vendor: revendor metrics-server, custom-metrics-apiserver

vendor/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/lastappliedupdater.go

@@ -0,0 +1,117 @@
+/*
+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 fieldmanager
+
+import (
+	"fmt"
+
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/runtime"
+)
+
+type lastAppliedUpdater struct {
+	fieldManager Manager
+}
+
+var _ Manager = &lastAppliedUpdater{}
+
+// NewLastAppliedUpdater sets the client-side apply annotation up to date with
+// server-side apply managed fields
+func NewLastAppliedUpdater(fieldManager Manager) Manager {
+	return &lastAppliedUpdater{
+		fieldManager: fieldManager,
+	}
+}
+
+// Update implements Manager.
+func (f *lastAppliedUpdater) Update(liveObj, newObj runtime.Object, managed Managed, manager string) (runtime.Object, Managed, error) {
+	return f.fieldManager.Update(liveObj, newObj, managed, manager)
+}
+
+// server-side apply managed fields
+func (f *lastAppliedUpdater) Apply(liveObj, newObj runtime.Object, managed Managed, manager string, force bool) (runtime.Object, Managed, error) {
+	liveObj, managed, err := f.fieldManager.Apply(liveObj, newObj, managed, manager, force)
+	if err != nil {
+		return liveObj, managed, err
+	}
+
+	// Sync the client-side apply annotation only from kubectl server-side apply.
+	// To opt-out of this behavior, users may specify a different field manager.
+	//
+	// If the client-side apply annotation doesn't exist,
+	// then continue because we have no annotation to update
+	if manager == "kubectl" && hasLastApplied(liveObj) {
+		lastAppliedValue, err := buildLastApplied(newObj)
+		if err != nil {
+			return nil, nil, fmt.Errorf("failed to build last-applied annotation: %v", err)
+		}
+		err = setLastApplied(liveObj, lastAppliedValue)
+		if err != nil {
+			return nil, nil, fmt.Errorf("failed to set last-applied annotation: %v", err)
+		}
+	}
+	return liveObj, managed, err
+}
+
+func hasLastApplied(obj runtime.Object) bool {
+	var accessor, err = meta.Accessor(obj)
+	if err != nil {
+		panic(fmt.Sprintf("couldn't get accessor: %v", err))
+	}
+	var annotations = accessor.GetAnnotations()
+	if annotations == nil {
+		return false
+	}
+	_, ok := annotations[corev1.LastAppliedConfigAnnotation]
+	return ok
+}
+
+func setLastApplied(obj runtime.Object, value string) error {
+	accessor, err := meta.Accessor(obj)
+	if err != nil {
+		panic(fmt.Sprintf("couldn't get accessor: %v", err))
+	}
+	var annotations = accessor.GetAnnotations()
+	if annotations == nil {
+		annotations = map[string]string{}
+	}
+	annotations[corev1.LastAppliedConfigAnnotation] = value
+	accessor.SetAnnotations(annotations)
+	return nil
+}
+
+func buildLastApplied(obj runtime.Object) (string, error) {
+	obj = obj.DeepCopyObject()
+
+	var accessor, err = meta.Accessor(obj)
+	if err != nil {
+		panic(fmt.Sprintf("couldn't get accessor: %v", err))
+	}
+
+	// Remove the annotation from the object before encoding the object
+	var annotations = accessor.GetAnnotations()
+	delete(annotations, corev1.LastAppliedConfigAnnotation)
+	accessor.SetAnnotations(annotations)
+
+	lastApplied, err := runtime.Encode(unstructured.UnstructuredJSONScheme, obj)
+	if err != nil {
+		return "", fmt.Errorf("couldn't encode object into last applied annotation: %v", err)
+	}
+	return string(lastApplied), nil
+}