#!/bin/bash
#
# Nagios plugin to check slapd schema
# 
# Author : Benjamin Renard <brenard@easter-eggs.com>
# Date : Wed, 12 Jun 2019 13:15:33 +0200
# Source : http://gogs.zionetrix.net/check_slapd_schema
#

SUDO_USER=""
MDB_STAT=mdb_stat
DB_PATH="/var/lib/ldap"
USED_PAGES_PERC_WARNING_LIMIT=70
USED_PAGES_PERC_CRITICAL_LIMIT=90
DEBUG=0

function debug() {
	if [ $DEBUG -eq 1 ]
	then
		>&2 echo -e "[DEBUG] $1"
	fi
}

function format_size() {
        SIZE=$1
        UNIT="b"
        if [ -z "$SIZE" -o "$SIZE" == "0" ]
        then
                SIZE="0"
                UNIT=""
        elif [ $SIZE -ge 1073741824 ]
        then
                SIZE=$( echo "scale=1; $SIZE/1073741824"|bc )
                UNIT="Gb"

        elif [ $SIZE -ge 1048576 ]
        then
                SIZE=$( echo "scale=1; $SIZE/1048576"|bc )
                UNIT="Mb"
        elif [ $SIZE -ge 1024 ]
        then
                SIZE=$( echo "scale=1; $SIZE/1024"|bc )
                UNIT="Kb"
        fi
        echo "${SIZE}${UNIT}"
}

function usage() {
	cat << EOF
Usage : $0 [-d] [-h] [-w warning] [-c critical] [options]
	-u			Sudo as specified user to run mdb_stat
	-s			Path to mdb_stat (Default : auto-detected)
	-p			Database path (Default : $DB_PATH)
	-w			Used pages percentage warning limit (Default: $USED_PAGES_PERC_WARNING_LIMIT)
	-c			Used pages percentage critical limit (Default: $USED_PAGES_PERC_CRITICAL_LIMIT)
	-d			Debug mode
	-h 			Show this message
EOF
}

while getopts "hu:s:p:d" OPTION
do
	case $OPTION in
		u)
			SUDO_USER=$OPTARG
		;;
		s)
			MDB_STAT=$OPTARG
		;;
		p)
			DB_PATH=$OPTARG
		;;
		w)
			USED_PAGES_PERC_WARNING_LIMIT=$OPTARG
		;;
		c)
			USED_PAGES_PERC_CRITICAL_LIMIT=$OPTARG
		;;
		d)
			DEBUG=1
		;;
		h)
			usage
			exit 0
		;;
		*)
			echo "Unkown option '$OPTION'"
			usage
			exit 1
	esac
done

CMD="$MDB_STAT -e $DB_PATH"
debug "mdb_stat command = '$CMD'"

if [ -n "$SUDO_USER" ]
then
	debug "run slapdschema command as $SUDO_USER"
	OUTPUT=$( sudo -u $SUDO_USER $CMD 2>&1 )
	EXITCODE=$?
else
	OUTPUT=$( $CMD 2>&1 )
	EXITCODE=$?
fi
debug "Output :\n$OUTPUT"
debug "Exit code : $EXITCODE"

if [ $EXITCODE -ne 0 -o -z "$OUTPUT" ]
then
	echo "UNKNOWN - mdb_stat exit with $EXITCODE"
	exit 3
fi

max_pages=$( echo -e "$OUTPUT"|grep -E '^ +Max pages: '|sed 's/^ \+Max pages: \([0-9]\+\)$/\1/' )
used_pages=$( echo -e "$OUTPUT"|grep -E '^ +Number of pages used: '|sed 's/^ \+Number of pages used: \([0-9]\+\)$/\1/' )
let perc_used=$used_pages*100/$max_pages
debug "Used/max pages: $used_pages / $max_pages ($perc_used%)"

page_size=$( echo -e "$OUTPUT"|grep -E '^ +Page size:'|sed 's/^ \+Page size: \([0-9]\+\)$/\1/' )
debug "Page size: $page_size"

let max_size=$max_pages*$page_size
let used_size=$used_pages*$page_size
debug "Used/max sizes: $used_size/$max_size"


if [ $perc_used -gt $USED_PAGES_PERC_CRITICAL_LIMIT ]
then
	STATE=CRITICAL
	EXITCODE=2
elif [ $perc_used -gt $USED_PAGES_PERC_WARNING_LIMIT ]
then
	STATE=WARNING
	EXITCODE=1
else
	STATE=OK
	EXITCODE=0
fi

echo "$STATE - $perc_used% pages used ($used_pages pages on $max_pages / $( format_size $used_size) on $( format_size $max_size ))"
exit $EXITCODE