* Rename const for topology.../zone
* Rename const for topology.../region
* Rename const for failure-domain.../zone
* Rename const for failure-domain.../region
* Restore old names for compat
When kubelet is restarted, it will now remove the resources for huge
page sizes no longer supported. This is required when:
- node disables huge pages
- changing the default huge page size in older versions of linux
(because it will then only support the newly set default).
- Software updates that change what sizes are supported (eg. by changing
boot parameters).
When node lease feature is enabled, kubelet reports node status to api server
only if there is some change or it didn't report over last report interval.
This extends the Kubelet to create and periodically update leases in a
new kube-node-lease namespace. Based on [KEP-0009](https://github.com/kubernetes/community/blob/master/keps/sig-node/0009-node-heartbeat.md),
these leases can be used as a node health signal, and will allow us to
reduce the load caused by over-frequent node status reporting.
- add NodeLease feature gate
- add kube-node-lease system namespace for node leases
- add Kubelet option for lease duration
- add Kubelet-internal lease controller to create and update lease
- add e2e test for NodeLease feature
- modify node authorizer and node restriction admission controller
to allow Kubelets access to corresponding leases
Automatic merge from submit-queue (batch tested with PRs 66152, 66406, 66218, 66278, 65660). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Refactor kubelet node status setters, add test coverage
This internal refactor moves the node status setters to a new package, explicitly injects dependencies to facilitate unit testing, and adds individual unit tests for the setters.
I gave each setter a distinct commit to facilitate review.
Non-goals:
- I intentionally excluded the class of setters that return a "modified" boolean, as I want to think more carefully about how to cleanly handle the behavior, and this PR is already rather large.
- I would like to clean up the status update control loops as well, but that belongs in a separate PR.
```release-note
NONE
```
