Jedi Knight II: Jedi Outcast server

Run a Jedi Knight II: Jedi Outcast dedicated server with LinuxGSM, in Docker or directly on Linux.

jk2server Docker jk2idtech3

Steam ownership required. The Steam account LinuxGSM uses must own Jedi Knight II: Jedi Outcast.

NotesThis game server uses JK2MV community-made patch to improve and modernized JK2 client and server

Run with Docker

First install Docker Engine and the Compose plugin on your Linux host. Run the commands below from your project directory with a user allowed to access Docker; otherwise prefix Docker commands with sudo. The container manages its own linuxgsm user.

The jk2 image has LinuxGSM and every dependency for Jedi Knight II: Jedi Outcast already installed on Ubuntu 26.04. On first start it downloads the game server, then keeps it updated.

1. Create `compose.yaml`

compose.yaml

services:
  jk2server:
    image: ghcr.io/gameservermanagers/gameserver:jk2
    container_name: jk2server
    restart: unless-stopped
    network_mode: host
    volumes:
      - ./jk2server:/data
    environment:
      - UPDATE_CHECK=60

Also published on Docker Hub as gameservermanagers/gameserver:jk2. Prefer docker run? See Docker help.

2. Add your Steam login before the first start

Create the LinuxGSM config file inside the data directory. LinuxGSM reads it on first start and keeps it on updates.

shell

mkdir -p jk2server/config-lgsm/jk2server
nano jk2server/config-lgsm/jk2server/common.cfg

common.cfg

steamuser="username"
steampass='password'

3. Start it

shell

docker compose up -d
docker compose logs -f

The first start installs the server, which can take a while for large games. When it is ready the log shows the server details, including ports and passwords.

Ports

With network_mode: host the server uses the host's ports directly, so there is nothing to map. Open them in your firewall.

Setting	Default port
`port`	27960

Defaults from the LinuxGSM config. Run details to see every port and its protocol.

Manage the server

Show details, ports and passwords

docker exec -it --user linuxgsm jk2server ./jk2server details

Open the live console (leave with CTRL+b then d)

docker exec -it --user linuxgsm jk2server ./jk2server console

Restart the game server

docker restart jk2server

Check for a game update now

docker exec -it --user linuxgsm jk2server ./jk2server update

Update the image

docker compose pull && docker compose up -d

Server files, configs and logs live in ./jk2server on the host: back up that directory. Docker help below covers permissions, environment variables and bridge networking.

Docker help

Images and tags

Images are built weekly and published to two registries. They are identical, so use whichever you prefer.

Registry	Image
GitHub Container Registry	`ghcr.io/gameservermanagers/gameserver:jk2`
Docker Hub	`gameservermanagers/gameserver:jk2`

The image uses the base OS LinuxGSM recommends for this game. You do not need to match it on the host.

Use docker run instead of Compose

shell

docker run -d \
  --name jk2server \
  --network host \
  --restart unless-stopped \
  -v "$PWD/jk2server:/data" \
  -e UPDATE_CHECK=60 \
  ghcr.io/gameservermanagers/gameserver:jk2

Data and permissions

Everything that should survive a container update lives in /data inside the container, which is ./jk2server on the host.

Path in `/data`	Contents
`serverfiles/`	The game server itself
`config-lgsm/`	LinuxGSM config, including `common.cfg`
`log/`	Script, console and game logs
`data/`	LinuxGSM data and cache

The game server runs as the linuxgsm user, not root. On every start the container sets that user to UID and GID (both 1000 by default) and takes ownership of /data. If your host user has a different ID, set them to match so you can edit files on the host:

compose.yaml

environment:
      - UID=1001
      - GID=1001

Environment variables

Variable	Default	What it does
`UPDATE_CHECK`	`60`	Minutes between update checks, from `1` to `59`, or `60` for hourly. `0` turns scheduled checks off.
`UPDATE_ON_START`	`true`	Check for a game update every time the container starts.
`VALIDATE_ON_START`	`false`	Run a SteamCMD validate on start. Slow, but repairs broken files.
`UID` / `GID`	`1000`	User and group IDs the game server runs as.
`LGSM_GITHUBBRANCH`	`master`	LinuxGSM branch to run. Set `develop` to test unreleased fixes.

