#!/usr/bin/env python

"""
#===================================================================================#

FILE		: check_failover.py

USAGE		: ./check_failover.py

DESCRIPTION	: Nagios plugin to check if Red Hat cluster services has moved to another node.

OPTION(S)	: -i / --init & -v / --version & -h / --help
REQUIREMENTS	: RedHat cluster. Tested with clustat 1.9.53
BUGS		: Search for XXX in the script.
NOTES 		: Tab stop = 8. I prefer '#' inside the code for comments
		  I don't like the block comments with ''' so much as I am used to BASH and the colours that I work with in cream / vim.
AUTHOR(s)	: Martinus Nel (martinus.nel@linuxit.com)
COMPANY		: LinuxIT
VERSION		: 1.0
CREATED		: 16-07-08
WISH LIST	: 


Copyright (C) 2008  LinuxIT Europe LTD, www.linuxit.com
  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, see <http://www.gnu.org/licenses/>.

#===================================================================================#

#============#
# CHANGE LOG #
#============#

#===============#
# V2 - xx-xx-08 #
#===============#
Features
--------

Bugs
----

Please send bug reports / feature requests to Martinus Nel (martinus.nel@linuxit.com)
"""

import os, re, sys, getopt, string, pickle


#====================#
# Nagios exit status #
#====================#
STATE_OK = 0
STATE_WARNING = 1
STATE_CRITICAL = 2
STATE_UNKNOWN = 3
STATE_DEPENDENT = 4

#=================##
# Global variables #
#=================##
VERSION = 1
DATA_FILE = ''
CLUSTAT = '/usr/sbin/clustat'

#===========#
# Functions #
#===========#
def usage():
	print 'check_failover.py version %s' % (VERSION)
	print 'This is a Nagios check to see if Red Hat cluster services has moved to another node.'
	print '''
Copyright (C) 2008  LinuxIT Europe LTD, www.linuxit.com

Usage : check_failover.py

Options: -i / --init	-- Initialize for first run or use to re-initialize.
	 -h / --help	-- Displays this help message.
	 -v / --version	-- Displays version.
'''
	sys.exit(STATE_OK)


def get_data():
	pipe = os.popen(CLUSTAT)
	output = pipe.readlines()
	exit_status = pipe.close()

	# Next 2 lines is cutting out everything above the dashed lines.
	LOCATION = output.index('  ------- ----         ----- ------                   -----         \n')
	TAIL = output[LOCATION + 1:]

	# As I don't know any better, the following 3 lines takes :
	# ['  SERVICE                  NODE-NAME                       STATUS         \n']
	# and makes it:
	# ['SERVICE', 'NODE-NAME', 'STATUS']
	TAIL = str(TAIL)
	TAIL = TAIL.split()
	TAIL = TAIL[1:-1]

	COUNTER = 0
	DATA=[]

	# I only want the first 2 columns of clustat output (under Service Name).
	while COUNTER < len(TAIL):
		DATA.append(TAIL[COUNTER])
		COUNTER = COUNTER + 1
		DATA.append(TAIL[COUNTER])
		COUNTER = COUNTER + 4
	return DATA


def initialize():
	print 'Initializing now ...'
	try:
		INIT_FILE = open(DATA_FILE, 'w')
	except IOError:
		print 'Unable to write to file.  Make sure the Nagios user can read/write to %s.' % (DATA_FILE)
		sys.exit(STATE_CRITICAL)
	DATA = get_data()
	pickle.dump(DATA, INIT_FILE)
	INIT_FILE.close()
	print 'Initialization completed OK'
	sys.exit(STATE_OK)


#======#
# Main #
#======#

#===========================#
# Check options / arguments #
#===========================#
try:
	options, argument = getopt.getopt(sys.argv[1:],'ihv', ["init", "help", "version"])
except getopt.error:
	usage()

for a in options[:]:
	if a[0] == '-i' or a[0] == '--init':
		initialize()
for a in options[:]:
	if a[0] == '-h' or a[0] == '--help':
		usage()
for a in options[:]:
	if a[0] == '-v' or a[0] == '--version':
		print 'check_rhcluster.py version %s' % (VERSION)
		sys.exit(STATE_OK)

if len(argument) != 0:
	print "Incorrect amount of arguments."
	print "See 'check_failover.py -h' for more details"
	sys.exit(STATE_CRITICAL)

if DATA_FILE == '':
	print 'First set "DATA_FILE" variable in script.  Make sure the Nagios user can read/write to it.'
	sys.exit(STATE_CRITICAL)

if os.path.exists(DATA_FILE) != 1:
	print 'Could not find data file.'
	print 'Make sure the Nagios user can read/write to it and that you have initialized with -i / --init'
	sys.exit(STATE_CRITICAL)

#==================================#
# Get old and new data and compare #
#==================================#
CURRENT_DATA = get_data()
INIT_FILE = open(DATA_FILE, 'r') # Should add exception here ...
OLD_DATA = pickle.load(INIT_FILE)

if CURRENT_DATA == OLD_DATA:
	print 'No service failed over.'
	sys.exit(STATE_OK)
else:
	print 'Service failed over.'
	sys.exit(STATE_CRITICAL)