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#!/bin/bash
#
# Derived from -
# Joshua Davis
# http://shrubbery.mynetgear.net/c/display/W/Java+Daemon+Startup+Script
#
# This is a modification of the original script (which lets you run a java program as a deamon. 
# look bellow for more information) that lets you run a groovy script as a deamon.
#
# ============== OLD SCRIPT TEXT ==============
# 
# chkconfig: 345 99 05 
# description: Java deamon script
#
# A non-SUSE Linux start/stop script for Java daemons.
#
# Derived from -
# Home page: http://www.source-code.biz
# License:   GNU/LGPL (http://www.gnu.org/licenses/lgpl.html)
# Copyright 2006 Christian d'Heureuse, Inventec Informatik AG, Switzerland.
#
# History:
# 2009-03-04 Josh Davis: Ubuntu/Redhat version.
# 2006-06-27 Christian d'Heureuse: Script created.
# 2006-07-02 chdh: Minor improvements.
# 2006-07-10 chdh: Changes for SUSE 10.0.


# Set this to your Java installation
JAVA_HOME=/opt/java/jdk
export JAVA_HOME

# Groovy Home
GROOVY_HOME=/opt/java/groovy

scriptFile=$(readlink -fn $(type -p $0))                   # the absolute, dereferenced path of this script file
scriptDir=$(dirname $scriptFile)                           # absolute path of the script directory
serviceNameLo="service_name"                                  # service name with the first letter in lowercase
serviceName="Service_Name"                                    # service name
serviceUser="wbm"                                      # OS user name for the service
serviceGroup="wbm"                                    # OS group name for the service
applDir="/path/to/app/dir"                          # home directory of the service application
serviceUserHome="/home/$serviceUser"                       # home directory of the service user
serviceLogFile="/var/log/$serviceNameLo.log"               # log file for StdOut/StdErr
maxShutdownTime=15                                         # maximum number of seconds to wait for the daemon to terminate normally
pidFile="/var/run/$serviceNameLo.pid"                      # name of PID file (PID = process ID number)
groovyCommand="groovy"                                         # name of the Groovy launcher without the path
groovyExe="$GROOVY_HOME/bin/$groovyCommand"                      # file name of the Java application launcher executable
groovyArgs="-cp $applDir/lib/mysql-connector-java-5.1.13-bin.jar $applDir/consumer.groovy"                     # arguments for Groovy launcher
groovyCommandLine="$groovyExe $groovyArgs"                       # command line to start the Java service application
groovyCommandLineKeyword="consumer.groovy"                     # a keyword that occurs on the commandline, used to detect an already running service process and to distinguish it from others

# Makes the file $1 writable by the group $serviceGroup.
function makeFileWritable {
local filename="$1"
   touch $filename || return 1
   chgrp $serviceGroup $filename || return 1
   chmod g+w $filename || return 1
   return 0; }

# Returns 0 if the process with PID $1 is running.
function checkProcessIsRunning {
   local pid="$1"
   if [ -z "$pid" -o "$pid" == " " ]; then return 1; fi
   if [ ! -e /proc/$pid ]; then return 1; fi
   return 0; }

# Returns 0 if the process with PID $1 is our Java service process.
function checkProcessIsOurService {
   local pid="$1"
   if [ "$(ps -p $pid --no-headers -o comm)" != "java" ]; then return 1; fi
   grep -q --binary -F "$groovyCommandLineKeyword" /proc/$pid/cmdline
   if [ $? -ne 0 ]; then return 1; fi
   return 0; }

# Returns 0 when the service is running and sets the variable $pid to the PID.
function getServicePID {
   if [ ! -f $pidFile ]; then return 1; fi
   pid="$(<$pidFile)"
   checkProcessIsRunning $pid || return 1
   checkProcessIsOurService $pid || return 1
   return 0; }

function startServiceProcess {
   cd $applDir || return 1
   rm -f $pidFile
   makeFileWritable $pidFile || return 1
   makeFileWritable $serviceLogFile || return 1
   cmd="nohup $groovyCommandLine >>$serviceLogFile 2>&1 & echo \$! >$pidFile"
   # Don't forget to add -H so the HOME environment variable will be set correctly.
   sudo -u $serviceUser -H $SHELL -c "$cmd" || return 1
   sleep 0.1
   pid="$(<$pidFile)"
   if checkProcessIsRunning $pid; then :; else
      echo -ne "\n$serviceName start failed, see logfile."
      return 1
   fi
   return 0; }

function stopServiceProcess {
   kill $pid || return 1
   for ((i=0; i<maxShutdownTime*10; i++)); do
      checkProcessIsRunning $pid
      if [ $? -ne 0 ]; then
         rm -f $pidFile
         return 0
         fi
      sleep 0.1
      done
   echo -e "\n$serviceName did not terminate within $maxShutdownTime seconds, sending SIGKILL..."
   kill -s KILL $pid || return 1
   local killWaitTime=15
   for ((i=0; i<killWaitTime*10; i++)); do
      checkProcessIsRunning $pid
      if [ $? -ne 0 ]; then
         rm -f $pidFile
         return 0
         fi
      sleep 0.1
      done
   echo "Error: $serviceName could not be stopped within $maxShutdownTime+$killWaitTime seconds!"
   return 1; }

function startService {
   getServicePID
   if [ $? -eq 0 ]; then echo -n "$serviceName is already running"; RETVAL=0; return 0; fi
   echo -n "Starting $serviceName   "
   startServiceProcess
   if [ $? -ne 0 ]; then RETVAL=1; echo "failed"; return 1; fi
   echo "started PID=$pid"
   RETVAL=0
   return 0; }

function stopService {
   getServicePID
   if [ $? -ne 0 ]; then echo -n "$serviceName is not running"; RETVAL=0; echo ""; return 0; fi
   echo -n "Stopping $serviceName   "
   stopServiceProcess
   if [ $? -ne 0 ]; then RETVAL=1; echo "failed"; return 1; fi
   echo "stopped PID=$pid"
   RETVAL=0
   return 0; }

function checkServiceStatus {
   echo -n "Checking for $serviceName:   "
   if getServicePID; then
	echo "running PID=$pid"
	RETVAL=0
   else
	echo "stopped"
	RETVAL=3
   fi
   return 0; }

function main {
   RETVAL=0
   case "$1" in
      start)                                               # starts the Groovy program as a Linux service
         startService
         ;;
      stop)                                                # stops the Groovy program service
         stopService
         ;;
      restart)                                             # stops and restarts the service
         stopService && startService
         ;;
      status)                                              # displays the service status
         checkServiceStatus
         ;;
      *)
         echo "Usage: $0 {start|stop|restart|status}"
         exit 1
         ;;
      esac
   exit $RETVAL
}

main $1