so I have a Minetest server and I want to deploy it on the internet through my raspberry pi, so de RBPI acts as a firewall and IDS and all the traffic goes through it.
The Minetest server is on my laptop and my question is if the solution is connecting my laptop to the raspberry as it was a router, where it gonna be set up the firewall, and how to do that in a simple approach (using wired ethernet, wifi ap, ssh...).
On the Raspberry Pi OS you have its firewall nftables available. It is the successor of iptables and replaces the old popular iptables, ip6tables, arptables and ebtables. So I suggest to use nftables because it is the future and removes some limits of the old firewall. Install it with
rpi ~$ sudo apt install nftables
and have a look at its usage with man nft. It is very powerful and should be able to cover all of your use cases. Of course you can still use the old iptables out of the box as long as it will not become deprecated.