This is part of the transition to using framework/log instead
of the Logf inside the framework package. This will help with
import size/cycles when importing the framework or subpackages.
* merge pkg/api/v1/node with pkg/util/node
* update test case for utilnode
* remove package pkg/api/v1/node
* move isNodeReady to internal func
* Split GetNodeCondition into e2e and controller pkg
* fix import errors
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
