Honestly firewall-config does a pretty decent job with the firewalling part of things, if you don’t need anything too complicated. It’s not web based, but can be run over ssh without too much of an install footprint.

I think the way to go here would actually be to integrate some plugins with cockpit-project, which already has some of what you’d need.

Honestly one that seems relevant in light of the last two weeks is a web gui / front end for a Linux based firewall similar to what pfsense/opnsense are for BSD. Yes, there’s openwrt, but that’s not what I’m going for.

It’s kind of shocking that something like this doesn’t exist (even in component pieces) for a Debian based distro.