Due to a [tagging bug in our Release Engineering tooling](https://github.com/kubernetes/release/issues/1080) during `v1.18.0-alpha.3`, we needed to push a manual tag (`v1.18.0-alpha.4`).

**No binaries have been produced or will be provided for `v1.18.0-alpha.4`.**

The changelog for `v1.18.0-alpha.4` is included as part of the [changelog since v1.18.0-alpha.3][#changelog-since-v1180-alpha3] section.

# v1.18.0-alpha.3

 - Pods that are considered for preemption and haven't started don't produce an error log. ([#90241](https://github.com/kubernetes/kubernetes/pull/90241), [@alculquicondor](https://github.com/alculquicondor)) [SIG Scheduling]

by the Library, but which is not otherwise based on the Library.
Defining a subclass of a class defined by the Library is deemed a mode
of using an interface provided by the Library.

  A "Combined Work" is a work produced by combining or linking an
Application with the Library.  The particular version of the Library
with which the Combined Work was made is also called the "Linked
Version".

* Add masquerading rules by default to GCE/GKE ([#55178](https://github.com/kubernetes/kubernetes/pull/55178), [@dnardo](https://github.com/dnardo))

  The `DeclarativeValidationTakeover` feature gate remains disabled by default.  While disabled, validation errors produced by hand written validation are always return to the caller.  To switch to declarative validation is primary source of errors for migrated fields, enable this feature gate. ([#130728](https://github.com/kubernetes/kubernetes/pull/130728), [@jpbet...

  can also be scheduled to nodes with `GA` labels. ([#118923](https://github.com/kubernetes/kubernetes/pull/118923), [@AxeZhan](https://github.com/AxeZhan))
- Updated the generic apiserver library to produce an error if a new API server is configured with support for a data format other than JSON, YAML, or Protobuf. ([#121325](https://github.com/kubernetes/kubernetes/pull/121325), [@benluddy](https://github.com/benluddy)) [SIG API Machinery]

- Graduated the `LegacyServiceAccountTokenTracking` feature gate to Beta. The usage of auto-generated secret-based service account token now produces warnings by default, and relevant Secrets are labeled with a last-used timestamp (label key `kubernetes.io/legacy-token-last-used`). ([#114523](https://github.com/kubernetes/kubernetes/pull/114523), [@zshihang](https://github.com/zshihang)) [SIG...

- X.509 client certificate authentication to the kube-apiserver now produces credential IDs (derived from the certificate's signature) , for use in audit logging. ([#125634](https://github.com/kubernetes/kubernetes/pull/125634), [@ahmedtd](https://github.com/ahmedtd)) [SIG API Machinery, Auth and Testing]

- Allow CSI drivers to just run offline expansion tests. ([#102665](https://github.com/kubernetes/kubernetes/pull/102665), [@gnufied](https://github.com/gnufied))
- Changed buildmode of non static Kubernetes binaries to produce position independent executables (PIE). ([#102323](https://github.com/kubernetes/kubernetes/pull/102323), [@saschagrunert](https://github.com/saschagrunert))

* Add /bin/tee symlink to bazel build for busybox, so that CI builds have /bin/tee ([#55417](https://github.com/kubernetes/kubernetes/pull/55417), [@justinsb](https://github.com/justinsb))
* Reduce log noise produced by prometheus-to-sd, by bumping it to version 0.2.2. ([#54635](https://github.com/kubernetes/kubernetes/pull/54635), [@loburm](https://github.com/loburm))