Docker for VPS Deployments: The Developer's Playbook

# Install Docker on Ubuntu/Debian
curl -fsSL https://get.docker.com | sh

# Add your user to the docker group
sudo usermod -aG docker $USER

# Install Docker Compose v2
sudo apt install docker-compose-plugin -y

# Verify installation
docker --version
docker compose version

# Use specific version tags, never :latest
FROM node:20-alpine AS builder

WORKDIR /app

# Copy dependency files first (cache layer)
COPY package.json package-lock.json ./
RUN npm ci --production=false

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

# Production stage - minimal image
FROM node:20-alpine
WORKDIR /app

# Don't run as root
RUN addgroup --system app && adduser --system --group app

COPY --from=builder /app/dist ./dist
COPY --from=builder /app/node_modules ./node_modules
COPY --from=builder /app/package.json ./

USER app
EXPOSE 3000

HEALTHCHECK --interval=30s --timeout=3s --retries=3 \
  CMD wget --no-verbose --tries=1 --spider http://localhost:3000/health || exit 1

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

# docker-compose.yml
version: "3.8"

services:
  app:
    build: .
    restart: unless-stopped
    environment:
      - NODE_ENV=production
      - DATABASE_URL=postgresql://user:pass@db:5432/myapp
    depends_on:
      db:
        condition: service_healthy
    networks:
      - app-network

  db:
    image: postgres:16-alpine
    restart: unless-stopped
    environment:
      - POSTGRES_USER=user
      - POSTGRES_PASSWORD=securepassword
      - POSTGRES_DB=myapp
    volumes:
      - postgres_data:/var/lib/postgresql/data
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U user -d myapp"]
      interval: 10s
      timeout: 5s
      retries: 5
    networks:
      - app-network

  redis:
    image: redis:7-alpine
    restart: unless-stopped
    command: redis-server --maxmemory 256mb --maxmemory-policy allkeys-lru
    volumes:
      - redis_data:/data
    networks:
      - app-network

volumes:
  postgres_data:
  redis_data:

networks:
  app-network:

# Add to docker-compose.yml
  nginx:
    image: nginx:alpine
    restart: unless-stopped
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - ./nginx.conf:/etc/nginx/conf.d/default.conf:ro
      - ./certbot/conf:/etc/letsencrypt:ro
      - ./certbot/www:/var/www/certbot:ro
    depends_on:
      - app
    networks:
      - app-network

  certbot:
    image: certbot/certbot
    volumes:
      - ./certbot/conf:/etc/letsencrypt
      - ./certbot/www:/var/www/certbot
    entrypoint: "/bin/sh -c 'trap exit TERM; while :; do certbot renew; sleep 12h & wait ${!}; done;'"

# nginx.conf
server {
    listen 80;
    server_name yourdomain.com;
    
    location /.well-known/acme-challenge/ {
        root /var/www/certbot;
    }
    
    location / {
        return 301 https://$host$request_uri;
    }
}

server {
    listen 443 ssl;
    server_name yourdomain.com;
    
    ssl_certificate /etc/letsencrypt/live/yourdomain.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/yourdomain.com/privkey.pem;
    
    location / {
        proxy_pass http://app:3000;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}

#!/bin/bash
# deploy.sh - Zero-downtime deployment script
set -e

echo "Pulling latest code..."
git pull origin main

echo "Building new image..."
docker compose build app

echo "Rolling update..."
docker compose up -d --no-deps app

echo "Waiting for health check..."
sleep 10

if docker compose ps app | grep -q "healthy"; then
  echo "Deployment successful!"
  docker image prune -f
else
  echo "Health check failed! Rolling back..."
  docker compose rollback app
  exit 1
fi

# View logs for all services
docker compose logs -f

# View logs for a specific service
docker compose logs -f app --tail 100

# Check resource usage
docker stats

# Set up log rotation
# Add to docker-compose.yml under each service:
#   logging:
#     driver: "json-file"
#     options:
#       max-size: "10m"
#       max-file: "3"