Traefik forward auth to backend

I have searched through the docs, the github issues, and here for any reference to this and haven't been able to find anything yet. I would like to forward auth to a backend instead of a specific address.

The advantages are hopefully somewhat obvious since they are goodness of traefik, but to list a couple:

  • I don't need to restrict what my container name/hostname is set to on my auth backend (since it runs in docker)
  • I get all of the goodness of scaling and backend routing with traefik instead of relying on a single container that may go down for various reasons (upgrades being one of them)
  • I can now scale my auth containers up dynamically based on request volume, etc.

The only way I see to do it currently is to pass off auth requests to another traefik running in front of the auth service only. This seems ... not great ... to me, but I'm honestly just hoping I'm missing something simple in the setup that would allow me to do this.