Refactor fieldmanager to be more modular

staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/customresource_handler.go

@@ -823,18 +823,18 @@ func (r *crdHandler) getOrCreateServingInfoFor(uid types.UID, name string) (*crd
 		}
 		if utilfeature.DefaultFeatureGate.Enabled(features.ServerSideApply) {
 			reqScope := *requestScopes[v.Name]
-			fm, err := fieldmanager.NewCRDFieldManager(
+			reqScope.FieldManager, err = fieldmanager.NewDefaultCRDFieldManager(
 				openAPIModels,
 				reqScope.Convertor,
 				reqScope.Defaulter,
-				reqScope.Kind.GroupVersion(),
+				reqScope.Creater,
+				reqScope.Kind,
 				reqScope.HubGroupVersion,
 				*crd.Spec.PreserveUnknownFields,
 			)
 			if err != nil {
 				return nil, err
 			}
-			reqScope.FieldManager = fieldmanager.NewSkipNonAppliedManager(fm, reqScope.Creater, reqScope.Kind)
 			requestScopes[v.Name] = &reqScope
 		}
 

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

@@ -3,8 +3,11 @@ load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
 go_library(
     name = "go_default_library",
     srcs = [
+        "buildmanagerinfo.go",
         "fieldmanager.go",
         "skipnonapplied.go",
+        "stripmeta.go",
+        "structuredmerge.go",
     ],
     importmap = "k8s.io/kubernetes/vendor/k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager",
     importpath = "k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager",

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

@@ -0,0 +1,72 @@
+/*
+Copyright 2019 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"
+
+	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"
+)
+
+type buildManagerInfoManager struct {
+	fieldManager Manager
+	groupVersion schema.GroupVersion
+}
+
+var _ Manager = &buildManagerInfoManager{}
+
+// NewBuildManagerInfoManager creates a new Manager that converts the manager name into a unique identifier
+// combining operation and version for update requests, and just operation for apply requests.
+func NewBuildManagerInfoManager(f Manager, gv schema.GroupVersion) Manager {
+	return &buildManagerInfoManager{
+		fieldManager: f,
+		groupVersion: gv,
+	}
+}
+
+// Update implements Manager.
+func (f *buildManagerInfoManager) Update(liveObj, newObj runtime.Object, managed Managed, manager string) (runtime.Object, Managed, error) {
+	manager, err := f.buildManagerInfo(manager, metav1.ManagedFieldsOperationUpdate)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to build manager identifier: %v", err)
+	}
+	return f.fieldManager.Update(liveObj, newObj, managed, manager)
+}
+
+// Apply implements Manager.
+func (f *buildManagerInfoManager) Apply(liveObj runtime.Object, patch []byte, managed Managed, manager string, force bool) (runtime.Object, Managed, error) {
+	manager, err := f.buildManagerInfo(manager, metav1.ManagedFieldsOperationApply)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to build manager identifier: %v", err)
+	}
+	return f.fieldManager.Apply(liveObj, patch, managed, manager, force)
+}
+
+func (f *buildManagerInfoManager) buildManagerInfo(prefix string, operation metav1.ManagedFieldsOperationType) (string, error) {
+	managerInfo := metav1.ManagedFieldsEntry{
+		Manager:    prefix,
+		Operation:  operation,
+		APIVersion: f.groupVersion.String(),
+	}
+	if managerInfo.Manager == "" {
+		managerInfo.Manager = "unknown"
+	}
+	return internal.BuildManagerIdentifier(&managerInfo)
+}

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

@@ -18,302 +18,138 @@ package fieldmanager
 
 import (
 	"fmt"
-	"time"
 
-	"k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/internal"
-	"k8s.io/klog"
 	openapiproto "k8s.io/kube-openapi/pkg/util/proto"
 	"sigs.k8s.io/structured-merge-diff/fieldpath"
-	"sigs.k8s.io/structured-merge-diff/merge"
-	"sigs.k8s.io/yaml"
 )
 
-// FieldManager updates the managed fields and merge applied
-// configurations.
-type FieldManager interface {
+// Managed groups a fieldpath.ManagedFields together with the timestamps associated with each operation.
+type Managed interface {
+	// Fields gets the fieldpath.ManagedFields.
+	Fields() fieldpath.ManagedFields
+
+	// Times gets the timestamps associated with each operation.
+	Times() map[string]*metav1.Time
+}
+
+// Manager updates the managed fields and merges applied configurations.
+type Manager interface {
 	// Update is used when the object has already been merged (non-apply
 	// use-case), and simply updates the managed fields in the output
 	// object.
-	Update(liveObj, newObj runtime.Object, manager string) (runtime.Object, error)
+	Update(liveObj, newObj runtime.Object, managed Managed, manager string) (runtime.Object, Managed, error)
 
 	// Apply is used when server-side apply is called, as it merges the
-	// object and update the managed fields.
-	Apply(liveObj runtime.Object, patch []byte, fieldManager string, force bool) (runtime.Object, error)
+	// object and updates the managed fields.
+	Apply(liveObj runtime.Object, patch []byte, managed Managed, fieldManager string, force bool) (runtime.Object, Managed, error)
 }
 
-type fieldManager struct {
-	typeConverter   internal.TypeConverter
-	objectConverter runtime.ObjectConvertor
-	objectDefaulter runtime.ObjectDefaulter
-	groupVersion    schema.GroupVersion
-	hubVersion      schema.GroupVersion
-	updater         merge.Updater
+// FieldManager updates the managed fields and merge applied
+// configurations.
+type FieldManager struct {
+	fieldManager Manager
 }
 
-var _ FieldManager = &fieldManager{}
+// NewFieldManager creates a new FieldManager that decodes, manages, then re-encodes managedFields
+// on update and apply requests.
+func NewFieldManager(f Manager) *FieldManager {
+	return &FieldManager{f}
+}
 
