Without Docker: Your machine → Node 22, Ubuntu, specific libraries Server → Node 18, Alpine, different glibc Colleague's Mac → Node 20, macOS, different everything → "Works on my machine!" 😤 With Docker: Everyone → Same OS, same Node version, same dependencies → Works everywhere! 🎉 Without Docker: Your machine → Node 22, Ubuntu, specific libraries Server → Node 18, Alpine, different glibc Colleague's Mac → Node 20, macOS, different everything → "Works on my machine!" 😤 With Docker: Everyone → Same OS, same Node version, same dependencies → Works everywhere! 🎉 Without Docker: Your machine → Node 22, Ubuntu, specific libraries Server → Node 18, Alpine, different glibc Colleague's Mac → Node 20, macOS, different everything → "Works on my machine!" 😤 With Docker: Everyone → Same OS, same Node version, same dependencies → Works everywhere! 🎉 # Stage 1: Build FROM node:22-alpine AS builder WORKDIR /app # Copy dependency files first (layer caching!) COPY package*.json ./ RUN npm ci # Copy source code COPY . . RUN npm run build # Stage 2: Production (smaller image) FROM node:22-alpine AS runner WORKDIR /app RUN addgroup -g 1001 appuser && \ adduser -u 1001 -G appuser -s /bin/sh -D appuser # Copy built files from builder stage COPY --from=builder --chown=appuser:appuser /app/node_modules ./node_modules COPY --from=builder --chown=appuser:appuser /app/dist ./dist COPY --from=builder --chown=appuser:appuser /app/package.json ./package.json USER appuser EXPOSE 3000 CMD ["node", "dist/server.js"] # Stage 1: Build FROM node:22-alpine AS builder WORKDIR /app # Copy dependency files first (layer caching!) COPY package*.json ./ RUN npm ci # Copy source code COPY . . RUN npm run build # Stage 2: Production (smaller image) FROM node:22-alpine AS runner WORKDIR /app RUN addgroup -g 1001 appuser && \ adduser -u 1001 -G appuser -s /bin/sh -D appuser # Copy built files from builder stage COPY --from=builder --chown=appuser:appuser /app/node_modules ./node_modules COPY --from=builder --chown=appuser:appuser /app/dist ./dist COPY --from=builder --chown=appuser:appuser /app/package.json ./package.json USER appuser EXPOSE 3000 CMD ["node", "dist/server.js"] # Stage 1: Build FROM node:22-alpine AS builder WORKDIR /app # Copy dependency files first (layer caching!) COPY package*.json ./ RUN npm ci # Copy source code COPY . . RUN npm run build # Stage 2: Production (smaller image) FROM node:22-alpine AS runner WORKDIR /app RUN addgroup -g 1001 appuser && \ adduser -u 1001 -G appuser -s /bin/sh -D appuser # Copy built files from builder stage COPY --from=builder --chown=appuser:appuser /app/node_modules ./node_modules COPY --from=builder --chown=appuser:appuser /app/dist ./dist COPY --from=builder --chown=appuser:appuser /app/package.json ./package.json USER appuser EXPOSE 3000 CMD ["node", "dist/server.js"] # ❌ Bad: Single stage = big image with dev tools included FROM node:22 WORKDIR /app COPY . . RUN npm install # Installs ALL deps including devDependencies RUN npm run build CMD ["node", "server.js"] # Image size: ~1.5GB (includes TypeScript, test frameworks, etc.) # ✅ Good: Multi-stage = small production image FROM node:22 AS build # Has dev tools → npm install + build FROM node:22-alpine # Minimal runtime only → COPY --from=build # Only copy what you need # Image size: ~150MB (only runtime + your code) # ❌ Bad: Single stage = big image with dev tools included FROM node:22 WORKDIR /app COPY . . RUN npm install # Installs ALL deps including devDependencies RUN npm run build CMD ["node", "server.js"] # Image size: ~1.5GB (includes TypeScript, test frameworks, etc.) # ✅ Good: Multi-stage = small production image FROM node:22 AS build # Has dev tools → npm install + build FROM node:22-alpine # Minimal runtime only → COPY --from=build # Only copy what you need # Image size: ~150MB (only runtime + your code) # ❌ Bad: Single stage = big image with dev tools included FROM node:22 WORKDIR /app COPY . . RUN npm install # Installs ALL deps including devDependencies RUN npm run build CMD ["node", "server.js"] # Image size: ~1.5GB (includes TypeScript, test frameworks, etc.) # ✅ Good: Multi-stage = small production image FROM node:22 AS build # Has dev tools → npm install + build FROM node:22-alpine # Minimal runtime only → COPY --from=build # Only copy what you need # Image size: ~150MB (only runtime + your code) # Order matters! Docker caches each layer. # ✅ Good order — changes rarely → put first COPY package*.json ./ # Layer 1: Changes when deps change RUN npm ci # Layer 2: Cached if package.json didn't change COPY . . # Layer 3: Changes on every code edit RUN npm run build # Layer 4: Rebuilds only when source changes # ❌ Bad order — invalidates cache too often COPY . . # Changes every time you save a file! RUN npm install # Reinstalls