NGINX as Minecraft server proxy

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1

Hello
I am fairly new to DNS and am currently trying to get a docker setup with modded minecraft servers running.
I have a Dyndns set up that is only running with IPv6, becouse my ISP is only giving out double nat addresses.

The idea was to have the for now two minecraft servers to be accessible through diffrent subdomains without having to add a port at the end when entering the address in the game.

I have already been successfull in simply portforwarding it, but when trying to implement nginx I am only seeing that error below in the console.

2025/08/20 21:32:31 [error] 30#30: *7 no host in upstream "", client: 172.21.0.1, server: 0.0.0.0:25565, bytes from/to client:0/0, bytes from/to upstream:0/0

The containers are all in the same network.
This is the nginx.conf i last tried:
(The additional server that listens to port 25566 is for me to connect local)

events {
    worker_connections 1024;
}

# TCP stream module for Minecraft reverse proxy
stream {
    # Map subdomain to backend server
    map $ssl_preread_server_name $backend_server {
        server1.test.com    survival-test:25565;
        server2.test.com    mekanism-neoforge:25565;
    }

    # Minecraft proxy server
    server {
        listen 25565;
        proxy_pass $backend_server;
        proxy_timeout 10s;
        proxy_connect_timeout 5s;
        proxy_responses 1;
    }
    
    server {
        listen 25566;
        proxy_pass mekanism-neoforge:25565;
        proxy_timeout 10s;
        proxy_connect_timeout 5s;
        proxy_responses 1;
    }
    server {
        listen 25567;
        proxy_pass survival-test:25565;
        proxy_timeout 10s;
        proxy_connect_timeout 5s;
        proxy_responses 1;
    }
}

Thanks for reading
I am happy to give more information :D
2

Hey @FeatherStorm! Based on your config, the error you are encountering is most likely due to needing to define a resolver directive to proxy to a domain vs a static IP. You can find some examples on how to potentially configure such a setup here Dynamic DNS Resolution Open Sourced in NGINX – NGINX Community Blog :slight_smile: