Kubernetes

Uncategorized
- The dynamic client now support the `_request_timeout` parameter to configure connection and request timeouts. (1732, philipp-sontag-by)

API Change
- Add 2 new options for kube-proxy running in winkernel mode. `--forward-healthcheck-vip`, if specified as true, health check traffic whose destination is service VIP will be forwarded to kube-proxy's healthcheck service. `--root-hnsendpoint-name` specifies the name of the hns endpoint for the root network namespace. This option enables the pass-through load balancers like Google's GCLB to correctly health check the backend services. Without this change, the health check packets is dropped, and Windows node will be considered to be unhealthy by those load balancers. ([kubernetes/kubernetes99287](https://github.com/kubernetes/kubernetes/pull/99287), [anfernee](https://github.com/anfernee))
- Added CEL runtime cost calculation into CustomerResource validation. CustomerResource validation will fail if runtime cost exceeds the budget. ([kubernetes/kubernetes108482](https://github.com/kubernetes/kubernetes/pull/108482), [cici37](https://github.com/cici37))
- Added a new metric `webhook_fail_open_count` to monitor webhooks that fail to open. ([kubernetes/kubernetes107171](https://github.com/kubernetes/kubernetes/pull/107171), [ltagliamonte-dd](https://github.com/ltagliamonte-dd))
- Adds a new Status subresource in Network Policy objects ([kubernetes/kubernetes107963](https://github.com/kubernetes/kubernetes/pull/107963), [rikatz](https://github.com/rikatz))
- Adds support for `InterfaceNamePrefix` and `BridgeInterface` as arguments to `--detect-local-mode` option and also introduces a new optional `--pod-interface-name-prefix` and `--pod-bridge-interface` flags to kube-proxy. ([kubernetes/kubernetes95400](https://github.com/kubernetes/kubernetes/pull/95400), [tssurya](https://github.com/tssurya))
- CEL CRD validation expressions may now reference existing object state using the identifier `oldSelf`. ([kubernetes/kubernetes108073](https://github.com/kubernetes/kubernetes/pull/108073), [benluddy](https://github.com/benluddy))
- CRD deep copies should no longer contain shallow copies of `JSONSchemaProps.XValidations`. ([kubernetes/kubernetes107956](https://github.com/kubernetes/kubernetes/pull/107956), [benluddy](https://github.com/benluddy))
- CRD writes will generate validation errors if a CEL validation rule references the identifier `oldSelf` on a part of the schema that does not support it. ([kubernetes/kubernetes108013](https://github.com/kubernetes/kubernetes/pull/108013), [benluddy](https://github.com/benluddy))
- CSIStorageCapacity.storage.k8s.io: The v1beta1 version of this API is deprecated in favor of v1, and will be removed in v1.27. If a CSI driver supports storage capacity tracking, then it must get deployed with a release of external-provisioner that supports the v1 API. ([kubernetes/kubernetes108445](https://github.com/kubernetes/kubernetes/pull/108445), [pohly](https://github.com/pohly))
- Custom resource requests with `fieldValidation=Strict` consistently require `apiVersion` and `kind`, matching non-strict requests ([kubernetes/kubernetes109019](https://github.com/kubernetes/kubernetes/pull/109019), [liggitt](https://github.com/liggitt))
- Feature of `DefaultPodTopologySpread` is graduated to GA ([kubernetes/kubernetes108278](https://github.com/kubernetes/kubernetes/pull/108278), [kerthcet](https://github.com/kerthcet))
- Feature of `NonPreemptingPriority` is graduated to GA ([kubernetes/kubernetes107432](https://github.com/kubernetes/kubernetes/pull/107432), [denkensk](https://github.com/denkensk))
- Feature of `PodOverhead` is graduated to GA ([kubernetes/kubernetes108441](https://github.com/kubernetes/kubernetes/pull/108441), [pacoxu](https://github.com/pacoxu))
- Fixed OpenAPI serialization of the x-kubernetes-validations field ([kubernetes/kubernetes107970](https://github.com/kubernetes/kubernetes/pull/107970), [liggitt](https://github.com/liggitt))
- Fixed failed flushing logs in defer function when kubelet cmd exit 1. ([kubernetes/kubernetes104774](https://github.com/kubernetes/kubernetes/pull/104774), [kerthcet](https://github.com/kerthcet))
- Fixes a regression in v1beta1 PodDisruptionBudget handling of `strategic merge patch`-type API requests for the `selector` field. Prior to 1.21, these requests would merge `matchLabels` content and replace `matchExpressions` content. In 1.21, patch requests touching the `selector` field started replacing the entire selector. This is consistent with server-side apply and the v1 PodDisruptionBudget behavior, but should not have been changed for v1beta1. ([kubernetes/kubernetes108138](https://github.com/kubernetes/kubernetes/pull/108138), [liggitt](https://github.com/liggitt))
- Improve kubectl's user help commands readability ([kubernetes/kubernetes104736](https://github.com/kubernetes/kubernetes/pull/104736), [lauchokyip](https://github.com/lauchokyip))
- Indexed Jobs graduated to stable. ([kubernetes/kubernetes107395](https://github.com/kubernetes/kubernetes/pull/107395), [alculquicondor](https://github.com/alculquicondor))
- Introduce a v1alpha1 networking API for ClusterCIDRConfig ([kubernetes/kubernetes108290](https://github.com/kubernetes/kubernetes/pull/108290), [sarveshr7](https://github.com/sarveshr7))
- Introduction of a new "sync_proxy_rules_no_local_endpoints_total" proxy metric. This metric represents the number of services with no internal endpoints. The "traffic_policy" label will contain both "internal" or "external". ([kubernetes/kubernetes108930](https://github.com/kubernetes/kubernetes/pull/108930), [MaxRenaud](https://github.com/MaxRenaud))
- JobReadyPods graduates to Beta and it's enabled by default. ([kubernetes/kubernetes107476](https://github.com/kubernetes/kubernetes/pull/107476), [alculquicondor](https://github.com/alculquicondor))
- Kube-apiserver: `--audit-log-version` and `--audit-webhook-version` now only support the default value of `audit.k8s.io/v1`. The v1alpha1 and v1beta1 audit log versions, deprecated since 1.13, have been removed. ([kubernetes/kubernetes108092](https://github.com/kubernetes/kubernetes/pull/108092), [carlory](https://github.com/carlory))
- Kube-apiserver: the `metadata.selfLink` field can no longer be populated by kube-apiserver; it was deprecated in 1.16 and has not been populated by default since 1.20+. ([kubernetes/kubernetes107527](https://github.com/kubernetes/kubernetes/pull/107527), [wojtek-t](https://github.com/wojtek-t))
- Kubelet external Credential Provider feature is moved to Beta. Credential Provider Plugin and Credential Provider Config API's updated from v1alpha1 to v1beta1 with no API changes. ([kubernetes/kubernetes108847](https://github.com/kubernetes/kubernetes/pull/108847), [adisky](https://github.com/adisky))
- Make STS available replicas optional again. ([kubernetes/kubernetes109241](https://github.com/kubernetes/kubernetes/pull/109241), [ravisantoshgudimetla](https://github.com/ravisantoshgudimetla))
- MaxUnavailable for StatefulSets, allows faster RollingUpdate by taking down more than 1 pod at a time. The number of pods you want to take down during a RollingUpdate is configurable using maxUnavailable parameter. ([kubernetes/kubernetes82162](https://github.com/kubernetes/kubernetes/pull/82162), [krmayankk](https://github.com/krmayankk))
- Non-graceful node shutdown handling is enabled for stateful workload failovers ([kubernetes/kubernetes108486](https://github.com/kubernetes/kubernetes/pull/108486), [sonasingh46](https://github.com/sonasingh46))
- Omit enum declarations from the static openapi file captured at https://git.k8s.io/kubernetes/api/openapi-spec. This file is used to generate API clients, and use of enums in those generated clients (rather than strings) can break forward compatibility with additional future values in those fields. See https://issue.k8s.io/109177 for details. ([kubernetes/kubernetes#109178](https://github.com/kubernetes/kubernetes/pull/109178), [liggitt](https://github.com/liggitt))
- OpenAPI V3 is turned on by default ([kubernetes/kubernetes109031](https://github.com/kubernetes/kubernetes/pull/109031), [Jefftree](https://github.com/Jefftree))
- Pod affinity namespace selector and cross-namespace quota graduated to GA. The feature gate `PodAffinityNamespaceSelector` is locked and will be removed in 1.26. ([kubernetes/kubernetes108136](https://github.com/kubernetes/kubernetes/pull/108136), [ahg-g](https://github.com/ahg-g))
- Promote IdentifyPodOS feature to beta. ([kubernetes/kubernetes107859](https://github.com/kubernetes/kubernetes/pull/107859), [ravisantoshgudimetla](https://github.com/ravisantoshgudimetla))
- Remove a v1alpha1 networking API for ClusterCIDRConfig ([kubernetes/kubernetes109436](https://github.com/kubernetes/kubernetes/pull/109436), [JamesLaverack](https://github.com/JamesLaverack))
- Renamed metrics `evictions_number` to `evictions_total` and mark it as stable. The original `evictions_number` metrics name is marked as "Deprecated" and has been removed in kubernetes 1.23 . ([kubernetes/kubernetes106366](https://github.com/kubernetes/kubernetes/pull/106366), [cyclinder](https://github.com/cyclinder))
- Skip x-kubernetes-validations rules if having fundamental error against the OpenAPIv3 schema. ([kubernetes/kubernetes108859](https://github.com/kubernetes/kubernetes/pull/108859), [cici37](https://github.com/cici37))
- Support for gRPC probes is now in beta. GRPCContainerProbe feature gate is enabled by default. ([kubernetes/kubernetes108522](https://github.com/kubernetes/kubernetes/pull/108522), [SergeyKanzhelev](https://github.com/SergeyKanzhelev))
- Suspend job to GA. The feature gate `SuspendJob` is locked and will be removed in 1.26. ([kubernetes/kubernetes108129](https://github.com/kubernetes/kubernetes/pull/108129), [ahg-g](https://github.com/ahg-g))
- The AnyVolumeDataSource feature is now beta, and the feature gate is enabled by default. In order to provide user feedback on PVCs with data sources, deployers must install the VolumePopulators CRD and the data-source-validator controller. ([kubernetes/kubernetes108736](https://github.com/kubernetes/kubernetes/pull/108736), [bswartz](https://github.com/bswartz))
- The CertificateSigningRequest `spec.expirationSeconds` API field has graduated to GA. The `CSRDuration` feature gate for the field is now unconditionally enabled and will be removed in 1.26. ([kubernetes/kubernetes108782](https://github.com/kubernetes/kubernetes/pull/108782), [cfryanr](https://github.com/cfryanr))
- The `ServerSideFieldValidation` feature has graduated to beta and is now enabled by default. Kubectl 1.24 and newer will use server-side validation instead of client-side validation when writing to API servers with the feature enabled. ([kubernetes/kubernetes108889](https://github.com/kubernetes/kubernetes/pull/108889), [kevindelgado](https://github.com/kevindelgado))
- The `ServiceLBNodePortControl` feature has graduated to GA. The feature gate will be removed in 1.26. ([kubernetes/kubernetes107027](https://github.com/kubernetes/kubernetes/pull/107027), [uablrek](https://github.com/uablrek))
- The deprecated kube-controller-manager flag '--deployment-controller-sync-period' has been removed, it is not used by the deployment controller. ([kubernetes/kubernetes107178](https://github.com/kubernetes/kubernetes/pull/107178), [SataQiu](https://github.com/SataQiu))
- The feature `DynamicKubeletConfig` has been removed from the kubelet. ([kubernetes/kubernetes106932](https://github.com/kubernetes/kubernetes/pull/106932), [SergeyKanzhelev](https://github.com/SergeyKanzhelev))
- The infrastructure for contextual logging is complete (feature gate implemented, JSON backend ready). ([kubernetes/kubernetes108995](https://github.com/kubernetes/kubernetes/pull/108995), [pohly](https://github.com/pohly))
- This adds an optional `timeZone` field as part of the CronJob spec to support running cron jobs in a specific time zone. ([kubernetes/kubernetes108032](https://github.com/kubernetes/kubernetes/pull/108032), [deejross](https://github.com/deejross))
- Updated the default API priority-and-fairness config to avoid endpoint/configmaps operations from controller-manager to all match leader-election priority level. ([kubernetes/kubernetes106725](https://github.com/kubernetes/kubernetes/pull/106725), [wojtek-t](https://github.com/wojtek-t))
- `topologySpreadConstraints` includes `minDomains` field to limit the minimum number of topology domains. ([kubernetes/kubernetes107674](https://github.com/kubernetes/kubernetes/pull/107674), [sanposhiho](https://github.com/sanposhiho))
- Introduce a v1alpha1 networking API for ClusterCIDRConfig ([kubernetes/kubernetes108290](https://github.com/kubernetes/kubernetes/pull/108290), [sarveshr7](https://github.com/sarveshr7)) [SIG API Machinery, Apps, Auth, CLI, Cloud Provider, Instrumentation, Network and Testing]
- Introduction of a new "sync_proxy_rules_no_local_endpoints_total" proxy metric. This metric represents the number of services with no internal endpoints. The "traffic_policy" label will contain both "internal" or "external". ([kubernetes/kubernetes108930](https://github.com/kubernetes/kubernetes/pull/108930), [MaxRenaud](https://github.com/MaxRenaud)) [SIG API Machinery, Apps, Architecture, Auth, Autoscaling, CLI, Cloud Provider, Instrumentation, Network, Node, Release, Scheduling, Storage, Testing and Windows]
- Make STS available replicas optional again, ([kubernetes/kubernetes109241](https://github.com/kubernetes/kubernetes/pull/109241), [ravisantoshgudimetla](https://github.com/ravisantoshgudimetla)) [SIG API Machinery and Apps]
- Omit enum declarations from the static openapi file captured at https://git.k8s.io/kubernetes/api/openapi-spec. This file is used to generate API clients, and use of enums in those generated clients (rather than strings) can break forward compatibility with additional future values in those fields. See https://issue.k8s.io/109177 for details. ([kubernetes/kubernetes#109178](https://github.com/kubernetes/kubernetes/pull/109178), [liggitt](https://github.com/liggitt)) [SIG API Machinery and Auth]
- Remove a v1alpha1 networking API for ClusterCIDRConfig ([kubernetes/kubernetes109436](https://github.com/kubernetes/kubernetes/pull/109436), [JamesLaverack](https://github.com/JamesLaverack)) [SIG API Machinery, Apps, Auth, CLI, Network and Testing]
- The deprecated kube-controller-manager flag '--deployment-controller-sync-period' has been removed, it is not used by the deployment controller. ([kubernetes/kubernetes107178](https://github.com/kubernetes/kubernetes/pull/107178), [SataQiu](https://github.com/SataQiu)) [SIG API Machinery and Apps]
- Adds a new Status subresource in Network Policy objects ([kubernetes/kubernetes107963](https://github.com/kubernetes/kubernetes/pull/107963), [rikatz](https://github.com/rikatz)) [SIG API Machinery, Apps, Network and Testing]
- Adds support for "InterfaceNamePrefix" and "BridgeInterface" as arguments to --detect-local-mode option and also introduces a new optional `--pod-interface-name-prefix` and `--pod-bridge-interface` flags to kube-proxy. ([kubernetes/kubernetes95400](https://github.com/kubernetes/kubernetes/pull/95400), [tssurya](https://github.com/tssurya)) [SIG API Machinery and Network]
- CEL CRD validation expressions may now reference existing object state using the identifier `oldSelf`. ([kubernetes/kubernetes108073](https://github.com/kubernetes/kubernetes/pull/108073), [benluddy](https://github.com/benluddy)) [SIG API Machinery and Testing]
- CSIStorageCapacity.storage.k8s.io: The v1beta1 version of this API is deprecated in favor of v1, and will be removed in v1.27. If a CSI driver supports storage capacity tracking, then it must get deployed with a release of external-provisioner that supports the v1 API. ([kubernetes/kubernetes108445](https://github.com/kubernetes/kubernetes/pull/108445), [pohly](https://github.com/pohly)) [SIG API Machinery, Architecture, Auth, Scheduling, Storage and Testing]
- Custom resource requests with fieldValidation=Strict consistently require apiVersion and kind, matching non-strict requests ([kubernetes/kubernetes109019](https://github.com/kubernetes/kubernetes/pull/109019), [liggitt](https://github.com/liggitt)) [SIG API Machinery]
- Improve kubectl's user help commands readability ([kubernetes/kubernetes104736](https://github.com/kubernetes/kubernetes/pull/104736), [lauchokyip](https://github.com/lauchokyip)) [SIG API Machinery, Apps, Architecture, Auth, Autoscaling, CLI, Cloud Provider, Cluster Lifecycle, Contributor Experience, Instrumentation, Network, Node, Release, Scalability, Scheduling, Security, Storage, Testing and Windows]
- Indexed Jobs graduates to stable ([kubernetes/kubernetes107395](https://github.com/kubernetes/kubernetes/pull/107395), [alculquicondor](https://github.com/alculquicondor)) [SIG Apps, Architecture and Testing]
- Introduce a v1alpha1 networking API for ClusterCIDRConfig ([kubernetes/kubernetes108290](https://github.com/kubernetes/kubernetes/pull/108290), [sarveshr7](https://github.com/sarveshr7)) [SIG API Machinery, Apps, Auth, CLI, Cloud Provider, Instrumentation, Network and Testing]
- JobReadyPods graduates to Beta and it's enabled by default. ([kubernetes/kubernetes107476](https://github.com/kubernetes/kubernetes/pull/107476), [alculquicondor](https://github.com/alculquicondor)) [SIG API Machinery, Apps and Testing]
- Kubelet external Credential Provider feature is moved to Beta. Credential Provider Plugin and Credential Provider Config API's updated from v1alpha1 to v1beta1 with no API changes. ([kubernetes/kubernetes108847](https://github.com/kubernetes/kubernetes/pull/108847), [adisky](https://github.com/adisky)) [SIG API Machinery and Node]
- MaxUnavailable for StatefulSets, allows faster RollingUpdate by taking down more than 1 pod at a time. The number of pods you want to take down during a RollingUpdate is configurable using maxUnavailable parameter. ([kubernetes/kubernetes82162](https://github.com/kubernetes/kubernetes/pull/82162), [krmayankk](https://github.com/krmayankk)) [SIG API Machinery and Apps]
- Non graceful node shutdown handling. ([kubernetes/kubernetes108486](https://github.com/kubernetes/kubernetes/pull/108486), [sonasingh46](https://github.com/sonasingh46)) [SIG Apps, Node and Storage]
- OpenAPI V3 is turned on by default ([kubernetes/kubernetes109031](https://github.com/kubernetes/kubernetes/pull/109031), [Jefftree](https://github.com/Jefftree)) [SIG API Machinery, Apps, Architecture, Auth, Autoscaling, CLI, Cloud Provider, Cluster Lifecycle, Instrumentation, Network, Node, Scheduling, Storage and Testing]
- Promote IdentifyPodOS feature to beta. ([kubernetes/kubernetes107859](https://github.com/kubernetes/kubernetes/pull/107859), [ravisantoshgudimetla](https://github.com/ravisantoshgudimetla)) [SIG API Machinery, Apps, Node, Testing and Windows]
- Skip x-kubernetes-validations rules if having fundamental error against OpenAPIv3 schema. ([kubernetes/kubernetes108859](https://github.com/kubernetes/kubernetes/pull/108859), [cici37](https://github.com/cici37)) [SIG API Machinery and Testing]
- Support for gRPC probes is now in beta. GRPCContainerProbe feature gate is enabled by default. ([kubernetes/kubernetes108522](https://github.com/kubernetes/kubernetes/pull/108522), [SergeyKanzhelev](https://github.com/SergeyKanzhelev)) [SIG API Machinery, Apps, Node and Testing]
- The AnyVolumeDataSource feature is now beta, and the feature gate is enabled by default. In order to provide user feedback on PVCs with data sources, deployers must install the VolumePopulators CRD and the data-source-validator controller. ([kubernetes/kubernetes108736](https://github.com/kubernetes/kubernetes/pull/108736), [bswartz](https://github.com/bswartz)) [SIG Apps, Storage and Testing]
- The `ServerSideFieldValidation` feature has graduated to beta and is now enabled by default. Kubectl 1.24 and newer will use server-side validation instead of client-side validation when writing to API servers with the feature enabled. ([kubernetes/kubernetes108889](https://github.com/kubernetes/kubernetes/pull/108889), [kevindelgado](https://github.com/kevindelgado)) [SIG API Machinery, Architecture, CLI and Testing]
- The infrastructure for contextual logging is complete (feature gate implemented, JSON backend ready). ([kubernetes/kubernetes108995](https://github.com/kubernetes/kubernetes/pull/108995), [pohly](https://github.com/pohly)) [SIG API Machinery, Architecture, Auth, CLI, Cloud Provider, Cluster Lifecycle, Instrumentation, Network, Node, Scheduling and Testing]
- This adds an optional `timeZone` field as part of the CronJob spec to support running cron jobs in a specific time zone. ([kubernetes/kubernetes108032](https://github.com/kubernetes/kubernetes/pull/108032), [deejross](https://github.com/deejross)) [SIG API Machinery and Apps]
- Add 2 new options for kube-proxy running in winkernel mode.
`--forward-healthcheck-vip`, if specified as true, health check traffic whose destination is service VIP will be forwarded to kube-proxy's healthcheck service. `--root-hnsendpoint-name` specifies the name of the hns endpoint for the root network namespace.
This option enables the pass-through load balancers like Google's GCLB to correctly health check the backend services. Without this change, the health check packets is dropped, and Windows node will be considered to be unhealthy by those load balancers. ([kubernetes/kubernetes99287](https://github.com/kubernetes/kubernetes/pull/99287), [anfernee](https://github.com/anfernee)) [SIG API Machinery, Cloud Provider, Network, Testing and Windows]
- Added CEL runtime cost calculation into CustomerResource validation. CustomerResource validation will fail if runtime cost exceeds the budget. ([kubernetes/kubernetes108482](https://github.com/kubernetes/kubernetes/pull/108482), [cici37](https://github.com/cici37)) [SIG API Machinery]
- CRD writes will generate validation errors if a CEL validation rule references the identifier "oldSelf" on a part of the schema that does not support it. ([kubernetes/kubernetes108013](https://github.com/kubernetes/kubernetes/pull/108013), [benluddy](https://github.com/benluddy)) [SIG API Machinery]
- Feature of `DefaultPodTopologySpread` is graduated to GA ([kubernetes/kubernetes108278](https://github.com/kubernetes/kubernetes/pull/108278), [kerthcet](https://github.com/kerthcet)) [SIG Scheduling]
- Feature of `PodOverhead` is graduated to GA ([kubernetes/kubernetes108441](https://github.com/kubernetes/kubernetes/pull/108441), [pacoxu](https://github.com/pacoxu)) [SIG API Machinery, Apps, Node and Scheduling]
- Fixes a regression in v1beta1 PodDisruptionBudget handling of "strategic merge patch"-type API requests for the `selector` field. Prior to 1.21, these requests would merge `matchLabels` content and replace `matchExpressions` content. In 1.21, patch requests touching the `selector` field started replacing the entire selector. This is consistent with server-side apply and the v1 PodDisruptionBudget behavior, but should not have been changed for v1beta1. ([kubernetes/kubernetes108138](https://github.com/kubernetes/kubernetes/pull/108138), [liggitt](https://github.com/liggitt)) [SIG Apps, Auth and Testing]
- Kube-apiserver: --audit-log-version and --audit-webhook-version now only support the default value of audit.k8s.io/v1. The v1alpha1 and v1beta1 audit log versions, deprecated since 1.13, have been removed. ([kubernetes/kubernetes108092](https://github.com/kubernetes/kubernetes/pull/108092), [carlory](https://github.com/carlory)) [SIG API Machinery, Auth and Testing]
- Pod-affinity namespace selector and cross-namespace quota graduated to GA. The feature gate PodAffinityNamespaceSelector is locked and will be removed in 1.26. ([kubernetes/kubernetes108136](https://github.com/kubernetes/kubernetes/pull/108136), [ahg-g](https://github.com/ahg-g)) [SIG API Machinery, Apps, Scheduling and Testing]
- Suspend job to GA. The feature gate SuspendJob is locked and will be removed in 1.26. ([kubernetes/kubernetes108129](https://github.com/kubernetes/kubernetes/pull/108129), [ahg-g](https://github.com/ahg-g)) [SIG Apps and Testing]
- The CertificateSigningRequest `spec.expirationSeconds` API field has graduated to GA. The `CSRDuration` feature gate for the field is now unconditionally enabled and will be removed in 1.26. ([kubernetes/kubernetes108782](https://github.com/kubernetes/kubernetes/pull/108782), [cfryanr](https://github.com/cfryanr)) [SIG API Machinery, Apps, Auth, Instrumentation and Testing]
- TopologySpreadConstraints includes minDomains field to limit the minimum number of topology domains. ([kubernetes/kubernetes107674](https://github.com/kubernetes/kubernetes/pull/107674), [sanposhiho](https://github.com/sanposhiho)) [SIG API Machinery, Apps and Scheduling]
- CRD deep copies should no longer contain shallow copies of JSONSchemaProps.XValidations. ([kubernetes/kubernetes107956](https://github.com/kubernetes/kubernetes/pull/107956), [benluddy](https://github.com/benluddy)) [SIG API Machinery]
- Feature of `NonPreemptingPriority` is graduated to GA ([kubernetes/kubernetes107432](https://github.com/kubernetes/kubernetes/pull/107432), [denkensk](https://github.com/denkensk)) [SIG Apps, Scheduling and Testing]
- Fix OpenAPI serialization of the x-kubernetes-validations field ([kubernetes/kubernetes107970](https://github.com/kubernetes/kubernetes/pull/107970), [liggitt](https://github.com/liggitt)) [SIG API Machinery]
- Kube-apiserver: the `metadata.selfLink` field can no longer be populated by kube-apiserver; it was deprecated in 1.16 and has not been populated by default in 1.20+. ([kubernetes/kubernetes107527](https://github.com/kubernetes/kubernetes/pull/107527), [wojtek-t](https://github.com/wojtek-t)) [SIG API Machinery, Apps, Auth, Autoscaling, CLI, Cloud Provider, Network, Scheduling, Storage and Testing]
- Add a new metric `webhook_fail_open_count` to monitor webhooks that fail open ([kubernetes/kubernetes107171](https://github.com/kubernetes/kubernetes/pull/107171), [ltagliamonte-dd](https://github.com/ltagliamonte-dd)) [SIG API Machinery and Instrumentation]
- Fix failed flushing logs in defer function when kubelet cmd exit 1. ([kubernetes/kubernetes104774](https://github.com/kubernetes/kubernetes/pull/104774), [kerthcet](https://github.com/kerthcet)) [SIG Node and Scheduling]
- Rename metrics `evictions_number` to `evictions_total` and mark it as stable. The original `evictions_number` metrics name is marked as "Deprecated" and will be removed in kubernetes 1.23 ([kubernetes/kubernetes106366](https://github.com/kubernetes/kubernetes/pull/106366), [cyclinder](https://github.com/cyclinder)) [SIG API Machinery, Apps, Architecture, Auth, CLI, Cloud Provider, Cluster Lifecycle, Instrumentation, Network, Node, Release, Scalability, Scheduling, Storage, Testing and Windows]
- The `ServiceLBNodePortControl` feature graduates to GA. The feature gate will be removed in 1.26. ([kubernetes/kubernetes107027](https://github.com/kubernetes/kubernetes/pull/107027), [uablrek](https://github.com/uablrek)) [SIG Network and Testing]
- The feature DynamicKubeletConfig is removed from the kubelet. ([kubernetes/kubernetes106932](https://github.com/kubernetes/kubernetes/pull/106932), [SergeyKanzhelev](https://github.com/SergeyKanzhelev)) [SIG Apps, Auth, Instrumentation, Node and Testing]
- Update default API priority-and-fairness config to avoid endpoint/configmaps operations from controller-manager to all match leader-election priority level. ([kubernetes/kubernetes106725](https://github.com/kubernetes/kubernetes/pull/106725), [wojtek-t](https://github.com/wojtek-t)) [SIG API Machinery]

