Automatic merge from submit-queue (batch tested with PRs 50303, 50856)
Make route-controller list only relevant routes instead of all of them
Ref https://github.com/kubernetes/kubernetes/issues/50854 (somewhat related issue)
IIUC from the code, route-controller memory is mainly being used in storing routes and nodes (also CIDRs, but that's not much).
This should help reduce that memory usage (particularly when running in a project with large no. of routes), by moving filtering to server-side.
For e.g in kubernetes-scale project we have ~5000 routes (each about 600B) => 3 MB of routes
This doesn't help with reducing time to list the routes as filtering is also linear.
cc @kubernetes/sig-scalability-misc @wojtek-t @gmarek
4e4168121a