escaping/core-keeper-dedicated repository overview

⁠Core Keeper Dedicated Server

Explore an endless cavern of creatures, relics and resources in a mining sandbox adventure for 1-8 players. Mine, build, fight, craft and farm to unravel the mystery of the ancient Core. Get Core Keeper at the Steam Store⁠

⁠Supported tags and respective Dockerfile links

• latest (Dockerfile)⁠

⁠How to run

⁠ARM based configuration

This image currently includes the following Box64 build variants for the following devices:

• Generic [generic]
• Raspberry Pi 3 [rpi3]
• Raspberry Pi 4 [rpi4-pre3]
• Raspberry Pi 5 (4K page size) [rpi5]
• Raspberry Pi 5 (16K page size) [rpi5_16k]
• M1 (M-Series) Mac [m1]
• ADLink Ampere Altra (Oracle ARM CPUs) [adlink]

By default it is set to use generic. If you want to use another one, change the enviromental variable ARM64_DEVICE at the core.env file.

⁠Volumes

Create two directories where you want to run your server :

• server-data: mandatory if you want to keep configuration between each restart
• server-files: optional, contains all the files of the application

Then modify /host/path/to/server-data and/or /host/path/to/server-files in one of the examples below to match the paths of the folders you created.

⁠Using Docker CLI:

docker run -d \
  --name core-keeper-dedicated \
  -e WORLD_NAME="Core Keeper Server" \
  -e MAX_PLAYERS=5 \
  -v /host/path/to/server-data:/home/steam/core-keeper-data \
  -v /host/path/to/server-files:/home/steam/core-keeper-dedicated \
  escaping/core-keeper-dedicated:latest

⁠Using Docker Compose

Create a docker-compose.yml⁠ with the following content:

services:
  core-keeper:
    image: escaping/core-keeper-dedicated:latest
    container_name: core-keeper-dedicated
    restart: unless-stopped
    stop_grace_period: 2m
    # Port is only needed if using direct connection mode
    # ports:
    #   - "$SERVER_PORT:$SERVER_PORT/udp"
    volumes:
      - /host/path/to/server-files:/home/steam/core-keeper-dedicated
      - /host/path/to/server-data:/home/steam/core-keeper-data
    env_file:
      - path: core.env
        required: false

Create a core.env file and override the desired environmental variables for the dedicated server, see configuration for reference. Example:

ARM64_DEVICE=rpi5
MAX_PLAYERS=3

On the folder which contains the files run docker compose up -d.

A GameID.txt file will be created next to the executable containing the Game ID. If it doesn't appear you can check the docker logs (docker logs core-keeper-dedicated or docker compose logs) for errors.

To query the game ID run: docker exec -it core-keeper-dedicated cat /home/steam/core-keeper-dedicated/GameID.txt

⁠Configuration

These are the arguments you can use to customize server behavior with default values.

⁠Mod Support

The container supports automatically installing mods from mod.io⁠.

1. Get a mod.io API key from mod.io/me/access⁠
   • You'll need the API path that is generated along with the key (e.g. https://u-*.modapi.io/v1⁠)
2. Set the necessary environment variables in your core.env file (or in your docker-compose.yml)

• MODS_ENABLED=true
• MODIO_API_KEY=your_api_key
• MODIO_API_URL=your_api_url
• MODS=mod1,mod2 (see below)

⁠Specify mods to install

You'll need to get the mod string ID from mod.io for each mod you want to install. The easiest way to do this is to grab it from the URL.

For example, looking at the URL for CoreLib⁠ (https://mod.io/g/corekeeper/m/core-lib), you would use core-lib.

Specify mods as a comma-separated list, optionally providing a version:

# Format: <mod_id>[:<version>], ...
MODS=core-lib,coreliblocalization,corelibrewiredextension,ck-qol

Example using specific versions:

MODS=core-lib,coreliblocalization,corelibrewiredextension:3.0.1,ck-qol:1.9.4

• If version is not specified, the latest version will be installed.
• Mods are reinstalled whenever the container is started, so to update mods to their latest version, simply restart the container.

⁠Network Mode

Currently Core Keeper supports two network modes: SDR (Steam Datagram Relay) and Direct Connect.

⁠SDR (Steam Datagram Relay)

In this mode, the server uses Valve's Virtual Network⁠ to route traffic through Steam's relay infrastructure. Instead of players connecting directly to the server's IP address, all communication goes through secure relay nodes managed by Steam. This hides the server’s real IP, protects against DDoS attacks, and improves NAT traversal.

Because of this relay system, server operators do not need to open any ports on their router or firewall—as long as outbound connections to Steam are allowed, the server can communicate with clients reliably.

⁠Direct Connection

In Direct Connect mode, players connect straight to the server’s public IP address without going through Steam's relay network. This can result in lower latency and more direct communication, but it requires the server to be reachable from the internet.

Server operators must open and forward the necessary ports on their router or firewall to allow incoming connections. Unlike SDR, this mode exposes the server’s IP address to clients and may be more vulnerable to connection issues or attacks.

⁠Contributors

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Made with contrib.rocks⁠.