Expose an Application with Ingress¶

Goal¶

In this tutorial you will expose an application to external users using Kubernetes Ingress.

By the end you will understand how traffic flows through the cluster and how Ingress routes requests to services.

Problem¶

Applications running inside Kubernetes are not accessible from outside the cluster by default.

Pods run on an internal network, so external users cannot reach them directly.

Ingress solves this problem by providing HTTP and HTTPS routing into the cluster.

Architecture¶

Traffic flow in this tutorial:

User → Ingress → Service → Pod

Each component plays a specific role:

Prerequisites¶

Before starting ensure:

• a Kubernetes cluster is running
• kubectl is configured
• an Ingress controller is installed

Check cluster access:

kubectl get nodes

Expected output:

NAME           STATUS   ROLES
worker-node1   Ready    <none>

Step 1 : Deploy the Application¶

Create a deployment file deployment.yaml

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

Apply the deployment.

kubectl apply -f deployment.yaml

Verify the pods are running.

kubectl get pods

Expected output:

NAME                       READY   STATUS
web-app-abc123             1/1     Running
web-app-def456             1/1     Running

Step 2 : Create a Service¶

Pods are ephemeral and their IP addresses change.

A Service provides a stable internal endpoint for the application.

Create service.yaml.

apiVersion: v1
kind: Service
metadata:
  name: web-service
spec:
  selector:
    app: web-app
  ports:
    - port: 80
      targetPort: 80
  type: ClusterIP

Apply the service.

kubectl apply -f service.yaml

Verify it exists.

kubectl get services

Expected output:

NAME           TYPE        CLUSTER-IP
web-service    ClusterIP   10.96.x.x

Step 3 : Create the Ingress Resource¶

The Ingress resource defines how external traffic reaches the service. Create ingress.yaml.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: web-ingress
spec:
  rules:
    - host: myapp.local
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: web-service
                port:
                  number: 80

Apply the Ingress configuration.

kubectl apply -f ingress.yaml

Verify the Ingress resource.

kubectl get ingress

Expected output:

NAME          CLASS   HOSTS
web-ingress           myapp.local

Step 4 : Test the Application¶

Find the address of the Ingress controller.

kubectl get ingress

Example output:

NAME          HOSTS         ADDRESS
web-ingress   myapp.local   192.168.49.2

Add an entry to your hosts file if necessary:

192.168.49.2 myapp.local

Then open the application in a browser:

http://myapp.local

Step 5 : Verify Traffic Flow¶

You can verify the components involved.

Check the Ingress:

kubectl get ingress

Check the service:

kubectl get svc web-service

Check the pods:

kubectl get pods

This confirms the full routing path.

What Just Happened¶

You created a complete request path:

Traffic now flows through the cluster like this:

User → Ingress → Service → Pod

Troubleshooting¶

Ingress Not Accessible

Verify the Ingress controller is installed.

kubectl get pods -A

Look for something like:

ingress-nginx-controller

Service Not Routing Traffic

Check service endpoints.

kubectl get endpoints web-service

Expected output:

NAME          ENDPOINTS
web-service   10.244.x.x:80

Pods Not Running

Check deployment status.

kubectl get deployment

Inspect pod logs if needed.

kubectl logs <pod-name>

Clean Up¶

Delete the resources when finished.

kubectl delete -f ingress.yaml
kubectl delete -f service.yaml
kubectl delete -f deployment.yaml

Key Takeaways¶

In this tutorial you learned how to:

• deploy an application
• create a Kubernetes Service
• expose the service using Ingress
• route external HTTP traffic to pods Ingress is the standard method for exposing web applications in Kubernetes.

➡ Continue to the Advanced Kubernetes Guides