为什么我的init.d start-stop-daemon脚本没有在启动时启动应用程序，但是可以手动启动服务？

start-foo

#! /bin/sh
# chkconfig 345 85 60
# description: startup script for foo
# processname: foo

NAME=foo
DIR=/etc/foo/services
EXEC=foo.py
PID_FILE=/var/run/foo.pid
IEXE=/etc/init.d/foo
RUN_AS=root

### BEGIN INIT INFO
# Provides:          foo
# Required-Start:    $remote_fs $syslog
# Required-Stop:     $remote_fs $syslog
# Default-Start:     5
# Default-Stop:      0 1 2 3 6
# Description:       Starts the foo service
### END INIT INFO

if [ ! -f $DIR/$EXEC ]
then
        echo \"$DIR/$EXEC not found.\"
        exit
fi

case \"$1\" in
  start)
        echo -n \"Starting $NAME\"
    cd $DIR
    start-stop-daemon -d $DIR --start --background --pidfile $PID_FILE --make-pidfile --exec $EXEC --quiet
        echo \"$NAME are now running.\"
        ;;
  stop)
    echo -n \"Stopping $NAME\"
        kill -TERM `cat $PID_FILE`
    rm $PID_FILE
        echo \"$NAME.\"
        ;;
  force-reload|restart)
        $0 stop
        $0 start
        ;;
  *)
        echo \"Use: /etc/init.d/$NAME {start|stop|restart|force-reload}\"
        exit 1
    ;;
esac
exit 0

foo.py

make install:
  chmod +x start-foo
  cp start-foo /etc/init.d

sudo service start-foo start