#!/bin/sh
# $Header: $
# vim:nu:ai:sw=4:ts=4:
#
# Nagios check script for UPSes monitored by apcupsd
# Created by Wolfram Schlich <wschlich@gentoo.org>
# Distributed under the terms of the GNU General Public License v3
#
# External dependencies:
# - apcaccess
# - grep
#

##
## nagios state specific exit codes
##

declare -i state_ok=0
declare -i state_warning=1
declare -i state_critical=2
declare -i state_unknown=3
declare -i state_dependent=4

##
## functions
##

function usage() {
	echo
	echo "Usage: ${0##*/} APCUPSD_SERVER <load|battcharge|timeleft> WARN_VALUE CRIT_VALUE "
	echo "       ${0##*/} APCUPSD_SERVER status"
	echo
	echo "  APCUPSD_SERVER: apcupsd server host:port to connect to (e.g. localhost:3551)"
	echo
	echo "        load (%): WARN when load   is > WARN_VALUE, CRIT when load   is > CRIT_VALUE"
	echo "  battcharge (%): WARN when charge is < WARN_VALUE, CRIT when charge is < CRIT_VALUE"
	echo " timeleft (mins): WARN when time   is < WARN_VALUE, CRIT when time   is < CRIT_VALUE"
	echo "          status: CRIT if not online"
	echo
}

function checkargs() {
	if [[ -z "${apcupsd_server}" || -z "${warn_value}" || -z "${crit_value}" ]]; then
		usage
		exit ${state_unknown}
	fi
}

function run_apcaccess() {
	apcaccess status ${apcupsd_server}
}

function get_load() {
	line=$(run_apcaccess | grep '^LOADPCT')
	IFS=': '
	set -- ${line}
	load=${2%%.*}
	unset IFS
	set --
}

function get_battcharge() {
	line=$(run_apcaccess | grep '^BCHARGE')
	IFS=': '
	set -- ${line}
	battcharge=${2%%.*}
	unset IFS
	set --
}

function get_timeleft() {
	line=$(run_apcaccess | grep '^TIMELEFT')
	IFS=': '
	set -- ${line}
	timeleft=${2%%.*}
	unset IFS
	set --
}

function get_status() {
	line=$(run_apcaccess | grep '^STATUS')
	IFS=': '
	set -- ${line}
	status=${2}
	unset IFS
	set --
}

##
## main()
##

if [[ ! -x "$(type -p apcaccess 2>/dev/null)" ]]; then
	echo "ERROR: apcaccess not executable"
	exit ${state_unknown}
fi

apcupsd_server=${1}; shift
check=${1}; shift
warn_value=${1}; shift
crit_value=${1}; shift

case "${check}" in 
	load) 
		checkargs
		get_load
		if [ "${load}" -gt "${crit_value}" ]; then
			echo "UPS CRITICAL - Load: ${load}% > ${crit_value}%"
			exit ${state_critical}
		elif [ "${load}" -gt "${warn_value}" ]; then
			echo "UPS WARNING - Load: ${load}% > ${warn_value}%"
			exit ${state_warning}
		else
			echo "UPS OK - Load: ${load}%"
			exit ${state_ok}
		fi
		;;
	battcharge)
		checkargs
		get_battcharge
		if [ "${battcharge}" -lt "${crit_value}" ]; then
			echo "UPS CRITICAL - Battery charge: ${battcharge}% < ${crit_value}%"
			exit ${state_critical}
		elif [ "${battcharge}" -lt "${warn_value}" ]; then
			echo "UPS WARNING - Battery charge: ${battcharge}% < ${warn_value}%"
			exit ${state_warning}
		else
			echo "UPS OK - Battery charge: ${battcharge}%"
			exit ${state_ok}
		fi
		;;
	timeleft)
		checkargs
		get_timeleft
		if [ "${timeleft}" -lt "${crit_value}" ]; then
			echo "UPS CRITICAL - Time left: ${timeleft} mins < ${crit_value} mins"
			exit ${state_critical}
		elif [ "${timeleft}" -lt "${warn_value}" ]; then
			echo "UPS WARNING - Time left: ${timeleft} mins < ${warn_value} mins"
			exit ${state_warning}
		else
			echo "UPS OK - Time left: ${timeleft} mins"
			exit ${state_ok}
		fi
		;;
	status)
		get_status
		if [ "${status}" != 'ONLINE' ]; then
			echo "UPS CRITICAL - ${status}"
			exit ${state_critical}
		else
			echo "UPS OK - ${status}"
			exit ${state_ok}
		fi
		;;
	*)
		usage
		exit ${state_unknown}
		;;
esac

## should never reach this
echo "ERROR - there's an error in the matrix!"
exit ${state_unknown}