self-hosting/fabric

docker-mc-fabric

This repository helps you easily setup a modded Minecraft server using the Fabric mod loader.

Installing docker

You can follow the instructions here.

Building the image

To build the image, you must specify the Fabric version using the VERSION build argument. You can either do this using docker:

docker build -t mc-fabric-server:latest --build-arg VERSION=0.6.1.51 .

or using docker-compose, by specifying the argument in the docker-compose.yml file and running:

docker-compose build

See the provided docker-compose.yml file for an example of how to specify the build argument.

Useful mount points

The container has three useful mount points:

• /mc/config: this is where all server config files reside.
• /mc/config/mods: this is where all mods should be placed.
• /mc/worlds: this is where the world files are stored.

I recommend mounting these to either a local directory or a volume, as to not lose the server data.

Environment variables

The container has two environment variables which can be set, namely XMS and XMX. If XMX is not set, it will use XMS's value by default. Note that their value is expected to be an integer, which is then used as a quantity for gigabytes. Therefore, only gigabyte precision is possible.

Java flags

I use the Java flags defined here. If you don't agree with this decision, you can change the ENTRYPOINT at the end of the Dockerfile to the following:

ENTRYPOINT java \
-Xms"${XMS}G" \
-Xmx"${XMX:-$XMS}G" \
-jar fabric-server-launch.jar \
--universe /mc/worlds \
--nogui

This will only use the flags absolutely necessary, while still allowing you to tweak the memory variables.

Running the server

docker

You can start the server with the following command:

docker run \
    --rm \
    --interactive \
    --tty \
    --publish '25565:25565' \
    --detach \
    mc-fabric-server:latest

Or, more compact:

docker run --rm -dit -p '25565:25565' mc-fabric-server:latest

This will start the server and run it in the background.

docker-compose

If you prefer to use docker-compose (which I recommend), you can use the provided docker-compose.yml file and edit it to suit your needs. By default, it creates volumes for the three major mount points, and opens up port 25565. Then, you can start the server using docker-compose up --detach or docker-compose up -d, because no one likes typing long commands.