Resolved How to expose a Docker port to the public?

[philippL]

Server operating system version

Ubuntu 20.04 LTS

Plesk version and microupdate number

18.0.57 #5

I've installed the official MariaDB docker image and want to connect to it remotely. I've turned off Automatic Port Mapping and specified an external port. Trying to connect to that port on the LAN IP address of the server does not work. Turning off the firewall does not change that. Trying to connect to it locally (127.0.0.1) works fine.

I've tried adding a Docker Proxy Rule to a domain, but the connection did not work and my guess is that this makes no sense as MariaDB is no HTTP application and nginx does not allow to reverse proxy a non-HTTP protocol, unless it's been built -with-streams and Plesk's version has not been built with that.

On Using Docker it says that by default, "Docker binds to the specified port on all network interfaces of the host system". This does not seem to be true. If you check the server for LISTEN ports, then it specifically says that "docker-proxy" is only listening on 127.0.0.1, *not* all interfaces. top only lists docker-proxy commands running with "-host-ip 127.0.0.1". And /etc/docker/daemon.json only contains {"ip":"127.0.0.1"}.

So how can I change the docker network configuration (preferably for one particular docker image only) to expose the public port mapping to the correct network interface?

 

[philippL]

Just last week Plesk released an upgrade (Change Log for Plesk Obsidian) that allows you to specify whether the mapped port should be private or public. This new setting hopefully solves my problem.