The Reverse proxy role is to handle the customer facing : SSL, load balancing, page caching, etc... Traefik is a reverse proxy light, fast and reliable. Here is the documentation for Traefik: https://doc.traefik.io/traefik/
- The proxy is facing the customer and providing the SSL support in front of Dolibarr.
- The mysql server is isolated from the internet.
- Dolibarr needs internet access for some feature (mail, update checks, SIRET checks, etc..)