- Kubelet: improve the performance when waiting for a synchronization of the node list with the kube-apiserver ([#99336](https://github.com/kubernetes/kubernetes/pull/99336), [@neolit123](https://github.com/neolit123)) [SIG Node]

* Increase allowed lag for ssh key sync loop in tunneler to allow for one failure ([#60068](https://github.com/kubernetes/kubernetes/pull/60068), [@wojtek-t](https://github.com/wojtek-t))
* Fixing a bug in OpenStack cloud provider, where dual stack deployments (IPv4 and IPv6) did not work well when using kubenet as the network plugin. ([#59749](https://github.com/kubernetes/kubernetes/pull/59749), [@zioproto](https://github.com/zioproto))

        MaskedTensor(tf.experimental.ExtensionType): values: tf.Tensor mask:
        tf.Tensor` The `tf.ExtensionType` base class works similarly to
        [`typing.NamedTuple`](https://docs.python.org/3/library/typing.html#typing.NamedTuple)
        and
        [`@dataclasses.dataclass`](https://docs.python.org/3/library/dataclasses.html#dataclasses.dataclass)
        from the standard Python library.

      Licensor for the purpose of discussing and improving the Work, but
      excluding communication that is conspicuously marked or otherwise
      designated in writing by the copyright owner as "Not a Contribution."

      "Contributor" shall mean Licensor and any individual or Legal Entity
      on behalf of whom a Contribution has been received by Licensor and

- A new kubelet metric `image_pull_duration_seconds` was added. The metric tracks the duration (in seconds) it takes for an image to be pulled, including the time spent in the waiting queue of image puller. The metric is broken down by bucketed image size. ([#121719](https://github.com/kubernetes/kubernetes/pull/121719), [@ruiwen-zhao](https://github.com/ruiwen-zhao))

- Using `--log-file` is known to be problematic in 1.15. This presents as things being logged multiple times to the same file. The behaviour and details of this issue, as well as some preliminary attempts at fixing it are documented [here](https://github.com/kubernetes/kubernetes/issues/78734#issuecomment-501372131)

## Urgent Upgrade Notes

### (No, really, you MUST read this before you upgrade)

#### API Machinery

- In the `wait.PollUntilContextTimeout` function, if `immediate` is true, the condition will now be invoked before waiting, guaranteeing that the condition is invoked at least once and then wait a interval before executing again. ([#119762](https://github.com/kubernetes/kubernetes/pull/119762), [@AxeZhan](https://github.com/AxeZhan))

https://developer.paciellogroup.com/blog/2018/03/focus-visible-and-backwards-compatibility/\n[tabindex=\"-1\"]:focus:not(:focus-visible) {\n  outline: 0 !important;\n}\n\n\n// Content grouping\n//\n// 1. Add the correct box sizing in Firefox.\n// 2. Show the overflow in Edge and IE.\n\nhr {\n  box-sizing: content-box; // 1\n  height: 0; // 1\n  overflow: visible; // 2\n}\n\n\n//\n// Typography\n//\n\n// Remove top margins from headings\n//\n// By default, `<h1>`-`<h6>` all receive top and bottom margins. We nuke...

### API Change

- 'ACTION REQUIRED: The Dynamic Resource Allocation (DRA) driver's DaemonSet
  must be deployed with a service account that enables writing ResourceSlice
  and reading ResourceClaim objects.'
   ([#125163](https://github.com/kubernetes/kubernetes/pull/125163), [@pohly](https://github.com/pohly)) [SIG Auth, Node and Testing]

### Bug or Regression

- Bump sigs.k8s.io/apiserver-network-proxy/konnectivity-client to v0.0.30, fixing goroutine leaks in kube-apiserver. ([#108439](https://github.com/kubernetes/kubernetes/pull/108439), [@andrewsykim](https://github.com/andrewsykim)) [SIG API Machinery, Auth and Cloud Provider]