Revert "Remove references to openstack and cinder"

This reverts commit 9bbf01bae93600d3314bce0acbff1f3a0a42e74b.

Kubernetes-commit: 5b284a50b78cb7d68b12825f5c0cfa29503c1577

examples/README.md

@@ -19,6 +19,7 @@ Or you can load specific auth plugins:
 import _ "k8s.io/client-go/plugin/pkg/client/auth/azure"
 import _ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
 import _ "k8s.io/client-go/plugin/pkg/client/auth/oidc"
+import _ "k8s.io/client-go/plugin/pkg/client/auth/openstack"
 ```
 
 ### Configuration

examples/create-update-delete-deployment/main.go

@@ -40,6 +40,7 @@ import (
 	// _ "k8s.io/client-go/plugin/pkg/client/auth/azure"
 	// _ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
 	// _ "k8s.io/client-go/plugin/pkg/client/auth/oidc"
+	// _ "k8s.io/client-go/plugin/pkg/client/auth/openstack"
 )
 
 func main() {

examples/dynamic-create-update-delete-deployment/main.go

@@ -41,6 +41,7 @@ import (
 	// _ "k8s.io/client-go/plugin/pkg/client/auth/azure"
 	// _ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
 	// _ "k8s.io/client-go/plugin/pkg/client/auth/oidc"
+	// _ "k8s.io/client-go/plugin/pkg/client/auth/openstack"
 )
 
 func main() {

examples/in-cluster-client-configuration/main.go

@@ -34,6 +34,7 @@ import (
 	// _ "k8s.io/client-go/plugin/pkg/client/auth/azure"
 	// _ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
 	// _ "k8s.io/client-go/plugin/pkg/client/auth/oidc"
+	// _ "k8s.io/client-go/plugin/pkg/client/auth/openstack"
 )
 
 func main() {

examples/out-of-cluster-client-configuration/main.go

@@ -37,6 +37,7 @@ import (
 	// _ "k8s.io/client-go/plugin/pkg/client/auth/azure"
 	// _ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
 	// _ "k8s.io/client-go/plugin/pkg/client/auth/oidc"
+	// _ "k8s.io/client-go/plugin/pkg/client/auth/openstack"
 )
 
 func main() {

plugin/pkg/client/auth/openstack/openstack_stub.go

@@ -0,0 +1,36 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package openstack
+
+import (
+	"errors"
+
+	"k8s.io/client-go/rest"
+	"k8s.io/klog/v2"
+)
+
+func init() {
+	if err := rest.RegisterAuthProviderPlugin("openstack", newOpenstackAuthProvider); err != nil {
+		klog.Fatalf("Failed to register openstack auth plugin: %s", err)
+	}
+}
+
+func newOpenstackAuthProvider(_ string, _ map[string]string, _ rest.AuthProviderConfigPersister) (rest.AuthProvider, error) {
+	return nil, errors.New(`The openstack auth plugin has been removed.
+Please use the "client-keystone-auth" kubectl/client-go credential plugin instead.
+See https://github.com/kubernetes/cloud-provider-openstack/blob/master/docs/using-client-keystone-auth.md for further details`)
+}

plugin/pkg/client/auth/plugins_providers.go

@@ -23,4 +23,5 @@ import (
 	// Initialize client auth plugins for cloud providers.
 	_ "k8s.io/client-go/plugin/pkg/client/auth/azure"
 	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
+	_ "k8s.io/client-go/plugin/pkg/client/auth/openstack"
 )