Does anybody have an example of oathkeeper rules for use with kubernetes? I’m curious on how to set the upstream properly

My solution for the same is relatively simple although it may not be a valid answer from your perspective given different use cases. I decided on using Oathkeeper as a purely Decision API clubbing it with Ambassador's Emissary Ingress which has a feature to setup AuthService.

That sounds totally acceptable to me. Is that something you’re hosting yourself or are you using a cloud service?

Self hosting :)