-// NewFieldManager creates a new FieldManager that merges apply requests
+// NewDefaultFieldManager creates a new FieldManager that merges apply requests
 // and update managed fields for other types of requests.
-func NewFieldManager(models openapiproto.Models, objectConverter runtime.ObjectConvertor, objectDefaulter runtime.ObjectDefaulter, gv schema.GroupVersion, hub schema.GroupVersion) (FieldManager, error) {
-	typeConverter, err := internal.NewTypeConverter(models, false)
+func NewDefaultFieldManager(models openapiproto.Models, objectConverter runtime.ObjectConvertor, objectDefaulter runtime.ObjectDefaulter, objectCreater runtime.ObjectCreater, kind schema.GroupVersionKind, hub schema.GroupVersion) (*FieldManager, error) {
+	f, err := NewStructuredMergeManager(models, objectConverter, objectDefaulter, kind.GroupVersion(), hub)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("failed to create field manager: %v", err)
 	}
-
-	return &fieldManager{
-		typeConverter:   typeConverter,
-		objectConverter: objectConverter,
-		objectDefaulter: objectDefaulter,
-		groupVersion:    gv,
-		hubVersion:      hub,
-		updater: merge.Updater{
-			Converter: internal.NewVersionConverter(typeConverter, objectConverter, hub),
-		},
-	}, nil
+	return newDefaultFieldManager(f, objectCreater, kind), nil
 }
 
-// NewCRDFieldManager creates a new FieldManager specifically for
+// NewDefaultCRDFieldManager creates a new FieldManager specifically for
 // CRDs. This allows for the possibility of fields which are not defined
 // in models, as well as having no models defined at all.
-func NewCRDFieldManager(models openapiproto.Models, objectConverter runtime.ObjectConvertor, objectDefaulter runtime.ObjectDefaulter, gv schema.GroupVersion, hub schema.GroupVersion, preserveUnknownFields bool) (_ FieldManager, err error) {
-	var typeConverter internal.TypeConverter = internal.DeducedTypeConverter{}
-	if models != nil {
-		typeConverter, err = internal.NewTypeConverter(models, preserveUnknownFields)
-		if err != nil {
-			return nil, err
-		}
+func NewDefaultCRDFieldManager(models openapiproto.Models, objectConverter runtime.ObjectConvertor, objectDefaulter runtime.ObjectDefaulter, objectCreater runtime.ObjectCreater, kind schema.GroupVersionKind, hub schema.GroupVersion, preserveUnknownFields bool) (_ *FieldManager, err error) {
+	f, err := NewCRDStructuredMergeManager(models, objectConverter, objectDefaulter, kind.GroupVersion(), hub, preserveUnknownFields)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create field manager: %v", err)
 	}
-	return &fieldManager{
-		typeConverter:   typeConverter,
-		objectConverter: objectConverter,
-		objectDefaulter: objectDefaulter,
-		groupVersion:    gv,
-		hubVersion:      hub,
-		updater: merge.Updater{
-			Converter: internal.NewCRDVersionConverter(typeConverter, objectConverter, hub),
-		},
-	}, nil
+	return newDefaultFieldManager(f, objectCreater, kind), nil
 }
 
-// Update implements FieldManager.
-func (f *fieldManager) Update(liveObj, newObj runtime.Object, manager string) (runtime.Object, error) {
+// 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 = NewBuildManagerInfoManager(f, kind.GroupVersion())
+	f = NewSkipNonAppliedManager(f, objectCreater, kind)
+	return NewFieldManager(f)
+}
+
+// Update is used when the object has already been merged (non-apply
+// use-case), and simply updates the managed fields in the output
+// object.
+func (f *FieldManager) Update(liveObj, newObj runtime.Object, manager string) (object runtime.Object, err error) {
 	// If the object doesn't have metadata, we should just return without trying to
 	// set the managedFields at all, so creates/updates/patches will work normally.
-	if _, err := meta.Accessor(newObj); err != nil {
+	if _, err = meta.Accessor(newObj); err != nil {
 		return newObj, nil
 	}
 
 	// First try to decode the managed fields provided in the update,
 	// This is necessary to allow directly updating managed fields.
-	managed, err := internal.DecodeObjectManagedFields(newObj)
-
-	// If the managed field is empty or we failed to decode it,
-	// let's try the live object. This is to prevent clients who
-	// don't understand managedFields from deleting it accidentally.
-	if err != nil || len(managed.Fields) == 0 {
+	var managed Managed
+	if managed, err = internal.DecodeObjectManagedFields(newObj); err != nil || len(managed.Fields()) == 0 {
+		// If the managed field is empty or we failed to decode it,
+		// let's try the live object. This is to prevent clients who
+		// don't understand managedFields from deleting it accidentally.
 		managed, err = internal.DecodeObjectManagedFields(liveObj)
 		if err != nil {
 			return nil, fmt.Errorf("failed to decode managed fields: %v", err)
 		}
 	}
-	newObjVersioned, err := f.toVersioned(newObj)
-	if err != nil {
-		return nil, fmt.Errorf("failed to convert new object to proper version: %v", err)
-	}
-	liveObjVersioned, err := f.toVersioned(liveObj)
-	if err != nil {
-		return nil, fmt.Errorf("failed to convert live object to proper version: %v", err)
-	}
-	internal.RemoveObjectManagedFields(liveObjVersioned)
-	internal.RemoveObjectManagedFields(newObjVersioned)
-	newObjTyped, err := f.typeConverter.ObjectToTyped(newObjVersioned)
-	if err != nil {
-		// Return newObj and just by-pass fields update. This really shouldn't happen.
-		klog.Errorf("[SHOULD NOT HAPPEN] failed to create typed new object: %v", err)
-		return newObj, nil
-	}
-	liveObjTyped, err := f.typeConverter.ObjectToTyped(liveObjVersioned)
-	if err != nil {
-		// Return newObj and just by-pass fields update. This really shouldn't happen.
-		klog.Errorf("[SHOULD NOT HAPPEN] failed to create typed live object: %v", err)
-		return newObj, nil
-	}
-	apiVersion := fieldpath.APIVersion(f.groupVersion.String())
 
