#! /bin/bash

###
#
# This plugin check the state of a Cyber Power UPS using the utility tool
# named pwrstat This utility is provided directly from CyberPower. 
#
# @AUTHOR: Patrik Dufresne (http://patrikdufresne.com)
# Copyright 2012 Patrik Dufresne
# Create 2012-09-15
# Last modified 2020-11-22
# Please send all comments, suggestions, bugs and patches to (info AT patrikdufresne DOT 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, version 2 of the License.
#
# 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/>.
###

# you probably want to uncomment the following lines while developing
#shopt -o -s xtrace
# if you turn this on, then you have to alter the check_value calls to be able to check $?
#shopt -o -s errexit

# You should provide a meaningful VERSION
VERSION=0.1
# Who can be contacted about this?
AUTHOR="Patrik Dufresne"
# Name what is being checked to be printed out next to OK/WARNING/CRITICAL/UNKNOWN
SERVICE="PWRSTAT"

# Replacement for the exit function, will cleanup any tempfiles or such
# before exiting.
function cleanup {
	exit $1
}

declare -rx PROGNAME=${0##*/}
declare -rx PROGPATH=${0%/*}/

if [ -r "${PROGPATH}utils.sh" ] ; then
	source "${PROGPATH}utils.sh"
else
	echo "Can't find utils.sh. This plugin needs to be run from the same directory as utils.sh which is most likely something like /usr/lib/nagios/plugins or /usr/lib64/nagios/plugins"
	printf "Currently being run from %s\n" "$PROGPATH"
	# Since we couldn't define STATE_UNKNOWN since reading utils.sh
    # failed, we use 3 here but everywhere else after this use cleanup $STATE
	cleanup 3
fi

# Set STATE to UNKNOWN as soon as we can (right after reading in util.sh
# where the STATES are defined)
STATE=$STATE_UNKNOWN

# make sure that any external commands are installed, in the PATH and
# executable. The following example is stupid because of course date is
# installed but it's the only command this trivial check really uses
PWRSTAT=/usr/sbin/pwrstat
if [ ! -x "$PWRSTAT" ] ; then
	echo "pwrstat is not installed, in your path and executable. Exiting."
	cleanup $STATE_UNKNOWN
fi

# provide a quick one liner of how to use the program
function usage {
	printf " %s %s for Nagios - Usage %s \
[-wv <warning output voltage threshold>] [-cv <critical output voltage threshold>] \
[-wb <warning battery capacity threshold>] [-cb <critical battery capacity threshold>] \
[-wr <warning runtime threshold>] [-cr <critical runtime threshold>] \
[-wl <warning load pct threshold>] [-cl <critical load pct threshold>] \
[-t timeout] [-v [-v [-v]]]\n" "$PROGNAME" "$VERSION" "$PROGNAME"
	cleanup $STATE_UNKNOWN
}

# provide detailed explanations of the command line syntax
function longhelp {
	# put your long help here
	printf "%s plugin version %s for Nagios by %s
  -h, --help                   Display this message.
  --o, --warning-voltage=val  Set the warning output voltage threshold.
  --O, --critical-voltage=val Set the critical output voltage threshold.
  --b, --warning-battery=val  Set the warning percentage battery capacity threshold.
  --B, --critical-battery=val Set the critical percentage battery capacity threshold.
  --r, --warning-runtime=val  Set the warning remaining runtime threshold.
  --R, --critical-runtime=val Set the critical remaining runtime threshold.
  --l, --warning-load=val     Set the warning load percentage threshold.
  --L, --critical-load=val    Set the critical load percentage threshold.
  -t, --timeout=sec            Set script timeout in seconds.
  -v, --verbose                Up the verbosity level by one.
  --verbosity=val              Set the verbosity level to val.
  -V, --version                Print version information.
  --range_help                 Explain threshold ranges.
" "$PROGNAME" "$VERSION" "$AUTHOR"
	cleanup $STATE_UNKNOWN
}

# explanatory function you probably want to keep
function range_help {
	printf "
The format for ranges in Nagios can be confusing and it isn't always followed.

