check_ipmi_sensor_ikus

#! /bin/bash

###
# Check hardware sensor using `ipmitool sensor` command line provided by lm-sensors
#
# Required the following sudoers
#
#     nagios ALL=(ALL) NOPASSWD: /usr/bin/ipmitool sensor
#
# @AUTHOR: Patrik Dufresne (http://patrikdufresne.com)
# Copyright 2015 Patrik Dufresne
# Last modified 2015-02-22
# 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="SENSOR"

# 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
IPMITOOL=/usr/bin/ipmitool
if [ ! -x "$IPMITOOL" ] ; then
	echo "$IPMITOOL 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 -s <sensor name> \
-w <warning threshold> -c <critical 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.
  -s, --sensor        Set the sensor to monitor
  -w, --warning=val   Set the warning percentage threshold.
  -c, --critical=val  Set the critical 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 "$SCRIPT" --options "-h,-V,-v,-c:,-w:,-t:,-s:" --longoptions "help,version,verbose,verbosity:,warning:,critical:,timeout:,sensor:" -- "$@"`

# 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;;
		-w | --warning)
			shift
			WARNING=$1;;
		-c | --critical)
			shift
			CRITICAL=$1;;
		-t | --timeout)
			shift
			TIMELIMIT=$1;;
		-s | --sensor)
			shift
			SENSOR=$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
}

# 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 &

    # Check that sensor is provided
    if [ -z "$SENSOR" ] ; then
        usage
    fi

	# Check that the thresholds provided are valid strings
	if [ -z "$WARNING" -o -z "$CRITICAL" ] ; then
		range_help
	else
		# positive values only
		WARNFORMAT=`echo "$WARNING" | grep -c '^@\?\([0-9]\+:[0-9]*\|[0-9]\+\)$'`
		CRITFORMAT=`echo "$CRITICAL" | grep -c '^@\?\([0-9]\+:[0-9]*\|[0-9]\+\)$'`

		OK=$(( $WARNFORMAT + $CRITFORMAT ))
		if [ $OK -lt 2 ] ; then
			echo "Please check the format of your warning and critical thresholds."
			range_help
		fi
	fi

	# Get the sensor's value
    LINE=`sudo -n $IPMITOOL sensor | grep "$SENSOR" | head -n 1`
    if [[ -z "$LINE" ]]; then
	    #Given sensor doesn't exists
	    printf "UNKNOWN - Given sensors $SENSOR doesn't exists.\n"
        cleanup $STATE_UNKNOWN
    fi
    VALUE=`echo $(echo $LINE | cut -d '|' -f 2 | sed 's/\s\([0-9]*\).*/\1/')`
    VALUE_UNIT=`echo $(echo $LINE | cut -d '|' -f 3)`
    if [[ $VALUE_UNIT == "degrees C" ]]; then
        VALUE_UNIT="°C"
    fi
    SENSOR=`echo $(echo $LINE | cut -d '|' -f 1 | sed 's/\s/_/')`

	# 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 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 conditions - yes this is ugly, blame BASH. If you want to blame me, please provide a cleaner way that is as fast or faster
check_value "$CRITICAL" "$VALUE"
if [ $? -gt 0 ] ; then
	STATE=$STATE_CRITICAL
else
	check_value "$WARNING" "$VALUE"
	if [ $? -gt 0 ] ; then
		STATE=$STATE_WARNING
	else
		STATE=$STATE_OK
	fi
fi

# STATE - Message | 'label'=value[unit of measure];[warn];[crit];[min];[max]
OUT="$SENSOR $VALUE $VALUE_UNIT | $SENSOR=${VALUE};$WARNING;$CRITICAL"

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