#!/bin/bash

#  This script is Nagios plugin, part of JvmInspector tool
#  Version 2020121101 (YYYYMMDDxx)
#
#  Author: Dimitar Fidanov <dimitar@fidanov.net>
#
#  The latest version can be found at:
#  https://fidanov.net/c0d3/nagios-plugins/jvminspector/
#
#  See README for more details
#
#  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, either version 3 of the License, or
#  (at your option) any later version.
#
#  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/>.

##############################
### PATH TO JvmInspector.jar

JVMINSPECTOR="/opt/JvmInspector/JvmInspector.jar"

##############################

export PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
export ENV=""
export CDPATH=""

STATE_OK=0
STATE_WARNING=1
STATE_CRITICAL=2
STATE_UNKNOWN=3
MSG_OK="OK"
MSG_WARNING="WARNING"
MSG_CRITICAL="CRITICAL"
MSG_UNKNOWN="UNKNOWN"
SCRIPT_NAME=$(basename "$0")

p_ok () {
  echo "$MSG_OK $1"
  exit "$STATE_OK"
}
p_warning () {
  echo "$MSG_WARNING $1"
  exit "$STATE_WARNING"
}
p_critical () {
  echo "$MSG_CRITICAL $1"
  exit "$STATE_CRITICAL"
}
p_unknown () {
  echo "$MSG_UNKNOWN $1"
  exit "$STATE_UNKNOWN"
}

usage () {
  cat << EOF
This is Nagios plugin that checks local JVMs properies like heap & non-heap memory, threads and etc

Usage: $SCRIPT_NAME -n|--name <java_name> -p|--property <property> -w|--warning <warn> -c|--critical <crit>

Where: <propery> is one of: "heap|non-heap|threads|classes"
Hint: You can use "jps -l" or "java -jar JvmInspector.jar all" to get the java name
Example: $SCRIPT_NAME -n org.apache.catalina.startup.Bootstrap -p heap -w 1073741824 -c 2147483648

EOF
exit 0
}

[ "$#" -eq 0 ] && usage

while [ ! -z "$1" ]; do
  case $1 in
    -n|--name)     shift; NAME="$1";;
    -p|--property) shift; PROPERTY="$1";;
    -w|--warning)  shift; WARNING="$1";;
    -c|--critical) shift; CRITICAL="$1";;
    -h|--help)     usage;;
  esac
  shift
done

[ -z "$NAME" ] && p_unknown "Missing JVM app class name, use -n <value>"
[ -z "$PROPERTY" ] && p_unknown "Missing property, use -p <value>"
[ -z "$WARNING" ] && p_unknown "Missing warning thresholds, use -w <value>"
[ -z "$CRITICAL" ] && p_unknown "Missing critical thresholds, use -c <value>"

expr "${WARNING}"  : '[0-9]\+$' >/dev/null || p_unknown "Invalid warning threshold"
expr "${CRITICAL}"  : '[0-9]\+$' >/dev/null || p_unknown "Invalid critical threshold"
[ -f "$JVMINSPECTOR" ] || p_unknown "Can't find JvmInspector.jar, please install it and set JVMINSPECTOR var in this script"

PSLINE="$(ps axo pid,uid,command | grep [j]ava | grep "$NAME" | head -1)"
PID="$(echo "$PSLINE" | awk '{print $1}')"
PUID="$(echo "$PSLINE" | awk '{print $2}')"

[ -z "${PID}" ] && p_unknown "Can't find JVM with class name: $NAME"
expr "${PID}"  : '[0-9]\+$' >/dev/null || p_unknown "Bug"

[ "${PUID}" = "${EUID}" ] || p_unknown "JVM is running with different username, run this script with UID $PUID"

TIMEOUT="" ; timeout --version >/dev/null 2>&1 && TIMEOUT="timeout 7"
JVMDATA=$(${TIMEOUT} java -jar "${JVMINSPECTOR}" "${PID}" 2>&1)
[ $? -ne 0 ] && p_unknown "Can't connect to JVM: ${JVMDATA}"

echo "$JVMDATA" | grep "class count" >/dev/null 2>/dev/null || p_unknown "Can't connect to the JVM: $JVMDATA"

#echo "$JVMDATA"  # debug

if [ "${PROPERTY}" = "threads" ]; then
        RESULT="$(printf "%s" "$JVMDATA" | awk '/^  thread count/{print $3}')"
        FRESULT="${RESULT}"
        PERFDATA="${PROPERTY}=${RESULT};;;"
elif [ "${PROPERTY}" = "classes" ]; then
        RESULT=$(printf "%s" "$JVMDATA" | awk '/^  class count/{print $3}')
        FRESULT="${RESULT}"
        PERFDATA="${PROPERTY}=${RESULT};;;"
elif [ "${PROPERTY}" = "heap" ]; then
        TEMPDATA=$(printf "%s" "$JVMDATA" | awk 'BEGIN { FS = ": " } ;/^  heap memory/{print $2}')
        MAX=$(printf "%s" "$TEMPDATA" | awk 'BEGIN { FS="|" } {print $1}' | awk 'BEGIN { FS="=" } {print $2}')
        COMMITED=$(printf "%s" "$TEMPDATA" | awk 'BEGIN { FS="|" } {print $2}' | awk 'BEGIN { FS="=" } {print $2}')
        USED=$(printf "%s" "$TEMPDATA" | awk 'BEGIN { FS="|" } {print $3}' | awk 'BEGIN { FS="=" } {print $2}')
        RESULT="${USED}"
        FRESULT=$(echo "${RESULT}" | numfmt --to=iec 2>/dev/null) || FRESULT="${RESULT}"
        PERFDATA="max=${MAX};;; commited=${COMMITED};;; used=${USED};;;"
elif [ "${PROPERTY}" = "non-heap" ]; then
        TEMPDATA=$(printf "%s" "$JVMDATA" | awk 'BEGIN { FS = ": " } ;/^  non-heap memory/{print $2}')
        MAX=$(printf "%s" "$TEMPDATA" | awk 'BEGIN { FS="|" } {print $1}' | awk 'BEGIN { FS="=" } {print $2}')
        COMMITED=$(printf "%s" "$TEMPDATA" | awk 'BEGIN { FS="|" } {print $2}' | awk 'BEGIN { FS="=" } {print $2}')
        USED=$(printf "%s" "$TEMPDATA" | awk 'BEGIN { FS="|" } {print $3}' | awk 'BEGIN { FS="=" } {print $2}')
        RESULT="${USED}"
        FRESULT=$(echo "${RESULT}" | numfmt --to=iec 2>/dev/null) || FRESULT="${RESULT}"
        PERFDATA="max=${MAX};;; commited=${COMMITED};;; used=${USED};;;"
elif [ "${PROPERTY}" = "sessions" ]; then
	RESULT=$(printf "%s" "$JVMDATA" | awk '/^  active sessions/' | sed 's/^.*total\=\([0-9]*\)|.*$/\1/g')	
        FRESULT="${RESULT}"
        PERFDATA="sessions=${RESULT};;;"
else 
	p_unknown "Invalid property"
fi

[ -z "${RESULT}" ] && p_unknown "Invalid data"
expr "${RESULT}"  : '-\?[0-9]\+$' >/dev/null || p_unknown "Invalid data"

if [ "${RESULT}" -ge "$CRITICAL" ]; then
	p_critical "${FRESULT} |${PERFDATA}"
elif [ "${RESULT}" -ge "$WARNING" ]; then
	p_warning "${FRESULT} |${PERFDATA}"
else 
	p_ok "${FRESULT} |${PERFDATA}"
fi

exit 0