API Change
- Omits alpha-level enums from the static openapi file captured in api/openapi-spec ([kubernetes/kubernetes109179](https://github.com/kubernetes/kubernetes/pull/109179), [liggitt](https://github.com/liggitt)) [SIG Apps and Auth]
- Fixes a regression in v1beta1 PodDisruptionBudget handling of "strategic merge patch"-type API requests for the `selector` field. Prior to 1.21, these requests would merge `matchLabels` content and replace `matchExpressions` content. In 1.21, patch requests touching the `selector` field started replacing the entire selector. This is consistent with server-side apply and the v1 PodDisruptionBudget behavior, but should not have been changed for v1beta1. ([kubernetes/kubernetes108139](https://github.com/kubernetes/kubernetes/pull/108139), [liggitt](https://github.com/liggitt)) [SIG Auth and Testing]

API Change
- Fix OpenAPI serialization of the x-kubernetes-validations field ([kubernetes/kubernetes108030](https://github.com/kubernetes/kubernetes/pull/108030), [liggitt](https://github.com/liggitt)) [SIG API Machinery]

API Change
- A new field `omitManagedFields` has been added to both `audit.Policy` and `audit.PolicyRule`
so cluster operators can opt in to omit managed fields of the request and response bodies from
being written to the API audit log. ([kubernetes/kubernetes94986](https://github.com/kubernetes/kubernetes/pull/94986), [tkashem](https://github.com/tkashem)) [SIG API Machinery, Auth, Cloud Provider and Testing]
- A small regression in Service updates was fixed. The circumstances are so unlikely that probably nobody would ever hit it. ([kubernetes/kubernetes104601](https://github.com/kubernetes/kubernetes/pull/104601), [thockin](https://github.com/thockin))
- Added a feature gate `StatefulSetAutoDeletePVC`, which allows PVCs automatically created for StatefulSet pods to be automatically deleted. ([kubernetes/kubernetes99728](https://github.com/kubernetes/kubernetes/pull/99728), [mattcary](https://github.com/mattcary))
- Client-go impersonation config can specify a UID to pass impersonated uid information through in requests. ([kubernetes/kubernetes104483](https://github.com/kubernetes/kubernetes/pull/104483), [margocrawf](https://github.com/margocrawf))
- Create HPA v2 from v2beta2 with some fields changed. ([kubernetes/kubernetes102534](https://github.com/kubernetes/kubernetes/pull/102534), [wangyysde](https://github.com/wangyysde)) [SIG API Machinery, Apps, Auth, Autoscaling and Testing]
- Ephemeral containers graduated to beta and are now available by default. ([kubernetes/kubernetes105405](https://github.com/kubernetes/kubernetes/pull/105405), [verb](https://github.com/verb))
- Fix kube-proxy regression on UDP services because the logic to detect stale connections was not considering if the endpoint was ready. ([kubernetes/kubernetes106163](https://github.com/kubernetes/kubernetes/pull/106163), [aojea](https://github.com/aojea)) [SIG API Machinery, Apps, Architecture, Auth, Autoscaling, CLI, Cloud Provider, Contributor Experience, Instrumentation, Network, Node, Release, Scalability, Scheduling, Storage, Testing and Windows]
- If a conflict occurs when creating an object with `generateName`, the server now returns an "AlreadyExists" error with a retry option. ([kubernetes/kubernetes104699](https://github.com/kubernetes/kubernetes/pull/104699), [vincepri](https://github.com/vincepri))
- Implement support for recovering from volume expansion failures ([kubernetes/kubernetes106154](https://github.com/kubernetes/kubernetes/pull/106154), [gnufied](https://github.com/gnufied)) [SIG API Machinery, Apps and Storage]
- In kubelet, log verbosity and flush frequency can also be configured via the configuration file and not just via command line flags. In other commands (kube-apiserver, kube-controller-manager), the flags are listed in the "Logs flags" group and not under "Global" or "Misc". The type for `-vmodule` was made a bit more descriptive (`pattern=N,...` instead of `moduleSpec`). ([kubernetes/kubernetes106090](https://github.com/kubernetes/kubernetes/pull/106090), [pohly](https://github.com/pohly)) [SIG API Machinery, Architecture, CLI, Cluster Lifecycle, Instrumentation, Node and Scheduling]
- Introduce `OS` field in the PodSpec ([kubernetes/kubernetes104693](https://github.com/kubernetes/kubernetes/pull/104693), [ravisantoshgudimetla](https://github.com/ravisantoshgudimetla))
- Introduce `v1beta3` API for scheduler. This version
- increases the weight of user specifiable priorities.
The weights of following priority plugins are increased
- `TaintTolerations` to 3 - as leveraging node tainting to group nodes in the cluster is becoming a widely-adopted practice
- `NodeAffinity` to 2
- `InterPodAffinity` to 2

