build: move e2e dependencies into e2e/go.mod

Several packages are only used while running the e2e suite. These
packages are less important to update, as the they can not influence the
final executable that is part of the Ceph-CSI container-image.

By moving these dependencies out of the main Ceph-CSI go.mod, it is
easier to identify if a reported CVE affects Ceph-CSI, or only the
testing (like most of the Kubernetes CVEs).

Signed-off-by: Niels de Vos <ndevos@ibm.com>

e2e/vendor/github.com/google/gnostic-models/extensions/extensions.go

@@ -0,0 +1,64 @@
+// Copyright 2017 Google LLC. 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 gnostic_extension_v1
+
+import (
+	"io/ioutil"
+	"log"
+	"os"
+
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/types/known/anypb"
+)
+
+type extensionHandler func(name string, yamlInput string) (bool, proto.Message, error)
+
+// Main implements the main program of an extension handler.
+func Main(handler extensionHandler) {
+	// unpack the request
+	data, err := ioutil.ReadAll(os.Stdin)
+	if err != nil {
+		log.Println("File error:", err.Error())
+		os.Exit(1)
+	}
+	if len(data) == 0 {
+		log.Println("No input data.")
+		os.Exit(1)
+	}
+	request := &ExtensionHandlerRequest{}
+	err = proto.Unmarshal(data, request)
+	if err != nil {
+		log.Println("Input error:", err.Error())
+		os.Exit(1)
+	}
+	// call the handler
+	handled, output, err := handler(request.Wrapper.ExtensionName, request.Wrapper.Yaml)
+	// respond with the output of the handler
+	response := &ExtensionHandlerResponse{
+		Handled: false, // default assumption
+		Errors:  make([]string, 0),
+	}
+	if err != nil {
+		response.Errors = append(response.Errors, err.Error())
+	} else if handled {
+		response.Handled = true
+		response.Value, err = anypb.New(output)
+		if err != nil {
+			response.Errors = append(response.Errors, err.Error())
+		}
+	}
+	responseBytes, _ := proto.Marshal(response)
+	os.Stdout.Write(responseBytes)
+}