-	// TODO(apelisse) use the first return value when unions are implemented
-	_, managed.Fields, err = f.updater.Update(liveObjTyped, newObjTyped, apiVersion, managed.Fields, manager)
-	if err != nil {
-		return nil, fmt.Errorf("failed to update ManagedFields: %v", err)
-	}
-	managed.Fields = f.stripFields(managed.Fields, manager)
+	internal.RemoveObjectManagedFields(liveObj)
+	internal.RemoveObjectManagedFields(newObj)
 
-	// 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[manager]; ok {
-		delete(managed.Fields, manager)
-
-		// Build a manager identifier which will only match previous updates from the same manager
-		manager, err = f.buildManagerInfo(manager, metav1.ManagedFieldsOperationUpdate)
-		if err != nil {
-			return nil, fmt.Errorf("failed to build manager identifier: %v", err)
-		}
-
-		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
-		}
+	if object, managed, err = f.fieldManager.Update(liveObj, newObj, managed, manager); err != nil {
+		return nil, err
 	}
 
-	if err := internal.EncodeObjectManagedFields(newObj, managed); err != nil {
+	if err = internal.EncodeObjectManagedFields(object, managed); err != nil {
 		return nil, fmt.Errorf("failed to encode managed fields: %v", err)
 	}
 
-	return newObj, nil
+	return object, nil
 }
 
-// Apply implements FieldManager.
-func (f *fieldManager) Apply(liveObj runtime.Object, patch []byte, fieldManager string, force bool) (runtime.Object, error) {
+// Apply is used when server-side apply is called, as it merges the
+// object and updates the managed fields.
+func (f *FieldManager) Apply(liveObj runtime.Object, patch []byte, manager string, force bool) (object runtime.Object, err error) {
 	// If the object doesn't have metadata, apply isn't allowed.
-	_, err := meta.Accessor(liveObj)
-	if err != nil {
+	if _, err = meta.Accessor(liveObj); err != nil {
 		return nil, fmt.Errorf("couldn't get accessor: %v", err)
 	}
 
-	managed, err := internal.DecodeObjectManagedFields(liveObj)
-	if err != nil {
+	// Decode the managed fields in the live object, since it isn't allowed in the patch.
+	var managed Managed
+	if managed, err = internal.DecodeObjectManagedFields(liveObj); err != nil {
 		return nil, fmt.Errorf("failed to decode managed fields: %v", err)
 	}
-	// Check that the patch object has the same version as the live object
-	patchObj := &unstructured.Unstructured{Object: map[string]interface{}{}}
 
-	if err := yaml.Unmarshal(patch, &patchObj.Object); err != nil {
-		return nil, errors.NewBadRequest(fmt.Sprintf("error decoding YAML: %v", err))
-	}
+	internal.RemoveObjectManagedFields(liveObj)
 
-	if patchObj.GetManagedFields() != nil {
-		return nil, errors.NewBadRequest(fmt.Sprintf("metadata.managedFields must be nil"))
-	}
-
-	if patchObj.GetAPIVersion() != f.groupVersion.String() {
-		return nil,
-			errors.NewBadRequest(
-				fmt.Sprintf("Incorrect version specified in apply patch. "+
-					"Specified patch version: %s, expected: %s",
-					patchObj.GetAPIVersion(), f.groupVersion.String()))
-	}
-
-	liveObjVersioned, err := f.toVersioned(liveObj)
-	if err != nil {
-		return nil, fmt.Errorf("failed to convert live object to proper version: %v", err)
-	}
-	internal.RemoveObjectManagedFields(liveObjVersioned)
-
-	patchObjTyped, err := f.typeConverter.ObjectToTyped(patchObj)
-	if err != nil {
-		return nil, fmt.Errorf("failed to create typed patch object: %v", err)
-	}
-	liveObjTyped, err := f.typeConverter.ObjectToTyped(liveObjVersioned)
-	if err != nil {
-		return nil, fmt.Errorf("failed to create typed live object: %v", err)
-	}
-	manager, err := f.buildManagerInfo(fieldManager, metav1.ManagedFieldsOperationApply)
-	if err != nil {
-		return nil, fmt.Errorf("failed to build manager identifier: %v", err)
-	}
-
-	apiVersion := fieldpath.APIVersion(f.groupVersion.String())
-	newObjTyped, managedFields, err := f.updater.Apply(liveObjTyped, patchObjTyped, apiVersion, managed.Fields, manager, force)
-	if err != nil {
-		if conflicts, ok := err.(merge.Conflicts); ok {
-			return nil, internal.NewConflictError(conflicts)
-		}
+	if object, managed, err = f.fieldManager.Apply(liveObj, patch, managed, manager, force); err != nil {
 		return nil, err
 	}
-	managed.Fields = f.stripFields(managedFields, manager)
 
-	// 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, fmt.Errorf("failed to convert new typed object to object: %v", err)
-	}
-
-	if err := internal.EncodeObjectManagedFields(newObj, managed); err != nil {
+	if err = internal.EncodeObjectManagedFields(object, managed); err != nil {
 		return nil, fmt.Errorf("failed to encode managed fields: %v", err)
 	}
 
