Portfolio Project — Docker → Kubernetes → Scaling Guide

This README explains how to deploy the Portfolio React app using Docker and Kubernetes, and how to scale it and test load step by step.

Tested with: Windows + Docker Desktop + Minikube (kubectl)

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Prerequisites

Make sure you have:

• Docker Desktop installed
• Kubernetes enabled (Docker Desktop) or Minikube running
• kubectl installed
• Docker Hub account

Check:

kubectl version --client
kubectl config current-context

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Step 1 — Dockerize the React App (Nginx)

Dockerfile

# Step 1: Build React app
FROM node:18-alpine AS build
WORKDIR /app
COPY package*.json ./
RUN npm install
COPY . .
RUN npm run build

# Step 2: Serve using Nginx
FROM nginx:alpine
COPY --from=build /app/dist /usr/share/nginx/html
EXPOSE 80
CMD ["nginx", "-g", "daemon off;"]

Note: If using Create-React-App, replace /app/dist with /app/build.

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Step 2 — Build & Push Docker Image

docker build -t chandankumar55/portfolio:latest .
docker login
docker push chandankumar55/portfolio:latest

Why? Kubernetes pulls images from registries like Docker Hub, not from your local system.

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Step 3 — Kubernetes Deployment

deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: portfolio-deployment
spec:
  replicas: 1
  selector:
    matchLabels:
      app: portfolio
  template:
    metadata:
      labels:
        app: portfolio
    spec:
      containers:
      - name: portfolio
        image: chandankumar55/portfolio:latest
        ports:
        - containerPort: 80
        resources:
          requests:
            cpu: "100m"
            memory: "128Mi"
          limits:
            cpu: "500m"
            memory: "256Mi"

service.yaml

apiVersion: v1
kind: Service
metadata:
  name: portfolio-service
spec:
  type: NodePort
  selector:
    app: portfolio
  ports:
    - port: 80
      targetPort: 80
      nodePort: 30006

Apply:

kubectl apply -f deployment.yaml
kubectl apply -f service.yaml

Check:

kubectl get pods
kubectl get svc

Access:

http://localhost:30006

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Step 4 — Manual Scaling (Horizontal Scaling)

Increase pods:

kubectl scale deployment portfolio-deployment --replicas=3

Verify:

kubectl get pods

How traffic is handled

Kubernetes Service load-balances requests:

Request → Pod A
Request → Pod B
Request → Pod C

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Step 5 — Auto Scaling with HPA (Horizontal Pod Autoscaler)

HPA requires Metrics Server. Works best in Minikube or cloud clusters.

Enable metrics in Minikube

minikube addons enable metrics-server

Verify:

kubectl top nodes
kubectl top pods

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hpa.yaml

apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: portfolio-hpa
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: portfolio-deployment
  minReplicas: 1
  maxReplicas: 6
  metrics:
  - type: Resource
    resource:
      name: cpu
      target:
        type: Utilization
        averageUtilization: 50

Apply:

kubectl apply -f hpa.yaml

Check:

kubectl get hpa

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Step 6 — Generate Load (Test Autoscaling)

Delete old test pods

kubectl delete pod load-test

Create BusyBox load pod

kubectl run load-test --image=busybox --restart=Never -it -- sh

Inside pod:

while true; do wget -q -O- http://portfolio-service; done

Watch scaling

In another terminal:

kubectl get pods -w

If CPU increases and metrics are working, new pods will be created automatically.

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Important Reality

Frontend apps (React + Nginx):

• Very low CPU usage
• HPA may NOT trigger easily

Best autoscaling demo:

• Backend APIs (Node / Java / Python)

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Rolling Updates (Zero Downtime)

Push new image version and update:

kubectl set image deployment/portfolio-deployment portfolio=chandankumar55/portfolio:latest

Kubernetes will:

• Create new pod
• Remove old pod
• No downtime

---

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Production Architecture

Users
  ↓
Ingress (Nginx)
  ↓
Service
  ↓
Multiple Pods (Auto-scaled)
  ↓
Backend APIs
  ↓
Database (Replica Set)