Automatically configure interfaces on boot

[Knudn]

Hi,
I'm currently working on a cloud platform to automate the setup process for a network infrastructure.
Openstack is used to allocate network interface to my opnsense firewall, and it works great! But each time a new opnsense instance is create the interfaces has to be configured manually.

Would it be possible for me to create a script that automatically recognizes all the connected interfaces and configures them to be either LAN or WAN?
For example, if one of the connected interfaces has a 192.0.0.0/8 network, then the interfaces would automatically be configured to a LAN port.

I'm not asking anyone to create a script, just a pointer in the right direction!

Any help on this would be greatly appreciated!
Thanks