Ground rules as in “you have to compile with 100s of these google3 libraries to run a simple app”?

I don't think that's really true at all. You can pretty easily run any damned thing in Borg. If you want it to do stuff with other Google services then you need a lot of Google code, but if you just want to run 100000 replicas of `/bin/sleep 100000`, Borg makes it easy.

Sure but none of the stuff like authentication and access to any google systems will work. Kubernetes is complex bc it can take damn near any docker container and it can run seamlessly

Because from what I heard, all the other crucial to me benefits of k8s are provided through linking of lots and lots of Google internal libraries?