Add docker compose server setup guide (#343)

Author: Kumai01

content/for-server-hosts/setup/containers.md

@@ -9,9 +9,9 @@ aliases:
 ## Obtaining a server binary
 
 - The official image can be found [here](https://github.com/luanti-org/luanti/pkgs/container/luanti)
-    - ghcr.io/luanti-org/luanti:latest - latest stable release
-    - ghcr.io/luanti-org/luanti:\<tag> - a specific version (git tag)
-    - ghcr.io/luanti-org/luanti:master - latest dev version
+  - ghcr.io/luanti-org/luanti:latest - latest stable release
+  - ghcr.io/luanti-org/luanti:\<tag> - a specific version (git tag)
+  - ghcr.io/luanti-org/luanti:master - latest dev version
 
 - [Warr1024's Docker image](https://hub.docker.com/r/warr1024/minetestserver).
 
@@ -21,10 +21,82 @@ aliases:
 
 It is recommended that you use [docker compose](https://docs.docker.com/compose) to set up, configure, and run your server
 
+A simple `compose.yml` example:
+
+```yml
+services:
+  luanti_server:
+    image: ghcr.io/luanti-org/luanti:latest
+    restart: unless-stopped
+    volumes:
+      - ./config:/etc/minetest:ro
+      - ./data:/var/lib/minetest
+      - ./games:/var/lib/minetest/.minetest/games:ro
+      - ./mods:/var/lib/minetest/.minetest/mods:ro
+    ports:
+      - "30000:30000/udp"
+```
+
+Before starting the container:
+
+- create the necessary directories:
+
+  ```bash
+  mkdir -p data/.minetest config games mods
+  ```
+
+- change ownership of `data` to `minetest` user (UID 30000)
+
+  ```bash
+  sudo chown -R 30000:30000 data/
+  ```
+
+- copy content of the [minetest.conf.example](https://github.com/luanti-org/luanti/blob/master/minetest.conf.example) file to `config/minetest.conf`
+
+- install the game you want to play in `./games/`. Follow [this guide](https://content.luanti.org/help/installing/#installing-using-the-command-line). For example, to install `voxelibre` using `git`
+
+  ```bash
+  git clone https://git.minetest.land/VoxeLibre/VoxeLibre ./games/voxelibre/
+  ```
+
+- start the container
+  ```bash
+  docker compose up -d
+  ```
+
+`./data/.minetest/` has the directory `worlds/`, where the world will be saved.
+
+`./config/minetest.conf` has settings of the server.
+
+If you have multiple games or worlds, you can specify which one to run in `compose.yml`. For example:
+
+```yml
+services:
+  luanti_server:
+    image: ghcr.io/luanti-org/luanti:latest
+    restart: unless-stopped
+    volumes:
+      - ./config:/etc/minetest:ro
+      - ./data:/var/lib/minetest
+      - ./games:/var/lib/minetest/.minetest/games:ro
+      - ./mods:/var/lib/minetest/.minetest/mods:ro
+    ports:
+      - "30000:30000/udp"
+    command: --config /etc/minetest/minetest.conf --gameid voxelibre --worldname world
+```
+
+`--config /etc/minetest/minetest.conf` tells the server where to find the config file inside the container. Keep this flag as-is when using the volume mount from this guide.
+
+To see available flags run:
+
+```bash
+docker exec -it luanti_server luantiserver --help
+```
+
 ### Podman
 
 It is recommend that you use [podman quadlets](https://www.redhat.com/en/blog/quadlet-podman) to set up, configure, and run your server
 
 ## Next Steps
 
-Continue on to [next steps](/for-server-hosts/setup/#port-forwarding).
+Continue on to [next steps](/for-server-hosts/setup/#port-forwarding).