Creating service for nodejs app in Oracle linux

I have a nodejs app and I want to run it as a a service in oracle linux server. I have created the service file /etc/init.d/wsdlsrv and after that i run this commands:

cd /etc/init.d
chmod +x wsdlsrv
/sbin/chkconfig wsdlsrv on
systemctl start wsdlsrv

The wsdlsrv code is the following:

user="root"
. /etc/init.d/functions
export PATH="/usr/local/bin/:/usr/bin/:$PATH"  
name='wsdlsrv'
pid_file="/var/run/$name.pid" 
stdout_log="/var/log/$name.log"
stderr_log="/var/log/$name.err"
get_pid() {
    cat "$pid_file"
}
is_running() {
    [ -f "$pid_file" ] && ps `get_pid` > /dev/null 2>&1
}
case "$1" in
    start)
    if is_running; then
        echo "Already started"
    else
        echo "Starting $name"
        cd "/home/wsdlsrv"
            su $user -c "node app" >> "$stdout_log" 2>> "$stderr_log" &

        echo $! > "$pid_file"
        if ! is_running; then
            echo "Unable to start, see $stdout_log and $stderr_log"
            exit 1
        fi
    fi
    ;;
    stop)
    if is_running; then
        echo -n "Stopping $name.."
        kill `get_pid`
        for i in {1..10}
        do
            if ! is_running; then
                break
            fi

            echo -n "."
            sleep 1
        done
        echo

        if is_running; then
            echo "Not stopped; may still be shutting down or shutdown may have failed"
            exit 1
        else
            echo "Stopped"
                if [ -f "$pid_file" ]; then
                rm "$pid_file"
            fi
        fi
    else
        echo "Not running"
    fi
    ;;
    restart)
    $0 stop
    if is_running; then
        echo "Unable to stop, will not attempt to start"
        exit 1
    fi
    $0 start
    ;;
    status)
    if is_running; then
        echo "Running"
    else
        echo "Stopped"
        exit 1
    fi
    ;;
    *)
    echo "Usage: $0 {start|stop|restart|status}"
    exit 1
    ;;
esac

exit 0

But when i try to start the service with systemclt it throws and error: Job for wsdlsrv.service failed because the control process exited with error code. See "systemctl status wsdlsrv.service" and "journalctl -xe" for details.Job for wsdlsrv.service failed because the control process exited with error code. See "systemctl status wsdlsrv.service" and "journalctl -xe" for details.

via Eduardo Carrillo