Docker and Caddy: Zero-Config Automated HTTPS for Devs.Surf

While Nginx has been the traditional workhorse for reverse proxies, Caddy has emerged as the developer favorite due to one killer feature: automatic HTTPS by default. Caddy provisions, renews, and staples OCSP certificates out of the box without Certbot or cron jobs.

Step 1: Point Your Subdomain to Server IP

In your Devs.Surf DNS Manager, add an A Record pointing to your server's public IP address:

• Type: A
• Name: @
• Content: YOUR_SERVER_PUBLIC_IP
• TTL: 3600

Step 2: Docker Compose Setup

Here is a complete, production-ready docker-compose.yml file pairing Caddy with a backend container:

version: "3.8"

services:
  caddy:
    image: caddy:2-alpine
    restart: unless-stopped
    ports:
      - "80:80"
      - "443:443"
      - "443:443/udp" # HTTP/3 QUIC
    volumes:
      - ./Caddyfile:/etc/caddy/Caddyfile:ro
      - caddy_data:/data
      - caddy_config:/config

  app:
    image: node:20-alpine
    command: sh -c "npx serve -s /app -l 3000"
    volumes:
      - ./dist:/app:ro
    expose:
      - "3000"

volumes:
  caddy_data:
  caddy_config:

Step 3: The 3-Line Caddyfile

Create a file named Caddyfile in the same folder:

myproject.devs.surf {
    reverse_proxy app:3000
}

Step 4: Launch and Observe

Run docker compose up -d. Caddy immediately requests a TLS certificate from Let's Encrypt for myproject.devs.surf. In under 15 seconds, your application is live over HTTPS with HTTP/3 support.