#!/usr/bin/env bash
# Nagios plugin to check process group memory consumption
# Origin:
# @see http://unix.stackexchange.com/questions/233944/how-to-view-summaric-memory-usage-of-groups-of-commands-instead-of-processes
# @see https://github.com/jonschipp/nagios-plugins/blob/master/check_memory.sh

# Nagios Exit Codes
OK=0
WARNING=1
CRITICAL=2
UNKNOWN=3

# set default values for the thresholds
WARN=80
CRIT=90

usage()
{
cat <<EOF

Check memory consumption by process group.

     Options:
        -c         Critical threshold as percentage (0-100) (def: 90)
        -w         Warning threshold as percentage (0-100) (def: 80)

Usage: $0 -p procname -w 90 -c 95
Example: $0 -p httpd -w 30 -c 40
EOF
}

while getopts "p:c:w:h" ARG;
do
    case $ARG in
        p) PROCNAME=$OPTARG
           ;;
        w) WARN=$OPTARG
           ;;
        c) CRIT=$OPTARG
           ;;
        h) usage
           exit
           ;;
    esac
done

if [ -z $PROCNAME ]; then
    usage
    exit
fi

PERCENTAGE=`ps -C $PROCNAME --no-headers -o pmem | xargs | sed -e 's/ /+/g' | bc`
INTPERCENTAGE=${PERCENTAGE/.*/}
RESULT="$PROCNAME uses ${PERCENTAGE}% of memory"

if [ $INTPERCENTAGE -ge $CRIT ]; then
        echo "CRITICAL: $RESULT"
        exit $CRITICAL;
elif [ $INTPERCENTAGE -ge $WARN ]; then
        echo "WARNING: $RESULT"
        exit $WARNING;
else
        echo "OK: $RESULT"
        exit $OK;
fi