#!/bin/bash

#
#/
#/ Usage:
#/ check-load.sh --warning=<level> --critical=<level> --average=<level> --help
#/ 
#/ Checks the system load
#/ 
#/ Options:
#/  -w, --warning=<level>      The level of when to trigger a warning (level=loadavg/nproc)
#/  -c, --critical=<level>     The level of when to trigger a critical warning (level=loadavg/nproc)
#/  -a, --average=<average>    Which avarage to use for the load level (possible values are 1, 5 and 15)
#/  -h, --help                 Display this help message
#/ 
#/ Exit Codes:
#/  0 Everything OK
#/  1 Warning level exceeded
#/  2 Critical level exceeded
#/  3 Unknown status
#/


Usage() {
    grep '^#/' "${script_dir}/${script_name}" | sed 's/^#\/\w*//'
}

GetOptions() {
    # https://stackoverflow.com/a/29754866
    OPTIONS=w:c:a:h
    LONGOPTS=warning:,critical:,avarage:,help

    # -use ! and PIPESTATUS to get exit code with errexit set
    # -temporarily store output to be able to check for errors
    # -activate quoting/enhanced mode (e.g. by writing out “--options”)
    # -pass arguments only via   -- "$@"   to separate them correctly
    ! PARSED=$(getopt --options=$OPTIONS --longoptions=$LONGOPTS --name "$0" -- "$@")
    if [[ ${PIPESTATUS[0]} -ne 0 ]]; then
        # e.g. return value is 1
        #  then getopt has complained about wrong arguments to stdout
        Usage
        exit 2
    fi

    # read getopt's output this way to handle the quoting right:
    eval set -- "$PARSED"

    # now enjoy the options in order and nicely split until we see --
    while true; do
        case "$1" in
            -w|--warning)
                warn="$2"
                shift 2
                ;;
            -c|--critital)
                crit="$2"
                shift 2
                ;;
            -a|--average)
                if [[ ! " ${possibleavarages[*]} " =~ " ${2} " ]]; then
                    echo "LOAD UNKNOWN - ${2} is not a valid load avarage"
                    exit 3
                fi
                check="$2"
                shift 2
                ;;
            -h|--help)
                Usage
                exit 0
                ;;
            --)
                shift
                break
                ;;
            *)
                echo "LOAD UNKNOWN - ${1} is not a valid parameter"
                exit 3
                ;;
        esac
    done
}

warn=0.7
crit=1
check=5
script_name=$(basename "${0}")
script_dir=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
possibleavarages=("1" "5" "15")
GetOptions "$@"

nproc=$(nproc)
LOADVAL1=$(awk '{ print $1; }' < /proc/loadavg)
LOADVAL5=$(awk '{ print $2; }' < /proc/loadavg)
LOADVAL15=$(awk '{ print $3; }' < /proc/loadavg)
checkval=${LOADVAL5}
case "$check" in
    "1")
        checkval=${LOADVAL1}
        ;;
    "5")
        checkval=${LOADVAL5}
        ;;
    "15")
        checkval=${LOADVAL15}
        ;;
esac

val=$(echo ${checkval}/${nproc} | bc -l)
if (( $(echo "$val < ${warn}" | bc -l) )); then
    rval=0
    rmsg="OK"
elif (( $(echo "$val < ${crit}" | bc -l) )); then
    rval=1
    rmsg="WARNING"
else
    rval=2
    rmsg="CRITICAL"
fi
crit=${nproc}
warn=$(echo ${nproc}\*${warn} | bc -l)
min=0
unit=""

echo "LOAD ${rmsg} - ${LOADVAL1} ${LOADVAL5} ${LOADVAL15}|load1m=${LOADVAL1}${unit};$warn;$crit;$min load5m=${LOADVAL5}${unit};$warn;$crit;$min load15m=${LOADVAL15}${unit};$warn;$crit;$min"
exit $rval