allengaller / dockercraft

Docker + Minecraft = Dockercraft

Dockercraft

A simple Minecraft Docker client, to visualize and manage Docker containers.

YouTube video

How to run Dockercraft

1. Install Minecraft: minecraft.net

   The Minecraft client hasn't been modified, just get the official release.

2. Pull or build Dockercraft image: (an offical image will be available soon)

   docker pull gaetan/dockercraft
   

   or

   git clone [email protected]:docker/dockercraft.git
   docker build -t gaetan/dockercraft dockercraft
   

3. Run Dockercraft container:

   docker run -t -i -d -p 25565:25565 \
   -v /var/run/docker.sock:/var/run/docker.sock \
   --name dockercraft \
   gaetan/dockercraft
   

   Mounting /var/run/docker.sock inside the container is necessary to send requests to the Docker remote API.

   The default port for a Minecraft server is 25565, if you prefer a different one: -p <port>:25565

4. Open Minecraft > Multiplayer > Add Server

   The server address is the IP of Docker host. No need to specify a port if you used the default one.

   If you're using Docker Machine: docker-machine ip <machine_name>

5. Join Server!

   You should see at least one container in your world, which is the one hosting your Dockercraft server.

   You can start, stop and remove containers interacting with levers and buttons. Some Docker commands are also supported directly via Minecraft's chat window, which is displayed by pressing the T key (default) or / key.

How it works

The Minecraft client itself remains unmodified. All operations are done server side.

The Minecraft server we use is http://cuberite.org. A custom Minecraft compatible game server written in C++. github repo

This server accepts plugins, scripts written in LUA. So we did one for Docker. (world/Plugins/Docker)

Unfortunately, there's no nice API to communicate with these plugins. But there's a webadmin, and plugins can be responsible for "webtabs".

Plugin:AddWebTab("Docker",HandleRequest_Docker)

Basically it means the plungin can catch POST requests sent to http://127.0.0.1:8080/webadmin/Docker/Docker.

Goproxy

Events from the Docker remote API are transmitted to the LUA plugin by a small daemon (written in Go). (go/src/goproxy)

func MCServerRequest(data url.Values, client *http.Client) {
	req, _ := http.NewRequest("POST", "http://127.0.0.1:8080/webadmin/Docker/Docker", strings.NewReader(data.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	req.SetBasicAuth("admin", "admin")
	client.Do(req)
}

The goproxy binary can also be executed with parameters from the LUA plugin, to send requests to the daemon:

function PlayerJoined(Player)
	-- refresh containers
	r = os.execute("goproxy containers")
end

Contributing

Want to hack on Dockercraft? Docker's contributions guidelines apply.