Mineginx

A lightweight minecraft proxy server
Made to host multiple minecraft servers on the same ip:port with different domains.
Inspired by nginx

Configuration

In the configuration, you can specify servers list

name	description
`listen`	The address to which the clients will connect Can be any interface address, or 0.0.0.0 for any
`server_name`	The domain for which the redirect will be applied. The domain is taken from the server address in the client
`proxy_pass`	Address to minecraft server for redirect

Configuration examples

Single server machine

# Server1
# config/mineginx.yaml
servers:
- listen: "1.1.1.1:25565" # your public ip or 0.0.0.0 (any) and port
  server_name: "folleach.net" # domain, which will be redirected
  proxy_pass: "127.0.0.1:7878" # upstream server (vanilla, fabric, etc...)

NOTE: if the clients connect to other domain addresses or the server1 ip address (1.1.1.1), the connection will be closed by mineginx

graph LR;
subgraph Client
    A[Minecraft];
end

subgraph Server1
  B[Mineginx\nlisten: 1.1.1.1:25565]
  C[Minecraft server\nlisten: 127.0.0.1:7878]
end
    A--connect to folleach.net-->B
    B-->C

DNS records

Type	Name	Content
A	folleach.net	1.1.1.1

One proxy, multiple minecraft servers

# Server1
# config/mineginx.yaml
servers:
- listen: "0.0.0.0:25565"
  server_name: "folleach.net"
  proxy_pass: "10.0.0.100:25565"

- listen: "0.0.0.0:25565"
  server_name: "example.org"
  proxy_pass: "192.168.1.1:25565"

Sure, you can listen multiple port too.
Mineginx creates one server socket for one port

So, if you connect to the folleach.net, you will be redirected to the Server2

flowchart LR;
subgraph Client
    M1[Minecraft]
end

subgraph Server1
    B[Mineginx\nlisten: 1.1.1.1:25565]
end

subgraph Server2
    C[Minecraft server\nlisten: 10.0.0.100]
end

subgraph Server3
    E[Minecraft server\nlisten: 192.168.1.1]
end
    M1== "connect to folleach.net" ==>B
    B==>C
    B-.-E

Or if you connect to the example.org, you will redirected to the Server3

flowchart LR;
subgraph Client
    M1[Minecraft]
end

subgraph Server1
    B[Mineginx\nlisten: 1.1.1.1:25565]
end

subgraph Server2
    C[Minecraft server\nlisten: 10.0.0.100:255565]
end

subgraph Server3
    E[Minecraft server\nlisten: 192.168.1.1:25565]
end
    M1== "connect to example.org" ==>B
    B-.-C
    B==>E

DNS records

Type	Name	Content
A	folleach.net	1.1.1.1
A	example.org	1.1.1.1

Build & Run

cargo b -r && ./target/release/mineginx

Limitations

Max ~65k established connection to one upstream

Since mineginx is a proxy, connection will look like this

minecraft client -> proxy   -> minecraft server
1.2.3.4             1.1.1.1    10.0.0.1

This means that all connections will be created including between 1.1.1.1 and 10.0.0.1.
Operating systems will not be able to keep more than 65k connections between the same addresses
Because the connections are identified by an ip:port pair, ip always the same, but about 2^16 ports can be used in total.

TODO (balancing has not been implemented yet):
You can avoid this limitation if you map more than one address on your network to the "minecraft server".
Then you can specify multiple upstream in the config file

Epilogue

So, this was my hello world on rust :>
I liked this language and will use it again!