I would not under any circumstances describe traefik as a “better” tool than nginx or haproxy - particularly for a single host. It trades away at least a decade worth of hardening and optimizing for a mildly easier configuration format, and even that is subjective. Nor should anyone advocate using docker-compose for serious deployments.
Both nginx/haproxy would serve well at splitting one port number to two applications by some combination of host name and/or path, and will otherwise stay out of your way very well. It’s still trivial to automate LetsEncrypt with either one. I would ultimately still aim for @lpil’s suggestion of keeping to a single deployment if possible, though, and you’ll find Cowboy very capable in its own right.
