Authorization and Policies

Here are some thoughts on how to make authorization pluggable, and how to express authorization policy.
Maybe a less cardiac-challenging example would be a cluster dashboard app which:
  - runs in a pod, 
  - authenticates itself with the kubernetes API (using its own service account)
  - sends GET requests to kubernetes API to check the status of pods, etc.
  - we trust that its code is noy malicious, but it might have bugs.
  - because it makes requests at a high rate, we don't want to pollute the audit log with them
  - to prevent a bug in the dashboard from doing too much damage, we should still do an authorization check on its accesses (allow reads but not writes).