"content": {"application/x-level-0": {"schema": {}}},
                            },
                            "400": {"description": "Client error level 0"},
                            "422": {
                                "description": "Validation Error",
                                "content": {
                                    "application/json": {

    - [Client Binaries](#client-binaries-12)
    - [Server Binaries](#server-binaries-12)
    - [Node Binaries](#node-binaries-12)
- [Kubernetes 1.13 Release Notes](#kubernetes-113-release-notes)
  - [Security Content](#security-content)
  - [Urgent Upgrade Notes](#urgent-upgrade-notes)
    - [(No, really, you MUST do this before you upgrade)](#no-really-you-must-do-this-before-you-upgrade)
  - [Known Issues](#known-issues)

### API Change

### 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))

## 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.

- Kubeadm: fix a bug where kubeadm upgrade is failed if the content of the `kubeadm-flags.env` file is `KUBELET_KUBEADM_ARGS=""` ([#136131](https://github.com/kubernetes/kubernetes/pull/136131), [@carlory](https://github.com/carlory)) [SIG Cluster Lifecycle]

- 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]

- 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]

- 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. ([#...