mcs

Dockerized minecraft server.

Usage

Getting started

The simplest way to get up and running is to use a simple docker-compose.yml file like the following.

version: "3.9"
services:
  mcs:
    image: nicholaschiasson/mcs:alpine-3-1.16.5-0.2.0
    ports:
      - "25565:25565"

Then you can start the server using docker-compose from the directory with your docker-compose.yml.

docker-compose up -d

The version of Minecraft is specified in the image tag. The tag is composed of four segments of the following format:

{BASE_IMAGE}-{BASE_IMAGE_VERSION}-{MINECRAFT_VERSION}-{IMAGE_VERSION}

Thus, for the above example, we are running the container on a distribution of alpine linux, version 3, with Minecraft server version 1.16.5, and on release 0.2.0 of this project.

Refer to the docker hub page to view supported versions of minecraft.

If you would like support for more Minecraft versions or more platforms for the image, please open an issue or pull request.

Configuration

Server properties

You inject your own server.properties by mounting the file in your docker-compose.yml file.

version: "3.9"
services:
  mcs:
    image: nicholaschiasson/mcs:alpine-3-1.16.5-0.2.0
    ports:
      - "25565:25565"
    volumes:
      - ./server.properties:/etc/mcs/server.properties:ro

Using the server.properties file, you can specify the port the Minecraft server listens on. If you use a different port, make sure to also update the port binding in the docker-compose.yml file.

Also, it is a good idea to make the mounted server.properties file read only, hence the addition of :ro in our above example. You may know that the Minecraft server tries to overwrite the server.properties file that it reads, but making our mounted file read only will not impact this since the container tries copying /etc/mcs/server.properties to /root/server.properties before launching the server, and it is the latter file which is read into the server.

Java memory allocation

By default, the container will run the JVM with an initial memory allocation pool of 1024M and a maximum memory allocation pool of 1024M.

These values can be overriden via environment variables.

In your docker-compose.yml file, add an environment section to update the values for JAVA_INITIAL_MEMORY_ALLOCATION_POOL and JAVA_MAXIMUM_MEMORY_ALLOCATION_POOL.

version: "3.9"
services:
  mcs:
    image: nicholaschiasson/mcs:alpine-3-1.16.5-0.2.0
    environment:
      JAVA_INITIAL_MEMORY_ALLOCATION_POOL: 512M
      JAVA_MAXIMUM_MEMORY_ALLOCATION_POOL: 4G
    ports:
      - "25565:25565"
    volumes:
      - ./server.properties:/etc/mcs/server.properties:ro

Persistent data

You probably want to save your world to be able to stop and restart the server.

You can do this by mounting a directory to /run/mcs, which is the universe directory inside the image.

Create a data/ directory in the same directory as your docker-compose.yml file and then update the volumes section of docker-compose.yml like so:

version: "3.9"
services:
  mcs:
    image: nicholaschiasson/mcs:alpine-3-1.16.5-0.2.0
    environment:
      JAVA_INITIAL_MEMORY_ALLOCATION_POOL: 512M
      JAVA_MAXIMUM_MEMORY_ALLOCATION_POOL: 4G
    ports:
      - "25565:25565"
    volumes:
      - ./data:/run/mcs:rw
      - ./server.properties:/etc/mcs/server.properties:ro

Using this docker-compose.yml file, you will be able to configure the server using your own server.properties file, and you will also be able to backup your world.

Operating

Build

If you have cloned this repository and want to build the image, you can use the supplied docker-compose.yml file.

docker-compose build

Start

docker-compose up -d

Stop

docker-compose down

Attach

docker-compose exec mcs bash

Logs

docker-compose logs -f