LoadBalancer service type in Kubernetes - Mini Project: Build & Apply

Create a Kubernetes LoadBalancer Service

📖 Scenario: You have deployed a simple web application in Kubernetes using a Deployment. Now, you want to expose this application to the internet so users can access it from outside the cluster.

🎯 Goal: Learn how to create a Kubernetes Service of type LoadBalancer to expose your application externally.

📋 What You'll Learn

Create a Deployment named webapp running the nginx image with 2 replicas

Create a Service named webapp-service of type LoadBalancer

The Service should select pods with label app: webapp

The Service should expose port 80 and forward it to container port 80

Print the Service YAML manifest at the end

💡 Why This Matters

🌍 Real World

In real cloud environments, LoadBalancer Services provide a simple way to expose applications to the internet with a cloud provider's load balancer.

💼 Career

Understanding how to expose Kubernetes applications externally is essential for DevOps roles managing cloud-native applications.

1

Create the Deployment

Create a Deployment named webapp with 2 replicas using the nginx image. The pods should have the label app: webapp. Write the YAML manifest for this Deployment.

Kubernetes

# Write the Deployment YAML manifest here
# Your code here

Need a hint?

Use kind: Deployment and set replicas: 2. Add label app: webapp under template.metadata.labels.

2

Add the LoadBalancer Service configuration

Create a Service named webapp-service of type LoadBalancer. It should select pods with label app: webapp. Expose port 80 and forward it to container port 80. Write the YAML manifest for this Service below the Deployment manifest.

Kubernetes

apiVersion: apps/v1
kind: Deployment
metadata:
  name: webapp
spec:
  replicas: 2
  selector:
    matchLabels:
      app: webapp
  template:
    metadata:
      labels:
        app: webapp
    spec:
      containers:
      - name: nginx
        image: nginx
        ports:
        - containerPort: 80

# Write the Service YAML manifest here
# Your code here

Need a hint?

Use kind: Service and set type: LoadBalancer. Use selector: app: webapp and expose port 80.

3

Apply the manifests to the cluster

Use the kubectl apply -f command to apply the YAML manifest file named webapp.yaml that contains both the Deployment and Service manifests.

Kubernetes

apiVersion: apps/v1
kind: Deployment
metadata:
  name: webapp
spec:
  replicas: 2
  selector:
    matchLabels:
      app: webapp
  template:
    metadata:
      labels:
        app: webapp
    spec:
      containers:
      - name: nginx
        image: nginx
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: webapp-service
spec:
  type: LoadBalancer
  selector:
    app: webapp
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80

# Write the kubectl command to apply the manifest file named webapp.yaml
# Your code here

Need a hint?

Use kubectl apply -f webapp.yaml to apply the manifest file.

4

Display the Service details

Use the kubectl get service webapp-service command to display the details of the LoadBalancer Service and show its external IP address.

Kubernetes

apiVersion: apps/v1
kind: Deployment
metadata:
  name: webapp
spec:
  replicas: 2
  selector:
    matchLabels:
      app: webapp
  template:
    metadata:
      labels:
        app: webapp
    spec:
      containers:
      - name: nginx
        image: nginx
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: webapp-service
spec:
  type: LoadBalancer
  selector:
    app: webapp
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80

kubectl apply -f webapp.yaml

# Write the command to get the service details for webapp-service
# Your code here

Need a hint?

Use kubectl get service webapp-service to see the external IP and ports.