Running the application on the local k8s cluster

Deploying an ASP.NET Core Web App with Docker images to a Kubernetes environment involves creating deployments, exposing services, and scaling replicas. This guide walks you through running your app on a local Kubernetes cluster using kubectl.

Table of Contents

1. Verify Kubernetes Version
2. Create a Deployment
3. Expose the Deployment as a Service
4. Display the Machine Name in the Web App
5. Build and Tag a New Docker Image
6. Redeploy Using Version 2
7. Test the Load Balancer
8. Command Reference Table
9. Links and References

1. Verify Kubernetes Version

Before deploying, confirm the kubectl client and the local cluster version:

kubectl version --short

Sample output:

Flag --short has been deprecated, and will be removed in the future. The --short output will become the default.
Client Version: v1.25.4
Kustomize Version: v4.5.7
Server Version: v1.25.4

2. Create a Deployment

Create a Deployment named kodekloudapp using the kodekloudapp:v1 image with 2 replicas:

kubectl create deployment kodekloudapp \
  --image=kodekloudapp:v1 \
  --replicas=2

Verify:

kubectl get deployment kodekloudapp

Expected output:

NAME            READY   UP-TO-DATE   AVAILABLE   AGE
kodekloudapp    2/2     2            2           10s

3. Expose the Deployment as a Service

Expose the Deployment on port 8080 (host) → 80 (container). On a local cluster this defaults to a NodePort service, but in cloud environments it provisions a load balancer.

kubectl expose deployment kodekloudapp \
  --type=LoadBalancer \
  --port=8080 \
  --target-port=80

Check the Service:

kubectl get service kodekloudapp

Sample output:

NAME            TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)         AGE
kodekloudapp    LoadBalancer   10.106.40.151   localhost     8080:31032/TCP  30s

Open your browser at http://localhost:8080 to see the running app.

4. Display the Machine Name in the Web App

To confirm traffic distribution across replicas, update the Razor page to display the machine name.

Edit Pages/Index.cshtml:

@page
@model IndexModel

@{
    ViewData["Title"] = "Home page";
}

<div class="text-center">
    <h1 class="display-4">Welcome</h1>
    <p>Learn about <a href="https://docs.microsoft.com/aspnet/core">building Web apps with ASP.NET Core</a>.</p>
    <p>Message: @Model.Message</p>
    <p>Machine: @Environment.MachineName</p>
</div>

Save changes and restart the app locally to confirm the additional line appears.

5. Build and Tag a New Docker Image

After updating the code, build a new image tagged kodekloudapp:v2:

cd .\RiderProjects\KodeKloudApp\
docker build -t kodekloudapp:v2 .

List your local images:

docker image ls

You should see both v1 and v2 tags:

REPOSITORY      TAG  IMAGE ID       CREATED
kodekloudapp    v2   3693d7352914   7 seconds ago
kodekloudapp    v1   8177c6374c5c   42 minutes ago

6. Redeploy Using Version 2

First, clean up existing resources:

kubectl delete service kodekloudapp
kubectl delete deployment kodekloudapp

Recreate the Deployment with the v2 image:

kubectl create deployment kodekloudapp \
  --image=kodekloudapp:v2 \
  --replicas=2

Expose it again:

kubectl expose deployment kodekloudapp \
  --type=LoadBalancer \
  --port=8080 \
  --target-port=80

Verify:

kubectl get service kodekloudapp

7. Test the Load Balancer

Visit http://localhost:8080 in two different browser sessions. You’ll see the Machine field alternate between replica hosts, confirming load balancing across pods.

8. Command Reference Table

9. Links and References

• Kubernetes Basics
• kubectl Cheat Sheet
• ASP.NET Core Documentation
• Azure Kubernetes Service (AKS)