#!/usr/bin/bash
#
# CPU load monitor plugin for Nagios
# Written by Thomas Sluyter (nagios@kilala.nl)
# By request of KPN-IS, i-Provide, the Netherlands
# Last Modified: 10-07-2006
# 
# Usage: ./check_ntp_config
#
# Description:
#   Well, there's not much to tell. We have no way of making sure that our 
# NTP clients are all configured in the right way, so I thought I'd make
# a Nagios check for it. ^_^ 
#   You can change the NTP config at the top of this script, to match your
# own situation.
#
# Limitations:
#   This script should work properly on all implementations of Linux, Solaris
# and Mac OS X.
#
# Output:
#   If the NTP client config does not match what has been defined at the 
# top of this script, the script will return a WARN.
#
# Other notes:
#   If you ever run into problems with the script, set the DEBUG variable
# to 1. I'll need the output the script generates to do troubleshooting.
# See below for details.
#   I realise that all the debugging commands strewn throughout the script
# may make things a little harder to read. But in the end I'm sure it was
# well worth adding them. It makes troubleshooting so much easier. :3
#

# You may have to change this, depending on where you installed your
# Nagios plugins
PATH="/usr/bin:/usr/sbin:/bin:/sbin"
LIBEXEC="/usr/local/nagios/libexec"
. $LIBEXEC/utils.sh


### DEFINING THE NTP CLIENT CONFIGURATION AS IT SHOULD BE ###
NTP_SERVER="ntp.wxs.nl"


### DEBUGGING SETUP ###
# Cause you never know when you'll need to squash a bug or two
DEBUG="0"

if [ $DEBUG -gt 0 ]
then
        DEBUGFILE="/tmp/foobar"
        rm $DEBUGFILE >/dev/null 2>&1
fi


### REQUISITE NAGIOS COMMAND LINE STUFF ###

print_usage() {
	echo "Usage: $PROGNAME"
	echo "Usage: $PROGNAME --help"
}

print_help() {
	echo ""
	print_usage
	echo ""
	echo "NTP client configuration monitor plugin for Nagios"
	echo ""
	echo "This plugin not developped by the Nagios Plugin group."
	echo "Please do not e-mail them for support on this plugin, since"
	echo "they won't know what you're talking about :P"
	echo ""
	echo "For contact info, read the plugin itself..."
}

while test -n "$1" 
do
	case "$1" in
	  --help) print_help; exit $STATE_OK;;
	  -h) print_help; exit $STATE_OK;;
	  *) print_usage; exit $STATE_UNKNOWN;;
	esac
done


### DEFINING SUBROUTINES ###

function gather_config()
{
    case `uname` in
	Linux) CFGFILE="/etc/ntp.conf"; IP_SERVER=`host $NTP_SERVER | awk '{print $4}'` ;;
	SunOS) CFGFILE="/etc/inet/ntpd.conf"; IP_SERVER=`getent hosts $NTP_SERVER | awk '{print $2}'`;;
	Darwin) CFGFILE="/etc/ntp.conf"; IP_SERVER=`host $NTP_SERVER | awk '{print $4}'` ;;
	*) ;;
    esac

    REAL_SERVER=`cat $CFGFILE | grep ^server | awk '{print $2}'`

[ $DEBUG -gt 0 ] && echo "Gather_config: Host name for required server is $NTP_SERVER." >> $DEBUGFILE
[ $DEBUG -gt 0 ] && echo "Gather_config: IP address for required server is $IP_SERVER." >> $DEBUGFILE
[ $DEBUG -gt 0 ] && echo "Gather_config: currently configured server is $REAL_SERVER." >> $DEBUGFILE
} 

function check_config()
{
    if [ $REAL_SERVER != $NTP_SERVER ]
    then
	if [ $REAL_SERVER != $IP_SERVER ]
	then
	    echo "NOK - NTP client is not configured to speak to $NTP_SERVER"
	    exit $STATE_WARNING
     	fi
    fi
}


### FINALLY, THE MAIN ROUTINE ###

gather_config
check_config

# Nothing caused us to exit early, so we're okay.
echo "OK - NTP client configured correctly."
exit $STATE_OK