#!/bin/bash
#
# Nagios plugin to check paste version
#
# Author : Obitanz <hb+chapril@unenieme.eu>
# Date :  18 Jul 2023
#

OK=0
WARNING=1
CRITICAL=2
UNKNOWN=3

function usage {
    echo "Usage : $0"
    echo "This script check if minetest services are UP (except test instance)"
    echo "    and if UDP ports are listening"
    result=${UNKNOWN}
}

if [ "$#" -ne 0 ]; then
    usage
else
    nb_problem=0
    for instance in $(ls -1d /srv/minetest.chapril.org/instances/* | grep -v "30000-test");
    do
        shortname=$(echo ${instance} | cut -d "/" -f 5)
        instance_port=$(echo ${shortname} | cut -d "-" -f 1)
        is_active=$(systemctl is-active minetest-server@${shortname}.service)
        check_if_port_is_listening="netstat -l | grep udp | grep ${instance_port} > /dev/null 2>&1"
        eval $check_if_port_is_listening
        port_is_listening=$?

        if [ "${is_active}" = "active" ]; then
            result_msg="${result_msg}\n${shortname} service is UP"
        else
            result_msg="${result_msg}\n${shortname} service is DOWN"
            ((nb_problem++))
        fi

        if [ ${port_is_listening} -eq 0 ]; then
            result_msg="${result_msg}\n${shortname}'s port (${instance_port}) is listening"
        else
            result_msg="${result_msg}\n${shortname}'s port (${instance_port}) has a problem (not listening)"
            ((nb_problem++))
        fi
    done

    if [ ${nb_problem} -eq 0 ]; then
        echo "OK - all minetest services are UP and all minetest ports are listening"
        result=${OK}
    elif [ ${nb_problem} -eq 1 ]; then
        echo -e "WARNING - there is one problem with minetest services or ports${result_msg}"
        result=${WARNING}
    elif [ ${nb_problem} -ge 2 ]; then
        echo -e "CRITICAL - there are at least two problems with minetest services or ports${result_msg}"
        result=${CRITICAL}
    else
        echo "UNKNOWN - script failed"
        result=${UNKNOWN}
    fi
fi

exit $result