- Won't have `HealthzBindAddress`, `MetricsBindAddress` fields ([kubernetes/kubernetes104251](https://github.com/kubernetes/kubernetes/pull/104251), [ravisantoshgudimetla](https://github.com/ravisantoshgudimetla))
- Introduce v1beta2 for Priority and Fairness with no changes in API spec. ([kubernetes/kubernetes104399](https://github.com/kubernetes/kubernetes/pull/104399), [tkashem](https://github.com/tkashem))
- JSON log output is configurable and now supports writing info messages to stdout and error messages to stderr. Info messages can be buffered in memory. The default is to write both to stdout without buffering, as before. ([kubernetes/kubernetes104873](https://github.com/kubernetes/kubernetes/pull/104873), [pohly](https://github.com/pohly))
- JobTrackingWithFinalizers graduates to beta. Feature is enabled by default. ([kubernetes/kubernetes105687](https://github.com/kubernetes/kubernetes/pull/105687), [alculquicondor](https://github.com/alculquicondor))
- Kube-apiserver: Fixes handling of CRD schemas containing literal null values in enums. ([kubernetes/kubernetes104969](https://github.com/kubernetes/kubernetes/pull/104969), [liggitt](https://github.com/liggitt))
- Kube-apiserver: The `rbac.authorization.k8s.io/v1alpha1` API version is removed; use the `rbac.authorization.k8s.io/v1` API, available since v1.8. The `scheduling.k8s.io/v1alpha1` API version is removed; use the `scheduling.k8s.io/v1` API, available since v1.14. ([kubernetes/kubernetes104248](https://github.com/kubernetes/kubernetes/pull/104248), [liggitt](https://github.com/liggitt))
- Kube-scheduler: support for configuration file version `v1beta1` is removed. Update configuration files to v1beta2(xref: https://github.com/kubernetes/enhancements/issues/2901) or v1beta3 before upgrading to 1.23. ([kubernetes/kubernetes#104782](https://github.com/kubernetes/kubernetes/pull/104782), [kerthcet](https://github.com/kerthcet))
- KubeSchedulerConfiguration provides a new field `MultiPoint` which will register a plugin for all valid extension points ([kubernetes/kubernetes105611](https://github.com/kubernetes/kubernetes/pull/105611), [damemi](https://github.com/damemi)) [SIG Scheduling and Testing]
- Kubelet should reject pods whose OS doesn't match the node's OS label. ([kubernetes/kubernetes105292](https://github.com/kubernetes/kubernetes/pull/105292), [ravisantoshgudimetla](https://github.com/ravisantoshgudimetla)) [SIG Apps and Node]
- Kubelet: turn the KubeletConfiguration v1beta1 `ResolverConfig` field from a `string` to `*string`. ([kubernetes/kubernetes104624](https://github.com/kubernetes/kubernetes/pull/104624), [Haleygo](https://github.com/Haleygo))
- Kubernetes is now built using go 1.17. ([kubernetes/kubernetes103692](https://github.com/kubernetes/kubernetes/pull/103692), [justaugustus](https://github.com/justaugustus))
- Performs strict server side schema validation requests via the `fieldValidation=[Strict,Warn,Ignore]`. ([kubernetes/kubernetes105916](https://github.com/kubernetes/kubernetes/pull/105916), [kevindelgado](https://github.com/kevindelgado))
- Promote `IPv6DualStack` feature to stable.
Controller Manager flags for the node IPAM controller have slightly changed:
1. When configuring a dual-stack cluster, the user must specify both `--node-cidr-mask-size-ipv4` and `--node-cidr-mask-size-ipv6` to set the per-node IP mask sizes, instead of the previous `--node-cidr-mask-size` flag.
2. The `--node-cidr-mask-size` flag is mutually exclusive with `--node-cidr-mask-size-ipv4` and `--node-cidr-mask-size-ipv6`.
3. Single-stack clusters do not need to change, but may choose to use the more specific flags. Users can use either the older `--node-cidr-mask-size` flag or one of the newer `--node-cidr-mask-size-ipv4` or `--node-cidr-mask-size-ipv6` flags to configure the per-node IP mask size, provided that the flag's IP family matches the cluster's IP family (--cluster-cidr). ([kubernetes/kubernetes104691](https://github.com/kubernetes/kubernetes/pull/104691), [khenidak](https://github.com/khenidak))
- Remove `NodeLease` feature gate that was graduated and locked to stable in 1.17 release. ([kubernetes/kubernetes105222](https://github.com/kubernetes/kubernetes/pull/105222), [cyclinder](https://github.com/cyclinder))
- Removed deprecated `--seccomp-profile-root`/`seccompProfileRoot` config. ([kubernetes/kubernetes103941](https://github.com/kubernetes/kubernetes/pull/103941), [saschagrunert](https://github.com/saschagrunert))
- Since golang 1.17 both net.ParseIP and net.ParseCIDR rejects leading zeros in the dot-decimal notation of IPv4 addresses,
Kubernetes will keep allowing leading zeros on IPv4 address to not break the compatibility.
IMPORTANT: Kubernetes interprets leading zeros on IPv4 addresses as decimal, users must not rely on parser alignment to not being impacted by the associated security advisory:
CVE-2021-29923 golang standard library "net" - Improper Input Validation of octal literals in golang 1.16.2 and below standard library "net" results in indeterminate SSRF & RFI vulnerabilities.
Reference: https://nvd.nist.gov/vuln/detail/CVE-2021-29923 ([kubernetes/kubernetes#104368](https://github.com/kubernetes/kubernetes/pull/104368), [aojea](https://github.com/aojea))
- StatefulSet `minReadySeconds` is promoted to beta. ([kubernetes/kubernetes104045](https://github.com/kubernetes/kubernetes/pull/104045), [ravisantoshgudimetla](https://github.com/ravisantoshgudimetla))
- Support pod priority based node graceful shutdown. ([kubernetes/kubernetes102915](https://github.com/kubernetes/kubernetes/pull/102915), [wzshiming](https://github.com/wzshiming))
- The "Generic Ephemeral Volume" feature graduates to GA. It is now enabled unconditionally. ([kubernetes/kubernetes105609](https://github.com/kubernetes/kubernetes/pull/105609), [pohly](https://github.com/pohly))
- The Kubelet's `--register-with-taints` option is now available via the Kubelet config file field registerWithTaints ([kubernetes/kubernetes105437](https://github.com/kubernetes/kubernetes/pull/105437), [cmssczy](https://github.com/cmssczy)) [SIG Node and Scalability]
- The `CSIDriver.Spec.StorageCapacity` can now be modified. ([kubernetes/kubernetes101789](https://github.com/kubernetes/kubernetes/pull/101789), [pohly](https://github.com/pohly))
- The `CSIVolumeFSGroupPolicy` feature has moved from beta to GA. ([kubernetes/kubernetes105940](https://github.com/kubernetes/kubernetes/pull/105940), [dobsonj](https://github.com/dobsonj))
- The `IngressClass.Spec.Parameters.Namespace` field is now GA. ([kubernetes/kubernetes104636](https://github.com/kubernetes/kubernetes/pull/104636), [hbagdi](https://github.com/hbagdi))
- The `Service.spec.ipFamilyPolicy` field is now *required* in order to create or update a Service as dual-stack. This is a breaking change from the beta behavior. Previously the server would try to infer the value of that field from either `ipFamilies` or `clusterIPs`, but that caused ambiguity on updates. Users who want a dual-stack Service MUST specify `ipFamilyPolicy` as either "PreferDualStack" or "RequireDualStack". ([kubernetes/kubernetes96684](https://github.com/kubernetes/kubernetes/pull/96684), [thockin](https://github.com/thockin))
- The `TTLAfterFinished` feature gate is now GA and enabled by default. ([kubernetes/kubernetes105219](https://github.com/kubernetes/kubernetes/pull/105219), [sahilvv](https://github.com/sahilvv))
- The `kube-controller-manager` supports `--concurrent-ephemeralvolume-syncs` flag to set the number of ephemeral volume controller workers. ([kubernetes/kubernetes102981](https://github.com/kubernetes/kubernetes/pull/102981), [SataQiu](https://github.com/SataQiu))
- The legacy scheduler policy config is removed in v1.23, the associated flags `policy-config-file`, `policy-configmap`, `policy-configmap-namespace` and `use-legacy-policy-config` are also removed. Migrate to Component Config instead, see https://kubernetes.io/docs/reference/scheduling/config/ for details. ([kubernetes/kubernetes#105424](https://github.com/kubernetes/kubernetes/pull/105424), [kerthcet](https://github.com/kerthcet))
- Track the number of Pods with a Ready condition in Job status. The feature is alpha and needs the feature gate JobReadyPods to be enabled. ([kubernetes/kubernetes104915](https://github.com/kubernetes/kubernetes/pull/104915), [alculquicondor](https://github.com/alculquicondor))
- Users of `LogFormatRegistry` in component-base must update their code to use the logr v1.0.0 API. The JSON log output now uses the format from go-logr/zapr (no `v` field for error messages, additional information for invalid calls) and has some fixes (correct source code location for warnings about invalid log calls). ([kubernetes/kubernetes104103](https://github.com/kubernetes/kubernetes/pull/104103), [pohly](https://github.com/pohly))
- Validation rules for Custom Resource Definitions can be written in the [CEL expression language](https://github.com/google/cel-spec) using the `x-kubernetes-validations` extension in OpenAPIv3 schemas (alpha). This is gated by the alpha "CustomResourceValidationExpressions" feature gate. ([kubernetes/kubernetes#106051](https://github.com/kubernetes/kubernetes/pull/106051), [jpbetz](https://github.com/jpbetz)) [SIG API Machinery, Architecture, Auth, CLI, Cloud Provider, Cluster Lifecycle, Instrumentation, Node, Storage and Testing]
- Add gRPC probe to Pod.Spec.Container.{Liveness,Readiness,Startup}Probe (106463, SergeyKanzhelev) [SIG API Machinery, Apps, CLI, Node and Testing]
- Adds a feature gate StatefulSetAutoDeletePVC, which allows PVCs automatically created for StatefulSet pods to be automatically deleted. (99728, mattcary) [SIG API Machinery, Apps, Auth and Testing]
- Performs strict server side schema validation requests via the `fieldValidation=[Strict,Warn,Ignore]` query parameter. (105916, kevindelgado) [SIG API Machinery, Apps, Auth, Cloud Provider and Testing]
- Support pod priority based node graceful shutdown (102915, wzshiming) [SIG Node and Testing]
- A new field `omitManagedFields` has been added to both `audit.Policy` and `audit.PolicyRule`
so cluster operators can opt in to omit managed fields of the request and response bodies from
being written to the API audit log. (94986, tkashem) [SIG API Machinery, Auth, Cloud Provider and Testing]
- Create HPA v2 from v2beta2 with some fields changed. (102534, wangyysde) [SIG API Machinery, Apps, Auth, Autoscaling and Testing]
- Fix kube-proxy regression on UDP services because the logic to detect stale connections was not considering if the endpoint was ready. (106163, aojea) [SIG API Machinery, Apps, Architecture, Auth, Autoscaling, CLI, Cloud Provider, Contributor Experience, Instrumentation, Network, Node, Release, Scalability, Scheduling, Storage, Testing and Windows]
- Implement support for recovering from volume expansion failures (106154, gnufied) [SIG API Machinery, Apps and Storage]
- In kubelet, log verbosity and flush frequency can also be configured via the configuration file and not just via command line flags. In other commands (kube-apiserver, kube-controller-manager), the flags are listed in the "Logs flags" group and not under "Global" or "Misc". The type for `-vmodule` was made a bit more descriptive (`pattern=N,...` instead of `moduleSpec`). (106090, pohly) [SIG API Machinery, Architecture, CLI, Cluster Lifecycle, Instrumentation, Node and Scheduling]
- IngressClass.Spec.Parameters.Namespace field is now GA. (104636, hbagdi) [SIG Network and Testing]
- KubeSchedulerConfiguration provides a new field `MultiPoint` which will register a plugin for all valid extension points (105611, damemi) [SIG Scheduling and Testing]
- Kubelet should reject pods whose OS doesn't match the node's OS label. (105292, ravisantoshgudimetla) [SIG Apps and Node]
- The CSIVolumeFSGroupPolicy feature has moved from beta to GA. (105940, dobsonj) [SIG Storage]
- The Kubelet's `--register-with-taints` option is now available via the Kubelet config file field registerWithTaints (105437, cmssczy) [SIG Node and Scalability]
- Validation rules for Custom Resource Definitions can be written in the [CEL expression language](https://github.com/google/cel-spec) using the `x-kubernetes-validations` extension in OpenAPIv3 schemas (alpha). This is gated by the alpha "CustomResourceValidationExpressions" feature gate. (#106051, jpbetz) [SIG API Machinery, Architecture, Auth, CLI, Cloud Provider, Cluster Lifecycle, Instrumentation, Node, Storage and Testing]
- Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

