Site is at https://forum.practical-pl.org.
If you go there now, you will get a “mixed content” warning from your browser. That’s because the docker is listening on a Unix domain socket, and an NGINX front end is redirecting traffic to it. This redirection also includes the SSL termination (i.e. - the certificates are installed at the reverse proxy, not the discourse client itself).
As a result, any absolute URL that discourse generates is an HTTP URL rather than HTTPS. Most notably, this includes the site’s icons and the activation links sent to new users.
How do I tell discourse to generate https links?