-	newObjVersioned, err := f.toVersioned(newObj)
-	if err != nil {
-		return nil, fmt.Errorf("failed to convert new object to proper version: %v", err)
-	}
-	f.objectDefaulter.Default(newObjVersioned)
-
-	newObjUnversioned, err := f.toUnversioned(newObjVersioned)
-	if err != nil {
-		return nil, fmt.Errorf("failed to convert to unversioned: %v", err)
-	}
-	return newObjUnversioned, nil
-}
-
-func (f *fieldManager) toVersioned(obj runtime.Object) (runtime.Object, error) {
-	return f.objectConverter.ConvertToVersion(obj, f.groupVersion)
-}
-
-func (f *fieldManager) toUnversioned(obj runtime.Object) (runtime.Object, error) {
-	return f.objectConverter.ConvertToVersion(obj, f.hubVersion)
-}
-
-func (f *fieldManager) buildManagerInfo(prefix string, operation metav1.ManagedFieldsOperationType) (string, error) {
-	managerInfo := metav1.ManagedFieldsEntry{
-		Manager:    prefix,
-		Operation:  operation,
-		APIVersion: f.groupVersion.String(),
-	}
-	if managerInfo.Manager == "" {
-		managerInfo.Manager = "unknown"
-	}
-	return internal.BuildManagerIdentifier(&managerInfo)
-}
-
-// stripSet is the list of fields that should never be part of a mangedFields.
-var stripSet = fieldpath.NewSet(
-	fieldpath.MakePathOrDie("apiVersion"),
-	fieldpath.MakePathOrDie("kind"),
-	fieldpath.MakePathOrDie("metadata"),
-	fieldpath.MakePathOrDie("metadata", "name"),
-	fieldpath.MakePathOrDie("metadata", "namespace"),
-	fieldpath.MakePathOrDie("metadata", "creationTimestamp"),
-	fieldpath.MakePathOrDie("metadata", "selfLink"),
-	fieldpath.MakePathOrDie("metadata", "uid"),
-	fieldpath.MakePathOrDie("metadata", "clusterName"),
-	fieldpath.MakePathOrDie("metadata", "generation"),
-	fieldpath.MakePathOrDie("metadata", "managedFields"),
-	fieldpath.MakePathOrDie("metadata", "resourceVersion"),
-)
-
-// stripFields removes a predefined set of paths found in typed from managed and returns the updated ManagedFields
-func (f *fieldManager) stripFields(managed fieldpath.ManagedFields, manager string) fieldpath.ManagedFields {
-	vs, ok := managed[manager]
-	if ok {
-		if vs == nil {
-			panic(fmt.Sprintf("Found unexpected nil manager which should never happen: %s", manager))
-		}
-		newSet := vs.Set().Difference(stripSet)
-		if newSet.Empty() {
-			delete(managed, manager)
-		} else {
-			managed[manager] = fieldpath.NewVersionedSet(newSet, vs.APIVersion(), vs.Applied())
-		}
-	}
-
-	return managed
+	return object, nil
 }

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

@@ -65,7 +65,7 @@ type fakeObjectDefaulter struct{}
 func (d *fakeObjectDefaulter) Default(in runtime.Object) {}
 
 type TestFieldManager struct {
-	fieldManager fieldmanager.FieldManager
+	fieldManager fieldmanager.Manager
 	emptyObj     runtime.Object
 	liveObj      runtime.Object
 }
@@ -80,7 +80,7 @@ func NewTestFieldManager(gvk schema.GroupVersionKind) TestFieldManager {
 		panic(err)
 	}
 
-	f, err := fieldmanager.NewFieldManager(
+	f, err := fieldmanager.NewStructuredMergeManager(
 		m,
 		&fakeObjectConvertor{},
 		&fakeObjectDefaulter{},
@@ -93,6 +93,8 @@ func NewTestFieldManager(gvk schema.GroupVersionKind) TestFieldManager {
 	live := &unstructured.Unstructured{}
 	live.SetKind(gvk.Kind)
 	live.SetAPIVersion(gvk.GroupVersion().String())
+	f = fieldmanager.NewStripMetaManager(f)
+	f = fieldmanager.NewBuildManagerInfoManager(f, gvk.GroupVersion())
 	return TestFieldManager{
 		fieldManager: f,
 		emptyObj:     live,
@@ -105,7 +107,7 @@ func (f *TestFieldManager) Reset() {
 }
 
 func (f *TestFieldManager) Apply(obj []byte, manager string, force bool) error {
-	out, err := f.fieldManager.Apply(f.liveObj, obj, manager, force)
+	out, err := fieldmanager.NewFieldManager(f.fieldManager).Apply(f.liveObj, obj, manager, force)
 	if err == nil {
 		f.liveObj = out
 	}
@@ -113,7 +115,7 @@ func (f *TestFieldManager) Apply(obj []byte, manager string, force bool) error {
 }
 
 func (f *TestFieldManager) Update(obj runtime.Object, manager string) error {
-	out, err := f.fieldManager.Update(f.liveObj, obj, manager)
+	out, err := fieldmanager.NewFieldManager(f.fieldManager).Update(f.liveObj, obj, manager)
 	if err == nil {
 		f.liveObj = out
 	}

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

@@ -28,10 +28,38 @@ import (
 	"sigs.k8s.io/structured-merge-diff/fieldpath"
 )
 
-// Managed groups a fieldpath.ManagedFields together with the timestamps associated with each operation.
-type Managed struct {
-	Fields fieldpath.ManagedFields
-	Times  map[string]*metav1.Time
+// ManagedInterface groups a fieldpath.ManagedFields together with the timestamps associated with each operation.
+type ManagedInterface interface {
+	// Fields gets the fieldpath.ManagedFields.
+	Fields() fieldpath.ManagedFields
+
+	// Times gets the timestamps associated with each operation.
+	Times() map[string]*metav1.Time
+}
+
+type managedStruct struct {
+	fields fieldpath.ManagedFields
+	times  map[string]*metav1.Time
+}
+
+var _ ManagedInterface = &managedStruct{}
+
+// Fields implements ManagedInterface.
+func (m *managedStruct) Fields() fieldpath.ManagedFields {
+	return m.fields
+}
+
+// Times implements ManagedInterface.
+func (m *managedStruct) Times() map[string]*metav1.Time {
+	return m.times
+}
+
+// NewManaged creates a ManagedInterface from a fieldpath.ManagedFields and the timestamps associated with each operation.
+func NewManaged(f fieldpath.ManagedFields, t map[string]*metav1.Time) ManagedInterface {
+	return &managedStruct{
+		fields: f,
+		times:  t,
+	}
 }
 
