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🩺 Kubernetes Health Probes (Liveness & Readiness)

Container orchestrators like Kubernetes require standardized HTTP endpoints to monitor application health and manage pod lifecycles:

  • Liveness Probe (/healthz): Indicates whether the application process is running. If it fails, Kubernetes restarts the container.
  • Readiness Probe (/readyz): Indicates whether the application is ready to handle incoming traffic (e.g. database pools connected, caches warmed). If it fails, Kubernetes removes the pod from load balancer routing.

ferrox-health provides built-in HTTP health check routers.

1. Attaching health_router​

Attach health_router() to your main HTTP router:

use axum::Router;
use ferrox_health::health_router;

pub fn app_router() -> Router {
    Router::new()
        .merge(health_router()) // Adds /healthz and /readyz
}

2. Health Endpoint Responses​

Liveness Probe (GET /healthz)​

curl http://localhost:3000/healthz

Response (200 OK):

{
  "status": "UP",
  "timestamp": 1788602400
}

Readiness Probe (GET /readyz)​

curl http://localhost:3000/readyz

Response (200 OK):

{
  "status": "READY",
  "timestamp": 1788602400
}

3. Kubernetes Deployment YAML Configuration​

Configure your Kubernetes deployment manifest:

livenessProbe:
  httpGet:
    path: /healthz
    port: 3000
  initialDelaySeconds: 5
  periodSeconds: 10
readinessProbe:
  httpGet:
    path: /readyz
    port: 3000
  initialDelaySeconds: 10
  periodSeconds: 5

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