I built something like this back in 2002 when I was at Red Hat for a client that wanted to have their firewalls to have read-only configurations on a diskless s

I built something like this back in 2002 when I was at Red Hat for a client that wanted to have their firewalls to have read-only configurations on a diskless system. They would update the rules/config/system by burning a new CD and booting it up. It worked basically how a Live CD worked - creating a temporary filesystem in ram, and I only learned later that they already existed (I didn't know at the time and the Internet wasn't as good at finding things as it is today :) )