Striking while the iron is hot: I love dokku and I've used it for many years. That said, I thought I'd do something similar but with the goal of supporting k8s manifests

https://github.com/skateco/skate

It's daemonless, multi-host with multi-host networking, service discovery and like I said, allows you to create deployments, cronjobs, and route traffic via ingress resources.

Comes with letsencrypt out of the box.