- 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:

- The underlying format of the `CPUManager` state file has changed. Upgrades should be seamless, but any third-party tools that rely on reading the previous format need to be updated. ([#84462](https://github.com/kubernetes/kubernetes/pull/84462), [@klueska](https://github.com/klueska)) [SIG Node and Testing]

### API Change

- '`kube-apiserver`: adds `--authentication-config` flag for reading `AuthenticationConfiguration`
  files. `--authentication-config` flag is mutually exclusive with the existing `--oidc-*`

- Fixed file permission issues that happened during update of `Secret`/`ConfigMap`/`projected volume` when `fsGroup` is used. The problem caused a race condition where application gets intermittent permission denied error when reading files that were just updated, before the correct permissions were applied. ([#114464](https://github.com/kubernetes/kubernetes/pull/114464), [@tsaarni](https://github.com/tsaarni))

* Add fallbacks to ARM API when getting empty node IP from Azure IMDS ([#69077](https://github.com/kubernetes/kubernetes/pull/69077), [@feiskyer](https://github.com/feiskyer))
* Deduplicate PATH items when reading plugins. ([#69089](https://github.com/kubernetes/kubernetes/pull/69089), [@soltysh](https://github.com/soltysh))

### API Change

- 'ACTION REQUIRED: The Dynamic Resource Allocation (DRA) driver's DaemonSet
  must be deployed with a service account that enables writing ResourceSlice
  and reading ResourceClaim objects.'
   ([#125163](https://github.com/kubernetes/kubernetes/pull/125163), [@pohly](https://github.com/pohly)) [SIG Auth, Node and Testing]

  // It is provided as a write-only input field for convenience.
  // All keys and values are merged into the data field on write, overwriting any existing values.
  // The stringData field is never output when reading from the API.
  // +k8s:conversion-gen=false
  // +optional
  map<string, string> stringData = 4;

  // Used to facilitate programmatic handling of secret data.

- Removed leading zeros from the etcd member ID in kubeadm log messages. ([#117919](https://github.com/kubernetes/kubernetes/pull/117919), [@dlipovetsky](https://github.com/dlipovetsky)) [SIG Cluster Lifecycle]

CustomResourceDefinitions also have new support for defaulting, with defaults specified using the `default` keyword in the OpenAPI validation schema. Defaults are set for unspecified fields in an object sent to the API, and when reading from etcd.

Defaulting will be available as alpha in Kubernetes 1.15 and requires structural schemas.

#### CustomResourceDefinition OpenAPI Publishing

* Get public IP for Azure vmss nodes. ([#68498](https://github.com/kubernetes/kubernetes/pull/68498), [@feiskyer](https://github.com/feiskyer))
* Deduplicate PATH items when reading plugins. ([#69170](https://github.com/kubernetes/kubernetes/pull/69170), [@soltysh](https://github.com/soltysh))



# v1.12.0

[Documentation](https://docs.k8s.io)

## Downloads for v1.12.0