Updates and health checks

The game server updates itself. The container checks every UPDATE_CHECK minutes and on start. If an update is out, it stops the server, updates it and starts it again.

The image brings new LinuxGSM releases, dependency fixes and OS updates. Pull it now and then with docker compose pull && docker compose up -d.

The image runs LinuxGSM's monitor as the Docker health check every minute, so docker ps shows whether the game server is answering, not just whether the container is up.

Bridge networking

network_mode: host is the simplest choice: the game server uses the host's ports directly, the way it would without Docker, and query ports work without extra setup.

If you need bridge networking, publish each port the server uses. Run details to see them, then add them with the right protocol:

compose.yaml

ports:
      - "PORT:PORT/udp"
      - "PORT:PORT/tcp"

Bridge networking can hide the server's real IP from the game, which breaks some server browsers. Use host networking if players cannot find the server.

Troubleshooting

Permission denied in /data: set UID and GID to the owner of the host directory.
Server not listed in game: check the ports are open, use host networking, and add a GSLT if the game needs one.
Install fails at SteamCMD: the game may need a Steam login. Check the notes at the top of this page.
Will not start: stop the container, then run docker compose run --rm jk2server debug to see why.
Still stuck: run details and debug, then ask on Discord or GitHub Discussions with the output.

Install on Linux

Install directly on a server running Ubuntu 26.04, Debian 11 or Enterprise Linux 8.

1. Create a user and log in

Creating users and installing system packages require administrator privileges. From your administrator account, use sudo below (omit it if already root). Install curl, tar and an editor such as nano with your distribution's package manager first.

administrator shell

sudo adduser jk2server

Give the user a strong password, then switch to its login shell:

administrator shell

sudo su - jk2server

Run all remaining commands as jk2server from its home directory, without sudo. On Enterprise Linux, create the account with sudo useradd -m jk2server and set its password with sudo passwd jk2server instead of adduser.

2. Download LinuxGSM

shell

curl -Lo linuxgsm.sh https://linuxgsm.sh && chmod +x linuxgsm.sh && bash linuxgsm.sh jk2server

3. Add your Steam login

Create lgsm/config-lgsm/jk2server/common.cfg relative to the game-server user's home directory and add your dedicated Steam account:

shell

mkdir -p lgsm/config-lgsm/jk2server
nano lgsm/config-lgsm/jk2server/common.cfg

common.cfg

steamuser="username"
steampass='password'

4. Install

shell

./jk2server install

LinuxGSM checks dependencies and installs the game files. If this user has sudo access, it can install missing packages when prompted. Otherwise, ask an administrator to install the packages listed by LinuxGSM, then rerun this command as jk2server. Running ./jk2server install as root only installs dependencies, not the game server.

5. Configure and start the server

Review your LinuxGSM settings in lgsm/config-lgsm/jk2server/jk2server.cfg (instance settings) or lgsm/config-lgsm/jk2server/common.cfg (shared settings). Do not edit _default.cfg, which LinuxGSM updates automatically. Game settings use a separate config file; run ./jk2server details to find its path. Once configured, start the server explicitly:

shell

./jk2server start

Common commands

Start the server

start

./jk2server start

Stop the server

stop

./jk2server stop

Restart the server

restart

./jk2server restart

Show details, ports and passwords

./jk2server details

Open the live console (leave with CTRL+b then d; CTRL+c stops the server)

./jk2server console

Update the game server

./jk2server update

Run in the foreground to debug

./jk2server debug

Back up the whole server

./jk2server backup

List every command

./jk2server

Automate with cron

Restart the server if it crashes, apply game updates and keep LinuxGSM current. Add these with crontab -e.

crontab

*/5 * * * * /home/jk2server/jk2server monitor > /dev/null 2>&1
*/30 * * * * /home/jk2server/jk2server update > /dev/null 2>&1
0 0 * * 0 /home/jk2server/jk2server update-lgsm > /dev/null 2>&1

Jedi Knight II: Jedi Outcast server

Run with Docker

1. Create compose.yaml

2. Add your Steam login before the first start

3. Start it

Ports

Manage the server

Docker help

Install on Linux

1. Create a user and log in

2. Download LinuxGSM

3. Add your Steam login

4. Install

5. Configure and start the server

Common commands

Automate with cron

1. Create `compose.yaml`