Merge pull request #52753 from munnerz/sample-controller

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

sample-controller: add example CRD controller

**What this PR does / why we need it**:

Adds a sample-controller example repository

fixes #52752

**Special notes for your reviewer**:

This is currently based on the sttts:sttts-codegen-scripts branch and should not be merged until that is (ref https://github.com/kubernetes/kubernetes/pull/52186)

**Release note**:

```
Add sample-controller repository
```

/cc @sttts @nikhita @colemickens

Kubernetes-commit: 9a7800f7d2efb88b397674672ac56f898826cf7c

vendor/github.com/googleapis/gnostic/extensions/extensions.go

@@ -0,0 +1,82 @@
+// Copyright 2017 Google Inc. All Rights Reserved.
+//
+// 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 openapiextension_v1
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/ptypes"
+)
+
+type documentHandler func(version string, extensionName string, document string)
+type extensionHandler func(name string, yamlInput string) (bool, proto.Message, error)
+
+func forInputYamlFromOpenapic(handler documentHandler) {
+	data, err := ioutil.ReadAll(os.Stdin)
+	if err != nil {
+		fmt.Println("File error:", err.Error())
+		os.Exit(1)
+	}
+	if len(data) == 0 {
+		fmt.Println("No input data.")
+		os.Exit(1)
+	}
+	request := &ExtensionHandlerRequest{}
+	err = proto.Unmarshal(data, request)
+	if err != nil {
+		fmt.Println("Input error:", err.Error())
+		os.Exit(1)
+	}
+	handler(request.Wrapper.Version, request.Wrapper.ExtensionName, request.Wrapper.Yaml)
+}
+
+// ProcessExtension calles the handler for a specified extension.
+func ProcessExtension(handleExtension extensionHandler) {
+	response := &ExtensionHandlerResponse{}
+	forInputYamlFromOpenapic(
+		func(version string, extensionName string, yamlInput string) {
+			var newObject proto.Message
+			var err error
+
+			handled, newObject, err := handleExtension(extensionName, yamlInput)
+			if !handled {
+				responseBytes, _ := proto.Marshal(response)
+				os.Stdout.Write(responseBytes)
+				os.Exit(0)
+			}
+
+			// If we reach here, then the extension is handled
+			response.Handled = true
+			if err != nil {
+				response.Error = append(response.Error, err.Error())
+				responseBytes, _ := proto.Marshal(response)
+				os.Stdout.Write(responseBytes)
+				os.Exit(0)
+			}
+			response.Value, err = ptypes.MarshalAny(newObject)
+			if err != nil {
+				response.Error = append(response.Error, err.Error())
+				responseBytes, _ := proto.Marshal(response)
+				os.Stdout.Write(responseBytes)
+				os.Exit(0)
+			}
+		})
+
+	responseBytes, _ := proto.Marshal(response)
+	os.Stdout.Write(responseBytes)
+}