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Cover image for Part-106: 🚀Implementing Headless Services in Google Kubernetes Engine (GKE)
Latchu@DevOps
Latchu@DevOps

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Part-106: 🚀Implementing Headless Services in Google Kubernetes Engine (GKE)

#cloud #devops #kubernetes #googlecloud

In this guide, we’ll explore how to implement ClusterIP and Headless Services in Google Kubernetes Engine. You’ll learn the difference between them and how Headless Services allow direct DNS resolution to Pod IPs.

📌 Step-01: Introduction

  • Implement Kubernetes ClusterIP and Headless Service
  • Understand how Headless Services resolve directly to Pod IPs

📌 Step-02: Kubernetes Deployment

01-kubernetes-deployment.yaml

apiVersion: apps/v1
kind: Deployment 
metadata:
  name: myapp1-deployment
spec:
  replicas: 4
  selector:
    matchLabels:
      app: myapp1
  template:  
    metadata:
      name: myapp1-pod
      labels:
        app: myapp1
    spec:
      containers:
        - name: myapp1-container
          image: us-docker.pkg.dev/google-samples/containers/gke/hello-app:2.0
          ports: 
            - containerPort: 8080
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📌 Step-03: ClusterIP Service

02-kubernetes-clusterip-service.yaml

apiVersion: v1
kind: Service 
metadata:
  name: myapp1-cip-service
spec:
  type: ClusterIP
  selector:
    app: myapp1
  ports: 
    - name: http
      port: 80
      targetPort: 8080
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📌 Step-04: Headless Service

The key difference is:

👉 clusterIP: None

03-kubernetes-headless-service.yaml

apiVersion: v1
kind: Service 
metadata:
  name: myapp1-headless-service
spec:
  clusterIP: None
  selector:
    app: myapp1
  ports: 
    - name: http
      port: 80
      targetPort: 8080
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🔑 Important Note

  • Headless Service does not get a Cluster IP.
  • DNS resolves directly to Pod IPs.
  • You must use the container port (8080 here).

📌 Step-05: Deploy Manifests 

# Deploy manifests
kubectl apply -f headless/

# Verify deployments
kubectl get deploy
kubectl get pods -o wide

# Check services
kubectl get svc
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✅ You’ll notice:

  • ClusterIP Service → has a ClusterIP.
  • Headless Service → CLUSTER-IP is None.

📌 Step-06: Curl Pod Manifest

To test DNS resolution, create a Curl Pod:

apiVersion: v1
kind: Pod
metadata:
  name: curl-pod
spec:
  containers:
  - name: curl
    image: curlimages/curl
    command: [ "sleep", "600" ]
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📌 Step-07: Verify ClusterIP vs Headless Service 

kubectl apply -f headless/curl.yaml 
kubectl exec -it curl-pod -- sh
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🔹 Test ClusterIP Service

nslookup myapp1-cip-service.default.svc.cluster.local
curl myapp1-cip-service.default.svc.cluster.local
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👉 Returns the ClusterIP.

🔹 Test Headless Service

nslookup myapp1-headless-service.default.svc.cluster.local
curl myapp1-headless-service.default.svc.cluster.local:8080
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👉 Returns multiple Pod IPs.

🎯 Now, traffic is directly resolved to Pod IPs instead of a Service IP.

📌 Step-08: Clean-Up 

kubectl delete -f headless/
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✅ Summary

  • ClusterIP Service → provides a stable IP inside the cluster.
  • Headless Service → bypasses ClusterIP, resolving directly to Pod IPs.
  • Useful in stateful applications, DNS-based service discovery, and databases (e.g., Cassandra, StatefulSets).

🌟 Thanks for reading! If this post added value, a like ❤️, follow, or share would encourage me to keep creating more content.

— Latchu | Senior DevOps & Cloud Engineer

☁️ AWS | GCP | ☸️ Kubernetes | 🔐 Security | ⚡ Automation
📌 Sharing hands-on guides, best practices & real-world cloud solutions

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