fieldmanager: Move ManagedFields update logic into its own class

Author: Antoine Pelisse

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/BUILD

@@ -6,6 +6,7 @@ go_library(
         "buildmanagerinfo.go",
         "capmanagers.go",
         "fieldmanager.go",
+        "managedfieldsupdater.go",
         "skipnonapplied.go",
         "stripmeta.go",
         "structuredmerge.go",

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/fieldmanager.go

@@ -94,6 +94,7 @@ func NewDefaultCRDFieldManager(models openapiproto.Models, objectConverter runti
 // newDefaultFieldManager is a helper function which wraps a Manager with certain default logic.
 func newDefaultFieldManager(f Manager, objectCreater runtime.ObjectCreater, kind schema.GroupVersionKind) *FieldManager {
 	f = NewStripMetaManager(f)
+	f = NewManagedFieldsUpdater(f)
 	f = NewBuildManagerInfoManager(f, kind.GroupVersion())
 	f = NewCapManagersManager(f, DefaultMaxUpdateManagers)
 	f = NewProbabilisticSkipNonAppliedManager(f, objectCreater, kind, DefaultTrackOnCreateProbability)

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/fieldmanager_test.go

@@ -104,6 +104,7 @@ func NewTestFieldManager(gvk schema.GroupVersionKind) TestFieldManager {
 	live.SetKind(gvk.Kind)
 	live.SetAPIVersion(gvk.GroupVersion().String())
 	f = fieldmanager.NewStripMetaManager(f)
+	f = fieldmanager.NewManagedFieldsUpdater(f)
 	f = fieldmanager.NewBuildManagerInfoManager(f, gvk.GroupVersion())
 	return TestFieldManager{
 		fieldManager: f,

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/managedfieldsupdater.go

@@ -0,0 +1,76 @@
+/*
+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 (
+	"time"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"sigs.k8s.io/structured-merge-diff/v3/fieldpath"
+)
+
+type managedFieldsUpdater struct {
+	fieldManager Manager
+}
+
+var _ Manager = &managedFieldsUpdater{}
+
+// NewManagedFieldsUpdater is responsible for updating the managedfields
+// in the object, updating the time of the operation as necessary. For
+// updates, it uses a hard-coded manager to detect if things have
+// changed, and swaps back the correct manager after the operation is
+// done.
+func NewManagedFieldsUpdater(fieldManager Manager) Manager {
+	return &managedFieldsUpdater{
+		fieldManager: fieldManager,
+	}
+}
+
+// Update implements Manager.
+func (f *managedFieldsUpdater) Update(liveObj, newObj runtime.Object, managed Managed, manager string) (runtime.Object, Managed, error) {
+	self := "current-operation"
+	object, managed, err := f.fieldManager.Update(liveObj, newObj, managed, self)
+	if err != nil {
+		return object, managed, err
+	}
+
+	// If the current operation took any fields from anything, it means the object changed,
+	// so update the timestamp of the managedFieldsEntry and merge with any previous updates from the same manager
+	if vs, ok := managed.Fields()[self]; ok {
+		delete(managed.Fields(), self)
+
+		managed.Times()[manager] = &metav1.Time{Time: time.Now().UTC()}
+		if previous, ok := managed.Fields()[manager]; ok {
+			managed.Fields()[manager] = fieldpath.NewVersionedSet(vs.Set().Union(previous.Set()), vs.APIVersion(), vs.Applied())
+		} else {
+			managed.Fields()[manager] = vs
+		}
+	}
+
+	return object, managed, nil
+}
+
+// Apply implements Manager.
+func (f *managedFieldsUpdater) Apply(liveObj, appliedObj runtime.Object, managed Managed, fieldManager string, force bool) (runtime.Object, Managed, error) {
+	object, managed, err := f.fieldManager.Apply(liveObj, appliedObj, managed, fieldManager, force)
+	if err != nil {
+		return object, managed, err
+	}
+	managed.Times()[fieldManager] = &metav1.Time{Time: time.Now().UTC()}
+	return object, managed, nil
+}

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/structuredmerge.go

@@ -22,7 +22,6 @@ import (
 
 	"k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/meta"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/internal"
@@ -116,26 +115,12 @@ func (f *structuredMergeManager) Update(liveObj, newObj runtime.Object, managed
 	apiVersion := fieldpath.APIVersion(f.groupVersion.String())
 
 	// TODO(apelisse) use the first return value when unions are implemented
-	self := "current-operation"
-	_, managedFields, err := f.updater.Update(liveObjTyped, newObjTyped, apiVersion, managed.Fields(), self)
+	_, managedFields, err := f.updater.Update(liveObjTyped, newObjTyped, apiVersion, managed.Fields(), manager)
 	if err != nil {
 		return nil, nil, fmt.Errorf("failed to update ManagedFields: %v", err)
 	}
 	managed = internal.NewManaged(managedFields, managed.Times())
 
-	// If the current operation took any fields from anything, it means the object changed,
-	// so update the timestamp of the managedFieldsEntry and merge with any previous updates from the same manager
-	if vs, ok := managed.Fields()[self]; ok {
-		delete(managed.Fields(), self)
-
-		managed.Times()[manager] = &metav1.Time{Time: time.Now().UTC()}
-		if previous, ok := managed.Fields()[manager]; ok {
-			managed.Fields()[manager] = fieldpath.NewVersionedSet(vs.Set().Union(previous.Set()), vs.APIVersion(), vs.Applied())
-		} else {
-			managed.Fields()[manager] = vs
-		}
-	}
-
 	return newObj, managed, nil
 }
 
@@ -182,9 +167,6 @@ func (f *structuredMergeManager) Apply(liveObj, patchObj runtime.Object, managed
 	}
 	managed = internal.NewManaged(managedFields, managed.Times())
 
-	// Update the time in the managedFieldsEntry for this operation
-	managed.Times()[manager] = &metav1.Time{Time: time.Now().UTC()}
-
 	newObj, err := f.typeConverter.TypedToObject(newObjTyped)
 	if err != nil {
 		return nil, nil, fmt.Errorf("failed to convert new typed object to object: %v", err)