Guide Docker, Nginx as a Reverse Proxy & Let's Encrypt for multiple websites

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In this guide I'll show you how to set up a reverse proxy using Nginx in Docker and automatic .conf and SSLs generated by Let's encrypt.

• jwilder/nginx-proxy – for auto-detecting services via Docker labels
• jrcs/letsencrypt-nginx-proxy-companion – for automatic SSL cert issuing & renewal

1. Create external Docker network​

docker network create nginx-proxy

2. Setup Nginx Proxy & Let's Encrypt Companion​

Save this as /opt/stacks/nginx-proxy/docker-compose.yml:

#version: '3'

services:
  nginx-proxy:
    image: jwilder/nginx-proxy:alpine
    container_name: nginx-proxy
    restart: always

    ports:
      - "80:80"
      - "443:443"

    volumes:
      - /var/run/docker.sock:/tmp/docker.sock:ro
      - nginx-conf:/etc/nginx/conf.d
      - nginx-vhost:/etc/nginx/vhost.d
      - html:/usr/share/nginx/html
      - certs:/etc/nginx/certs:ro

    networks:
      - nginx-proxy

  letsencrypt:
    image: jrcs/letsencrypt-nginx-proxy-companion
    container_name: letsencrypt
    restart: always
    environment:
      - NGINX_PROXY_CONTAINER=nginx-proxy

    volumes:
      - /var/run/docker.sock:/var/run/docker.sock:ro
      - nginx-conf:/etc/nginx/conf.d
      - nginx-vhost:/etc/nginx/vhost.d
      - html:/usr/share/nginx/html
      - certs:/etc/nginx/certs:rw

    depends_on:
      - nginx-proxy

    networks:
      - nginx-proxy

volumes:
  nginx-conf:
  nginx-vhost:
  html:
  certs:

networks:
  nginx-proxy:
    external: true

3. Launch the proxy stack​

cd /opt/stacks/nginx-proxy
docker compose up -d

4. Deploy a service (example: Flowise)​

Save this as /opt/stacks/flowise/docker-compose.yml:

#version: '3'
services:
  flowise:
    image: flowiseai/flowise
    container_name: flowise
    restart: always
    environment:
      - VIRTUAL_HOST=sub.domain.com
      - VIRTUAL_PORT=3000
      - LETSENCRYPT_HOST=sub.domain.com
      - [email protected]
    expose:
      - "3000"
    networks:
      - nginx-proxy

networks:
  nginx-proxy:
    external: true

5. Launch the service​

cd /opt/stacks/flowise
docker compose up -d

6. Repeat for other services​

Each service needs:

• To join the nginx-proxy external network
• VIRTUAL_HOST, LETSENCRYPT_HOST, LETSENCRYPT_EMAIL variables
• expose instead of ports unless you need local dev access

7. Done!​

Let’s Encrypt will auto-issue the certificate via HTTP-01 challenge. No manual certbot steps needed. HTTP is redirected to HTTPS automatically.

Troubleshooting​

• Use docker logs <container> to inspect problems
• Make sure domain DNS is pointing to your server before launching the service
• Certificates are stored in /etc/nginx/certs inside the proxy container