2.2 KiB
Build arguments
Two build arguments are required, namely MC_VERSION and FABRIC_VERSION.
The latter is the version of Fabric you wish to install. You can find the list
of versions here. 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 XMX is required; XMS is
just set to the same value as XMX 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:
/app/config: this is where all server config files reside, as well as the mods./app/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.
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"${XMS:-$XMX}G" \
-Xmx"${XMX}G" \
-jar fabric-server-launch.jar \
--universe /app/worlds \
--nogui
This will only use the flags absolutely necessary, while still allowing you to tweak the memory variables.
Broken symlink
You might've noticed a broken symlink called server.jar in your config
directory. This is an (admittedly ugly) fix for the issue where Fabric expects
the vanilla server jar to be in the current working directory. Considering a
server also has to run within its config directory, this would mean that the
vanilla jar should be in the config directory. As I wanted to keep any
version-specific data out of the config/worlds directories, I have opted to use
a symlink to the server jar in question instead. This symlink can be safely
deleted, and will just get re-created when needed.