Production Hardening

Health Check Endpoints

Health checks tell Kubernetes whether your process is alive and functioning. Liveness probes detect deadlocks and infinite loops. They should never depend on external resources.

Readiness Probes

Readiness probes indicate whether your service can accept traffic. They check dependencies: database connections, cache availability, and configuration loading.

Startup Probes

Startup probes run once when the container starts. They give slow-starting services time to initialize without triggering liveness failures.

Configuration Validation

Validate configuration at startup, not at runtime. Fail fast with clear error messages. Never start a service with invalid configuration.

Resource Limits

Set CPU and memory limits for your containers. This prevents one service from starving others and enables efficient bin-packing on nodes.

apiVersion: apps/v1
kind: Deployment
spec:
  template:
    spec:
      containers:
        - name: server
          resources:
            requests:
              cpu: "100m"     # 0.1 CPU cores
              memory: "128Mi" # Guaranteed memory
            limits:
              cpu: "500m"     # Max 0.5 CPU cores
              memory: "512Mi" # OOMKilled if exceeded

          # Liveness probe
          livenessProbe:
            httpGet:
              path: /healthz
              port: 8080
            initialDelaySeconds: 10
            periodSeconds: 15

          # Readiness probe
          readinessProbe:
            httpGet:
              path: /readyz
              port: 8080
            initialDelaySeconds: 5
            periodSeconds: 10

          # Startup probe
          startupProbe:
            httpGet:
              path: /started
              port: 8080
            failureThreshold: 30
            periodSeconds: 2

Circuit Breakers

Circuit breakers prevent cascading failures. When a dependency fails repeatedly, the breaker opens and fails fast instead of timing out on every request.