Persistent configuration on HA OS

Hi all,
I have HA OS on HA Yellow. I need some host OS configurations that will survive a restart. Things like iptables and sysctl. What is a good way to install these configurations persistently? Is there any rc.local type of script or file where I can stash these config lines?
Thanks in advance for any insight.

Any insight, anyone? There must be some way to have a change persist, right?