At this point I consider myself pretty knowledgeable on Kubernetes.

I bought Kubernetes Up & Running a year ago, I was disappointed to see it is a very over-the-top view, without getting into details.

I skimmed over Kubernetes in Action a couple months ago. Nothing really catched my eye either.

The last one I read was Kubernetes Security by Liz Rize. Either there's not that much to securing Kubernetes or the book is very introductory too.

The only parts of K8s I don't know a lot about are storage (haven't got past the NFS driver yet), CRDs and distributions like OpenShift. But in the same way I'm lacking storage expertise outside of Kubernetes.