rebase: update kubernetes to v1.20.0

updated kubernetes packages to latest
release.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

vendor/k8s.io/apiserver/pkg/warning/context.go

@@ -0,0 +1,59 @@
+/*
+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 warning
+
+import (
+	"context"
+)
+
+// The key type is unexported to prevent collisions
+type key int
+
+const (
+	// auditAnnotationsKey is the context key for the audit annotations.
+	warningRecorderKey key = iota
+)
+
+// Recorder provides a method for recording warnings
+type Recorder interface {
+	// AddWarning adds the specified warning to the response.
+	// agent must be valid UTF-8, and must not contain spaces, quotes, backslashes, or control characters.
+	// text must be valid UTF-8, and must not contain control characters.
+	AddWarning(agent, text string)
+}
+
+// WithWarningRecorder returns a new context that wraps the provided context and contains the provided Recorder implementation.
+// The returned context can be passed to AddWarning().
+func WithWarningRecorder(ctx context.Context, recorder Recorder) context.Context {
+	return context.WithValue(ctx, warningRecorderKey, recorder)
+}
+func warningRecorderFrom(ctx context.Context) (Recorder, bool) {
+	recorder, ok := ctx.Value(warningRecorderKey).(Recorder)
+	return recorder, ok
+}
+
+// AddWarning records a warning for the specified agent and text to the Recorder added to the provided context using WithWarningRecorder().
+// If no Recorder exists in the provided context, this is a no-op.
+// agent must be valid UTF-8, and must not contain spaces, quotes, backslashes, or control characters.
+// text must be valid UTF-8, and must not contain control characters.
+func AddWarning(ctx context.Context, agent string, text string) {
+	recorder, ok := warningRecorderFrom(ctx)
+	if !ok {
+		return
+	}
+	recorder.AddWarning(agent, text)
+}