I'd like to make a firstboot script for CentOS 5/6 and Ubuntu 12.04/12.10/14.04. If possible, I'd like to use one method to trigger this script to run.
From what I can tell, this rules out chkconfig, firstboot file, upstarts jobs, etc. I'm a bit confused with the plethora of terminology/technology. Is there one method I can use for all these platforms that will run a small script on first boot (after other services is fine)?