<!--
This section can be blank if this pull request does not require a release note.

When adding links which point to resources within git repositories, like
KEPs or supporting documentation, please reference a specific commit and avoid
linking directly to the master branch. This ensures that links reference a
specific point in time, rather than a document that may change over time.

See here for guidance on getting permanent links to files: https://help.github.com/en/articles/getting-permanent-links-to-files

Please use the following format for linking documentation:
- [KEP]: <link>
- [Usage]: <link>
- [Other doc]: <link>
--> (104782, kerthcet) [SIG Scheduling and Testing]
- Ephemeral containers have reached beta maturity and are now available by default. (105405, verb) [SIG API Machinery, Apps, Node and Testing]
- Introduce OS field in the Pod Spec (104693, ravisantoshgudimetla) [SIG API Machinery and Apps]
- Introduce v1beta3 api for scheduler. This version
- increases the weight of user specifiable priorities.
The weights of following priority plugins are increased
- TaintTolerations to 3 - as leveraging node tainting to group nodes in the cluster is becoming a widely-adopted practice
- NodeAffinity to 2
- InterPodAffinity to 2

- Won't have HealthzBindAddress, MetricsBindAddress fields (104251, ravisantoshgudimetla) [SIG Scheduling and Testing]
- JSON log output is configurable and now supports writing info messages to stdout and error messages to stderr. Info messages can be buffered in memory. The default is to write both to stdout without buffering, as before. (104873, pohly) [SIG API Machinery, Architecture, CLI, Cluster Lifecycle, Instrumentation, Node and Scheduling]
- JobTrackingWithFinalizers graduates to beta. Feature is enabled by default. (105687, alculquicondor) [SIG Apps and Testing]
- Remove NodeLease feature gate that was graduated and locked to stable in 1.17 release. (105222, cyclinder) [SIG Apps, Node and Testing]
- TTLAfterFinished is now GA and enabled by default (105219, sahilvv) [SIG API Machinery, Apps, Auth and Testing]
- The "Generic Ephemeral Volume" feature graduates to GA. It is now enabled unconditionally. (105609, pohly) [SIG API Machinery, Apps, Auth, Node, Scheduling, Storage and Testing]
- The legacy scheduler policy config is removed in v1.23, the associated flags policy-config-file, policy-configmap, policy-configmap-namespace and use-legacy-policy-config are also removed. Migrate to Component Config instead, see https://kubernetes.io/docs/reference/scheduling/config/ for details. (#105424, kerthcet) [SIG Scheduling and Testing]
- Track the number of Pods with a Ready condition in Job status. The feature is alpha and needs the feature gate JobReadyPods to be enabled. (104915, alculquicondor) [SIG API Machinery, Apps, CLI and Testing]
- Client-go impersonation config can specify a UID to pass impersonated uid information through in requests. ([kubernetes/kubernetes104483](https://github.com/kubernetes/kubernetes/pull/104483), [margocrawf](https://github.com/margocrawf)) [SIG API Machinery, Auth and Testing]
- IPv6DualStack feature moved to stable.
Controller Manager flags for the node IPAM controller have slightly changed:
1. When configuring a dual-stack cluster, the user must specify both --node-cidr-mask-size-ipv4 and --node-cidr-mask-size-ipv6 to set the per-node IP mask sizes, instead of the previous --node-cidr-mask-size flag.
2. The --node-cidr-mask-size flag is mutually exclusive with --node-cidr-mask-size-ipv4 and --node-cidr-mask-size-ipv6.
3. Single-stack clusters do not need to change, but may choose to use the more specific flags. Users can use either the older --node-cidr-mask-size flag or one of the newer --node-cidr-mask-size-ipv4 or --node-cidr-mask-size-ipv6 flags to configure the per-node IP mask size, provided that the flag's IP family matches the cluster's IP family (--cluster-cidr). ([kubernetes/kubernetes104691](https://github.com/kubernetes/kubernetes/pull/104691), [khenidak](https://github.com/khenidak)) [SIG API Machinery, Apps, Auth, Cloud Provider, Cluster Lifecycle, Network, Node and Testing]
- Kubelet: turn the KubeletConfiguration v1beta1 `ResolverConfig` field from a `string` to `*string`. ([kubernetes/kubernetes104624](https://github.com/kubernetes/kubernetes/pull/104624), [Haleygo](https://github.com/Haleygo)) [SIG Cluster Lifecycle and Node]
- A small regression in Service updates was fixed. The circumstances are so unlikely that probably nobody would ever hit it. ([kubernetes/kubernetes104601](https://github.com/kubernetes/kubernetes/pull/104601), [thockin](https://github.com/thockin)) [SIG Network]
- Introduce v1beta2 for Priority and Fairness with no changes in API spec ([kubernetes/kubernetes104399](https://github.com/kubernetes/kubernetes/pull/104399), [tkashem](https://github.com/tkashem)) [SIG API Machinery and Testing]
- Kube-apiserver: Fixes handling of CRD schemas containing literal null values in enums. ([kubernetes/kubernetes104969](https://github.com/kubernetes/kubernetes/pull/104969), [liggitt](https://github.com/liggitt)) [SIG API Machinery, Apps and Network]
- Kubelet: turn the KubeletConfiguration v1beta1 `ResolverConfig` field from a `string` to `*string`. ([kubernetes/kubernetes104624](https://github.com/kubernetes/kubernetes/pull/104624), [Haleygo](https://github.com/Haleygo)) [SIG Cluster Lifecycle and Node]
- Kubernetes is now built using go1.17 ([kubernetes/kubernetes103692](https://github.com/kubernetes/kubernetes/pull/103692), [justaugustus](https://github.com/justaugustus)) [SIG API Machinery, Apps, Architecture, Auth, Autoscaling, CLI, Cloud Provider, Cluster Lifecycle, Instrumentation, Network, Node, Release, Scheduling, Storage and Testing]
- Removed deprecated `--seccomp-profile-root`/`seccompProfileRoot` config ([kubernetes/kubernetes103941](https://github.com/kubernetes/kubernetes/pull/103941), [saschagrunert](https://github.com/saschagrunert)) [SIG Node]
- Since golang 1.17 both net.ParseIP and net.ParseCIDR rejects leading zeros in the dot-decimal notation of IPv4 addresses.
Kubernetes will keep allowing leading zeros on IPv4 address to not break the compatibility.
IMPORTANT: Kubernetes interprets leading zeros on IPv4 addresses as decimal, users must not rely on parser alignment to not being impacted by the associated security advisory:
CVE-2021-29923 golang standard library "net" - Improper Input Validation of octal literals in golang 1.16.2 and below standard library "net" results in indeterminate SSRF & RFI vulnerabilities.
Reference: https://nvd.nist.gov/vuln/detail/CVE-2021-29923 ([kubernetes/kubernetes#104368](https://github.com/kubernetes/kubernetes/pull/104368), [aojea](https://github.com/aojea)) [SIG API Machinery, Apps, Architecture, Auth, CLI, Cloud Provider, Cluster Lifecycle, Instrumentation, Network, Node, Release, Scalability, Scheduling, Storage and Testing]
- StatefulSet minReadySeconds is promoted to beta ([kubernetes/kubernetes104045](https://github.com/kubernetes/kubernetes/pull/104045), [ravisantoshgudimetla](https://github.com/ravisantoshgudimetla)) [SIG Apps and Testing]
- The `Service.spec.ipFamilyPolicy` field is now *required* in order to create or update a Service as dual-stack. This is a breaking change from the beta behavior. Previously the server would try to infer the value of that field from either `ipFamilies` or `clusterIPs`, but that caused ambiguity on updates. Users who want a dual-stack Service MUST specify `ipFamilyPolicy` as either "PreferDualStack" or "RequireDualStack". ([kubernetes/kubernetes96684](https://github.com/kubernetes/kubernetes/pull/96684), [thockin](https://github.com/thockin)) [SIG API Machinery, Apps, Network and Testing]
- Users of LogFormatRegistry in component-base must update their code to use the logr v1.0.0 API. The JSON log output now uses the format from go-logr/zapr (no `v` field for error messages, additional information for invalid calls) and has some fixes (correct source code location for warnings about invalid log calls). ([kubernetes/kubernetes104103](https://github.com/kubernetes/kubernetes/pull/104103), [pohly](https://github.com/pohly)) [SIG API Machinery, Architecture, Auth, CLI, Cloud Provider, Cluster Lifecycle, Instrumentation and Storage]
- When creating an object with generateName, if a conflict occurs the server now returns an AlreadyExists error with a retry option. ([kubernetes/kubernetes104699](https://github.com/kubernetes/kubernetes/pull/104699), [vincepri](https://github.com/vincepri)) [SIG API Machinery]
- CSIDriver.Spec.StorageCapacity can now be modified. ([kubernetes/kubernetes101789](https://github.com/kubernetes/kubernetes/pull/101789), [pohly](https://github.com/pohly)) [SIG Storage]
- Kube-apiserver: The `rbac.authorization.k8s.io/v1alpha1` API version is removed; use the `rbac.authorization.k8s.io/v1` API, available since v1.8. The `scheduling.k8s.io/v1alpha1` API version is removed; use the `scheduling.k8s.io/v1` API, available since v1.14. ([kubernetes/kubernetes104248](https://github.com/kubernetes/kubernetes/pull/104248), [liggitt](https://github.com/liggitt)) [SIG API Machinery, Auth, Network and Testing]
- Kube-controller-manager supports '--concurrent-ephemeralvolume-syncs' flag to set the number of ephemeral volume controller workers. ([kubernetes/kubernetes102981](https://github.com/kubernetes/kubernetes/pull/102981), [SataQiu](https://github.com/SataQiu)) [SIG API Machinery and Apps]