[@]start[:[end]]

Here are some example ranges:

Range   |  Generate an alert if value is    |  In English
--------+-----------------------------------+---------------------------------
10      |  outside the range of {0 .. 10}   |  Greater than 10
@10     |  inside the range of {0 .. 10}    |  Less than or equal to 10
10:     |  outside {10 .. ∞}                |  Greater than 10
~:10    |  outside the range of {-∞ .. 10}  |  Less than 10 including negative
10:20   |  outside the range of {10 .. 20}  |  Between 10 and 20
@10:20  |  inside the range of {10 .. 20}   |  Anything from 10 to 20
10      |  outside the range of {0 .. 10}   |  Greater than 10 or less than 0

Formal Rules:
1. start ≤ end
2. start and ":" is not required if start=0
3. if range is of format \"start:\" and end is not specified, end is infinity
4. to specify negative infinity, use "~"
5. alert is raised if metric is outside start and end range (inclusive)
6. if range starts with "@", then alert if inside this range (inclusive)
    10      < 0 or > 10, (outside the range of {0 .. 10})
    10:     < 10, (outside {10 .. ∞})
    ~:10    > 10, (outside the range of {-∞ .. 10})
    10:20   < 10 or > 20, (outside the range of {10 .. 20})
    @10:20  ≥ 10 and ≤ 20, (inside the range of {10 .. 20})
    10      < 0 or > 10, (outside the range of {0 .. 10})

More help at http://nagiosplug.sourceforge.net/developer-guidelines.html
"
	cleanup $STATE_UNKNOWN
}

#if [ $# -eq 0 ] ; then
#	usage
#fi

# use getopt, trust me on this one. It's the easiest way
getopt -T
if [ $? -ne 4 ] ; then
	printf "%s: getopt is in compatibility mode.\n" "$SCRIPT"
	cleanup $STATE_UNKNOWN
fi

# Tell it which switches and longswitches you'll take and place a trailing
# colon (:) on the ones take arguments. Nagios guidelines require you to
# use all the ones specified below with the exception of --verbosity which I've
# added to circumvent the awkward -v -v -v syntax. Getopt takes care of
# positional parameters and errors for missing expected arguments so we can
# shift later without checking
RESULT=`getopt --name "$SCRIPT" --options "-h,-V,-v,-t:,-o:,-O:,-b:,-B:,-r:,-R:,-l:,-L:" \
--longoptions "help,version,verbose,verbosity:,warning-voltage:,warning-battery:,warning-runtime:,warning-load:,critical-voltage:,critical-battery:,critical-runtime:,critical-load:,timeout:" -- "$@"`

# make the result of getopt your new argument list ($@)
eval set -- "$RESULT"

declare WARNING
declare CRITICAL
# all scripts should have a mechanism to terminate themselves if they are
# running for too long. Scripts you might think of as innocuous could end
# up waiting forever on I/O, especially if a disk is failing
declare -i TIMELIMIT=15
# Nagios defines behavior for VERBOSITY 0 (default) through 3
declare -i VERBOSITY=0

while [ $# -gt 0 ] ; do
	case "$1" in
		-h | --help)
			longhelp;;
		-V | --version)
			print_revision "$PROGNAME" "$VERSION"
			cleanup $STATE;;
		-v | --verbose)
			VERBOSITY=$(($VERBOSITY + 1));;
		--verbosity)
			shift
			VERBOSITY=$1;;
		-o | --warning-voltage)
			shift
			VOLTAGE_WARNING=$1;;
		-b | --warning-battery)
			shift
			BATTERY_WARNING=$1;;
		-r | --warning-runtime)
			shift
			RUNTIME_WARNING=$1;;
		-l | --warning-load)
			shift
			LOAD_WARNING=$1;;
		-O | --critical-voltage)
			shift
			VOLTAGE_CRITICAL=$1;;
		-B | --critical-battery)
			shift
			BATTERY_CRITICAL=$1;;
		-R | --critical-runtime)
			shift
			RUNTIME_CRITICAL=$1;;
		-L | --critical-load)
			shift
			LOAD_CRITICAL=$1;;
		-t | --timeout)
			shift
			TIMELIMIT=$1;;
		--)
			shift
			break;;
		*)
			echo "Option $1 not supported. Ignored." >&2;;
	esac
	shift
done

