So, while this is not exactly a typical “self-hosting” question as many users might not be using domains, I would be curious if anyone else has any experience with this.

I have NGinx Proxy Manager installed on a vps and a few docker instances that host various services (wordpress, a gitlab, etc etc) that I have bound to specific ports (wordpress to port 80, gitlab to port 3000, to give made up arbitrary examples.)

I also have a domain and a few subdomains registered as Type A resource records that look like:
[www.]somedomain[.com]
[gitlab.]somedomain[.com]

The essence of the question: When I go to NGinx Proxy Manager and register a “Proxy Host” for the gitlab subdomain, like:

Domain: gitlab.somedomain.com
Scheme: http
Forward Hostname: <IP ADDRESS HERE>
Forward Port: 3000 (AKA the port gitlab is hosted on)

This works, but it comes with the drawback that the port number is then exposed in the url bar like so:

gitlab.somedomain.com:3000

So is there some way to fix this on the NGINX proxy manager side of things? Or is this a case where I’m doing this completely wrong and someone with web-dev experience can help me see the light. While it’s not a huge hindrance to my use-case, it would still be nice to understand how this is supposed to work so that I can host more services myself that require domain names without having to shell out for isolated IPs. So if I hosted a lemmy or kbin, for example, I could actually configure it to use my subdomains correctly.

  • lemmyvoreEnglish
    4·
    9 months ago

    You should not be able to access port 3000 in your scenario. The fact you can suggests that you used network_type: host for your gitlab container which has exposed it on the host’s interface and that your firewall is not filtering it.

    • Block everything on the VPS public interface except 443, 80 and 8081 which should be forwarded to the NPM container.
    • All your containers should use network mode “bridge” unless they explicitly require another mode for pertinent reasons.But on a VPS there’s usually not going to be a reason to do that.
    • In bridge mode you can expose ports inside the container to the host with the “ports:” directive but only NPM 80, 443 and 8081 (admin interface) should be exposed that way. For everything else it’s best to use a docker network instead and connect containers to the NPM container instead, since that’s the only one that really needs to access them.

    How this works:

    • Regular containers expose their ports only to the NPM container on the private docker network.
    • 443 on the VPS external interface gets through the firewall and forwarded to 443 on the NPM container.
    • NPM looks at the domain name and proxies the connection to the appropriate host/ip container and port as you configured it. Btw it’s easier to give containers hostnames and refer to them by name than to track docker bridge IPs.
    • Port 80 behaves the same way but as soon as you get Let’s Encrypt certificates and get 443 going you can close it down (in both the VPS firewall and the NPM container port mapping).
    • You should also set up a domain proxy forward to the NPM admin interface on 8081 at which point you can stop forwarding/mapping that one too.