t".Request).{Do,DoRaw,Stream,Watch}` now require callers to pass a `context.Context` as an argument. The context is used for timeout and cancellation signaling and to pass supplementary information to round trippers in the wrapped transport chain. If you don't need any of this functionality, it is sufficient to pass a context created with `context.Background()` to these functions. The `(*"k8s.io/client-go/rest".Request).Context` method is removed now that all methods that execute a request accept...

([#62695](https://github.com/kubernetes/kubernetes/pull/62695), [@CaoShuFeng](https://github.com/CaoShuFeng))
* HTTP transport now uses `context.Context` to cancel dial operations. k8s.io/client-go/transport/Config struct has been updated to accept a function with a `context.Context` parameter. This is a breaking change if you use this field in your code. ([#60012](https://github.com/kubernetes/kubernetes/pull/60012), [@ash2k](https://github.com/ash2k))

- Callers of `wait.ExponentialBackoffWithContext` now must pass a `ConditionWithContextFunc` to be consistent with the signature and avoid creating a duplicate context. If your condition does not need a context you can use the `ConditionFunc.WithContext()` helper to ignore the context, or use `ExponentialBackoff` directly. ([#115113](https://github.com/kubernetes/kubernetes/pull/115113), [@smarterclayton](https://github.com/smarterclayton))

- `kubectl config set-context` can now set attributes of the current context, such as the current namespace, by passing `--current` instead of a specific context name ([#66140](https://github.com/kubernetes/kubernetes/pull/66140), [@liggitt](https://github.com/liggitt))

### Other (Cleanup or Flake)

- Client-go header logging (at verbosity levels >= 9) now masks `Authorization` header contents ([#95316](https://github.com/kubernetes/kubernetes/pull/95316), [@sfowl](https://github.com/sfowl)) [SIG API Machinery]

## Dependencies

### Added
_Nothing has changed._

### Changed

- K8s.io/apimachinery/pkg/util/runtime: Added support for new calls to handle panics and errors in the context where they occur. `PanicHandlers` and `ErrorHandlers` now must accept a context parameter for that. Log output is structured instead of unstructured. ([#121970](https://github.com/kubernetes/kubernetes/pull/121970), [@pohly](https://github.com/pohly)) [SIG API Machinery and Instrumentation]...

- Client-side apply will now use OpenAPI `v3` by default. ([#120707](https://github.com/kubernetes/kubernetes/pull/120707), [@Jefftree](https://github.com/Jefftree))
- Decoding etcd's response now respects the timeout context. ([#121614](https://github.com/kubernetes/kubernetes/pull/121614), [@HirazawaUi](https://github.com/HirazawaUi))

- Added reconstruction of SELinux mount context after kubelet restart. Feature `SELinuxMountReadWriteOncePod` is now fully implemented and kubelet does not lose its cache of SELinux contexts after kubelet process restart. ([#113596](https://github.com/kubernetes/kubernetes/pull/113596), [@jsafrane](https://github.com/jsafrane))

* Fixes CVE-2019-11250: client-go header logging (at verbosity levels >= 7) now masks `Authorization` header contents ([#81330](https://github.com/kubernetes/kubernetes/pull/81330), [@tedyu](https://github.com/tedyu))

### Azure