#!/usr/bin/python

# A global event handler for Nagios

# Cleaned up for NZNOG 2008 presentation
# Sam Sargeant <sam@onesquared.net>
#
# TODO: This has no external config file. All the logic is contained
#       inside the main() function. If you don't understand Python objects
#       this will be very opaque.
#
# This code is released under a Creative Commons licence
# http://creativecommons.org/licenses/by/3.0/nz/
#
# You are free: 
# to Share Ñ to copy, distribute and transmit the work
# to Remix Ñ to adapt the work
#
# Under the following conditions:
#
# Attribution. You must attribute the work in the manner specified by the
# author or licensor (but not in any way that suggests that they endorse you or
# your use of the work).
#
# For any reuse or distribution, you must make clear to others the license
# terms of this work. The best way to do this is with a link to the URL above.
# Any of the above conditions can be waived if you get permission from the
# copyright holder. Nothing in this license impairs or restricts the author's
# moral rights.


import sys, logging, os, urllib
from optparse import OptionParser

version = '1.1'

log = logging.getLogger('')
log.setLevel(logging.INFO)

formatter = logging.Formatter('%(asctime)s %(levelname)s %(message)s')

try:
	logfile = logging.FileHandler('/usr/local/nagios/var/event_handler.log')
except IOError, e:
	log.error("Cannot create logging.FileHandler: " + e.strerror)
else:
	logfile.setFormatter(formatter)
	log.addHandler(logfile)

def main():
	## Here is where you add your handlers.
	iis_handler = SaveIISStatus()
	iis_handler.target_host = 'iis.myorg.com'

	handlers = [ iis_handler, DemoHandler(), PlutoRestartHandler() ]

	parser = OptionParser(version=version)
	parser.add_option('--host', dest='host',
			help='host this event has occured on')
	parser.add_option('--host-address', dest='host_address', metavar='IP_ADDR',
			help='IP address of the host')
	parser.add_option('--host-state', dest='host_state', metavar='STATE',
			help='the current state of the host')
	parser.add_option('--host-attempt', dest='host_attempt', metavar='NUM', type='int',
			help='number of host checks that have occured in this state')
	parser.add_option('--service', dest='service',
			help='service this event has occured on')
	parser.add_option('--service-state', dest='service_state', metavar='STATE',
			help='state of the service')
	parser.add_option('--service-attempt', dest='service_attempt', type='int', metavar='NUM',
			help='number of service checks that have occured in this state')
	parser.add_option('--output', dest='output',
			help='the text output from the check')
	parser.add_option('--type', dest='type',
			help='the event type from Nagios: [hard|soft]')

	parser.add_option('-v', '--verbose', dest='verbose', action='store_true',
			help='verbose mode')
	parser.add_option('-d', '--debug', dest='debug', action='store_true',
			help='debug mode')
	parser.add_option('-n', '--no-action', dest='no_action', action='store_true',
			help='dry-run only')

	options, args = parser.parse_args()

	if options.debug:
		log.setLevel(logging.DEBUG)
		log.debug("Debug mode enabled")

	if options.debug:
		log.debug("Loaded handlers: %s" % [h.__class__.__name__ for h in handlers])

	if options.verbose:
		logstdout = logging.StreamHandler()
		logstdout.setFormatter(formatter)
		log.addHandler(logstdout)

	event = Event()
	event.host = options.host
	event.host_address = options.host_address
	event.host_state = options.host_state
	event.service = options.service
	event.service_state = options.service_state
	event.service_attempt = options.service_attempt
	event.output = options.output
	event.type = options.type

	if options.debug:
		log.debug("Loaded event: %s" % event)
		log.debug("isHost: %s" % event.isHost())
		log.debug("isService: %s" % event.isService())


	# Load event handlers
	for handler in handlers:
		log.debug("Checking if handler %s wants %s" % (handler, event))
		if handler.wants(event):
			log.debug("%s wants %s" % (handler, event))
			if options.verbose: log.info("Running %s for %s" % (handler, event))
			if not options.no_action:
				try:
					handler.run(event)
				except Exception, e:
					log.error('%s threw exception: %s' % (handler, e))

class Event:
	def isHost(self):
		if not self.service: return True
		return False

	def isService(self):
		if self.service: return True
		return False

	def __repr__(self):
		if self.service:
			return 'service event %s on %s is %s (%s)' % ( self.service, self.host, self.service_state, self.type)
		else:
			return 'host event %s is %s (%s)' % ( self.host, self.host_state, self.type)

class Handler:
	def __str__(self):
		return self.__class__.__name__
	def wants(self, event): raise NotImplemented
	def run(self, event): raise NotImplemented

class DemoHandler(Handler):
	def wants(self, event):
		return True

	def run(self, event):
		print event

class SaveIISStatus(Handler):
	target_host = None

	def wants(self, event):
		if event.host == self.target_host: return True

	def run(self, event):
		# Save http://host/iisstatus.dll to /var/log/iisstatus/host_yyyymmddhhmm.html
		import mx.DateTime, urllib2

		log.info('Saving iisstatus.dll page for %s' % event.host)

		timestamp = mx.DateTime.now().strftime('%Y%m%d%H%M')
		filename = '/var/log/iisstatus/%s_%s.html' % (event.host, timestamp)
		log.debug('Target filename: %s' % filename)
		url = 'http://%s/iisstatus.dll' % event.host_address
		log.debug('Source URL: %s' % url)

		filein = urllib2.urlopen(url)
		fileout = open(filename, 'w')
		fileout.write(filein.read())
		fileout.close()
		filein.close()

class MagicRestartHandler(Handler):
	def wants(self, event):
		if event.host.endswith('.mysystem.myorg.com') and event.service == 'HTTP' and event.service_attempt == 2:
			return True

	def run(self, event):
		url = 'http://%s:666/?secret-restart-url-modified' % event.host
		log.info('Restarting MySystem on %s' % event.host)
		log.debug('Using URL %s' % url)
		urllib.urlopen(url)

if __name__ == '__main__':
	main()