init.d script fo running prerender.io as a service with logging (redhat/centos)

prerender

#!/bin/sh

#
# chkconfig: 35 99 99
# description: prerender.js server for the given user
#

. /etc/rc.d/init.d/functions

APPNAME="Prerender"

USER="<user that runs prerender>"
DAEMON="/usr/local/node" 
ROOT_DIR="<path to prerender>"

SCRIPT="$(basename $0)"
PIDFILE="/var/run/$SCRIPT.pid"


SERVER="$ROOT_DIR/server.js"
LOG_FILE="/var/log/prerender.log"
SHUTDOWN_WAIT=20

app_pid()
{
	echo `ps -aefw | grep "$DAEMON $SERVER" | grep -v " grep " | awk '{print $2}'`
}

do_start()
{
        echo -n $"Starting $SERVER: "
		pid=$(app_pid)
		if [ -n "$pid" ]
		then
			echo "$APPNAME is already running (pid: $pid)"
		else
			if [ ! -w $LOG_FILE ]
			then
				if [ ! -e $LOG_FILE ]
				then
				 touch $LOG_FILE
				fi
				chown $USER $LOG_FILE
			fi
			echo "$APPNAME  is not running - starting it up!"
	                runuser  --shell=/bin/bash -l "$USER" -c "$DAEMON $SERVER >> $LOG_FILE 2>&1 &"
			pid=$(app_pid)
			echo $pid > ${PIDFILE}
			do_status
	                RETVAL=$?
                echo
                [ $RETVAL -eq 0 ]
		fi
		return 0
}

do_wait()
{
	echo "Waiting for process to exit";
	pid=$(app_pid)
	if [ -n "$pid" ]
        then
		let kwait=$SHUTDOWN_WAIT
		count=0;
		until [ `ps -p $pid | grep -c $pid` = '0' ] || [ $count -gt $kwait ]
		do
			echo -n -e "\nwaiting for processes to exit";
			sleep 1
			let count=$count+1;
		done
	fi
	return 0
}

do_stop()
{
        echo -n $"Stopping $APPNAME : "
        pid=`ps -aefw | grep "$DAEMON $SERVER" | grep -v " grep " | awk '{print $2}'`
        kill -9 $pid > /dev/null 2>&1 && echo_success || echo_failure
	if [ -f ${PIDFILE} ]; then
		rm ${PIDFILE}
	fi
        RETVAL=$?
        echo
        [ $RETVAL -eq 0 ]
}

do_status()
{
	pid=$(app_pid)
	if [ -n "$pid" ]
		then
			echo -n "$APPNAME is running (pid: $pid)"
			echo_success
		else
			echo -n "$APPNAME is not running"
		        echo_failure
		fi
		echo
		return 0
}

case "$1" in
        start)
                do_start
                ;;
        stop)
                do_stop
                ;;
        status)
        	do_status
        	;;
        restart)
                do_stop
		do_wait
                do_start
                ;;
        *)
                echo "Usage: $0 {start|stop|restart|status}"
                RETVAL=1
esac

exit $RETVAL

Thanks!!!

Thanks！！！