- Resolves a spurious "Unknown discovery response content-type" error in client-go discovery requests by tolerating extra content-type parameters in API responses ([#117637](https://github.com/kubernetes/kubernetes/pull/117637), [@seans3](https://github.com/seans3)) [SIG API Machinery]

* Add a check for file size if the reading content returns empty ([#33976](https://github.com/kubernetes/kubernetes/pull/33976), [@jingxu97](https://github.com/jingxu97))
* Add a retry when reading a file content from a container ([#35560](https://github.com/kubernetes/kubernetes/pull/35560), [@jingxu97](https://github.com/jingxu97))

### API Change

  * apiserver_request_total
  * apiserver_request_duration_seconds  
New "APPLY" value for the "verb" metric label which indicates a PATCH with "Content-Type: apply-patch+yaml". This value is experimental and will only be present if the ServerSideApply alpha feature is enabled. ([#74997](https://github.com/kubernetes/kubernetes/pull/74997), [@jennybuckley](https://github.com/jennybuckley))

      name: Age
      type: date
    name: v1
    schema:
      openAPIV3Schema:
        properties:
          spec:
            description: 'Configuration affecting label/content routing, sni routing,
              etc. See more details at: https://istio.io/docs/reference/config/networking/virtual-service.html'
            properties:
              exportTo:

### API Change

	cache := store.lock()
	defer store.unlock()

	// Handle policy mapping removal.
	if policy == "" {
		if store.getUsersSysType() == LDAPUsersSysType {
			// Add a fallback removal towards previous content that may come back
			// as a ghost user due to lack of delete, this change occurred
			// introduced in PR #11840
			store.deleteMappedPolicy(ctx, name, regUser, false)
		}

- Resolves a spurious "Unknown discovery response content-type" error in client-go discovery requests by tolerating extra content-type parameters in API responses ([#117571](https://github.com/kubernetes/kubernetes/pull/117571), [@seans3](https://github.com/seans3)) [SIG API Machinery]

## Introduction to v1.8.0

Kubernetes version 1.8 includes new features and enhancements, as well as fixes to identified issues. The release notes contain a brief overview of the important changes introduced in this release. The content is organized by Special Interest Groups ([SIGs][]).

For initial installations, see the [Setup topics][] in the Kubernetes
documentation.

- 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. ([#...