using haproxy instead

[imacks]

I would like to use haproxy in rancher instead of nginx, so instead of mapping container to host ports directly in compose, I expose the container ports internally, and then I can use haproxy to map the ports on a per-domain basis.

I also run letsencrypt and haproxy uses the cert generated exclusively. so I would prefer to get rid of nginx altogether and not let any mailu container have access to the cert private keys.

is what I described here doable?