Health checks in K8s Go app

Add a /healthz endpoint to your Go HTTP server that returns a 200 OK status, then configure your Kubernetes Deployment to use a livenessProbe and readinessProbe pointing to that path.

package main

import (
	"net/http"
)

func main() {
	http.HandleFunc("/healthz", func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
	})
	http.ListenAndServe(":8080", nil)
}

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-go-app
spec:
  template:
    spec:
      containers:
      - name: app
        image: my-go-app:latest
        ports:
        - containerPort: 8080
        livenessProbe:
          httpGet:
            path: /healthz
            port: 8080
          initialDelaySeconds: 5
          periodSeconds: 10
        readinessProbe:
          httpGet:
            path: /healthz
            port: 8080
          initialDelaySeconds: 5
          periodSeconds: 5

Health checks are automated tests Kubernetes runs to see if your application is alive and ready to handle traffic. If the check fails, Kubernetes restarts the container or stops sending new requests to it. Think of it like a doctor taking your pulse to ensure you are awake and breathing before letting you drive a car.