# Build arguments Only one build argument is required, namely `FABRIC_VERSION`. This is the version of Fabric you wish to install. You can find the list of versions [here](https://fabricmc.net/use/). For example, you can then set `FABRIC_VERSION=0.6.1.51` in the `.env` file. # Environment variables The two possible environment variables are `XMS` and `XMX`. These specify the initial RAM & maximum RAM usage respectively. Only `XMS` is required; `XMX` is just set to the same value as `XMS` if not specified. You must specify them as a number, e.g. `XMS=4`. This number represents a quantity of gigabytes. # Mount points There a three useful mount points defined: * `/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. You can mount these directories somewhere in the host file system by specifying the mount paths in the `.env` file. These can be both absolute or relative paths. # Other config variables The only other config variable is `PORT`. This specifies on what port your server will be discoverable over the internet. The default Minecraft port is `25565`. # Java flags I use the Java flags defined [here](https://aikar.co/2018/07/02/tuning-the-jvm-g1gc-garbage-collector-flags-for-minecraft/). 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.