deps every time (slow!) RUN npm run build # Order matters! Docker caches each layer. # ✅ Good order — changes rarely → put first COPY package*.json ./ # Layer 1: Changes when deps change RUN npm ci # Layer 2: Cached if package.json didn't change COPY . . # Layer 3: Changes on every code edit RUN npm run build # Layer 4: Rebuilds only when source changes # ❌ Bad order — invalidates cache too often COPY . . # Changes every time you save a file! RUN npm install # Reinstalls deps every time (slow!) RUN npm run build # Order matters! Docker caches each layer. # ✅ Good order — changes rarely → put first COPY package*.json ./ # Layer 1: Changes when deps change RUN npm ci # Layer 2: Cached if package.json didn't change COPY . . # Layer 3: Changes on every code edit RUN npm run build # Layer 4: Rebuilds only when source changes # ❌ Bad order — invalidates cache too often COPY . . # Changes every time you save a file! RUN npm install # Reinstalls deps every time (slow!) RUN npm run build # Like .gitignore for Docker — reduces context size node_modules npm-debug.log dist .git .env .env.local coverage .vscode .idea *.md Dockerfile* docker-compose* # Like .gitignore for Docker — reduces context size node_modules npm-debug.log dist .git .env .env.local coverage .vscode .idea *.md Dockerfile* docker-compose* # Like .gitignore for Docker — reduces context size node_modules npm-debug.log dist .git .env .env.local coverage .vscode .idea *.md Dockerfile* docker-compose* version: '3.8' services: app: build: context: . dockerfile: Dockerfile.dev ports: - '3000:3000' volumes: # Hot reload: map local files into container - .:/app - /app/node_modules # Use container's node_modules environment: - NODE_ENV=development - DATABASE_URL=postgres://postgres:password@db:5432/myapp - REDIS_URL=redis://redis:6379 depends_on: db: condition: service_healthy redis: condition: service_healthy db: image: postgres:16-alpine environment: POSTGRES_USER: postgres POSTGRES_PASSWORD: password POSTGRES_DB: myapp ports: - '5432:5432' volumes: - pgdata:/var/lib/postgresql/data healthcheck: test: ['CMD-SHELL', 'pg_isready -U postgres'] interval: 5s timeout: 5s retries: 5 redis: image: redis:7-alpine ports: - '6379:6379' volumes: - redisdata:/data healthcheck: test: ['CMD', 'redis-cli', 'ping'] interval: 5s volumes: pgdata: redisdata: version: '3.8' services: app: build: context: . dockerfile: Dockerfile.dev ports: - '3000:3000' volumes: # Hot reload: map local files into container - .:/app - /app/node_modules # Use container's node_modules environment: - NODE_ENV=development - DATABASE_URL=postgres://postgres:password@db:5432/myapp - REDIS_URL=redis://redis:6379 depends_on: db: condition: service_healthy redis: condition: service_healthy db: image: postgres:16-alpine environment: POSTGRES_USER: postgres POSTGRES_PASSWORD: password POSTGRES_DB: myapp ports: - '5432:5432' volumes: - pgdata:/var/lib/postgresql/data healthcheck: test: ['CMD-SHELL', 'pg_isready -U postgres'] interval: 5s timeout: 5s retries: 5 redis: image: redis:7-alpine ports: - '6379:6379' volumes: - redisdata:/data healthcheck: test: ['CMD', 'redis-cli', 'ping'] interval: 5s volumes: pgdata: redisdata: version: '3.8' services: app: build: context: . dockerfile: Dockerfile.dev ports: - '3000:3000' volumes: # Hot reload: map local files into container - .:/app - /app/node_modules # Use container's node_modules environment: - NODE_ENV=development - DATABASE_URL=postgres://postgres:password@db:5432/myapp - REDIS_URL=redis://redis:6379 depends_on: db: condition: service_healthy redis: condition: service_healthy db: image: postgres:16-alpine environment: POSTGRES_USER: postgres POSTGRES_PASSWORD: password POSTGRES_DB: myapp ports: - '5432:5432' volumes: - pgdata:/var/lib/postgresql/data healthcheck: test: ['CMD-SHELL', 'pg_isready -U postgres'] interval: 5s timeout: 5s retries: 5 redis: image: redis:7-alpine ports: - '6379:6379' volumes: - redisdata:/data healthcheck: test: ['CMD', 'redis-cli', 'ping'] interval: 5s volumes: pgdata: redisdata: # Dockerfile.dev — optimized for development FROM node:22-alpine WORKDIR /app # Install dev tools needed for hot reload RUN npm install -g nodemon # Copy deps first (cached layer) COPY package*.json ./ RUN npm ci # Don't copy source here — use volume mount instead EXPOSE 3000 CMD ["nodemon", "--legacy-watch", "server.js"] # --legacy-watch: fixes file watching in mounted volumes # Dockerfile.dev — optimized for development FROM node:22-alpine WORKDIR /app # Install dev tools needed for hot reload RUN npm install -g nodemon # Copy deps first (cached layer) COPY package*.json ./ RUN npm ci # Don't copy source here — use volume mount instead EXPOSE 3000 CMD ["nodemon", "--legacy-watch", "server.js"] # --legacy-watch: fixes file watching in