string of the current object or application
+ @type version: str
+ @param base_dir: the base directory of all operations
+ @type base_dir: str
+ @param initialized: initialisation is complete after __init__()
+ of this object
+ @type initialized: bool
+ @param simulate: simulation mode
+ @type simulate: bool
+ @param timeout: timeout in seconds for IO operations on pidfile
+ @type timeout: int
+
+ @return: None
+ """
+
+ self._created = False
+ """
+ @ivar: the pidfile was created by this current object
+ @type: bool
+ """
+
+ super(PidFile, self).__init__(
+ appname=appname,
+ verbose=verbose,
+ version=version,
+ base_dir=base_dir,
+ initialized=False,
+ )
+
+ if not filename:
+ raise ValueError(_('No filename given on initializing PidFile object.'))
+
+ self._filename = os.path.abspath(str(filename))
+ """
+ @ivar: The filename of the pidfile
+ @type: str
+ """
+
+ self._auto_remove = bool(auto_remove)
+ """
+ @ivar: Remove the self created pidfile on destroying the current object
+ @type: bool
+ """
+
+ self._simulate = bool(simulate)
+ """
+ @ivar: Simulation mode
+ @type: bool
+ """
+
+ self._timeout = int(timeout)
+ """
+ @ivar: timeout in seconds for IO operations on pidfile
+ @type: int
+ """
+
+ # -----------------------------------------------------------
+ @property
+ def filename(self):
+ """The filename of the pidfile."""
+ return self._filename
+
+ # -----------------------------------------------------------
+ @property
+ def auto_remove(self):
+ """Remove the self created pidfile on destroying the current object."""
+ return self._auto_remove
+
+ @auto_remove.setter
+ def auto_remove(self, value):
+ self._auto_remove = bool(value)
+
+ # -----------------------------------------------------------
+ @property
+ def simulate(self):
+ """Simulation mode."""
+ return self._simulate
+
+ # -----------------------------------------------------------
+ @property
+ def created(self):
+ """The pidfile was created by this current object."""
+ return self._created
+
+ # -----------------------------------------------------------
+ @property
+ def timeout(self):
+ """The timeout in seconds for IO operations on pidfile."""
+ return self._timeout
+
+ # -----------------------------------------------------------
+ @property
+ def parent_dir(self):
+ """The directory containing the pidfile."""
+ return os.path.dirname(self.filename)
+
+ # -------------------------------------------------------------------------
+ def as_dict(self, short=True):
+ """
+ Transforms the elements of the object into a dict
+
+ @param short: don't include local properties in resulting dict.
+ @type short: bool
+
+ @return: structure as dict
+ @rtype: dict
+ """
+
+ res = super(PidFile, self).as_dict(short=short)
+ res['filename'] = self.filename
+ res['auto_remove'] = self.auto_remove
+ res['simulate'] = self.simulate
+ res['created'] = self.created
+ res['timeout'] = self.timeout
+ res['parent_dir'] = self.parent_dir
+
+ return res
+
+ # -------------------------------------------------------------------------
+ def __repr__(self):
+ """Typecasting into a string for reproduction."""
+
+ out = "<%s(" % (self.__class__.__name__)
+
+ fields = []
+ fields.append("filename=%r" % (self.filename))
+ fields.append("auto_remove=%r" % (self.auto_remove))
+ fields.append("appname=%r" % (self.appname))
+ fields.append("verbose=%r" % (self.verbose))
+ fields.append("base_dir=%r" % (self.base_dir))
+ fields.append("initialized=%r" % (self.initialized))
+ fields.append("simulate=%r" % (self.simulate))
+ fields.append("timeout=%r" % (self.timeout))
+
+ out += ", ".join(fields) + ")>"
+ return out
+
+ # -------------------------------------------------------------------------
+ def __del__(self):
+ """Destructor. Removes the pidfile, if it was created by ourselfes."""
+
+ if not self.created:
+ return
+
+ if not os.path.exists(self.filename):
+ if self.verbose > 3:
+ LOG.debug("Pidfile {!r} doesn't exists, not removing.".format(self.filename))
+ return
+
+ if not self.auto_remove:
+ if self.verbose > 3:
+ LOG.debug("Auto removing disabled, don't deleting {!r}.".format(self.filename))
+ return
+
+ if self.verbose > 1:
+ LOG.debug("Removing pidfile {!r} ...".format(self.filename))
+ if self.simulate:
+ if self.verbose > 1:
+ LOG.debug("Just kidding ..")
+ return
+ try:
+ os.remove(self.filename)
+ except OSError as e:
+ LOG.err("Could not delete pidfile {!r}: {}".format(self.filename, e))
+ except Exception as e:
+ self.handle_error(str(e), e.__class__.__name__, True)
+
+ # -------------------------------------------------------------------------
+ def create(self, pid=None):
+ """
+ The main method of this class. It tries to write the PID of the process
+ into the pidfile.
+
+ @param pid: the pid to write into the pidfile. If not given, the PID of
+ the current process will taken.
+ @type pid: int
+
+ """
+
+ if pid:
+ pid = int(pid)
+ if pid <= 0:
+ msg = "Invalid PID {} for creating pidfile {!r} given.".format(pid, self.filename)
+ raise PidFileError(msg)
+ else:
+ pid = os.getpid()
+
+ if self.check():
+
+ LOG.info("Deleting pidfile {!r} ...".format(self.filename))
+ if self.simulate:
+ LOG.debug("Just kidding ..")
