- Kube-apiserver: Promoted the `ExternalServiceAccountTokenSigner` feature to beta, which enabled external signing of service account tokens and fetching of public verifying keys. This was accomplished by enabling the beta `ExternalServiceAccountTokenSigner` feature gate and specifying the `--service-account-signing-endpoint` flag. The flag value could either be the path to a Unix domain socket on the filesystem, or be prefixed with @ to indicate a Unix domain...

*   `etcd2` as a backend is deprecated and support will be removed in Kubernetes 1.13 or 1.14.

### **Auth**

*   Default controller-manager options for `--cluster-signing-cert-file` and `--cluster-signing-key-file` are deprecated and will be removed in a future release. ([#54495](https://github.com/kubernetes/kubernetes/pull/54495),[ @mikedanese](https://github.com/mikedanese))

- The kube-controller-manager managed signers can now have distinct signing certificates and keys.  See the help about `--cluster-signing-[signer-name]-{cert,key}-file`.  `--cluster-signing-{cert,key}-file` is still the default. ([#90822](https://github.com/kubernetes/kubernetes/pull/90822), [@deads2k](https://github.com/deads2k)) [SIG API Machinery, Apps and Auth]

- Azure: set dest prefix and port for IPv6 inbound security rule ([#91831](https://github.com/kubernetes/kubernetes/pull/91831), [@aramase](https://github.com/aramase)) [SIG Cloud Provider]
- Fix public IP not shown issues after assigning public IP to Azure VMs ([#90886](https://github.com/kubernetes/kubernetes/pull/90886), [@feiskyer](https://github.com/feiskyer)) [SIG Cloud Provider]

    * configuration scripts to allow configuration of signing duration of
    * certificates issued via the Certificate Signing Request API.

kube-controller-manager has dropped support for the `--insecure-experimental-approve-all-kubelet-csrs-for-group` flag. It is accepted in 1.7, but ignored. Instead, the csrapproving controller uses authorization checks to determine whether to approve certificate signing requests: ([#45619](https://github.com/kubernetes/kubernetes/pull/45619), [@mikedanese](https://github.com/mikedanese))

    * Before upgrading, users must ensure their controller manager will enable the csrapproving controller, create...

- Added support to the kube-apiserver for an alpha feature enabling external signing of service account tokens and fetching of public verifying keys, by enabling the Alpha `ExternalServiceAccountTokenSigner` feature gate and specifying `--service-account-signing-endpoint`. The flag value can either be the location of a Unix domain socket on a filesystem, or be prefixed with an @ symbol and name a Unix domain socket in...

- Fix public IP not shown issues after assigning public IP to Azure VMs ([#90886](https://github.com/kubernetes/kubernetes/pull/90886), [@feiskyer](https://github.com/feiskyer)) [SIG Cloud Provider]

- The kube-controller-manager's deprecated `--experimental-cluster-signing-duration` flag is now removed. Adapt your machinery to use the `--cluster-signing-duration` flag that is available since v1.19. ([#108476](https://github.com/kubernetes/kubernetes/pull/108476), [@ialidzhikov](https://github.com/ialidzhikov))

  - [Major Themes](#major-themes)
    - [Dockershim Removed from kubelet](#dockershim-removed-from-kubelet)
    - [Beta APIs Off by Default](#beta-apis-off-by-default)
    - [Signing Release Artifacts](#signing-release-artifacts)
    - [OpenAPI v3](#openapi-v3)
    - [Storage Capacity and Volume Expansion Are Generally Available](#storage-capacity-and-volume-expansion-are-generally-available)