- Do not include preemptor pod metadata in the event message ([#114923](https://github.com/kubernetes/kubernetes/pull/114923), [@mimowo](https://github.com/mimowo)) [SIG Scheduling]

    * setting `ENABLE_METADATA_CONCEALMENT=true` in kube-up will now set a `cloud.google.com/metadata-proxy-ready=true` label on new nodes. In v1.16, the metadata proxy add-on will switch to using that label as a node selector.

* Fix logrotate config on GCI ([#29139](https://github.com/kubernetes/kubernetes/pull/29139), [@adityakali](https://github.com/adityakali))
* Do not query the metadata server to find out if running on GCE.  Retry metadata server query for gcr if running on gce. ([#28871](https://github.com/kubernetes/kubernetes/pull/28871), [@vishh](https://github.com/vishh))

 * Update NPN dependency to target `jdk7u60-b13` and `Oracle jdk7u55-b13`.
 * Ensure SPDY variants support zero-length DELETE and POST.
 * Prevent leaking a cache item's InputStreams when metadata read fails.
 * Use a string to identify TLS versions in routes.
 * Add frame logger for HTTP/2.
 * Replacing `httpMinorVersion` with `Protocol`. Expose HTTP/1.0 as a potential protocol.
 * Use `Protocol` to describe framing.

- Zero-value `metadata.creationTimestamp` values are now omitted and no longer serialize an explicit `null` in JSON, YAML, and CBOR output ([#130989](https://github.com/kubernetes/kubernetes/pull/130989), [@liggitt](https://github.com/liggitt)) [SIG API Machinery, Apps,...

## Changelog since v1.17.6

## Changes by Kind

### API Change

- Resolve regression in metadata.managedFields handling in update/patch requests submitted by older API clients ([#92008](https://github.com/kubernetes/kubernetes/pull/92008), [@apelisse](https://github.com/apelisse)) [SIG API Machinery and Testing]

### Feature

* Add path exist check in getPodVolumePathListFromDisk ([#38909](https://github.com/kubernetes/kubernetes/pull/38909), [@jingxu97](https://github.com/jingxu97))
* Ensure the GCI metadata files do not have newline at the end ([#38727](https://github.com/kubernetes/kubernetes/pull/38727), [@Amey-D](https://github.com/Amey-D))

    String CRAWLER_METADATA_CONTENT_EXCLUDES = "crawler.metadata.content.excludes";

    /** The key of the configuration. e.g. title=title:string<br>
     * Title=title:string<br>
     * dc:title=title:string<br>
     *  */
    String CRAWLER_METADATA_NAME_MAPPING = "crawler.metadata.name.mapping";

    /** The key of the configuration. e.g. //BODY */

- Improved memory usage of `kube-scheduler` by dropping the `.metadata.managedFields` field that `kube-scheduler` doesn't require. ([#119556](https://github.com/kubernetes/kubernetes/pull/119556), [@linxiulei](https://github.com/linxiulei))

- Namespace API objects now have a `kubernetes.io/metadata.name` label matching their metadata.name field to allow selecting any namespace by its name using a label selector. ([#96968](https://github.com/kubernetes/kubernetes/pull/96968), [@jayunit100](https://github.com/jayunit100)) [SIG API Machinery, Apps, Cloud Provider,...