Health Check

API Gateway provides health check functionality for both the gateway itself and backend services.

External Health Check

The external health check provides an endpoint that can be used to verify the gateway is running.

Configuration

healthcheck:
  outer:
    enable: true
    path: /healthz
    ok: true

Options

Field	Type	Default	Description
enable	bool	false	Enable the health check endpoint
path	string	/healthz	Path for the health check endpoint
ok	bool	true	Always return OK (skip actual checks)

Usage

When enabled, the gateway responds to health check requests:

curl http://localhost:8080/healthz
# Returns: ok

This is useful for:

• Load balancer health checks
• Kubernetes liveness/readiness probes
• Monitoring systems

Example

healthcheck:
  outer:
    enable: true
    path: /healthz
    ok: true

Kubernetes probe configuration:

livenessProbe:
  httpGet:
    path: /healthz
    port: 8080
  initialDelaySeconds: 10
  periodSeconds: 5

Internal Health Check

The internal health check monitors backend services to ensure they are available.

Configuration

healthcheck:
  inner:
    enable: true
    interval: 30
    timeout: 5

Options

Field	Type	Default	Description
enable	bool	false	Enable internal health checks
interval	int	30	Check interval in seconds
timeout	int	5	Request timeout in seconds

Service Health Check

You can configure health checks for individual services:

routes:
  - name: api
    path: /api
    backend:
      service:
        name: api.example.com
        port: 8080
        health_check:
          enable: true
          method: GET
          path: /health
          status: [200]
          ok: false

Service Health Check Options

Field	Type	Default	Description
enable	bool	false	Enable health check for this service
method	string	GET	HTTP method for health check
path	string	/health	Health check endpoint path
status	array	[200]	Valid HTTP status codes
interval	int	30	Check interval in seconds
timeout	int	5	Request timeout in seconds
ok	bool	false	Always consider service healthy (skip checks)

Health Check Behavior

When a service health check fails:

• The gateway may stop routing requests to that service
• Errors are logged for monitoring
• The gateway continues to operate for other services

Health Check Examples

Basic Configuration

healthcheck:
  outer:
    enable: true
    path: /healthz
  inner:
    enable: true
    interval: 30
    timeout: 5

Service-Specific Health Check

routes:
  - name: user-service
    path: /users
    backend:
      service:
        name: user-service.example.com
        port: 8080
        health_check:
          enable: true
          path: /api/health
          status: [200, 201]

Kubernetes Integration

# Gateway configuration
healthcheck:
  outer:
    enable: true
    path: /healthz

---
# Kubernetes deployment
apiVersion: apps/v1
kind: Deployment
metadata:
  name: api-gateway
spec:
  template:
    spec:
      containers:
      - name: api-gateway
        image: gozoox/api-gateway:latest
        livenessProbe:
          httpGet:
            path: /healthz
            port: 8080
          initialDelaySeconds: 10
          periodSeconds: 5
        readinessProbe:
          httpGet:
            path: /healthz
            port: 8080
          initialDelaySeconds: 5
          periodSeconds: 3

Monitoring

Health check status can be monitored through:

• Gateway logs
• External monitoring systems (Prometheus, etc.)
• Kubernetes events

Best Practices

1. Use Simple Endpoints: Keep health check endpoints lightweight
2. Appropriate Intervals: Balance between responsiveness and overhead
3. Timeout Configuration: Set reasonable timeouts to avoid hanging requests
4. Status Codes: Use appropriate HTTP status codes for health status
5. Separate Endpoints: Use different endpoints for liveness and readiness if needed

Next Steps

• Configuration - Complete configuration reference
• Routing - Configure routes with health checks
• Examples - See health check examples