You’re probably already aware of this, but if you run Docker on linux and use ufw or firewalld - it will bypass all your firewall rules. It doesn’t matter what your defaults are or how strict you are about opening ports; Docker has free reign to send and receive from the host as it pleases.

If you are good at manipulating iptables there is a way around this, but it also affects outgoing traffic and could interfere with the bridge. Unless you’re a pointy head with a fetish for iptables this will be a world of pain, so isn’t really a solution.

There is a tool called ufw-docker that mitigates this by manipulating iptables for you. I was happy with this as a solution and it used to work well on my rig, but for some unknown reason its no-longer working and Docker is back to doing its own thing.

Am I missing an obvious solution here?

It seems odd for a popular tool like Docker - that is also used by enterprise - not to have a pain-free way around this.

  • Melmi@lemmy.blahaj.zoneEnglish
    8·
    14 hours ago

    If there’s a port you want accessible from the host/other containers but not beyond the host, consider using the expose directive instead of ports. As an added bonus, you don’t need to come up with arbitrary ports to assign on the host for every container with a shared port.

    IMO its more intuitive to connect to a service via container_name:443 instead of localhost:8443