 // RemoveObjectManagedFields removes the ManagedFields from the object
@@ -46,9 +74,9 @@ func RemoveObjectManagedFields(obj runtime.Object) {
 }
 
 // DecodeObjectManagedFields extracts and converts the objects ManagedFields into a fieldpath.ManagedFields.
-func DecodeObjectManagedFields(from runtime.Object) (Managed, error) {
+func DecodeObjectManagedFields(from runtime.Object) (ManagedInterface, error) {
 	if from == nil {
-		return Managed{}, nil
+		return &managedStruct{}, nil
 	}
 	accessor, err := meta.Accessor(from)
 	if err != nil {
@@ -57,13 +85,13 @@ func DecodeObjectManagedFields(from runtime.Object) (Managed, error) {
 
 	managed, err := decodeManagedFields(accessor.GetManagedFields())
 	if err != nil {
-		return Managed{}, fmt.Errorf("failed to convert managed fields from API: %v", err)
+		return nil, fmt.Errorf("failed to convert managed fields from API: %v", err)
 	}
-	return managed, err
+	return &managed, nil
 }
 
 // EncodeObjectManagedFields converts and stores the fieldpathManagedFields into the objects ManagedFields
-func EncodeObjectManagedFields(obj runtime.Object, managed Managed) error {
+func EncodeObjectManagedFields(obj runtime.Object, managed ManagedInterface) error {
 	accessor, err := meta.Accessor(obj)
 	if err != nil {
 		panic(fmt.Sprintf("couldn't get accessor: %v", err))
@@ -80,19 +108,19 @@ func EncodeObjectManagedFields(obj runtime.Object, managed Managed) error {
 
 // decodeManagedFields converts ManagedFields from the wire format (api format)
 // to the format used by sigs.k8s.io/structured-merge-diff
-func decodeManagedFields(encodedManagedFields []metav1.ManagedFieldsEntry) (managed Managed, err error) {
-	managed.Fields = make(fieldpath.ManagedFields, len(encodedManagedFields))
-	managed.Times = make(map[string]*metav1.Time, len(encodedManagedFields))
+func decodeManagedFields(encodedManagedFields []metav1.ManagedFieldsEntry) (managed managedStruct, err error) {
+	managed.fields = make(fieldpath.ManagedFields, len(encodedManagedFields))
+	managed.times = make(map[string]*metav1.Time, len(encodedManagedFields))
 	for _, encodedVersionedSet := range encodedManagedFields {
 		manager, err := BuildManagerIdentifier(&encodedVersionedSet)
 		if err != nil {
-			return Managed{}, fmt.Errorf("error decoding manager from %v: %v", encodedVersionedSet, err)
+			return managedStruct{}, fmt.Errorf("error decoding manager from %v: %v", encodedVersionedSet, err)
 		}
-		managed.Fields[manager], err = decodeVersionedSet(&encodedVersionedSet)
+		managed.fields[manager], err = decodeVersionedSet(&encodedVersionedSet)
 		if err != nil {
-			return Managed{}, fmt.Errorf("error decoding versioned set from %v: %v", encodedVersionedSet, err)
+			return managedStruct{}, fmt.Errorf("error decoding versioned set from %v: %v", encodedVersionedSet, err)
 		}
-		managed.Times[manager] = encodedVersionedSet.Time
+		managed.times[manager] = encodedVersionedSet.Time
 	}
 	return managed, nil
 }
@@ -139,15 +167,18 @@ func decodeVersionedSet(encodedVersionedSet *metav1.ManagedFieldsEntry) (version
 
 // encodeManagedFields converts ManagedFields from the format used by
 // sigs.k8s.io/structured-merge-diff to the wire format (api format)
-func encodeManagedFields(managed Managed) (encodedManagedFields []metav1.ManagedFieldsEntry, err error) {
+func encodeManagedFields(managed ManagedInterface) (encodedManagedFields []metav1.ManagedFieldsEntry, err error) {
+	if len(managed.Fields()) == 0 {
+		return nil, nil
+	}
 	encodedManagedFields = []metav1.ManagedFieldsEntry{}
-	for manager := range managed.Fields {
-		versionedSet := managed.Fields[manager]
+	for manager := range managed.Fields() {
+		versionedSet := managed.Fields()[manager]
 		v, err := encodeManagerVersionedSet(manager, versionedSet)
 		if err != nil {
 			return nil, fmt.Errorf("error encoding versioned set for %v: %v", manager, err)
 		}
-		if t, ok := managed.Times[manager]; ok {
+		if t, ok := managed.Times()[manager]; ok {
 			v.Time = t
 		}
 		encodedManagedFields = append(encodedManagedFields, *v)

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

@@ -31,6 +31,8 @@ import (
 // (api format) to the format used by sigs.k8s.io/structured-merge-diff and back
 func TestRoundTripManagedFields(t *testing.T) {
 	tests := []string{
+		`null
+`,
 		`- apiVersion: v1
   fieldsType: FieldsV1
   fieldsV1:
@@ -146,7 +148,7 @@ func TestRoundTripManagedFields(t *testing.T) {
 			if err != nil {
 				t.Fatalf("did not expect decoding error but got: %v", err)
 			}
-			encoded, err := encodeManagedFields(decoded)
+			encoded, err := encodeManagedFields(&decoded)
 			if err != nil {
 				t.Fatalf("did not expect encoding error but got: %v", err)
 			}

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

@@ -19,61 +19,48 @@ package fieldmanager
 import (
 	"fmt"
 
-	"k8s.io/apimachinery/pkg/api/meta"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 )
 
 type skipNonAppliedManager struct {
-	fieldManager  FieldManager
-	objectCreater runtime.ObjectCreater
-	gvk           schema.GroupVersionKind
+	fieldManager           Manager
+	objectCreater          runtime.ObjectCreater
+	gvk                    schema.GroupVersionKind
+	beforeApplyManagerName string
 }
 
-var _ FieldManager = &skipNonAppliedManager{}
+var _ Manager = &skipNonAppliedManager{}
 
