Client → Ingress → Service → Pod(s) chạy Node.js API → MongoDB
                   ↑
                HPA tự động mở rộng pods

nodejs-kubernates/
├── src/
│   ├── config/db.js          # Kết nối MongoDB
│   ├── controllers/          # Logic nghiệp vụ
│   ├── models/product.model.js
│   ├── routes/product.routes.js
│   ├── middlewares/          # Xử lý lỗi, xác thực
│   └── server.js             # Điểm vào của Express
├── k8s/
│   ├── deployment.yaml       # Triển khai ứng dụng
│   ├── service.yaml          # Dịch vụ ClusterIP
│   ├── ingress.yaml          # Ingress (mở rộng API)
│   ├── secret.yaml           # Thông tin xác thực MongoDB
│   └── hpa.yaml              # Cấu hình tự động mở rộng
├── Dockerfile
├── docker-compose.yml        # Phát triển cục bộ
└── package.json

const productSchema = new mongoose.Schema({
  name: { type: String, required: true, trim: true },
  description: { type: String, default: '' },
  price: { type: Number, required: true, min: 0 },
  inStock: { type: Boolean, default: true }
}, { timestamps: true });

curl -X POST http://localhost:5000/api/products \
  -H "Content-Type: application/json" \
  -d '{"name":"Laptop","price":999.99,"inStock":true}'

FROM node:18-alpine
WORKDIR /app
COPY package*.json ./
RUN npm ci --only=production
COPY . .
CMD ["node", "src/server.js"]

docker build -t nodejs-kubernates .
docker run -p 5000:5000 \
  -e MONGO_URI=mongodb://host.docker.internal:27017/product-api \
  nodejs-kubernates

apiVersion: apps/v1
kind: Deployment
metadata:
  name: product-api
spec:
  replicas: 2
  selector:
    matchLabels:
      app: product-api
  template:
    metadata:
      labels:
        app: product-api
    spec:
      containers:
        - name: product-api
          image: <REGISTRY>/nodejs-kubernates:latest
          ports:
            - containerPort: 5000
          env:
            - name: MONGO_URI
              valueFrom:
                secretKeyRef:
                  name: app-secrets
                  key: MONGO_URI

apiVersion: v1
kind: Service
metadata:
  name: product-api-svc
spec:
  selector:
    app: product-api
  ports:
    - port: 80
      targetPort: 5000
  type: ClusterIP

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: product-api-ingress
  annotations:
    kubernetes.io/ingress.class: alb
spec:
  rules:
    - http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: product-api-svc
                port:
                  number: 80

apiVersion: v1
kind: Secret
metadata:
  name: app-secrets
type: Opaque
data:
  MONGO_URI: <base64-encoded-uri>

echo -n "mongodb://user:pass@host:27017/product-api" | base64

apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: product-api-hpa
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: product-api
  minReplicas: 2
  maxReplicas: 10
  metrics:
    - type: Resource
      resource:
        name: cpu
        target:
          type: Utilization
          averageUtilization: 70

kubectl apply -f k8s/

kubectl get pods
kubectl get svc
kubectl get ingress

curl http://<INGRESS-HOST>/api/products