#Verbosity level	Type of output
#0			Single line, minimal output. Summary
#1			Single line, additional information (eg list processes that fail)
#2			Multi line, configuration debug output (eg ps command used)
#3			Lots of detail for plugin problem diagnosis
if [ $VERBOSITY -gt 2 ] ; then
	shopt -o -s xtrace
fi

# what needs to happen in the event of a timeout
function timeout {
	echo "UNKNOWN - script timed out after $TIMELIMIT seconds."
	cleanup $STATE_UNKNOWN
}

function check_range {
	# # positive values only
	if [ ! -z "$1" ] ; then
		WARNFORMAT=`echo "$1" | grep -c '^@\?\([0-9]\+:[0-9]*\|[0-9]\+\)$'`
		if [ $WARNFORMAT -lt 1 ] ; then
			echo "Please check the format of your warning and critical thresholds."
			range_help
		fi
	fi
	if [ ! -z "$2" ] ; then
		CRITFORMAT=`echo "$2" | grep -c '^@\?\([0-9]\+:[0-9]*\|[0-9]\+\)$'`
		if [ $CRITFORMAT -lt 1 ] ; then
			echo "Please check the format of your warning and critical thresholds."
			range_help
		fi
	fi
}

check_range "$VOLTAGE_WARNING" "$VOLTAGE_CRITICAL"
check_range "$BATTERY_WARNING" "$BATTERY_CRITICAL"
check_range "$RUNTIME_WARNING" "$RUNTIME_CRITICAL"
check_range "$LOAD_WARNING" "$LOAD_CRITICAL"

# since we've processed the options which potentially set the timeout limit,
# we can setup a timeout trap now
trap timeout USR1
	# what we're doing here sending a USR1 signal back to this process which
	# we just set a trap to catch and run the timeout function the syntax of
	# this is important and very odd - if you know of a better way to do this, 
	# please email me what we're doing is starting another process in the
	# background that sleeps for TIMELIMIT seconds and then uses pgrep when
	# it 'wakes up' to see if a process with our number, name and user exists,
	# only then will the USR1 signal be sent we have to use pgrep so that we
	# don't sent a USR1 signal to just any program. The only risk we run with
	# this is sending USR1 to another instance of this script that just happens
	# to get assigned the same process ID it should be reasonable to assume
	# that your Nagios check interval is greater than the specified timeout
	# still, if you havea better idea...
	( sleep $TIMELIMIT; if [ `pgrep -U $USER -f "$SCRIPT" | grep -c ^$$$` -gt 0 ] ; then kill -USR1 $$ ; fi; ) </dev/null &>/dev/null &

	# Get the sensor's value
	DATA=`$PWRSTAT -status`
	if [ $VERBOSITY -gt 2 ] ; then
		echo "$DATA"
	fi
	UPSSTATE=`echo "$DATA" | grep State |sed 's/.*State[ \.]\{1,\}\(.*\)/\1/'`
	if [ "$UPSSTATE" != "Lost Communication" ]; then
		VOLTAGE=`echo "$DATA" | grep 'Output Voltage' | grep -oe '[0-9]*'`
		BATTERY=`echo "$DATA" | grep 'Battery Capacity' | grep -oe '[0-9]*'`
		RUNTIME=`echo "$DATA" | grep 'Remaining Runtime' | grep -oe '[0-9]*'`
		LOAD=`echo "$DATA" | grep Load | grep -oe '[0-9]* %' | grep -oe '[0-9]*'`
	fi

	# Once we're done doing work that could take any real time, we can end the
    # trap because from here on out it's just comparisons and string
    # concatenation
trap - USR1

function check_value {
	if [ -z "$1" ]; then
		return 0
	fi

	# If the range starts with an @, alert if value is inside the range,
    # otherwise alert if value is outside of range.
	INSIDE=`echo "$1" | grep -c '^@'`
	RANGE=`echo "$1" | sed 's/^@//'`

