Oracle Linux 7: Autostart Oracle with init.d

I try to make Oracle 12.1.0.2.0 start with the system via init.d on my Oracle Linux 7.3 machine.

I followed this example: https://oracle-base.com/articles/linux/automating-database-startup-and-shutdown-on-linux

This is my script to start the db:

#!/bin/sh
# chkconfig: 345 99 10
# description: Oracle auto start-stop script.
#
# Set ORA_HOME to be equivalent to the $ORACLE_HOME
# from which you wish to execute dbstart and dbshut;
#
# Set ORA_OWNER to the user id of the owner of the 
# Oracle database in ORA_HOME.

ORA_HOME=/u01/app/oracle/product/12.1.0.2/db_1
ORA_OWNER=oracle

case "$1" in
    'start')
        # Start the Oracle databases:
        # The following command assumes that the oracle login 
        # will not prompt the user for any values
        # Remove "&" if you don't want startup as a background process.
        su $ORA_OWNER -c "$ORA_HOME/bin/lsnrctl start" &
        su $ORA_OWNER -c $ORA_HOME/bin/dbstart &
        touch /var/lock/subsys/dbora
        ;;
    'stop')
        # Stop the Oracle databases:
        # The following command assumes that the oracle login 
        # will not prompt the user for any values
        su $ORA_OWNER -c $ORA_HOME/bin/dbshut
        su $ORA_OWNER -c "$ORA_HOME/bin/lsnrctl stop"
        rm -f /var/lock/subsys/dbora
        ;;
esac

Nothing happens upon start. I created soft links in /etc/rc0.d and /etc/rc3.d:

ln -s /etc/init.d/dbora /etc/rc0.d/K10dbora
ln -s /etc/init.d/dbora /etc/rc3.d/S99dbora
chkconfig --level 2345 dbora on

chkconfig lists the dbora.sh with runlevel 2345 on

manually starting with a short script works just fine, like this:

#!/bin/sh
$ORACLE_HOME/bin/lsnrctl start
$ORACLE_HOME/bin/dbstart

What am I missing?