Automatic merge from submit-queue (batch tested with PRs 50254, 50174, 50179)
Revert "Merge pull request #47353 from apelisse/http-cache"
Some issues were discovered with the caching merged in #47353:
* uses a disk-based cache that is not safe between processes (does not use atomic fs operations)
* writes get/list responses to disk that should not be cached (like `kubectl get secrets`)
* is vulnerable to partially written cache responses being used as responses to future requests
* breaks uses of the client transport that make use of websockets
* defaults to enabling the cache for any client builder using RecommendedConfigOverrideFlags or DefaultClientConfig which affects more components than just kubectl
This reverts commit fc89743dca6b563063b74728c3b28100cf674d9d, reversing changes made to 29ab38e898988c36e2de34f77fa33be556eb21bd.
Kubernetes-commit: 187e6ab0bc35f696d8f5f574fab9aa457f253d34
Automatic merge from submit-queue (batch tested with PRs 50087, 39587, 50042, 50241, 49914)
plugin/pkg/client/auth: add openstack auth provider
This is an implementation of auth provider for OpenStack world, just like python-openstackclient, we read the environment variables of a list `OS_*`, and client will cache a token to interact with each components, we can do the same here, the client side can cache a token locally at the first time, and rotate automatically when it expires.
This requires an implementation of token authenticator at server side, refer:
1. [made by me] https://github.com/kubernetes/kubernetes/pull/25536, I can carry this on when it is fine to go.
2. [made by @kfox1111] https://github.com/kubernetes/kubernetes/pull/25391
The reason why I want to add this is due to the `client-side` nature, it will be confusing to implement it downstream, we would like to add this support here, and customers can get `kubectl` like they usually do(`brew install kubernetes-cli`), and it will just work.
When this is done, we can deprecate the password keystone authenticator as the following reasons:
1. as mentioned at some other places, the `domain` is another parameters which should be provided.
2. in case the user supplies `apikey` and `secrets`, we might want to fill the `UserInfo` with the real name which is not implemented for now.
cc @erictune @liggitt
```
add openstack auth provider
```
Kubernetes-commit: 59b8fa32f129be29f146bfd4888a5d1ab7e71ca5
Automatic merge from submit-queue
go-client: Use httpcache client for all requests, even though only openapi returns ETags for caching
**What this PR does / why we need it**: Use HTTP ETag for caching Swagger spec download
This also adds a new command-line flag "cachedir" to specify where the cache should keep its file. It defaults to `$HOME/.kube/http-cache`.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: partly #38637
**Special notes for your reviewer**:
Because this adds a bunch of dependencies, and removes a couple of files, I do recommend reading each commit individually.
**Release note**:
```release-note
```
Kubernetes-commit: fc89743dca6b563063b74728c3b28100cf674d9d
Automatic merge from submit-queue
Switch from package syscall to golang.org/x/sys/unix
**What this PR does / why we need it**:
The syscall package is locked down and the comment in https://github.com/golang/go/blob/master/src/syscall/syscall.go#L21-L24 advises to switch code to use the corresponding package from golang.org/x/sys. This PR does so and replaces usage of package syscall with package golang.org/x/sys/unix where applicable. This will also allow to get updates and fixes
without having to use a new go version.
In order to get the latest functionality, golang.org/x/sys/ is re-vendored. This also allows to use Eventfd() from this package instead of calling the eventfd() C function.
**Special notes for your reviewer**:
This follows previous works in other Go projects, see e.g. moby/moby#33399, cilium/cilium#588
**Release note**:
```release-note
NONE
```
Kubernetes-commit: 5d24a2c19923d6da46110b827619f4b21cf689ac
