Automatic merge from submit-queue (batch tested with PRs 41814, 41922, 41957, 41406, 41077)
add kubectl can-i to see if you can perform an action
Adds `kubectl auth can-i <verb> <resource> [<name>]` so that a user can see if they are allowed to perform an action.
@kubernetes/sig-cli-pr-reviews @fabianofranz
This particular command satisfies the immediate need of knowing if you can perform an action without trying that action. When using RBAC in a script that is adding permissions, there is a lag between adding the permission and the permission being realized in the RBAC cache. As a user on the CLI, you almost never see it, but as a script adding a binding and then using that new power, you hit it quite often.
There are natural follow-ons to the same area (hence the `auth` subcommand) to figure out if someone else can perform an action, what actions you can perform in total, and who can perform a given action. Someone else is an API we have already, what-can-i-do was a proposed API a while back and a very useful one for interfaces, and who-can is common question if someone is administering a namespace.
a1490926d6