## 0.51.0

* Re-export utils from Starlette:
    * This allows using things like `from fastapi.responses import JSONResponse` instead of `from starlette.responses import JSONResponse`.
    * It's mainly syntax sugar, a convenience for developer experience.

* etcd2: watching from 0 returns all initial states as ADDED events ([#38079](https://github.com/kubernetes/kubernetes/pull/38079), [@hongchao...

- API
  - Ingress resources will no longer be served from `extensions/v1beta1` in v1.19. Migrate use to the `networking.k8s.io/v1beta1` API, available since v1.14. Existing persisted data can be retrieved via the `networking.k8s.io/v1beta1` API.

- Upon receiving a LIST request with an expired continue token, the apiserver now returns a continue token together with the 410 "the from parameter is too old" error. If the client does not care about getting a list from a consistent snapshot, the client can use this token to continue listing from the next key, but the returned chunk will be from the latest snapshot. ([#67284](https://github.com/kubernetes/kubernetes/pull/67284), [@caesarxuchao](https://github.com/caesarxuchao))

message ConfigMapEnvSource {
  // The ConfigMap to select from.
  optional LocalObjectReference localObjectReference = 1;

  // Specify whether the ConfigMap must be defined
  // +optional
  optional bool optional = 2;
}

// Selects a key from a ConfigMap.
// +structType=atomic
message ConfigMapKeySelector {
  // The ConfigMap to select from.
  optional LocalObjectReference localObjectReference = 1;

    * cAdvisor metrics can now be scraped from `/metrics/cadvisor` on the kubelet ports.
    * Note that you have to update your scraping jobs to get kubelet-only metrics from `/metrics` and `container_*` metrics from `/metrics/cadvisor`

 `http_response_size_bytes_sum`
 `http_response_size_bytes_count`
 due to removal from the prometheus client library. Prometheus http request meta-metrics are now generated from [`promhttp.InstrumentMetricHandler`](https://godoc.org/github.com/prometheus/client_golang/prometheus/promhttp#InstrumentMetricHandler) instead.
- Following metrics from kube-controller-manager are now marked as with the ALPHA stability level:

- Kube-apiserver: fixes a 1.27+ regression in watch stability by serving watch requests without a resourceVersion from the watch cache by default, as in <1.27 (disabling the change in #115096 by default). This mitigates the impact of an etcd watch bug (https://github.com/etcd-io/etcd/pull/17555). If the 1.27 change in #115096 to serve these requests from underlying storage is still desired despite the impact on watch stability, it can be re-enabled with a `WatchFromStorageWithoutResourceVersion`...

- Kubeadm: get k8s CI version markers from k8s infra bucket ([#98836](https://github.com/kubernetes/kubernetes/pull/98836), [@hasheddan](https://github.com/hasheddan)) [SIG Cluster Lifecycle and Release]
- Kubelet should ignore cgroup driver check on Windows node. ([#98384](https://github.com/kubernetes/kubernetes/pull/98384), [@pacoxu](https://github.com/pacoxu)) [SIG Node]
- TerminationGracePeriodSeconds from pod spec is respected for the mirror pod

    * `kubectl create configmap` has a new option `--from-env-file` that populates a configmap from file which follows a key=val format for each line. ([#38882](https://github.com/kubernetes/kubernetes/pull/38882), [@fraenkel](https://github.com/fraenkel))

    * `kubectl create secret` has a new option `--from-env-file` that populates a secret from file which follows a key=val format for each line.

  * Printing/describe