mounted volumes # Dockerfile.dev — optimized for development FROM node:22-alpine WORKDIR /app # Install dev tools needed for hot reload RUN npm install -g nodemon # Copy deps first (cached layer) COPY package*.json ./ RUN npm ci # Don't copy source here — use volume mount instead EXPOSE 3000 CMD ["nodemon", "--legacy-watch", "server.js"] # --legacy-watch: fixes file watching in mounted volumes # Build and run docker-compose up --build # Build + start all services docker-compose up -d # Start in background docker-compose down # Stop and remove containers docker-compose logs -f app # Follow app logs docker-compose exec app sh # Shell into container docker-compose exec db psql -U postgres # Connect to Postgres # One-off commands docker-compose exec app npm run migrate docker-compose exec app npm run seed docker-compose exec app npx jest # Cleanup (when things get weird) docker system prune -a # Remove unused images/containers/volumes docker compose down -v # Remove volumes too (resets DB!) # Debug container docker run -it --rm myimage sh # Interactive shell docker logs <container_id> # View logs docker stats # Resource usage of running containers # Build and run docker-compose up --build # Build + start all services docker-compose up -d # Start in background docker-compose down # Stop and remove containers docker-compose logs -f app # Follow app logs docker-compose exec app sh # Shell into container docker-compose exec db psql -U postgres # Connect to Postgres # One-off commands docker-compose exec app npm run migrate docker-compose exec app npm run seed docker-compose exec app npx jest # Cleanup (when things get weird) docker system prune -a # Remove unused images/containers/volumes docker compose down -v # Remove volumes too (resets DB!) # Debug container docker run -it --rm myimage sh # Interactive shell docker logs <container_id> # View logs docker stats # Resource usage of running containers # Build and run docker-compose up --build # Build + start all services docker-compose up -d # Start in background docker-compose down # Stop and remove containers docker-compose logs -f app # Follow app logs docker-compose exec app sh # Shell into container docker-compose exec db psql -U postgres # Connect to Postgres # One-off commands docker-compose exec app npm run migrate docker-compose exec app npm run seed docker-compose exec app npx jest # Cleanup (when things get weird) docker system prune -a # Remove unused images/containers/volumes docker compose down -v # Remove volumes too (resets DB!) # Debug container docker run -it --rm myimage sh # Interactive shell docker logs <container_id> # View logs docker stats # Resource usage of running containers # Production optimizations FROM node:22-alpine # Security: Run as non-root user RUN addgroup -g 1001 app && \ adduser -u 1001 -G app -s /bin/sh -D app # Health check HEALTHCHECK --interval=30s --timeout=3s \ CMD wget --no-verbose --tries=1 --spider http://localhost:3000/health || exit 1 # Set Node to production mode ENV NODE_ENV=production # Optimize Node.js memory ENV NODE_OPTIONS="--max-old-space-size=512" WORKDIR /app COPY --from=builder --chown=app:app ./dist ./dist COPY --from=builder --chown=app:app ./node_modules ./node_modules COPY --from=builder --chown=app:app ./package.json ./package.json USER app EXPOSE 3000 # Graceful shutdown STOPSIGNAL SIGTERM CMD ["node", "dist/server.js"] # Production optimizations FROM node:22-alpine # Security: Run as non-root user RUN addgroup -g 1001 app && \ adduser -u 1001 -G app -s /bin/sh -D app # Health check HEALTHCHECK --interval=30s --timeout=3s \ CMD wget --no-verbose --tries=1 --spider http://localhost:3000/health || exit 1 # Set Node to production mode ENV NODE_ENV=production # Optimize Node.js memory ENV NODE_OPTIONS="--max-old-space-size=512" WORKDIR /app COPY --from=builder --chown=app:app ./dist ./dist COPY --from=builder --chown=app:app ./node_modules ./node_modules COPY --from=builder --chown=app:app ./package.json ./package.json USER app EXPOSE 3000 # Graceful shutdown STOPSIGNAL SIGTERM CMD ["node", "dist/server.js"] # Production optimizations FROM node:22-alpine # Security: Run as non-root user RUN addgroup -g 1001 app && \ adduser -u 1001 -G app -s /bin/sh -D app # Health check HEALTHCHECK --interval=30s --timeout=3s \ CMD wget --no-verbose --tries=1 --spider http://localhost:3000/health || exit 1 # Set Node to production mode ENV NODE_ENV=production # Optimize Node.js memory ENV NODE_OPTIONS="--max-old-space-size=512" WORKDIR /app COPY --from=builder --chown=app:app ./dist ./dist COPY --from=builder --chown=app:app ./node_modules ./node_modules COPY --from=builder --chown=app:app ./package.json ./package.json USER app EXPOSE 3000 # Graceful shutdown STOPSIGNAL SIGTERM CMD ["node", "dist/server.js"]