-// NewSkipNonAppliedManager creates a new wrapped FieldManager that only starts tracking managers after the first apply
-func NewSkipNonAppliedManager(fieldManager FieldManager, objectCreater runtime.ObjectCreater, gvk schema.GroupVersionKind) FieldManager {
+// NewSkipNonAppliedManager creates a new wrapped FieldManager that only starts tracking managers after the first apply.
+func NewSkipNonAppliedManager(fieldManager Manager, objectCreater runtime.ObjectCreater, gvk schema.GroupVersionKind) Manager {
 	return &skipNonAppliedManager{
-		fieldManager:  fieldManager,
-		objectCreater: objectCreater,
-		gvk:           gvk,
+		fieldManager:           fieldManager,
+		objectCreater:          objectCreater,
+		gvk:                    gvk,
+		beforeApplyManagerName: "before-first-apply",
 	}
 }
 
-// Update implements FieldManager.
-func (f *skipNonAppliedManager) Update(liveObj, newObj runtime.Object, manager string) (runtime.Object, error) {
-	liveObjAccessor, err := meta.Accessor(liveObj)
-	if err != nil {
-		return newObj, nil
+// Update implements Manager.
+func (f *skipNonAppliedManager) Update(liveObj, newObj runtime.Object, managed Managed, manager string) (runtime.Object, Managed, error) {
+	if len(managed.Fields()) == 0 {
+		return newObj, managed, nil
 	}
-	newObjAccessor, err := meta.Accessor(newObj)
-	if err != nil {
-		return newObj, nil
-	}
-	if len(liveObjAccessor.GetManagedFields()) == 0 && len(newObjAccessor.GetManagedFields()) == 0 {
-		return newObj, nil
-	}
-
-	return f.fieldManager.Update(liveObj, newObj, manager)
+	return f.fieldManager.Update(liveObj, newObj, managed, manager)
 }
 
-// Apply implements FieldManager.
-func (f *skipNonAppliedManager) Apply(liveObj runtime.Object, patch []byte, fieldManager string, force bool) (runtime.Object, error) {
-	liveObjAccessor, err := meta.Accessor(liveObj)
-	if err != nil {
-		return nil, fmt.Errorf("couldn't get accessor: %v", err)
-	}
-	if len(liveObjAccessor.GetManagedFields()) == 0 {
+// Apply implements Manager.
+func (f *skipNonAppliedManager) Apply(liveObj runtime.Object, patch []byte, managed Managed, fieldManager string, force bool) (runtime.Object, Managed, error) {
+	if len(managed.Fields()) == 0 {
 		emptyObj, err := f.objectCreater.New(f.gvk)
 		if err != nil {
-			return nil, fmt.Errorf("failed to create empty object of type %v: %v", f.gvk, err)
+			return nil, nil, fmt.Errorf("failed to create empty object of type %v: %v", f.gvk, err)
 		}
-		liveObj, err = f.fieldManager.Update(emptyObj, liveObj, "before-first-apply")
+		liveObj, managed, err = f.fieldManager.Update(emptyObj, liveObj, managed, f.beforeApplyManagerName)
 		if err != nil {
-			return nil, fmt.Errorf("failed to create manager for existing fields: %v", err)
+			return nil, nil, fmt.Errorf("failed to create manager for existing fields: %v", err)
 		}
 	}
-
-	return f.fieldManager.Apply(liveObj, patch, fieldManager, force)
+	return f.fieldManager.Apply(liveObj, patch, managed, fieldManager, force)
 }

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

@@ -0,0 +1,90 @@
+/*
+Copyright 2019 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"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	"sigs.k8s.io/structured-merge-diff/fieldpath"
+)
+
+type stripMetaManager struct {
+	fieldManager Manager
+
+	// stripSet is the list of fields that should never be part of a mangedFields.
+	stripSet *fieldpath.Set
+}
+
+var _ Manager = &stripMetaManager{}
+
+// NewStripMetaManager creates a new Manager that strips metadata and typemeta fields from the manager's fieldset.
+func NewStripMetaManager(fieldManager Manager) Manager {
+	return &stripMetaManager{
+		fieldManager: fieldManager,
+		stripSet: fieldpath.NewSet(
+			fieldpath.MakePathOrDie("apiVersion"),
+			fieldpath.MakePathOrDie("kind"),
+			fieldpath.MakePathOrDie("metadata"),
+			fieldpath.MakePathOrDie("metadata", "name"),
+			fieldpath.MakePathOrDie("metadata", "namespace"),
+			fieldpath.MakePathOrDie("metadata", "creationTimestamp"),
+			fieldpath.MakePathOrDie("metadata", "selfLink"),
+			fieldpath.MakePathOrDie("metadata", "uid"),
+			fieldpath.MakePathOrDie("metadata", "clusterName"),
+			fieldpath.MakePathOrDie("metadata", "generation"),
+			fieldpath.MakePathOrDie("metadata", "managedFields"),
+			fieldpath.MakePathOrDie("metadata", "resourceVersion"),
+		),
+	}
+}
+
+// Update implements Manager.
+func (f *stripMetaManager) Update(liveObj, newObj runtime.Object, managed Managed, manager string) (runtime.Object, Managed, error) {
+	newObj, managed, err := f.fieldManager.Update(liveObj, newObj, managed, manager)
+	if err != nil {
+		return nil, nil, err
+	}
+	f.stripFields(managed.Fields(), manager)
+	return newObj, managed, nil
+}
+
+// Apply implements Manager.
+func (f *stripMetaManager) Apply(liveObj runtime.Object, patch []byte, managed Managed, manager string, force bool) (runtime.Object, Managed, error) {
+	newObj, managed, err := f.fieldManager.Apply(liveObj, patch, managed, manager, force)
+	if err != nil {
+		return nil, nil, err
+	}
+	f.stripFields(managed.Fields(), manager)
+	return newObj, managed, nil
+}
+
+// stripFields removes a predefined set of paths found in typed from managed
+func (f *stripMetaManager) stripFields(managed fieldpath.ManagedFields, manager string) {
+	vs, ok := managed[manager]
+	if ok {
+		if vs == nil {
+			panic(fmt.Sprintf("Found unexpected nil manager which should never happen: %s", manager))
+		}
+		newSet := vs.Set().Difference(f.stripSet)
+		if newSet.Empty() {
+			delete(managed, manager)
+		} else {
+			managed[manager] = fieldpath.NewVersionedSet(newSet, vs.APIVersion(), vs.Applied())
+		}
+	}
+}

