Demo of Deployment in Kubernetes

Step-by-Step on Ubuntu + Minikube

Step 1️⃣ — Start Minikube

$ minikube start –driver=docker

Step 2️⃣ — Create Deployment YAML

Save this as deployment.yaml:

apiVersion: apps/v1
kind: Deployment
metadata:
name: dotnet-deployment
spec:
replicas: 3
selector:
    matchLabels:
      app: dotnet-app
template:
    metadata:
      labels:
        app: dotnet-app
    spec:
      containers:
        – name: dotnet-container
          image: mcr.microsoft.com/dotnet/samples:aspnetapp
          ports:
            – containerPort: 80

Step 3️⃣ — Apply the Deployment

$ kubectl apply -f deployment.yaml

Check it:

$ kubectl get deployments

$ kubectl get pods

You should see 3 running Pods automatically created by the Deployment (through a ReplicaSet).

🔁 Rolling Update Demonstration

Now suppose you want to update your .NET app version (for example, change the image).

Step 4️⃣ — Update the Deployment

Edit the YAML or use kubectl edit deployment dotnet-deployment.

Change:

image: mcr.microsoft.com/dotnet/samples:aspnetapp

image: mcr.microsoft.com/dotnet/samples:aspnetapp:7.0

Then apply the changes:

$ kubectl apply -f deployment.yaml

Kubernetes will create new Pods with the new version and gradually terminate old ones — this is the rolling update.

You can monitor this with:

$ kubectl rollout status deployment/dotnet-deployment

⏪ Rollback Demonstration

If something goes wrong after your update (say, Pods crash):

Step 5️⃣ — Rollback to previous version

$ kubectl rollout undo deployment/dotnet-deployment

Then check rollout status again:

$ kubectl rollout status deployment/dotnet-deployment

✅ This brings your app back to the previous working version.

📈 Scaling Your Deployment

To scale your app (increase or decrease replicas):

$ kubectl scale deployment dotnet-deployment –replicas=5

Now you’ll have 5 running Pods.

Check:

$ kubectl get pods

🌐 Exposing the Deployment (Optional but useful)

To access the app from your browser:

$ kubectl expose deployment dotnet-deployment –type=NodePort –port=80

$ minikube service dotnet-deployment

This command opens your .NET app in the browser.

Later, you can delete deployment by

$ kubectl delete deployment –all

$ kubectl delete svc –all

$ kubectl delete ingress –all

$ kubectl delete pods –all