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Health Server

An optional lightweight HTTP health server that validates ARK RCON connectivity via arkmanager rconcmd. Useful for container orchestrators (Kubernetes, Docker Swarm) that need application-level health checks rather than simple TCP port probes.

Why?

TCP health checks only verify that a port is open — they don't confirm the ARK server is actually running and responsive. In environments with service meshes (Istio, Linkerd) or reverse proxies, TCP handshakes may succeed even when the game server is down because the proxy completes the connection on behalf of the backend.

The health server performs a real RCON ListPlayers command against the running ARK server. If RCON responds, the server is genuinely up and accepting game connections.

Enabling

Set the HEALTH_SERVER environment variable to true:

docker run -d \
    -e HEALTH_SERVER=true \
    -p 8080:8080 \
    ...
    drpsychick/arkserver
# docker-compose.yml
services:
  ark:
    image: drpsychick/arkserver
    environment:
      HEALTH_SERVER: "true"
    ports:
      - "8080:8080"

Configuration

Variable Default Description
HEALTH_SERVER false Enable the health server
HEALTH_SERVER_PORT 8080 Port the health server listens on

Endpoints

Path Method Description
/healthz GET RCON readiness check — 200 if RCON responds, 503 otherwise
/livez GET Process liveness — always 200 if the health server is running

Any other path returns 404.

Response Format

All responses are application/json.

/healthz — healthy:

{"status": "healthy"}

/healthz — unhealthy (server starting up, crashed, or RCON unreachable):

{"status": "unhealthy"}

/livez:

{"status": "alive"}

Kubernetes Example

containers:
  - name: ark
    image: drpsychick/arkserver
    env:
      - name: HEALTH_SERVER
        value: "true"
    ports:
      - containerPort: 8080
        protocol: TCP
        name: health
    readinessProbe:
      httpGet:
        path: /healthz
        port: 8080
      initialDelaySeconds: 120
      periodSeconds: 30
      timeoutSeconds: 10
    livenessProbe:
      httpGet:
        path: /livez
        port: 8080
      initialDelaySeconds: 30
      periodSeconds: 10

How It Works

The health server is a Python 3 ThreadingHTTPServer that runs as a background process alongside the ARK server. On each /healthz request it executes:

arkmanager rconcmd ListPlayers
  • If arkmanager returns exit code 0, the server is healthy
  • If it returns non-zero or times out (15s), the server is unhealthy
  • Failures are logged to stderr for debugging
  • Request logs are suppressed to avoid noise

The server starts right before arkmanager start in the entrypoint, so /livez becomes available almost immediately while /healthz will return 503 until the ARK server finishes loading and RCON becomes responsive.