#!/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: 22-06-2006
# 
# Usage: ./check_load2
#
# Description:
#   Ethan's original version of the check_load script is very flexible.
# It allows you to specifically set WARN and CRIT levels regarding 
# the CPU load of the system you're monitoring.
#   However: flexibility is not always a good thing. Say for example that
# you want to monitor the CPU load across a few hundred of systems having
# various CPU configurations. You -could- define host groups for single, dual
# quad (and so on) processor systems and assign unique check_load command
# definitions to each group.
#   Or you could write a script which checks the amount of active CPUs and
# then makes an educated guess at the WARN and CRIT levels for the system. 
# In most cases this should really be enough. 
#
# Limitations:
# This script should work properly on all implementations of Linux, Solaris
# and Mac OS X.
#
# Output:
# Depending on the levels defined at the top of the script,
# the script returns an OK, WARN or CRIT to Nagios based on CPU load.
#
# 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


### DEBUGGING SETUP ###
# Cause you never know when you'll need to squash a bug or two
DEBUG="0"
DEBUGFILE="/tmp/foobar"
rm $DEBUGFILE


### REQUISITE NAGIOS COMMAND LINE STUFF ###

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

print_help() {
	echo ""
	print_usage
	echo ""
	echo "Semi-intelligent CPU load 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


### SETTING UP THE WARN AND CRIT FACTORS ###
# Please be aware that these are -factors- and not real load average values.
# The numbers below will be multiplied by the amount of processors to come
# to the desired WARN and CRIT levels. Feel free to adjust these factors, if
# you feel the need to tweak them.

WARN_1min="2.00"
WARN_5min="1.50"
WARN_15min="1.50"
[ $DEBUG -gt 0 ] && echo "Factors: warning factors are at $WARN_1min, $WARN_5min, $WARN_15min." >> $DEBUGFILE

CRIT_1min="3.00"
CRIT_5min="2.00"
CRIT_15min="2.00"
[ $DEBUG -gt 0 ] && echo "Factors: critical factors are at $CRIT_1min, $CRIT_5min, $CRIT_15min." >> $DEBUGFILE


### DEFINING SUBROUTINES ###

function gather_procs_linux()
{
    NUMPROCS=`cat /proc/cpuinfo | grep ^processor | wc -l` 
[ $DEBUG -gt 0 ] && echo "Numprocs: Number of processors detected is $NUMPROCS." >> $DEBUGFILE
} 

function gather_procs_sunos()
{
    NUMPROCS=`/usr/bin/mpstat | grep -v CPU | wc -l` 
[ $DEBUG -gt 0 ] && echo "Numprocs: Number of processors detected is $NUMPROCS." >> $DEBUGFILE
}

function gather_procs_darwin()
{
    NUMPROCS=`/usr/bin/hostinfo | grep "Default processor set" | awk '{print $8}'` 
[ $DEBUG -gt 0 ] && echo "Numprocs: Number of processors detected is $NUMPROCS." >> $DEBUGFILE
}

function gather_load_linux()
{
    REAL_1min=`cat /proc/loadavg | awk '{print $1}'`
    REAL_5min=`cat /proc/loadavg | awk '{print $2}'`
    REAL_15min=`cat /proc/loadavg | awk '{print $3}'`
[ $DEBUG -gt 0 ] && echo "Gather_load: Detected load averages are $REAL_1min, $REAL_5min, $REAL_15min." >> $DEBUGFILE
}

function gather_load_sunos()
{
    REAL_1min=`w | grep "load average" | awk -F, '{print $4}' | awk '{print $3}'`
    REAL_5min=`w | grep "load average" | awk -F, '{print $5}'`
    REAL_15min=`w | grep "load average" | awk -F, '{print $6}'`
[ $DEBUG -gt 0 ] && echo "Gather_load: Detected load averages are $REAL_1min, $REAL_5min, $REAL_15min." >> $DEBUGFILE
}

function gather_load_darwin()
{
    REAL_1min=`sysctl -n vm.loadavg | awk '{print $1}'`
    REAL_5min=`sysctl -n vm.loadavg | awk '{print $2}'`
    REAL_15min=`sysctl -n vm.loadavg | awk '{print $3}'`
[ $DEBUG -gt 0 ] && echo "Gather_load: Detected load averages are $REAL_1min, $REAL_5min, $REAL_15min." >> $DEBUGFILE
}

function check_load()
{
    WARN="0"; CRIT="0"

    [ `echo "if(($NUMPROCS * $WARN_1min) > $REAL_1min) 0; if(($NUMPROCS * $WARN_1min) <= $REAL_1min) 1" | bc` -gt 0 ] && let WARN=$WARN+1
    [ `echo "if(($NUMPROCS * $WARN_5min) > $REAL_5min) 0; if(($NUMPROCS * $WARN_5min) <= $REAL_5min) 1" | bc` -gt 0 ] && let WARN=$WARN+1
    [ `echo "if(($NUMPROCS * $WARN_15min) > $REAL_15min) 0; if(($NUMPROCS * $WARN_15min) <= $REAL_15min) 1" | bc` -gt 0 ] && let WARN=$WARN+1
[ $DEBUG -gt 0 ] && echo "Check_load: warning levels are `echo "$NUMPROCS * $WARN_1min"|bc`, `echo "$NUMPROCS * $WARN_5min"|bc`, `echo "$NUMPROCS * $WARN_15min"|bc`," >> $DEBUGFILE

    [ `echo "if(($NUMPROCS * $CRIT_1min) > $REAL_1min) 0; if(($NUMPROCS * $CRIT_1min) <= $REAL_1min) 1" | bc` -gt 0 ] && let CRIT=$CRIT+1
    [ `echo "if(($NUMPROCS * $CRIT_5min) > $REAL_5min) 0; if(($NUMPROCS * $CRIT_5min) <= $REAL_5min) 1" | bc` -gt 0 ] && let CRIT=$CRIT+1
    [ `echo "if(($NUMPROCS * $CRIT_15min) > $REAL_15min) 0; if(($NUMPROCS * $CRIT_15min) <= $REAL_15min) 1" | bc` -gt 0 ] && let CRIT=$CRIT+1
[ $DEBUG -gt 0 ] && echo "Check_load: critical levels are `echo "$NUMPROCS * $CRIT_1min"|bc`, `echo "$NUMPROCS * $CRIT_5min"|bc`, `echo "$NUMPROCS * $CRIT_15min"|bc`," >> $DEBUGFILE

    [ $WARN -gt 0 ] && (echo "NOK: load averages are at $REAL_1min, $REAL_5min, $REAL_15min"; exit $STATE_WARNING)
    [ $CRIT -gt 0 ] && (echo "NOK: load averages are at $REAL_1min, $REAL_5min, $REAL_15min"; exit $STATE_CRITICAL)
}

### FINALLY, THE MAIN ROUTINE ###

NUMPROCS="0"

case `uname` in
            Linux) gather_procs_linux; gather_load_linux; check_load;;
            Darwin) gather_procs_darwin; gather_load_darwin; check_load;;
            SunOS) gather_procs_sunos; gather_load_sunos; check_load;;
            *) echo "OS not supported by this check."; exit 1;;
esac

# Nothing caused us to exit early, so we're okay.
echo "OK - load averages are at $REAL_1min, $REAL_5min, $REAL_15min"
exit $STATE_OK