- Added a new command line argument `--interactive` to kubectl. The new command line argument lets a user confirm deletion requests per resource interactively. ([#114530](https://github.com/kubernetes/kubernetes/pull/114530), [@ardaguclu](https://github.com/ardaguclu)) [SIG CLI and Testing]

    * clusters. When that var is set to true, the command line flag enabling kubelet
    * client certificate rotation will be added to the kubelet command line.
* Make sure that resources being updated are handled correctly by Quota system ([#52452](https://github.com/kubernetes/kubernetes/pull/52452), [@gnufied](https://github.com/gnufied))

- A kubelet parameter and config option has been added to change the CFS quota period from the default 100ms to some other value between 1µs and 1s. This was done to improve response latencies for workloads running in clusters with guaranteed and burstable QoS classes. ([#63437](https://github.com/kubernetes/kubernetes/pull/63437), [@szuecs](https://github.com/szuecs)) Courtesy of SIG API Machinery, SIG Apps,...

#### kubelet:
- `--enable-cadvisor-json-endpoints` is now disabled by default. If you need access to the cAdvisor v1 Json API please enable it explicitly in the kubelet command line. Please note that this flag was deprecated in 1.15 and will be removed in 1.19. ([#87440](https://github.com/kubernetes/kubernetes/pull/87440), [@dims](https://github.com/dims)) [SIG Instrumentation, Node and Testing]

- A new `--prefix` flag added into kubectl logs which prepends each log line with information about it's source (pod name and container name) ([#76471](https://github.com/kubernetes/kubernetes/pull/76471), [@m1kola](https://github.com/m1kola))

## API Changes

work-in-progress for removing the in-tree provider. This work, being done in conjunction with SIG Cloud Provider, is focusing on moving internal APIs that the OpenStack (and other providers) depends upon to staging to guarantee API stability. This work also included abstracting the in-tree Cinder API and refactoring code to the external Cinder provider to remove additional Cinder volume provider code.

Additional work was also done to implement an OpenStack driver for the Cluster API effort lead...

* fixes an issue with multi-line annotations injected via downward API files getting scrambled ([#65992](https://github.com/kubernetes/kubernetes/pull/65992), [@liggitt](https://github.com/liggitt))

     * Dynamic Configuration (ConfigMap API in the core API group) enables application
configuration to be stored as a Kubernetes API object and pulled dynamically on
container startup, as an alternative to baking in command-line flags when a
container is built.
     * Turnkey Deployments (Deployment API (Beta) in the Extensions API group)
automate deployment and rolling updates of applications, specified

* [Breaking change, client-go]: The WaitFor function returns, probably an ErrWaitTimeout, when the done channel is closed, even if the `WaitFunc` doesn't handle the done channel. ([#72364](https://github.com/kubernetes/kubernetes/pull/72364), [@kdada](https://github.com/kdada))

- The `kube-proxy` command-line documentation was updated to clarify that
  `--bind-address` does not actually have anything to do with binding to an