	# Start is anything left of the colon or 0.
    # End is anything right of the colon or the whole string if there's no
    # colon or infinity if there is a colon and nothing to the right of it

	# is there a colon?
	PARTS=`echo "$RANGE" | awk -F : '{ print NF }'`
	if [ $PARTS -gt 1 ] ; then
		START=${RANGE%%:*}
		END=${RANGE##*:}
	else
		START=0
		END=$RANGE
	fi

	# 4. to specify negative infinity, use "~"
	if [ "$START" == "~" ] ; then
		START=-999999999
	fi

	if [ -z "$END" ] ; then
		END=999999999
	fi

	if [ $START -gt $END ] ; then
		echo "In threshold START:END, START must be less than or equal to END"
		range_help
	fi

	# if the range starts with an @, alert if value is inside the range,
	# otherwise alert if value is outside of range all ranges are inclusive
	# of endpoints so we use less than or equal on the inside and just less
	# than on the outside
	if [ "$INSIDE" -gt 0 ] ; then
		if [ "$START" -le "$2" -a "$2" -le "$END" ] ; then
			return 1
		fi
	else
		if [ "$2" -lt "$START" -o "$END" -lt "$2" ] ; then
			return 1
		fi
	fi

	return 0
}

# Check UPS state
if [ "$UPSSTATE" = "Lost Communication" ]; then
	OUT="Can't get UPS status: $UPSSTATE"
	printf "%s UNKNOWN - %s\n" "$SERVICE" "$OUT"
	cleanup $STATE_UNKNOWN
fi

# Check critical threshold
STATE=$STATE_OK
check_value "$VOLTAGE_CRITICAL" "$VOLTAGE"
if [ $? -gt 0 ] ; then
	STATE=$STATE_CRITICAL
fi
check_value "$BATTERY_CRITICAL" "$BATTERY"
if [ $? -gt 0 ] ; then
	STATE=$STATE_CRITICAL
fi
check_value "$RUNTIME_CRITICAL" "$RUNTIME"
if [ $? -gt 0 ] ; then
	STATE=$STATE_CRITICAL
fi
check_value "$LOAD_CRITICAL" "$LOAD"
if [ $? -gt 0 ] ; then
	STATE=$STATE_CRITICAL
fi

# Check warning treshold
if [ $STATE -ne $STATE_CRITICAL ]; then
	check_value "$VOLTAGE_WARNING" "$VOLTAGE"
	if [ $? -gt 0 ] ; then
		STATE=$STATE_WARNING
	fi
	check_value "$BATTERY_WARNING" "$BATTERY"
	if [ $? -gt 0 ] ; then
		STATE=$STATE_WARNING
	fi
	check_value "$RUNTIME_WARNING" "$RUNTIME"
	if [ $? -gt 0 ] ; then
		STATE=$STATE_WARNING
	fi
	check_value "$LOAD_WARNING" "$LOAD"
	if [ $? -gt 0 ] ; then
		STATE=$STATE_WARNING
	fi
fi

# Check ups state
if [ "$UPSSTATE" = "Power Failure" ] ; then
	STATE=$STATE_CRITICAL
fi

# STATE - Message | 'label'=value[unit of measure];[warn];[crit];[min];[max]
OUT="state: $UPSSTATE, output voltage: $VOLTAGE volt, battery: $BATTERY%, remaining runtime: $RUNTIME min, load: $LOAD% | voltage=$VOLTAGE batery=$BATTERY% runtime=$RUNTIME load=$LOAD%"

case $STATE in
	$STATE_OK)
		printf "%s OK - %s\n" "$SERVICE" "$OUT";;
	$STATE_WARNING)
		printf "%s WARNING - %s\n" "$SERVICE" "$OUT";;
	$STATE_CRITICAL)
		printf "%s CRITICAL - %s\n" "$SERVICE" "$OUT";;
	$STATE_UNKNOWN)
		printf "%s UNKNOWN - %s\n" "$SERVICE" "$OUT";;
esac

cleanup $STATE