purpurmc-docker

Unofficial docker image for purpurmc with a few extra features.

Usage Example

docker run -v "/host/purpur:/opt/purpur" -e EULA=true -e UPDATE=true -e MEMORY=2G ghcr.io/n0r1uno/purpurmc-docker

• default version is 1.20.1
• EULA=true is required
• add UPDATE=true to always download the version's latest purpurmc build on startup
• pass custom jvm arguments with ARGS="..."
• mount /opt/purpur to persist data
• root user not recommended (see below)
• experimental: mount /ramdisk to use ramdisk mode (see below)

Run as unprivileged user (linux only)

By setting UID and GID to an unprivileged user, the server will run as that user instead of root.
The user must exist on the host system and have read/write access to the mounted volume.

Example to create an unprivileged user minecraft on the host system, set up permissions and run the container as that user:

1. useradd --no-create-home -s /sbin/nologin -U minecraft
2. mkdir -p /opt/purpur
3. chown -R minecraft:minecraft /opt/purpur
4. set env variables UID and GUID on startup
   (see id [-u/-g] minecraft)

Example docker-compose

services:
 purpurmc:
   image: ghcr.io/n0r1uno/purpurmc-docker
   container_name: purpurmc
   environment:
     - EULA=true
     - GID=1001 # unprivileged user
     - UID=1001 # unprivileged user
     - VERSION=1.20.1
     - UPDATE=true
     - MEMORY=4G
   volumes:
     - /opt/purpur:/opt/purpur
   ports:
     - 25565:25565
   restart: unless-stopped

Experimental: Ramdisk mode (linux only)

Ramdisk mode runs the server in a tmpfs, resulting in faster read/write speeds (mostly noticeable during chunk operations).
All worlds and important configs will be backed up every BACKUP=30m (default) and on container stop.

❗️ Notice: Ramdisk mode is experimental and can result in data loss if the system crashes.
This mode only makes sense if your system runs on a slow HDD but has sufficient RAM. If you've got a fast SSD, you probably won't notice any difference. In general, I wouldn't use it if the server has no problems with chunk operations. Otherwise, just try it out and see if it gives you any benefits. More info can be found here.

To create a 4GB ramdisk run the following commands as root (or with sudo) on your host system.

1. mkdir -p /ramdisk
2. mount -t tmpfs -o size=4G tmpfs /ramdisk
   For more information (e.g. auto-mount on system startup) see ArchWiki

To use ramdisk mode, mount your ramdisk to /ramdisk in the container. The backup interval can be changed with BACKUP=... (default is 30m).
Example: docker run -v "/ramdisk:/ramdisk" -e BACKUP=1h ...