"400": {"description": "Client error level 0"},
                        "401": {"description": "Client error level 1"},
                        "422": {
                            "description": "Validation Error",
                            "content": {
                                "application/json": {
                                    "schema": {

- The Pod API field `.spec.schedulingGates[*].name` now requires qualified names (like `example.com/mygate`), matching validation for names of `.spec.readinessGates[*].name`. Any uses of the alpha scheduling gate feature prior to 1.27 that do not match that validation must be renamed or deleted before upgrading to 1.27. ([#115821](https://github.com/kubernetes/kubernetes/pull/115821), [@lianghao208](https://github.com/lianghao208)) [SIG Apps...

  - true/strict - perform validation and error the request on any invalid fields in the ojbect. It will attempt to perform server-side validation if it is enabled on the apiserver, otherwise it will fall back to client-side validation.

that workloads (e.g. Deployments, DaemonSets, etc.) which used `PersistentDisk` volumes were using them in read-only mode.  This validation provided very little value at relatively host implementation cost, and will no longer be validated.  If this is a problem for a specific use-case, please set the `SkipReadOnlyValidationGCE` gate to false to re-enable the validation, and file a Kubernetes bug with details. ([#121083](https://github.com/kubernetes/kubernetes/pull/121083), [@thockin](https://github.com/thockin))...

//     restrictions like, "must refer only to types A and B" or "UID not honored" or "name must be restricted".
//     Those cannot be well described when embedded.
//  3. Inconsistent validation.  Because the usages are different, the validation rules are different by usage, which makes it hard for users to predict what will happen.

- Fixed EndpointSlice port name validation to match Endpoint port name validation (allowing port names longer than 15 characters) ([#84481](https://github.com/kubernetes/kubernetes/pull/84481), [@robscott](https://github.com/robscott))

Pruning requires that CRD developer provides complete, structural validation schemas, either at the top-level or for all versions of the CRD.

#### CustomResourceDefinition Defaulting

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.

This release contains changes that address the following vulnerabilities:

### CVE-2021-25735: Validating Admission Webhook does not observe some previous fields

A security issue was discovered in kube-apiserver that could allow node
updates to bypass a Validating Admission Webhook. You are only affected
by this vulnerability if you run a Validating Admission Webhook for Nodes
that denies admission based at least partially on the old state of the

Service Level Indicators (SLIs) and Service Level Objectives (SLOs) for the system.
Here's the release [scalability validation report].

[SIG Scalability]: https://github.com/kubernetes/community/tree/master/sig-scalability
[scalability validation report]: https://github.com/kubernetes/sig-release/blob/master/releases/release-1.8/scalability_validation_report.md

### SIG Scheduling

    *   Make crictl command more user friendly and add more subcommands.
    *   Integrate with CRI verbose option to provide extra debug information.
    *   Update CRI to kubernetes v1.9.
    *   Bug fixes in validation test suites.