Traefik is amazing - you can add it as a service with almost no config and get http2, https (with good defaults), letsencrypt and auto-discovery of services

I also use it as a frontend to all local dev

Does it support more advanced forms of authentication than http basic?

Digest. But you probably want to be doing auth on whatever Traefik is pointing at

What was the reasoning of traefik vs haproxy?

Traefik was written before haproxy had hot reloading configuration in 1.7

It does one thing and does it well - auto configured and discoverable lb and proxying designed to run in container environments

Easy to get running, easy to know everything it can do and without much effort it gets a lot accomplished

Not that nginx and HAProxy still don't have their place, but if you want to front a docker swarm or k8 stack traefik is just easy whereas nginx/haproxy have to be configured for that task

Haven't used traefik but HAProxy doesn't have HTTP/2 support yet.