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

@@ -0,0 +1,209 @@
+/*
+Copyright 2019 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"
+	"time"
+
+	"k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager/internal"
+	"k8s.io/klog"
+	openapiproto "k8s.io/kube-openapi/pkg/util/proto"
+	"sigs.k8s.io/structured-merge-diff/fieldpath"
+	"sigs.k8s.io/structured-merge-diff/merge"
+	"sigs.k8s.io/yaml"
+)
+
+type structuredMergeManager struct {
+	typeConverter   internal.TypeConverter
+	objectConverter runtime.ObjectConvertor
+	objectDefaulter runtime.ObjectDefaulter
+	groupVersion    schema.GroupVersion
+	hubVersion      schema.GroupVersion
+	updater         merge.Updater
+}
+
+var _ Manager = &structuredMergeManager{}
+
+// NewStructuredMergeManager creates a new Manager that merges apply requests
+// and update managed fields for other types of requests.
+func NewStructuredMergeManager(models openapiproto.Models, objectConverter runtime.ObjectConvertor, objectDefaulter runtime.ObjectDefaulter, gv schema.GroupVersion, hub schema.GroupVersion) (Manager, error) {
+	typeConverter, err := internal.NewTypeConverter(models, false)
+	if err != nil {
+		return nil, err
+	}
+
+	return &structuredMergeManager{
+		typeConverter:   typeConverter,
+		objectConverter: objectConverter,
+		objectDefaulter: objectDefaulter,
+		groupVersion:    gv,
+		hubVersion:      hub,
+		updater: merge.Updater{
+			Converter: internal.NewVersionConverter(typeConverter, objectConverter, hub),
+		},
+	}, nil
+}
+
+// NewCRDStructuredMergeManager creates a new Manager specifically for
+// CRDs. This allows for the possibility of fields which are not defined
+// in models, as well as having no models defined at all.
+func NewCRDStructuredMergeManager(models openapiproto.Models, objectConverter runtime.ObjectConvertor, objectDefaulter runtime.ObjectDefaulter, gv schema.GroupVersion, hub schema.GroupVersion, preserveUnknownFields bool) (_ Manager, err error) {
+	var typeConverter internal.TypeConverter = internal.DeducedTypeConverter{}
+	if models != nil {
+		typeConverter, err = internal.NewTypeConverter(models, preserveUnknownFields)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return &structuredMergeManager{
+		typeConverter:   typeConverter,
+		objectConverter: objectConverter,
+		objectDefaulter: objectDefaulter,
+		groupVersion:    gv,
+		hubVersion:      hub,
+		updater: merge.Updater{
+			Converter: internal.NewCRDVersionConverter(typeConverter, objectConverter, hub),
+		},
+	}, nil
+}
+
+// Update implements Manager.
+func (f *structuredMergeManager) Update(liveObj, newObj runtime.Object, managed Managed, manager string) (runtime.Object, Managed, error) {
+	newObjVersioned, err := f.toVersioned(newObj)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to convert new object to proper version: %v", err)
+	}
+	liveObjVersioned, err := f.toVersioned(liveObj)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to convert live object to proper version: %v", err)
+	}
+	newObjTyped, err := f.typeConverter.ObjectToTyped(newObjVersioned)
+	if err != nil {
+		// Return newObj and just by-pass fields update. This really shouldn't happen.
+		klog.Errorf("[SHOULD NOT HAPPEN] failed to create typed new object: %v", err)
+		return newObj, managed, nil
+	}
+	liveObjTyped, err := f.typeConverter.ObjectToTyped(liveObjVersioned)
+	if err != nil {
+		// Return newObj and just by-pass fields update. This really shouldn't happen.
+		klog.Errorf("[SHOULD NOT HAPPEN] failed to create typed live object: %v", err)
+		return newObj, managed, nil
+	}
+	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)
+	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
+}
+
+// Apply implements Manager.
+func (f *structuredMergeManager) Apply(liveObj runtime.Object, patch []byte, managed Managed, manager string, force bool) (runtime.Object, Managed, error) {
+	patchObj := &unstructured.Unstructured{Object: map[string]interface{}{}}
+	if err := yaml.Unmarshal(patch, &patchObj.Object); err != nil {
+		return nil, nil, errors.NewBadRequest(fmt.Sprintf("error decoding YAML: %v", err))
+	}
+
+	// Check that the patch object has the same version as the live object
+	if patchObj.GetAPIVersion() != f.groupVersion.String() {
+		return nil, nil,
+			errors.NewBadRequest(
+				fmt.Sprintf("Incorrect version specified in apply patch. "+
+					"Specified patch version: %s, expected: %s",
+					patchObj.GetAPIVersion(), f.groupVersion.String()))
+	}
+
+	if patchObj.GetManagedFields() != nil {
+		return nil, nil, errors.NewBadRequest(fmt.Sprintf("metadata.managedFields must be nil"))
+	}
+
+	liveObjVersioned, err := f.toVersioned(liveObj)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to convert live object to proper version: %v", err)
+	}
+
+	patchObjTyped, err := f.typeConverter.ObjectToTyped(patchObj)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to create typed patch object: %v", err)
+	}
+	liveObjTyped, err := f.typeConverter.ObjectToTyped(liveObjVersioned)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to create typed live object: %v", err)
+	}
+
+	apiVersion := fieldpath.APIVersion(f.groupVersion.String())
+	newObjTyped, managedFields, err := f.updater.Apply(liveObjTyped, patchObjTyped, apiVersion, managed.Fields(), manager, force)
+	if err != nil {
+		if conflicts, ok := err.(merge.Conflicts); ok {
+			return nil, nil, internal.NewConflictError(conflicts)
+		}
+		return nil, nil, err
+	}
+	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)
+	}
+
+	newObjVersioned, err := f.toVersioned(newObj)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to convert new object to proper version: %v", err)
+	}
+	f.objectDefaulter.Default(newObjVersioned)
+
+	newObjUnversioned, err := f.toUnversioned(newObjVersioned)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to convert to unversioned: %v", err)
+	}
+	return newObjUnversioned, managed, nil
+}
+
+func (f *structuredMergeManager) toVersioned(obj runtime.Object) (runtime.Object, error) {
+	return f.objectConverter.ConvertToVersion(obj, f.groupVersion)
+}
+
+func (f *structuredMergeManager) toUnversioned(obj runtime.Object) (runtime.Object, error) {
+	return f.objectConverter.ConvertToVersion(obj, f.hubVersion)
+}