API Change
- Kube-apiserver: Fixes handling of CRD schemas containing literal null values in enums (104988, liggitt) [SIG API Machinery, Apps and Network]
- A new score extension for NodeResourcesFit plugin that merges the functionality of `NodeResourcesLeastAllocated`, `NodeResourcesMostAllocated`, `RequestedToCapacityRatio` plugins, which are marked as deprecated as of v1beta2. In v1beta1, the three plugins can still be used in v1beta1 but not at the same time with the score extension of `NodeResourcesFit`. ([kubernetes/kubernetes101822](https://github.com/kubernetes/kubernetes/pull/101822), [yuzhiquan](https://github.com/yuzhiquan))
- A value of `Auto` is now a valid for the `service.kubernetes.io/topology-aware-hints` annotation. ([kubernetes/kubernetes100728](https://github.com/kubernetes/kubernetes/pull/100728), [robscott](https://github.com/robscott))
- Add `DataSourceRef` alpha field to PVC spec, which allows contents other than `PVCs` and `VolumeSnapshots` to be data sources. ([kubernetes/kubernetes103276](https://github.com/kubernetes/kubernetes/pull/103276), [bswartz](https://github.com/bswartz))
- Add `PersistentVolumeClaimDeletePoilcy` to StatefulSet API. ([kubernetes/kubernetes99378](https://github.com/kubernetes/kubernetes/pull/99378), [mattcary](https://github.com/mattcary))
- Add a new Priority and Fairness rule that exempts all probes (`/readyz`, `/healthz`, `/livez`) to prevent restarting of healthy `kube-apiserver` instance by kubelet. ([kubernetes/kubernetes100678](https://github.com/kubernetes/kubernetes/pull/100678), [tkashem](https://github.com/tkashem))
- Add alpha support for HostProcess containers on Windows ([kubernetes/kubernetes99576](https://github.com/kubernetes/kubernetes/pull/99576), [marosset](https://github.com/marosset)) [SIG API Machinery, Apps, Node, Testing and Windows]
- Add distributed tracing to the `kube-apiserver`. It is can be enabled with the feature gate `APIServerTracing` ([kubernetes/kubernetes94942](https://github.com/kubernetes/kubernetes/pull/94942), [dashpole](https://github.com/dashpole))
- Add three metrics to the job controller to monitor if a job works in healthy condition.
`IndexedJob` has been promoted to Beta. ([kubernetes/kubernetes101292](https://github.com/kubernetes/kubernetes/pull/101292), [AliceZhang2016](https://github.com/AliceZhang2016))
- Added field `.status.uncountedTerminatedPods` to the Job resource. This field is used by the job controller to keep track of finished pods before adding them to the Job status counters. Pods created by the job controller get the finalizer `batch.kubernetes.io/job-tracking`
Jobs that are tracked using this mechanism get the annotation `batch.kubernetes.io/job-tracking`. This is a temporary measure. Two releases after this feature graduates to beta, the annotation won't be added to Jobs anymore. ([kubernetes/kubernetes98817](https://github.com/kubernetes/kubernetes/pull/98817), [alculquicondor](https://github.com/alculquicondor))
- Added new kubelet alpha feature `SeccompDefault`. This feature enables falling back to
the `RuntimeDefault` (former `runtime/default`) seccomp profile if nothing else is specified
in the pod/container `SecurityContext` or the pod annotation level. To use the feature, enable
the feature gate as well as set the kubelet configuration option `SeccompDefault`
(`--seccomp-default`) to `true`. ([kubernetes/kubernetes101943](https://github.com/kubernetes/kubernetes/pull/101943), [saschagrunert](https://github.com/saschagrunert)) [SIG Node]
- Adds the `ReadWriteOncePod` access mode for `PersistentVolumes` and `PersistentVolumeClaims`. Restricts volume access to a single pod on a single node. ([kubernetes/kubernetes102028](https://github.com/kubernetes/kubernetes/pull/102028), [chrishenzie](https://github.com/chrishenzie))
- Alpha swap support can now be enabled on Kubernetes nodes with the `NodeSwapEnabled` feature flag. See [KEP-2400](https://github.com/kubernetes/enhancements/blob/master/keps/sig-node/2400-node-swap/README.md#design-details) for details. ([kubernetes/kubernetes102823](https://github.com/kubernetes/kubernetes/pull/102823), [ehashman](https://github.com/ehashman))
- Because of the implementation logic of `time.Format` in golang, the displayed time zone is not consistent. ([kubernetes/kubernetes102366](https://github.com/kubernetes/kubernetes/pull/102366), [cndoit18](https://github.com/cndoit18))
- Corrected the documentation for escaping dollar signs in a container's env, command and args property. ([kubernetes/kubernetes101916](https://github.com/kubernetes/kubernetes/pull/101916), [MartinKanters](https://github.com/MartinKanters)) [SIG Apps]
- Enable `MaxSurge` for `DaemonSet` by default. ([kubernetes/kubernetes101742](https://github.com/kubernetes/kubernetes/pull/101742), [ravisantoshgudimetla](https://github.com/ravisantoshgudimetla))
- Enforce the `ReadWriteOncePod` PVC access mode during scheduling ([kubernetes/kubernetes103082](https://github.com/kubernetes/kubernetes/pull/103082), [chrishenzie](https://github.com/chrishenzie))
- Ephemeral containers are now allowed to configure a `securityContext` that differs from that of the Pod. Cluster administrators should ensure that security policy controllers support `EphemeralContainers` before enabling this feature in clusters. ([kubernetes/kubernetes99023](https://github.com/kubernetes/kubernetes/pull/99023), [verb](https://github.com/verb))
- Exec plugin authors can override default handling of standard input via new `interactiveMode` kubeconfig field. ([kubernetes/kubernetes99310](https://github.com/kubernetes/kubernetes/pull/99310), [ankeesler](https://github.com/ankeesler))
- If someone had the `ProbeTerminationGracePeriod` alpha feature enabled in 1.21, they should update/delete any workloads/pods with probe `terminationGracePeriods` < 1 before upgrading ([kubernetes/kubernetes103245](https://github.com/kubernetes/kubernetes/pull/103245), [wzshiming](https://github.com/wzshiming))
- Improved parsing of label selectors ([kubernetes/kubernetes102188](https://github.com/kubernetes/kubernetes/pull/102188), [alculquicondor](https://github.com/alculquicondor)) [SIG API Machinery]
- Introduce `minReadySeconds` api to the `StatefulSets`. ([kubernetes/kubernetes100842](https://github.com/kubernetes/kubernetes/pull/100842), [ravisantoshgudimetla](https://github.com/ravisantoshgudimetla))
- Introducing Memory quality of service support with `cgroups v2 (Alpha)`. The `MemoryQoS` feature is now in Alpha. This allows `kubelet` running with `cgroups v2` to set memory QoS at container, pod and QoS level to protect and guarantee better memory quality. This feature can be enabled through feature gate Memory QoS. ([kubernetes/kubernetes102970](https://github.com/kubernetes/kubernetes/pull/102970), [borgerli](https://github.com/borgerli))
- Kube API server accepts `Impersonate-Uid` header to impersonate a user with a specific UID, in the same way that you can currently use `Impersonate-User`, `Impersonate-Group` and `Impersonate-Extra`. ([kubernetes/kubernetes99961](https://github.com/kubernetes/kubernetes/pull/99961), [margocrawf](https://github.com/margocrawf))
- Kube-apiserver: `--service-account-issuer` can be specified multiple times now, to enable non-disruptive change of issuer. ([kubernetes/kubernetes101155](https://github.com/kubernetes/kubernetes/pull/101155), [zshihang](https://github.com/zshihang)) [SIG API Machinery, Auth, Node and Testing]
- Kube-controller-manager: the `--horizontal-pod-autoscaler-use-rest-clients` flag and Heapster support in the horizontal pod autoscaler, deprecated since 1.12, is removed. ([kubernetes/kubernetes90368](https://github.com/kubernetes/kubernetes/pull/90368), [serathius](https://github.com/serathius))
- Kube-scheduler: a plugin enabled in a v1beta2 configuration file takes precedence over the default configuration for that plugin. This simplifies enabling default plugins with custom configuration without needing to explicitly disable those default plugins. ([kubernetes/kubernetes99582](https://github.com/kubernetes/kubernetes/pull/99582), [chendave](https://github.com/chendave))
- New `node-high` priority-level has been added to Suggested API Priority and ([kubernetes/kubernetes101151](https://github.com/kubernetes/kubernetes/pull/101151), [mborsz](https://github.com/mborsz))
- NodeSwapEnabled feature flag was renamed to NodeSwap

