Source code for mentat.daemon.component.filter

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#-------------------------------------------------------------------------------
# This file is part of Mentat system (https://mentat.cesnet.cz/).
#
# Copyright (C) since 2011 CESNET, z.s.p.o (http://www.ces.net/)
# Use of this source is governed by the MIT license, see LICENSE file.
#-------------------------------------------------------------------------------


"""
Daemon component capable of filtering incoming messages with complex filtering
rules.

It is dependent on services of following modules:

* :py:mod:`pynspect.filters`

  Filtering rule library.

* :py:mod:`pynspect.compilers`

  Filtering rule compilation library.

The implementation is based on :py:class:`pyzenkit.zendaemon.ZenDaemonComponent`.
"""


__author__ = "Jan Mach <jan.mach@cesnet.cz>"
__credits__ = "Pavel Kácha <pavel.kacha@cesnet.cz>, Andrea Kropáčová <andrea.kropacova@cesnet.cz>"


import sys
import pprint

#
# Custom libraries.
#
import pyzenkit.zendaemon
from pynspect.gparser import PynspectFilterParser
from pynspect.filters import DataObjectFilter

from mentat.idea.internal import IDEAFilterCompiler


[docs]class FilterDaemonComponent(pyzenkit.zendaemon.ZenDaemonComponent): """ Implementation of ZenDaemonComponent encapsulating pynspect library. """ EVENT_MSG_PROCESS = 'message_process' def __init__(self, **kwargs): """ Perform component initializations. """ super().__init__(**kwargs) # Unique component identifier self.cid = kwargs.get('cid', 'filer') self.filter_rules_key = kwargs.get('filter_rules_key', 'filter_rules') self.filter_parser = PynspectFilterParser() self.filter_compiler = IDEAFilterCompiler() self.filter = DataObjectFilter() self.filter_parser.build() # Permit changing of default event mapping self.event_map = kwargs.get('event_map', { self.EVENT_MSG_PROCESS: self.EVENT_MSG_PROCESS })
[docs] def get_events(self): """ Get the list of event names and their appropriate callback handlers. """ return [ { 'event': self.event_map[self.EVENT_MSG_PROCESS], 'callback': self.cbk_event_message_process, 'prepend': False } ]
[docs] def setup(self, daemon): """ Perform component setup. """ self.filter_rules_cfg = daemon.c(self.filter_rules_key) daemon.dbgout("[STATUS] Component '{}': Loading filter rules {}".format(self.cid, pprint.pformat(self.filter_rules_cfg))) self.filter_rules = [] for rule in self.filter_rules_cfg: try: flt = self.filter_parser.parse(rule['rule']) flt = self.filter_compiler.compile(flt) nme = rule.get('name', rule['rule']) self.filter_rules.append({ "rule": nme, "filter": flt }) daemon.logger.debug("[STATUS] Component '{}': Loaded filter rule '{}'".format(self.cid, nme)) except Exception: daemon.logger.debug("[STATUS] Component '{}': Unable to load filter rule '{}'".format(self.cid, rule))
#---------------------------------------------------------------------------
[docs] def cbk_event_message_process(self, daemon, args): """ Print the message contents into the log. """ daemon.logger.debug("Filtering message: '{}'".format(args['id'])) try: for rule in self.filter_rules: if self.filter.filter(rule["filter"], args['idea']): daemon.logger.debug("Message '{}' filtered out by filter '{}'".format(args['id'], rule["rule"])) daemon.queue.schedule('message_cancel', args) return (daemon.FLAG_STOP, args) else: daemon.logger.debug("Message '{}' passed by filter '{}'".format(args['id'], rule["rule"])) return (daemon.FLAG_CONTINUE, args) except Exception: daemon.logger.debug("Message '{}' caused some trouble during processing: '{}'".format(args['id'], sys.exc_info()[1])) daemon.queue.schedule('message_banish', args) return (daemon.FLAG_STOP, args)