🧪 Helm Day-1: Deploy App on EKS

🎯 Goal

• Understand Helm basics

• Deploy an app to EKS using Helm

• Learn chart, values, install, upgrade, uninstall

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🧰 Prerequisites (Quick Check)

Make sure these already work:

kubectl get nodes

You should see EKS worker nodes.

helm version

If Helm not installed:

curl https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3 | bash

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🧠 What is Helm? (1-line)

Helm = Package manager for Kubernetes

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📁 Step 1: Create a Helm Chart

helm create myapp

Directory structure:

myapp/
├── Chart.yaml
├── values.yaml
├── templates/
│   ├── deployment.yaml
│   ├── service.yaml
│   └── _helpers.tpl

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📄 Step 2: Understand Key Files (Very Important)

Chart.yaml

Metadata of your app (name, version)

values.yaml

👉 Default configuration (replicas, image, ports)

templates/

👉 Kubernetes YAML files with variables

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✏️ Step 3: Update values.yaml (Simple)

Edit values.yaml:

replicaCount: 2

image:
  repository: nginx
  tag: "latest"

service:
  type: LoadBalancer
  port: 80

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🔍 Step 4: Dry Run (Always do this)

helm install myapp-release myapp --dry-run --debug

✔ Checks template rendering
✔ No resources created yet

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🚀 Step 5: Install Helm Chart on EKS

helm install myapp-release myapp

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🔎 Step 6: Verify Deployment

kubectl get pods
kubectl get svc

You should see:

• 2 nginx pods

• LoadBalancer service

Get external IP:

kubectl get svc myapp-release

Open in browser:

http://<EXTERNAL-IP>

🎉 NGINX page loads!

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🔄 Step 7: Helm Upgrade (Real-World Use)

Change replicas to 3 in values.yaml:

replicaCount: 3

Upgrade:

helm upgrade myapp-release myapp

Verify:

kubectl get pods

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📜 Step 8: Helm Commands You MUST Know

helm list
helm status myapp-release
helm history myapp-release

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❌ Step 9: Uninstall (Cleanup)

helm uninstall myapp-release

Check:

kubectl get all

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🧠 Helm vs kubectl (Interview Gold)

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🔁 Bonus: Rollback Demo (Optional)

helm rollback myapp-release 1

🧠 Day-1 Key Takeaways

• Helm uses charts

• values.yaml controls configuration

• Helm supports install, upgrade, rollback

• Perfect for EKS production deployments

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✅ What You Learned Today

✔ Helm basics
✔ Deploy app on EKS
✔ Upgrade & rollback
✔ Interview-ready commands