The flag was only available in the 1.22.0-beta.1 release, and the new flag should be used going forward. ([kubernetes/kubernetes103553](https://github.com/kubernetes/kubernetes/pull/103553), [ehashman](https://github.com/ehashman)) [SIG Node]
- Omit comparison with boolean constant ([kubernetes/kubernetes101523](https://github.com/kubernetes/kubernetes/pull/101523), [chuntaochen](https://github.com/chuntaochen)) [SIG CLI and Cloud Provider]
- Removed the feature flag for probe-level termination grace period from Kubelet. If a user wants to disable this feature on already created pods, they will have to delete and recreate the pods. ([kubernetes/kubernetes103168](https://github.com/kubernetes/kubernetes/pull/103168), [raisaat](https://github.com/raisaat)) [SIG Apps and Node]
- Revert addition of Add `PersistentVolumeClaimDeletePoilcy` to `StatefulSet`API. ([kubernetes/kubernetes103747](https://github.com/kubernetes/kubernetes/pull/103747), [mattcary](https://github.com/mattcary))
- Scheduler could be configured to consider new resources beside CPU and memory, GPU for example, for the score plugin of `NodeResourcesBalancedAllocation`. ([kubernetes/kubernetes101946](https://github.com/kubernetes/kubernetes/pull/101946), [chendave](https://github.com/chendave)) [SIG Scheduling]
- Server Side Apply now treats all <Some>Selector fields as atomic (meaning the entire selector is managed by a single writer and updated together), since they contain interrelated and inseparable fields that do not merge in intuitive ways. ([kubernetes/kubernetes97989](https://github.com/kubernetes/kubernetes/pull/97989), [Danil-Grigorev](https://github.com/Danil-Grigorev)) [SIG API Machinery]
- Suspend Job feature graduated to beta. Added the `action` label to Job controller sync metrics `job_sync_total` and `job_sync_duration_seconds`. ([kubernetes/kubernetes102022](https://github.com/kubernetes/kubernetes/pull/102022), [adtac](https://github.com/adtac))
- The API documentation for the DaemonSet's `spec.updateStrategy.rollingUpdate.maxUnavailable` field was corrected to state that the value is rounded up. ([kubernetes/kubernetes101296](https://github.com/kubernetes/kubernetes/pull/101296), [Miciah](https://github.com/Miciah))
- The `CSIServiceAccountToken` graduates to Ga and is unconditionally enabled. ([kubernetes/kubernetes103001](https://github.com/kubernetes/kubernetes/pull/103001), [zshihang](https://github.com/zshihang))
- The `CertificateSigningRequest.certificates.k8s.io` API supports an optional expirationSeconds field to allow the client to request a particular duration for the issued certificate. The default signer implementations provided by the Kubernetes controller manager will honor this field as long as it does not exceed the --cluster-signing-duration flag. ([kubernetes/kubernetes99494](https://github.com/kubernetes/kubernetes/pull/99494), [enj](https://github.com/enj))
- The `EndpointSlicen Mirroring controller` no longer mirrors the `last-applied-configuration` annotation created by `kubectl` to update `EndpointSlices`. ([kubernetes/kubernetes102731](https://github.com/kubernetes/kubernetes/pull/102731), [sharmarajdaksh](https://github.com/sharmarajdaksh))
- The `NetworkPolicyEndPort` is graduated to beta and is enabled by default. ([kubernetes/kubernetes102834](https://github.com/kubernetes/kubernetes/pull/102834), [rikatz](https://github.com/rikatz))
- The `PodDeletionCost` feature has been promoted to beta, and enabled by default. ([kubernetes/kubernetes101080](https://github.com/kubernetes/kubernetes/pull/101080), [ahg-g](https://github.com/ahg-g))
- The `Server Side Apply` treats certain structs as atomic. Meaning the entire selector field is managed by a single writer and updated together. ([kubernetes/kubernetes100684](https://github.com/kubernetes/kubernetes/pull/100684), [Jefftree](https://github.com/Jefftree))
- The `ServiceAppProtocol` feature gate has been removed. It reached GA in Kubernetes ([kubernetes/kubernetes103190](https://github.com/kubernetes/kubernetes/pull/103190), [robscott](https://github.com/robscott))
- The `TerminationGracePeriodSeconds` on pod specs and container probes should not be negative. Negative values of `TerminationGracePeriodSeconds` will be treated as the value `1s` on the delete path. Immutable field validation will be relaxed in order to update negative values. In a future release, negative values will not be permitted. ([kubernetes/kubernetes98866](https://github.com/kubernetes/kubernetes/pull/98866), [wzshiming](https://github.com/wzshiming))
- The `kube-scheduler` component config `v1beta2` API available
Three scheduler plugins deprecated (`NodeLabel`, `ServiceAffinity`, `NodePreferAvoidPods`). ([kubernetes/kubernetes99597](https://github.com/kubernetes/kubernetes/pull/99597), [adtac](https://github.com/adtac))
- The `pod/eviction` subresource now accepts `policy/v1` eviction requests in addition to `policy/v1beta1` eviction requests ([kubernetes/kubernetes100724](https://github.com/kubernetes/kubernetes/pull/100724), [liggitt](https://github.com/liggitt))
- The `podAffinity`, `NamespaceSelector` and the associated `CrossNamespaceAffinity` quota scope features graduate to Beta and they are now enabled by default. ([kubernetes/kubernetes101496](https://github.com/kubernetes/kubernetes/pull/101496), [ahg-g](https://github.com/ahg-g))
- The `pods/ephemeralcontainers` API now returns and expects a `Pod` object instead of `EphemeralContainers`. This is incompatible with the previous alpha-level API. ([kubernetes/kubernetes101034](https://github.com/kubernetes/kubernetes/pull/101034), [verb](https://github.com/verb)) [SIG Apps, Auth, CLI and Testing]
- The `v1.Node` and `.status.images[].names` are now optional. ([kubernetes/kubernetes102159](https://github.com/kubernetes/kubernetes/pull/102159), [roycaihw](https://github.com/roycaihw))
- The deprecated flag `--algorithm-provider` has been removed from `kube-scheduler`. Use instead `ComponentConfig` to configure the set of enabled plugins. ([kubernetes/kubernetes102239](https://github.com/kubernetes/kubernetes/pull/102239), [Haleygo](https://github.com/Haleygo))
- The options `--ssh-user` and `--ssh-key` are removed. They only functioned on GCE, and only in-tree. Use the apiserver network proxy instead. ([kubernetes/kubernetes102297](https://github.com/kubernetes/kubernetes/pull/102297), [deads2k](https://github.com/deads2k))
- Track Job completion through status and Pod finalizers, removing dependency on Pod tombstones. ([kubernetes/kubernetes98238](https://github.com/kubernetes/kubernetes/pull/98238), [alculquicondor](https://github.com/alculquicondor)) [SIG API Machinery, Apps, Auth and Testing]
- Track ownership of scale subresource for all scalable resources i.e. Deployment, ReplicaSet, StatefulSet, ReplicationController, and Custom Resources. ([kubernetes/kubernetes98377](https://github.com/kubernetes/kubernetes/pull/98377), [nodo](https://github.com/nodo)) [SIG API Machinery and Testing]
- Revert addition of Add PersistentVolumeClaimDeletePoilcy to StatefulSet API. ([kubernetes/kubernetes103747](https://github.com/kubernetes/kubernetes/pull/103747), [mattcary](https://github.com/mattcary)) [SIG API Machinery and Apps]
- Added field .status.uncountedTerminatedPods to the Job resource. This field is used by the job controller to keep track of finished pods before adding them to the Job status counters.

Pods created by the job controller get the finalizer batch.kubernetes.io/job-tracking

Jobs that are tracked using this mechanism get the annotation batch.kubernetes.io/job-tracking. This is a temporary measure. Two releases after this feature graduates to beta, the annotation won't be added to Jobs anymore. ([kubernetes/kubernetes98817](https://github.com/kubernetes/kubernetes/pull/98817), [alculquicondor](https://github.com/alculquicondor)) [SIG API Machinery, Apps, Auth and CLI]
- Ephemeral containers are now allowed to configure a securityContext that differs from that of the Pod.

Cluster administrators should ensure that security policy controllers support EphemeralContainers before enabling this feature in clusters. ([kubernetes/kubernetes99023](https://github.com/kubernetes/kubernetes/pull/99023), [verb](https://github.com/verb)) [SIG API Machinery, Apps, Auth and Node]
- If someone had the ProbeTerminationGracePeriod alpha feature enabled in 1.21, they should update/delete any workloads/pods with probe terminationGracePeriods < 1 before upgrading ([kubernetes/kubernetes103245](https://github.com/kubernetes/kubernetes/pull/103245), [wzshiming](https://github.com/wzshiming)) [SIG Apps and Node]
- Introducing Memory QoS support with cgroups v2 (Alpha)
The MemoryQoS feature is now in Alpha. This allows kubelet running with cgroups v2 to set memory QoS at container, pod and QoS level to protect and guarantee better memory quality. This feature can be enabled through feature gate MemoryQoS. ([kubernetes/kubernetes102970](https://github.com/kubernetes/kubernetes/pull/102970), [borgerli](https://github.com/borgerli)) [SIG Node and Storage]
- NodeSwapEnabled feature flag was renamed to NodeSwap

