Show HN: Automated Let's Encrypt Certificate Provisioning in Kubernetes

Great stuff! I actually just finished a long session of reading through many of the docs & source for Ingress Controllers and kube-lego.

One piece I still don't quite get is why the Ingress Controller requires a default backend/404-server at all.

Could you please elaborate on why default backends are needed in general for nginx Ingress Controllers? It almost seems a bit extraneous to have another webserver just serving a 404 at / and a 200 at /healthz, especially if I'm defining specific Ingresses and their associated Services which could handle their own versions of those paths.