#!/usr/bin/env python

#**************************************************************************
#   Copyright (C) 2008-2015 by Walter Brisken                             *
#                                                                         *
#   This program is free software; you can redistribute it and/or modify  *
#   it under the terms of the GNU General Public License as published by  *
#   the Free Software Foundation; either version 3 of the License, or     *
#   (at your option) any later version.                                   *
#                                                                         *
#   This program is distributed in the hope that it will be useful,       *
#   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
#   GNU General Public License for more details.                          *
#                                                                         *
#   You should have received a copy of the GNU General Public License     *
#   along with this program; if not, write to the                         *
#   Free Software Foundation, Inc.,                                       *
#   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
#**************************************************************************

#===========================================================================
# SVN properties (DO NOT CHANGE)
#
# $Id$
# $HeadURL: $
# $LastChangedRevision$
# $Author$
# $LastChangedDate$
#
#============================================================================

from string import split, strip, find, upper, lower
from sys import argv, exit
from os import popen, getenv
from glob import glob
import socket
import struct
from xml.parsers import expat
from copy import deepcopy
from time import asctime
import signal

program = 'errormon'
author  = 'Walter Brisken'
version = '0.8'
verdate = '20150811'

alertLevels = ['FATAL', 'SEVERE', 'ERROR', 'WARNING', 'INFO', 'VERBOSE', 'DEBUG', 'IGNORE']

def signal_handler(signal, frame):
	print('You pressed Ctrl+C!')
	exit(0)

def usage(prog):
	print '%s ver. %s  %s  %s\n' % (program, version, author, verdate)
	print 'Usage: %s [options] [<maxlevel>]\n' % prog
	print 'options can include:'
	print '  --help'
	print '  -h        print help information and quit\n'
	print '<maxlevel>  is the max alert error level to print.  The levels are:'
	for level in range(len(alertLevels)):
		print '    %d = %s' % (level, alertLevels[level])
	print ''

class Parser:

	def __init__(self):
		self._parser = expat.ParserCreate()
		self._parser.StartElementHandler = self.start
		self._parser.EndElementHandler = self.end
		self._parser.CharacterDataHandler = self.data
		self.message = ''
		self.severity = -1
		self.tmp = ''
		self.ok = False
		self.unit = ''
		self.mpiid = -1
		self.id = ''
		self.tag = ''

	def feed(self, data):
		self._parser.Parse(data, 0)

	def close(self):
		self._parser.Parse("", 1) # end of data
		del self._parser # get rid of circular references

	def start(self, tag, attrs):
		self.tag = tag
		self.tmp = ''
		if tag == 'difxAlert':
			self.ok = True

	def end(self, tag):
		if tag == 'alertMessage' and self.ok:
			self.message = self.tmp
		elif tag == 'severity':
			self.severity = int(self.tmp)
		elif tag == 'from':
			self.unit = lower(self.tmp)
		elif tag == 'identifier':
			self.id = self.tmp
		elif tag == 'mpiProcessId':
			self.mpiid = int(self.tmp)

	def data(self, data):
		if self.tag == 'alertMessage':
			self.tmp = self.tmp + data	
		else:
			self.tmp = data

	def getinfo(self):
		if self.ok:
			return 'MPI[%2d] %-9s %-12s %-7s %s' % (self.mpiid, self.unit, self.id, alertLevels[self.severity], self.message)
		else:
			return ''

def run(maxlevel):
	
	port = getenv('DIFX_MESSAGE_PORT')
	if port == None:
		print 'DIFX_MESSAGE_PORT needs to be defined'
		exit(0)
	else:
		port = int(port)
	group = getenv('DIFX_MESSAGE_GROUP')
	if group == None:
		print 'DIFX_MESSAGE_GROUP needs to be defined'
		exit(0)

	# Is this a multicast IP address?
	groupint = struct.unpack("!I", socket.inet_aton(group))[0]
	if (groupint>>28==14):
		multicast = True
	else:
		multicast = False

	s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
	s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
	s.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 768000)
	s.bind(('', port))
	if (multicast):
		mreq = struct.pack("4sl", socket.inet_aton(group), socket.INADDR_ANY)
		s.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)
	#s.settimeout(dt)

	try:
		while 1:
			try:
				message = s.recv(1500)
				if len(message) > 0 and message[0] == '<':
					p = Parser()
					p.feed(message)
					info = p.getinfo()
					p.close()
					if len(info) > 0 and p.severity <= maxlevel:
						print asctime(), info
			except socket.timeout:
				pass
			except expat.ExpatError:
				print asctime(), '*** Unparsable message received ***'
				print message
	except KeyboardInterrupt:
		pass


signal.signal(signal.SIGINT, signal_handler)

if len(argv) > 1:
	if argv[1] in ['-h', '--help']:
		usage(argv[0])
		exit(0)
	maxlevel = int(argv[1])
else:
	maxlevel = 8

run(maxlevel)

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