## 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.

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;

- [`KT-59342`](https://youtrack.jetbrains.com/issue/KT-59342) K2 IDE. FirLazyResolveContractViolationException: `lazyResolveToPhase(TYPES)` cannot be called from a transformer with a phase TYPES

    * 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`

  - *apiserver_cache_list_fetched_objects_total*: Counter of objects read from watch cache in the course of serving a LIST request, broken down by resource_prefix and index_name
  - *apiserver_cache_list_evaluated_objects_total*: Counter of objects tested in the course of serving a LIST request from watch cache, broken down by resource_prefix

  - apiserver-advertise-address / apiserver-bind-port: use either localAPIEndpoint from InitConfiguration or controlPlaneEndpoint from ClusterConfiguration.
  - cluster-name: use clusterName from ClusterConfiguration
  - cert-dir: use certificatesDir from ClusterConfiguration ([#94879](https://github.com/kubernetes/kubernetes/pull/94879), [@knight42](https://github.com/knight42)) [SIG Cluster Lifecycle]

registers all of its command-line flags with an internal flagset, which prevents flags from third party libraries from unintentionally leaking into the Kubelet's command-line API. Many unintentionally leaked flags are now marked deprecated, so that users have a chance to migrate away from them before they are removed. In addition, one previously leaked flag, --cloud-provider-gce-lb-src-cidrs, has been entirely removed from the Kubelet's command-line API, because it is irrelevant to Kubelet operation. The...

- 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.

    * `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

- 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`...