#!/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:
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:
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)