QuakeKube

QuakeKube is a Kubernetes-ified version of QuakeJS that runs a dedicated Quake 3 server in a Kubernetes Deployment, and then allow clients to connect via QuakeJS in the browser.

Quick start

With an existing K8s cluster

Deploy the example manifest:

$ kubectl apply -f https://raw.githubusercontent.com/criticalstack/quake-kube/master/example.yaml

Without an existing K8s cluster

Start an instance of Kubernetes locally using cinder (or kind):

$ cinder create cluster

Deploy the example manifest:

$ kubectl apply -f example.yaml

Finally, navigate to http://$(cinder get ip):30001 in the browser.

How it works

QuakeKube makes use of ioquake for the Quake 3 dedicated server, and QuakeJS, a port of ioquake to javascript using Emscripten, to provide an in-browser game client.

Networking

The client/server protocol of Quake 3 uses UDP to synchronize game state. Browsers do not natively support sending UDP packets so QuakeJS wraps the client and dedicated server net code in websockets, allowing the browser-based clients to send messages and enable multiplayer for other clients. This ends up preventing the browser client from using any other Quake 3 dedicated server. In order to use other Quake 3 dedicated servers, a proxy handles websocket traffic coming from browser clients and translates that into UDP to the backend. This gives the flexibility of being able to talk to other existing Quake 3 servers, but also allows using ioquake (instead of the javascript translation of it), which uses considerably less CPU and memory.

QuakeKube also uses a cool trick with cmux to multiplex the client and websocket traffic into the same connection. Having all the traffic go through the same address makes routing a client to its backend much easier (since it can just use its document.location.host).

Quake 3 demo EULA

The Quake 3 dedicated server requires an End-User License Agreement be agreed to by the user before distributing the Quake 3 demo files that are used (maps, textures, etc). To ensure that the installer is aware of, and agrees to, this EULA, the flag --agree-eula must be passed to q3 server at runtime. This flag is not set by default in the container image and is therefore required for the dedicated server to pass the prompt for EULA. The example.yaml manifest demonstrates usage of this flag to agree to the EULA.

Configuration

The server and maps are configured via ConfigMap that is mounted to the container:

apiVersion: v1
kind: ConfigMap
metadata:
  name: quake3-server-config
data:
  fragLimit: 25
  timeLimit: 15m
  game:
    motd: "Welcome to Critical Stack"
    type: FreeForAll
    forceRespawn: false
    inactivity: 10m
    quadFactor: 3
    weaponRespawn: 3
  server:
    hostname: "quakekube"
    maxClients: 12
    password: "changeme"
  maps:
  - name: q3dm7
    type: FreeForAll
  - name: q3dm17
    type: FreeForAll
  - name: q3wctf1
    type: CaptureTheFlag
    captureLimit: 8
  - name: q3tourney2
    type: Tournament
  - name: q3wctf3
    type: CaptureTheFlag
    captureLimit: 8
  - name: ztn3tourney1
    type: Tournament

The time limit and frag limit can be specified with each map (it will change it for subsequent maps in the list):

- name: q3dm17
  type: FreeForAll
  fragLimit: 30
  timeLimit: 30

Capture limit for CTF maps can also be configured:

- name: q3wctf3
  type: CaptureTheFlag
  captureLimit: 8

Add custom maps

The content server hosts a small upload app to allow uploading pk3 or zip files containing maps. The content server in the example.yaml shares a volume with the game server, effectively "side-loading" the map content, however, in the future the game server will introspect into the maps and make sure that it can fulfill the users map configuration before starting.

Credits

inolen/quakejs - The really awesome QuakeJS project that makes this possible.
ioquake/ioq3 - The community supported version of Quake 3 used by QuakeJS. It is licensed under the GPLv2.
begleysm/quakejs - Information in the README.md (very helpful) was used as a guide, as well as, some forked assets of this project (which came from quakejs-web originally) were used.
joz3d.net - Useful information about configuration values.

ktravis / quake-kube