zlacker

>>jakels+(OP)
> I also enabled UFW (which I should have done ages ago)

I disrecommend UFW.

firewalld is a much better pick in current year and will not grow unmaintainable the way UFW rules can.

    firewall-cmd --persistent --set-default-zone=block
    firewall-cmd --persistent --zone=block --add-service=ssh
    firewall-cmd --persistent --zone=block --add-service=https
    firewall-cmd --persistent --zone=block --add-port=80/tcp
    firewall-cmd --reload

Configuration is backed by xml files in /etc/firewalld and /usr/lib/firewalld instead of the brittle pile of sticks that is the ufw rules files. Use the nftables backend unless you have your own reasons for needing legacy iptables.

Specifically for docker it is a very common gotcha that the container runtime can and will bypass firewall rules and open ports anyway. Depending on your configuration, those firewall rules in OP may not actually do anything to prevent docker from opening incoming ports.

Newer versions of firewalld gives an easy way to configure this via StrictForwardPorts=yes in /etc/firewalld/firewalld.conf.

>>3np+pm
UFW and Firewall-CMD both just use iptables in that context though. The real upgrade is in switching to nftables. I know I'm going to need to learn eBpf as the next step too, but for now nftables is readable and easy to grok especially after you rip out the iptables stuff, but technically nftables is still using netfilter.

And ufw supports nftables btw. I think the real lesson is write your own firewalls and make them non-permissive - then just template that shit with CaC.