Docker and Kubernetes for Web Developers: 2026 Guide

# Multi-stage build for Node.js application
FROM node:20-alpine AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci --only=production

FROM node:20-alpine AS runner
WORKDIR /app
COPY --from=builder /app/node_modules ./node_modules
COPY . .
EXPOSE 3000
CMD ["node", "server.js"]

apiVersion: apps/v1
kind: Deployment
metadata:
  name: web-app
spec:
  replicas: 3
  selector:
    matchLabels:
      app: web-app
  template:
    spec:
      containers:
      - name: web-app
        image: myapp:latest
        ports:
        - containerPort: 3000