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

@@ -296,7 +296,7 @@ type patchMechanism interface {
 type jsonPatcher struct {
 	*patcher
 
-	fieldManager fieldmanager.FieldManager
+	fieldManager *fieldmanager.FieldManager
 }
 
 func (p *jsonPatcher) applyPatchToCurrentObject(currentObject runtime.Object) (runtime.Object, error) {
@@ -382,7 +382,7 @@ type smpPatcher struct {
 
 	// Schema
 	schemaReferenceObj runtime.Object
-	fieldManager       fieldmanager.FieldManager
+	fieldManager       *fieldmanager.FieldManager
 }
 
 func (p *smpPatcher) applyPatchToCurrentObject(currentObject runtime.Object) (runtime.Object, error) {
@@ -422,7 +422,7 @@ type applyPatcher struct {
 	options      *metav1.PatchOptions
 	creater      runtime.ObjectCreater
 	kind         schema.GroupVersionKind
-	fieldManager fieldmanager.FieldManager
+	fieldManager *fieldmanager.FieldManager
 }
 
 func (p *applyPatcher) applyPatchToCurrentObject(obj runtime.Object) (runtime.Object, error) {

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

@@ -67,7 +67,7 @@ type RequestScope struct {
 	EquivalentResourceMapper runtime.EquivalentResourceMapper
 
 	TableConvertor rest.TableConvertor
-	FieldManager   fieldmanager.FieldManager
+	FieldManager   *fieldmanager.FieldManager
 
 	Resource    schema.GroupVersionResource
 	Kind        schema.GroupVersionKind

staging/src/k8s.io/apiserver/pkg/endpoints/installer.go

@@ -550,18 +550,17 @@ func (a *APIInstaller) registerResourceHandlers(path string, storage rest.Storag
 		reqScope.MetaGroupVersion = *a.group.MetaGroupVersion
 	}
 	if a.group.OpenAPIModels != nil && utilfeature.DefaultFeatureGate.Enabled(features.ServerSideApply) {
-		fm, err := fieldmanager.NewFieldManager(
+		reqScope.FieldManager, err = fieldmanager.NewDefaultFieldManager(
 			a.group.OpenAPIModels,
 			a.group.UnsafeConvertor,
 			a.group.Defaulter,
-			fqKindToRegister.GroupVersion(),
+			a.group.Creater,
+			fqKindToRegister,
 			reqScope.HubGroupVersion,
 		)
 		if err != nil {
 			return nil, fmt.Errorf("failed to create field manager: %v", err)
 		}
-		fm = fieldmanager.NewSkipNonAppliedManager(fm, a.group.Creater, fqKindToRegister)
-		reqScope.FieldManager = fm
 	}
 	for _, action := range actions {
 		producedObject := storageMeta.ProducesObject(action.Verb)

test/integration/apiserver/apply/apply_test.go

@@ -180,7 +180,7 @@ func TestNoOpUpdateSameResourceVersion(t *testing.T) {
 		}
 	}`)
 
-	o, err := client.CoreV1().RESTClient().Patch(types.ApplyPatchType).
+	_, err := client.CoreV1().RESTClient().Patch(types.ApplyPatchType).
 		Namespace("default").
 		Param("fieldManager", "apply_test").
 		Resource(podResource).
@@ -192,23 +192,6 @@ func TestNoOpUpdateSameResourceVersion(t *testing.T) {
 		t.Fatalf("Failed to create object: %v", err)
 	}
 
-	// Need to update once for some reason
-	// TODO (#82042): Remove this update once possible
-	b, err := json.MarshalIndent(o, "\t", "\t")
-	if err != nil {
-		t.Fatalf("Failed to marshal created object: %v", err)
-	}
-	_, err = client.CoreV1().RESTClient().Put().
-		Namespace("default").
-		Resource(podResource).
-		Name(podName).
-		Body(b).
-		Do().
-		Get()
-	if err != nil {
-		t.Fatalf("Failed to apply first no-op update: %v", err)
-	}
-
 	// Sleep for one second to make sure that the times of each update operation is different.
 	time.Sleep(1 * time.Second)
 
@@ -941,7 +924,7 @@ func TestApplyConvertsManagedFieldsVersion(t *testing.T) {
 		Time:       actual.Time,
 		FieldsType: "FieldsV1",
 		FieldsV1: &metav1.FieldsV1{
-			Raw: []byte(`{"f:metadata":{"f:labels":{"f:sidecar_version":{}}},"f:spec":{"f:template":{"f:spec":{"f:containers":{"k:{\"name\":\"sidecar\"}":{".":{},"f:image":{},"f:name":{}}}}}}}`),
+			Raw: []byte(`{"f:metadata":{"f:labels":{"f:sidecar_version":{}}},"f:spec":{"f:template":{"f:spec":{"f:containers":{"k:{\"name\":\"sidecar\"}":{"f:image":{},"f:name":{},".":{}}}}}}}`),
 		},
 	}