- kubeadm: Allowed to download certificate secrets uploaded by `init` or `upload-certs` phase, allowing to transfer certificate secrets (certificates and keys) from the cluster to other master machines when creating HA deployments. ([#74168](https://github.com/kubernetes/kubernetes/pull/74168), [@ereslibre](https://github.com/ereslibre))

is okay, because cmd/link also processes the cgo_import_static directive and
knows that _cgo_gcc_Cfunc_sin is expected to be supplied by a host
object file, so cmd/link does not treat the missing symbol as an error when
creating go.o. Indeed, the definition for _cgo_gcc_Cfunc_sin will be
provided to the host linker by foo2.cgo.o, which in turn will need the
symbol 'sin'. cmd/link also processes the cgo_ldflag directives, so that it

* fix incorrect error info when creating an azure file PVC failed ([#56550](https://github.com/kubernetes/kubernetes/pull/56550), [@andyzhangx](https://github.com/andyzhangx))
* Retry 'connection refused' errors when setting up clusters on GCE. ([#57394](https://github.com/kubernetes/kubernetes/pull/57394), [@mborsz](https://github.com/mborsz))

# Release 2.21.0

## TensorFlow

<INSERT SMALL BLURB ABOUT RELEASE FOCUS AREA AND POTENTIAL TOOLCHAIN CHANGES>

### Breaking Changes

* <DOCUMENT BREAKING CHANGES HERE>
* <THIS SECTION SHOULD CONTAIN API, ABI AND BEHAVIORAL BREAKING CHANGES>

### Known Caveats

* <CAVEATS REGARDING THE RELEASE (BUT NOT BREAKING CHANGES).>
* <ADDING/BUMPING DEPENDENCIES SHOULD GO HERE>
* <KNOWN LACK OF SUPPORT ON SOME PLATFORM, SHOULD GO HERE>

// for io.EOF.
//
// If an EOF happens after reading some but not all the bytes,
// ReadFile returns ErrUnexpectedEOF.
//
// If the BitrotVerifier is not nil or not verified ReadFile
// tries to verify whether the disk has bitrot.
//
// Additionally ReadFile also starts reading from an offset. ReadFile
// semantics are same as io.ReadFull.

  - https://github.com/kubernetes-sigs/kustomize/pull/4985: If you previously included...

- Fixed kubelet creating extra sandbox for pods with RestartPolicyOnFailure after all containers succeeded ([#92614](https://github.com/kubernetes/kubernetes/pull/92614), [@tnqn](https://github.com/tnqn)) [SIG Node and Testing]

- Bug fix in test/e2e/framework  Framework.RecordFlakeIfError ([#111048](https://github.com/kubernetes/kubernetes/pull/111048), [@alingse](https://github.com/alingse)) [SIG Testing]
- Client-go: fixed an error in the fake client when creating API requests are submitted to subresources like `pods/eviction`. ([#110425](https://github.com/kubernetes/kubernetes/pull/110425), [@LY-today](https://github.com/LY-today))

		}
		res, ok := val.([]string)
		if !ok {
			return nil, errors.New("unexpected policy type")
		}
		return res, nil
	}
	return getPolicies()
}

// AddUsersToGroup - adds users to group, creating the group if needed.
func (store *IAMStoreSys) AddUsersToGroup(ctx context.Context, group string, members []string) (updatedAt time.Time, err error) {
	if group == "" {
		return updatedAt, errInvalidArgument
	}

- The drop-in kubelet configuration directory feature has been targeted for Beta. ([#122907](https://github.com/kubernetes/kubernetes/pull/122907), [@sohankunkerkar](https://github.com/sohankunkerkar))
- The kubelet now rejects creating the pod if `hostUserns=false` and the CRI runtime does not support user namespaces. ([#123216](https://github.com/kubernetes/kubernetes/pull/123216), [@giuseppe](https://github.com/giuseppe))