Health Check Endpoint

Fuwafuwa Framework includes a built-in health check endpoint for monitoring application status, making it easy to integrate with monitoring tools and load balancers.

In production environments, it's critical to know whether your application is running and healthy. Health checks provide a standardized way for monitoring systems, load balancers, and orchestration platforms to query application status. The health check endpoint responds with simple success/failure indicators or detailed diagnostic information.

The framework supports both basic liveness probes (is the app running?) and detailed readiness probes (is the app ready to serve traffic?). Liveness probes are lightweight and return immediately, while readiness probes check dependencies like database connectivity, disk space, and memory usage. This separation allows your infrastructure to make intelligent routing decisions.

Basic Health Check

The simplest health check endpoint returns HTTP 200 when the application is running:

# Basic health check
GET /health

# Response
HTTP/1.1 200 OK
Content-Type: text/plain

OK

This is useful for simple load balancer health checks and Kubernetes liveness probes.

Health Check Response

The health check endpoint returns JSON with the current status of key system components. This allows monitoring systems and load balancers to programmatically determine application health.

The response includes overall status, timestamp, application version, and individual check results for database and cache. Monitoring systems can parse this JSON to trigger alerts when components fail.

Sample Response

{
  "status": "healthy",
  "timestamp": "2024-01-15T10:30:00+00:00",
  "version": "2.1.0",
  "checks": {
    "database": "healthy",
    "cache": "healthy"
  }
}

The response includes a top-level status field—healthy, degraded, or unhealthy—that monitoring systems can use for alerting. Each check component reports its individual status, making it easy to pinpoint the source of problems. Response times help track performance trends over time.

Status Codes

The health check uses HTTP status codes to communicate application state. A 200 status indicates the application is running and all checks passed. A 503 status indicates there's a problem with one or more checks.

Kubernetes Integration

Kubernetes uses health checks to manage container lifecycle. Liveness probes determine if a container needs to be restarted, while readiness probes indicate whether a container should receive traffic. Proper health check configuration prevents Kubernetes from routing traffic to containers that aren't ready to handle it.

Use the health endpoint for Kubernetes probes:

# deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: fuwafuwa-app
spec:
  template:
    spec:
      containers:
      - name: app
        image: fuwafuwa/app:latest
        livenessProbe:
          httpGet:
            path: /health
            port: 8080
          initialDelaySeconds: 30
          periodSeconds: 10
        readinessProbe:
          httpGet:
            path: /health
            port: 8080
          initialDelaySeconds: 5
          periodSeconds: 5

Probe Types