docker-deployment

# Build stage
FROM node:18-alpine AS builder
 
WORKDIR /app
 
COPY package*.json ./
RUN npm ci --only=production
 
COPY . .
 
# Production stage
FROM node:18-alpine
 
WORKDIR /app
 
# Copy from builder
COPY --from=builder /app/node_modules ./node_modules
COPY --from=builder /app .
 
# Create non-root user
RUN addgroup -g 1001 -S nodejs && \
    adduser -S nodejs -u 1001
 
USER nodejs
 
EXPOSE 3000
 
HEALTHCHECK --interval=30s --timeout=3s \
  CMD node healthcheck.js || exit 1
 
CMD ["node", "src/index.js"]

# docker-compose.yml
version: '3.8'
 
services:
  app:
    build: .
    ports:
      - "3000:3000"
    environment:
      - NODE_ENV=production
      - DATABASE_URL=postgresql://db:5432/myapp
      - REDIS_URL=redis://redis:6379
    depends_on:
      - db
      - redis
    restart: unless-stopped
 
  db:
    image: postgres:15-alpine
    environment:
      - POSTGRES_USER=myapp
      - POSTGRES_PASSWORD=secret
      - POSTGRES_DB=myapp
    volumes:
      - postgres-data:/var/lib/postgresql/data
 
  redis:
    image: redis:7-alpine
    volumes:
      - redis-data:/data
 
  nginx:
    image: nginx:alpine
    ports:
      - "80:80"
    volumes:
      - ./nginx.conf:/etc/nginx/nginx.conf:ro
    depends_on:
      - app
 
volumes:
  postgres-data:
  redis-data:

# Start services
docker-compose up -d
 
# View logs
docker-compose logs -f app
 
# Stop services
docker-compose down
 
# Rebuild images
docker-compose up -d --build
 
# Scale services
docker-compose up -d --scale app=3

node_modules
npm-debug.log
.git
.gitignore
.env
.env.local
.vscode
*.md
tests
coverage
.github
Dockerfile
docker-compose.yml

# Build image
docker build -t myapp:latest .
 
# Run container
docker run -d -p 3000:3000 --name myapp myapp:latest
 
# View logs
docker logs -f myapp
 
# Enter container
docker exec -it myapp sh
 
# Stop container
docker stop myapp
 
# Remove container
docker rm myapp
 
# List images
docker images
 
# Remove image
docker rmi myapp:latest
 
# Prune unused resources
docker system prune -a

# In Dockerfile
ENV NODE_ENV=production
ENV PORT=3000
 
# Or in docker-compose.yml
environment:
  - NODE_ENV=production
  - PORT=3000
 
# Or from .env file
env_file:
  - .env.production

services:
  app:
    volumes:
      - ./logs:/app/logs              # Bind mount
      - node_modules:/app/node_modules # Named volume
 
volumes:
  node_modules:

# In Dockerfile
HEALTHCHECK --interval=30s --timeout=3s --start-period=5s \
  CMD node healthcheck.js || exit 1

// healthcheck.js
const http = require('http');
 
const options = {
  host: 'localhost',
  port: 3000,
  path: '/health',
  timeout: 2000
};
 
const request = http.request(options, (res) => {
  console.log(`STATUS: ${res.statusCode}`);
  process.exit(res.statusCode === 200 ? 0 : 1);
});
 
request.on('error', (err) => {
  console.log('ERROR:', err);
  process.exit(1);
});
 
request.end();

# Use Alpine (smaller base image)
FROM node:18-alpine  # 180MB vs node:18 (1GB)
 
# Multi-stage build (remove build dependencies)
# Use .dockerignore (exclude unnecessary files)
# npm ci instead of npm install (faster, deterministic)
# Only production dependencies
RUN npm ci --only=production
 
# Combine RUN commands (fewer layers)
RUN apk add --no-cache git && \
    npm ci && \
    apk del git

FROM node:18-alpine
 
# Don't run as root
RUN addgroup -g 1001 -S nodejs && \
    adduser -S nodejs -u 1001
 
WORKDIR /app
 
COPY --chown=nodejs:nodejs package*.json ./
RUN npm ci --only=production
 
COPY --chown=nodejs:nodejs . .
 
USER nodejs
 
# Health check
HEALTHCHECK CMD node healthcheck.js || exit 1
 
# Use node instead of npm start (better signal handling)
CMD ["node", "src/index.js"]

# Login
docker login
 
# Tag image
docker tag myapp:latest username/myapp:1.0.0
docker tag myapp:latest username/myapp:latest
 
# Push to Docker Hub
docker push username/myapp:1.0.0
docker push username/myapp:latest
 
# Pull from Docker Hub
docker pull username/myapp:latest

name: Docker Build & Deploy
 
on:
  push:
    branches: [main]
 
jobs:
  build:
    runs-on: ubuntu-latest
 
    steps:
      - uses: actions/checkout@v3
 
      - uses: docker/setup-buildx-action@v2
 
      - uses: docker/login-action@v2
        with:
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_PASSWORD }}
 
      - uses: docker/build-push-action@v4
        with:
          push: true
          tags: username/myapp:latest
          cache-from: type=gha
          cache-to: type=gha,mode=max

# Cache node_modules layer
COPY package*.json ./
RUN npm ci
COPY . .  # This doesn't rebuild node_modules

# Use node directly (not npm)
CMD ["node", "src/index.js"]
 
# In app: Handle SIGTERM
process.on('SIGTERM', () => {
  server.close(() => process.exit(0));
});