+ else:
+ try:
+ os.remove(self.filename)
+ except OSError as e:
+ raise InvalidPidFileError(self.filename, str(e))
+
+ if self.verbose > 1:
+ LOG.debug("Trying opening {!r} exclusive ...".format(self.filename))
+
+ if self.simulate:
+ LOG.debug("Simulation mode - don't real writing in {!r}.".format(self.filename))
+ self._created = True
+ return
+
+ fd = None
+ try:
+ fd = os.open(
+ self.filename, os.O_CREAT | os.O_EXCL | os.O_WRONLY, 0o644)
+ except OSError as e:
+ error_tuple = sys.exc_info()
+ msg = "Error on creating pidfile {!r}: {}".format(self.filename, e)
+ reraise(PidFileError, msg, error_tuple[2])
+
+ if self.verbose > 2:
+ LOG.debug("Writing {} into {!r} ...".format(pid, self.filename))
+
+ out = to_utf8("%d\n" % (pid))
+ try:
+ os.write(fd, out)
+ finally:
+ os.close(fd)
+
+ self._created = True
+
+ # -------------------------------------------------------------------------
+ def recreate(self, pid=None):
+ """
+ Rewrites an even created pidfile with the current PID.
+
+ @param pid: the pid to write into the pidfile. If not given, the PID of
+ the current process will taken.
+ @type pid: int
+
+ """
+
+ if not self.created:
+ msg = "Calling recreate() on a not self created pidfile."
+ raise PidFileError(msg)
+
+ if pid:
+ pid = int(pid)
+ if pid <= 0:
+ msg = "Invalid PID {} for creating pidfile {!r} given.".format(pid, self.filename)
+ raise PidFileError(msg)
+ else:
+ pid = os.getpid()
+
+ if self.verbose > 1:
+ LOG.debug("Trying opening {!r} for recreate ...".format(self.filename))
+
+ if self.simulate:
+ LOG.debug("Simulation mode - don't real writing in {!r}.".format(self.filename))
+ return
+
+ fh = None
+ try:
+ fh = open(self.filename, 'w', self.open_args)
+ except OSError as e:
+ error_tuple = sys.exc_info()
+ msg = "Error on recreating pidfile {!r}: {}".format(self.filename, e)
+ reraise(PidFileError, msg, error_tuple[2])
+
+ if self.verbose > 2:
+ LOG.debug("Writing {} into {!r} ...".format(pid, self.filename))
+
+ try:
+ fh.write("%d\n" % (pid))
+ finally:
+ fh.close()
+
+ # -------------------------------------------------------------------------
+ def check(self):
+ """
+ This methods checks the usability of the pidfile.
+ If the method doesn't raise an exception, the pidfile is usable.
+
+ It returns, whether the pidfile exist and can be deleted or not.
+
+ @raise InvalidPidFileError: if the pidfile is unusable
+ @raise PidFileInUseError: if the pidfile is in use by another application
+ @raise PbReadTimeoutError: on timeout reading an existing pidfile
+ @raise OSError: on some other reasons, why the existing pidfile
+ couldn't be read
+
+ @return: the pidfile exists, but can be deleted - or it doesn't
+ exists.
+ @rtype: bool
+
+ """
+
+ if not os.path.exists(self.filename):
+ if not os.path.exists(self.parent_dir):
+ reason = "Pidfile parent directory {!r} doesn't exists.".format(self.parent_dir)
+ raise InvalidPidFileError(self.filename, reason)
+ if not os.path.isdir(self.parent_dir):
+ reason = "Pidfile parent directory {!r} is not a directory.".format(self.parent_dir)
+ raise InvalidPidFileError(self.filename, reason)
+ if not os.access(self.parent_dir, os.X_OK):
+ reason = "No write access to pidfile parent directory {!r}.".format(self.parent_dir)
+ raise InvalidPidFileError(self.filename, reason)
+
+ return False
+
+ if not os.path.isfile(self.filename):
+ reason = "It is not a regular file."
+ raise InvalidPidFileError(self.filename, self.parent_dir)
+
+ # ---------
+ def pidfile_read_alarm_caller(signum, sigframe):
+ """
+ This nested function will be called in event of a timeout.
+
+ @param signum: the signal number (POSIX) which happend
+ @type signum: int
+ @param sigframe: the frame of the signal
+ @type sigframe: object
+ """
+
+ return PbReadTimeoutError(self.timeout, self.filename)
+
+ if self.verbose > 1:
+ LOG.debug("Reading content of pidfile {!r} ...".format(self.filename))
+
+ signal.signal(signal.SIGALRM, pidfile_read_alarm_caller)
+ signal.alarm(self.timeout)
+
+ content = ''
+ fh = None
+
+ try:
+ fh = open(self.filename, 'r')
+ for line in fh.readlines():
+ content += line
+ finally:
+ if fh:
+ fh.close()
+ signal.alarm(0)
+
+ # Performing content of pidfile
+
+ pid = None
+ line = content.strip()
+ match = re.search(r'^\s*(\d+)\s*$', line)
+ if match:
+ pid = int(match.group(1))
+ else:
+ msg = "No useful information found in pidfile {!r}: {!r}".format(self.filename, line)
+ return True
+
+ if self.verbose > 1:
+ LOG.debug("Trying check for process with PID {} ...".format(pid))
+
+ try:
+ os.kill(pid, 0)
+ except OSError as err:
+ if err.errno == errno.ESRCH:
+ LOG.info("Process with PID {} anonymous died.".format(pid))
+ return True
+ elif err.errno == errno.EPERM:
+ error_tuple = sys.exc_info()
+ msg = "No permission to signal the process {} ...".format(pid)
+ reraise(PidFileError, msg, error_tuple[2])
+ else:
+ error_tuple = sys.exc_info()
+ msg = "Got a {}: {}.".format(err.__class__.__name__, err)
+ reraise(PidFileError, msg, error_tuple[2])
+ else:
+ raise PidFileInUseError(self.filename, pid)
+
+ return False
# =============================================================================
projects / pixelpark / admin-tools.git / commitdiff