The flag was only available in the 1.22.0-beta.1 release, and the new flag should be used going forward. ([kubernetes/kubernetes103553](https://github.com/kubernetes/kubernetes/pull/103553), [ehashman](https://github.com/ehashman)) [SIG Node]
- Removed the feature flag for probe-level termination grace period from Kubelet. If a user wants to disable this feature on already created pods, they will have to delete and recreate the pods. ([kubernetes/kubernetes103168](https://github.com/kubernetes/kubernetes/pull/103168), [raisaat](https://github.com/raisaat)) [SIG Apps and Node]
- Track Job completion through status and Pod finalizers, removing dependency on Pod tombstones. ([kubernetes/kubernetes98238](https://github.com/kubernetes/kubernetes/pull/98238), [alculquicondor](https://github.com/alculquicondor)) [SIG API Machinery, Apps, Auth and Testing]
- When using `kubectl replace` (or the equivalent API call) on a Service, the caller no longer needs to do a read-modify-write cycle to fetch the allocated values for `.spec.clusterIP` and `.spec.ports[].nodePort`. Instead the API server will automatically carry these forward from the original object when the new object does not specify them. ([kubernetes/kubernetes103532](https://github.com/kubernetes/kubernetes/pull/103532), [thockin](https://github.com/thockin)) [SIG Apps and Network]
- A new score extension for NodeResourcesFit plugin that merges the functionality of NodeResourcesLeastAllocated,NodeResourcesMostAllocated,RequestedToCapacityRatio plugins, which are marked as deprecated as of v1beta2. In v1beta1, the three plugins can still be used in v1beta1 but not at the same time with the score extension of NodeResourcesFit
- Add DataSourceRef alpha field to PVC spec, which allows contents other than PVCs and VolumeSnapshots to be data sources. ([kubernetes/kubernetes103276](https://github.com/kubernetes/kubernetes/pull/103276), [bswartz](https://github.com/bswartz)) [SIG API Machinery, Apps and Storage]
- Add PersistentVolumeClaimDeletePoilcy to StatefulSet API. ([kubernetes/kubernetes99378](https://github.com/kubernetes/kubernetes/pull/99378), [mattcary](https://github.com/mattcary)) [SIG API Machinery and Apps]
- Add distributed tracing to the kube-apiserver. It is can be enabled with the feature gate: APIServerTracing=true ([kubernetes/kubernetes94942](https://github.com/kubernetes/kubernetes/pull/94942), [dashpole](https://github.com/dashpole)) [SIG API Machinery, CLI, Cloud Provider, Cluster Lifecycle, Instrumentation, Node, Storage and Testing]
- Added new kubelet alpha feature `SeccompDefault`. This feature enables falling back to
the `RuntimeDefault` (former `runtime/default`) seccomp profile if nothing else is specified
in the pod/container `SecurityContext` or the pod annotation level. To use the feature, enable
the feature gate as well as set the kubelet configuration option `SeccompDefault`
(`--seccomp-default`) to `true`. ([kubernetes/kubernetes101943](https://github.com/kubernetes/kubernetes/pull/101943), [saschagrunert](https://github.com/saschagrunert)) [SIG Node]
- Adds the ReadWriteOncePod access mode for PersistentVolumes and PersistentVolumeClaims. Restricts volume access to a single pod on a single node. ([kubernetes/kubernetes102028](https://github.com/kubernetes/kubernetes/pull/102028), [chrishenzie](https://github.com/chrishenzie)) [SIG Apps, CLI, Node, Scheduling and Storage]
- Alpha swap support can now be enabled on Kubernetes nodes with the NodeSwapEnabled feature flag. See <website link> for details. ([kubernetes/kubernetes102823](https://github.com/kubernetes/kubernetes/pull/102823), [ehashman](https://github.com/ehashman)) [SIG Node]
- CSIServiceAccountToken is GA. ([kubernetes/kubernetes103001](https://github.com/kubernetes/kubernetes/pull/103001), [zshihang](https://github.com/zshihang)) [SIG Auth and Storage]
- Enforce the ReadWriteOncePod PVC access mode during scheduling ([kubernetes/kubernetes103082](https://github.com/kubernetes/kubernetes/pull/103082), [chrishenzie](https://github.com/chrishenzie)) [SIG Apps, CLI, Node, Scheduling and Storage]
- Improved parsing of label selectors ([kubernetes/kubernetes102188](https://github.com/kubernetes/kubernetes/pull/102188), [alculquicondor](https://github.com/alculquicondor)) [SIG API Machinery]
- Kube API server accepts Impersonate-Uid header to impersonate a user with a specific UID, in the same way that you can currently use Impersonate-User, Impersonate-Group and Impersonate-Extra ([kubernetes/kubernetes99961](https://github.com/kubernetes/kubernetes/pull/99961), [margocrawf](https://github.com/margocrawf)) [SIG API Machinery, Auth and Testing]
- Kube-scheduler: a plugin enabled in a v1beta2 configuration file takes precedence over the default configuration for that plugin; this simplifies enabling default plugins with custom configuration without needing to explicitly disable those default plugins. ([kubernetes/kubernetes99582](https://github.com/kubernetes/kubernetes/pull/99582), [chendave](https://github.com/chendave)) [SIG Scheduling]
- Scheduler could be configured to consider new resources beside CPU and memory, GPU for example, for the score plugin of `NodeResourcesBalancedAllocation`. ([kubernetes/kubernetes101946](https://github.com/kubernetes/kubernetes/pull/101946), [chendave](https://github.com/chendave)) [SIG Scheduling]
- Suspend Job feature graduated to beta
Added the "action" label to Job controller sync metrics job_sync_total and job_sync_duration_seconds ([kubernetes/kubernetes102022](https://github.com/kubernetes/kubernetes/pull/102022), [adtac](https://github.com/adtac)) [SIG Apps, Instrumentation and Testing]
- TerminationGracePeriodSeconds on pod specs and container probes should not be negative.
Negative values of TerminationGracePeriodSeconds will be treated as the value `1s` on the delete path.
Immutable field validation will be relaxed in order to update negative values.
In a future release, negative values will not be permitted. ([kubernetes/kubernetes98866](https://github.com/kubernetes/kubernetes/pull/98866), [wzshiming](https://github.com/wzshiming)) [SIG API Machinery, Apps and Node]
- The API documentation for the DaemonSet's spec.updateStrategy.rollingUpdate.maxUnavailable field was corrected to state that the value is rounded up. ([kubernetes/kubernetes101296](https://github.com/kubernetes/kubernetes/pull/101296), [Miciah](https://github.com/Miciah)) [SIG Apps and CLI]
- The CertificateSigningRequest.certificates.k8s.io API supports an optional expirationSeconds field to allow the client to request a particular duration for the issued certificate. The default signer implementations provided by the Kubernetes controller manager will honor this field as long as it does not exceed the --cluster-signing-duration flag. ([kubernetes/kubernetes99494](https://github.com/kubernetes/kubernetes/pull/99494), [enj](https://github.com/enj)) [SIG API Machinery, Apps, Auth, CLI, Instrumentation, Node, Security and Testing]
- The ServiceAppProtocol feature gate has been removed. It reached GA in Kubernetes 1.20. ([kubernetes/kubernetes103190](https://github.com/kubernetes/kubernetes/pull/103190), [robscott](https://github.com/robscott)) [SIG Network]
- Because of the implementation logic of time.Format in golang, the displayed time zone is not consistent ([kubernetes/kubernetes102366](https://github.com/kubernetes/kubernetes/pull/102366), [cndoit18](https://github.com/cndoit18)) [SIG Apps, Auth, Autoscaling, CLI, Cluster Lifecycle, Instrumentation, Network, Node and Testing]
- Endpoint slices mirroring controller no longer mirrors the last-applied-configuration annotation created by kubectl to updated endpoint slices ([kubernetes/kubernetes102731](https://github.com/kubernetes/kubernetes/pull/102731), [sharmarajdaksh](https://github.com/sharmarajdaksh)) [SIG API Machinery, Apps, Cloud Provider, Network, Release, Scheduling, Storage and Testing]
- Exec plugin authors can override default handling of standard input via new interactiveMode kubeconfig field ([kubernetes/kubernetes99310](https://github.com/kubernetes/kubernetes/pull/99310), [ankeesler](https://github.com/ankeesler)) [SIG API Machinery, Auth, CLI and Testing]
- Kube-scheduler component config v1beta2 API available
Three scheduler plugins deprecated (NodeLabel, ServiceAffinity, NodePreferAvoidPods) ([kubernetes/kubernetes99597](https://github.com/kubernetes/kubernetes/pull/99597), [adtac](https://github.com/adtac)) [SIG Scheduling]
- Network Policy EndPort is graduated to beta and is enabled by default ([kubernetes/kubernetes102834](https://github.com/kubernetes/kubernetes/pull/102834), [rikatz](https://github.com/rikatz)) [SIG Network]
- --ssh-user and --ssh-key options are removed. They only functioned on GCE, and only in-tree. Use the apiserver network proxy instead. ([kubernetes/kubernetes102297](https://github.com/kubernetes/kubernetes/pull/102297), [deads2k](https://github.com/deads2k)) [SIG API Machinery, Cloud Provider and Testing]
- Enable MaxSurge for DS by default ([kubernetes/kubernetes101742](https://github.com/kubernetes/kubernetes/pull/101742), [ravisantoshgudimetla](https://github.com/ravisantoshgudimetla)) [SIG Apps and Testing]
- Introduce minReadySeconds api to the StatefulSets. ([kubernetes/kubernetes100842](https://github.com/kubernetes/kubernetes/pull/100842), [ravisantoshgudimetla](https://github.com/ravisantoshgudimetla)) [SIG API Machinery, Apps and Testing]
- Kube-controller-manger: the `--horizontal-pod-autoscaler-use-rest-clients` flag and Heapster support in the horizontal pod autoscaler, deprecated since 1.12, is removed. ([kubernetes/kubernetes90368](https://github.com/kubernetes/kubernetes/pull/90368), [serathius](https://github.com/serathius)) [SIG API Machinery, Apps, Autoscaling, Cloud Provider and Instrumentation]
- The deprecated flag --algorithm-provider has been removed from kube-scheduler. Use instead ComponentConfig to configure the set of enabled plugins ([kubernetes/kubernetes102239](https://github.com/kubernetes/kubernetes/pull/102239), [Haleygo](https://github.com/Haleygo)) [SIG Cloud Provider and Scheduling]
- Add alpha support for HostProcess containers on Windows ([kubernetes/kubernetes99576](https://github.com/kubernetes/kubernetes/pull/99576), [marosset](https://github.com/marosset)) [SIG API Machinery, Apps, Node, Testing and Windows]
- Add three metrics to job controller to monitor if Job works in a healthy condition.
IndexedJob promoted to Beta ([kubernetes/kubernetes101292](https://github.com/kubernetes/kubernetes/pull/101292), [AliceZhang2016](https://github.com/AliceZhang2016)) [SIG Apps, Instrumentation and Testing]
- Corrected the documentation for escaping dollar signs in a container's env, command and args property. ([kubernetes/kubernetes101916](https://github.com/kubernetes/kubernetes/pull/101916), [MartinKanters](https://github.com/MartinKanters)) [SIG Apps]
- Omit comparison with boolean constant ([kubernetes/kubernetes101523](https://github.com/kubernetes/kubernetes/pull/101523), [GreenApple10](https://github.com/GreenApple10)) [SIG CLI and Cloud Provider]
- Pod Affinity NamespaceSelector and the associated CrossNamespaceAffinity quota scope graduated to beta ([kubernetes/kubernetes101496](https://github.com/kubernetes/kubernetes/pull/101496), [ahg-g](https://github.com/ahg-g)) [SIG API Machinery, Apps and Testing]
- V1.Node .status.images[].names is now optional ([kubernetes/kubernetes102159](https://github.com/kubernetes/kubernetes/pull/102159), [roycaihw](https://github.com/roycaihw)) [SIG Apps and Node]
- "Auto" is now a valid value for the `service.kubernetes.io/topology-aware-hints` annotation. ([kubernetes/kubernetes100728](https://github.com/kubernetes/kubernetes/pull/100728), [robscott](https://github.com/robscott)) [SIG Apps, Instrumentation and Network]
- Kube-apiserver: `--service-account-issuer` can be specified multiple times now, to enable non-disruptive change of issuer. ([kubernetes/kubernetes101155](https://github.com/kubernetes/kubernetes/pull/101155), [zshihang](https://github.com/zshihang)) [SIG API Machinery, Auth, Node and Testing]
- New "node-high" priority-level has been added to Suggested API Priority and Fairness configuration. ([kubernetes/kubernetes101151](https://github.com/kubernetes/kubernetes/pull/101151), [mborsz](https://github.com/mborsz)) [SIG API Machinery]
- PodDeletionCost promoted to Beta ([kubernetes/kubernetes101080](https://github.com/kubernetes/kubernetes/pull/101080), [ahg-g](https://github.com/ahg-g)) [SIG Apps]
- SSA treats certain structs as atomic ([kubernetes/kubernetes100684](https://github.com/kubernetes/kubernetes/pull/100684), [Jefftree](https://github.com/Jefftree)) [SIG API Machinery, Auth, Node and Storage]
- Server Side Apply now treats all <Some>Selector fields as atomic (meaning the entire selector is managed by a single writer and updated together), since they contain interrelated and inseparable fields that do not merge in intuitive ways. ([kubernetes/kubernetes97989](https://github.com/kubernetes/kubernetes/pull/97989), [Danil-Grigorev](https://github.com/Danil-Grigorev)) [SIG API Machinery]
- The `pods/ephemeralcontainers` API now returns and expects a `Pod` object instead of `EphemeralContainers`. This is incompatible with the previous alpha-level API. ([kubernetes/kubernetes101034](https://github.com/kubernetes/kubernetes/pull/101034), [verb](https://github.com/verb)) [SIG Apps, Auth, CLI and Testing]
- The pod/eviction subresource now accepts policy/v1 Eviction requests in addition to policy/v1beta1 Eviction requests ([kubernetes/kubernetes100724](https://github.com/kubernetes/kubernetes/pull/100724), [liggitt](https://github.com/liggitt)) [SIG API Machinery, Apps, Architecture, Auth, CLI, Storage and Testing]
- Track ownership of scale subresource for all scalable resources i.e. Deployment, ReplicaSet, StatefulSet, ReplicationController, and Custom Resources. ([kubernetes/kubernetes98377](https://github.com/kubernetes/kubernetes/pull/98377), [nodo](https://github.com/nodo)) [SIG API Machinery and Testing]
- We have added a new Priority & Fairness rule that exempts all probes (/readyz, /healthz, /livez) to prevent
restarting of "healthy" kube-apiserver instance(s) by kubelet. ([kubernetes/kubernetes100678](https://github.com/kubernetes/kubernetes/pull/100678), [tkashem](https://github.com/tkashem)) [SIG API Machinery]