18.2 Docker + TypeScript — Multi-Stage Builds and Production Optimization

Basic Dockerfile

# Dockerfile

# ===== Build Stage =====
FROM node:20-alpine AS builder

WORKDIR /app

# Copy dependencies first (leverage cache)
COPY package*.json ./
COPY tsconfig*.json ./

# Install all dependencies (production + dev required for build)
RUN npm ci

# Copy source and build
COPY src ./src
RUN npm run build

# ===== Dependencies Stage =====
FROM node:20-alpine AS dependencies

WORKDIR /app
COPY package*.json ./

# Install production dependencies only
RUN npm ci --only=production && npm cache clean --force

# ===== Production Stage =====
FROM node:20-alpine AS production

# Security: run as non-root user
RUN addgroup -g 1001 -S nodejs && \
    adduser -S nestjs -u 1001

WORKDIR /app

# Copy build output
COPY --from=builder --chown=nestjs:nodejs /app/dist ./dist

# Copy production dependencies only
COPY --from=dependencies --chown=nestjs:nodejs /app/node_modules ./node_modules

# Required config files
COPY --chown=nestjs:nodejs package.json ./

USER nestjs

# Expose port
EXPOSE 3000

# Health check
HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
  CMD wget -qO- http://localhost:3000/health || exit 1

CMD ["node", "dist/main.js"]

---

.dockerignore

# .dockerignore
node_modules
dist
build
.git
.gitignore
*.md
*.log
.env
.env.*
coverage
.nyc_output
.DS_Store
Thumbs.db

# Test files
**/*.test.ts
**/*.spec.ts
**/*.test.js
e2e/

---

docker-compose.yml

# docker-compose.yml
version: '3.8'

services:
  app:
    build:
      context: .
      dockerfile: Dockerfile
      target: production
    ports:
      - '3000:3000'
    environment:
      NODE_ENV: production
      DATABASE_URL: postgresql://postgres:password@db:5432/myapp
      JWT_SECRET: ${JWT_SECRET}
      REDIS_URL: redis://redis:6379
    depends_on:
      db:
        condition: service_healthy
      redis:
        condition: service_started
    restart: unless-stopped

  db:
    image: postgres:16-alpine
    environment:
      POSTGRES_DB: myapp
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: password
    volumes:
      - postgres_data:/var/lib/postgresql/data
    healthcheck:
      test: ['CMD-SHELL', 'pg_isready -U postgres']
      interval: 10s
      timeout: 5s
      retries: 5

  redis:
    image: redis:7-alpine
    volumes:
      - redis_data:/data

  # Development environment only
  app-dev:
    build:
      context: .
      target: builder  # Use build stage
    command: npm run start:dev
    volumes:
      - .:/app
      - /app/node_modules  # Preserve container node_modules
    ports:
      - '3000:3000'
      - '9229:9229'  # Debugger port
    environment:
      NODE_ENV: development
    profiles:
      - dev

volumes:
  postgres_data:
  redis_data:

---

tsconfig.json Build Optimization

// tsconfig.json — base configuration
{
  "compilerOptions": {
    "target": "ES2022",
    "module": "commonjs",
    "lib": ["ES2022"],
    "outDir": "./dist",
    "rootDir": "./src",
    "strict": true,
    "esModuleInterop": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true,
    "declarationMap": false,
    "sourceMap": false
  },
  "include": ["src/**/*"],
  "exclude": ["node_modules", "dist", "**/*.test.ts", "**/*.spec.ts"]
}

// tsconfig.build.json — production build only
{
  "extends": "./tsconfig.json",
  "compilerOptions": {
    "sourceMap": false,
    "declaration": false,
    "removeComments": true,
    "noEmit": false
  },
  "exclude": [
    "node_modules",
    "dist",
    "test",
    "**/*spec.ts",
    "**/*test.ts"
  ]
}

---

GitHub Actions CI/CD

# .github/workflows/deploy.yml
name: Build and Deploy

on:
  push:
    branches: [main]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: '20'
          cache: 'npm'
      - run: npm ci
      - run: npm run typecheck     # tsc --noEmit
      - run: npm run lint
      - run: npm run test:ci

  build-and-push:
    needs: test
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Build Docker image
        run: |
          docker build \
            --target production \
            -t my-app:${{ github.sha }} \
            -t my-app:latest \
            .

      - name: Push to registry
        run: |
          echo ${{ secrets.REGISTRY_PASSWORD }} | docker login -u ${{ secrets.REGISTRY_USERNAME }} --password-stdin
          docker push my-app:${{ github.sha }}
          docker push my-app:latest

  deploy:
    needs: build-and-push
    runs-on: ubuntu-latest
    steps:
      - name: Apply Prisma migrations
        run: |
          docker run --rm \
            -e DATABASE_URL=${{ secrets.DATABASE_URL }} \
            my-app:${{ github.sha }} \
            npx prisma migrate deploy

      - name: Deploy to production
        run: |
          # Run deployment script
          echo "Deploying version ${{ github.sha }}"

---

Pro Tips

Node.js Process Signal Handling

// src/main.ts
async function bootstrap() {
  const app = await NestFactory.create(AppModule)
  await app.listen(process.env.PORT ?? 3000)

  // Graceful Shutdown
  const signals: NodeJS.Signals[] = ['SIGTERM', 'SIGINT']

  signals.forEach(signal => {
    process.on(signal, async () => {
      console.log(`${signal} received, shutting down gracefully...`)
      await app.close()
      process.exit(0)
    })
  })
}

bootstrap()