Add "subresource" field to ManagedFieldEntry

This field is useful to namespace the managed field entries of a
subresource and differentiate them from the ones of the main resource.

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

@@ -872,7 +872,7 @@ func (r *crdHandler) getOrCreateServingInfoFor(uid types.UID, name string) (*crd
 				typeConverter,
 				reqScope,
 				resetFields,
-				false,
+				"",
 			)
 			if err != nil {
 				return nil, err
@@ -914,7 +914,7 @@ func (r *crdHandler) getOrCreateServingInfoFor(uid types.UID, name string) (*crd
 				typeConverter,
 				statusScope,
 				resetFields,
-				true,
+				"status",
 			)
 			if err != nil {
 				return nil, err
@@ -958,7 +958,7 @@ func (r *crdHandler) getOrCreateServingInfoFor(uid types.UID, name string) (*crd
 	return ret, nil
 }
 
-func scopeWithFieldManager(typeConverter fieldmanager.TypeConverter, reqScope handlers.RequestScope, resetFields map[fieldpath.APIVersion]*fieldpath.Set, ignoreManagedFieldsFromRequestObject bool) (handlers.RequestScope, error) {
+func scopeWithFieldManager(typeConverter fieldmanager.TypeConverter, reqScope handlers.RequestScope, resetFields map[fieldpath.APIVersion]*fieldpath.Set, subresource string) (handlers.RequestScope, error) {
 	fieldManager, err := fieldmanager.NewDefaultCRDFieldManager(
 		typeConverter,
 		reqScope.Convertor,
@@ -966,7 +966,7 @@ func scopeWithFieldManager(typeConverter fieldmanager.TypeConverter, reqScope ha
 		reqScope.Creater,
 		reqScope.Kind,
 		reqScope.HubGroupVersion,
-		ignoreManagedFieldsFromRequestObject,
+		subresource,
 		resetFields,
 	)
 	if err != nil {

staging/src/k8s.io/apimachinery/pkg/apis/meta/v1/types.go

@@ -1181,6 +1181,15 @@ type ManagedFieldsEntry struct {
 	// FieldsV1 holds the first JSON version format as described in the "FieldsV1" type.
 	// +optional
 	FieldsV1 *FieldsV1 `json:"fieldsV1,omitempty" protobuf:"bytes,7,opt,name=fieldsV1"`
+
+	// Subresource is the name of the subresource used to update that object, or
+	// empty string if the object was updated through the main resource. The
+	// value of this field is used to distinguish between managers, even if they
+	// share the same name. For example, a status update will be distinct from a
+	// regular update using the same manager name.
+	// Note that the APIVersion field is not related to the Subresource field and
+	// it always corresponds to the version of the main resource.
+	Subresource string `json:"subresource,omitempty" protobuf:"bytes,8,opt,name=subresource"`
 }
 
 // ManagedFieldsOperationType is the type of operation which lead to a ManagedFieldsEntry being created.

staging/src/k8s.io/apimachinery/pkg/apis/meta/v1/validation/validation.go

@@ -171,6 +171,8 @@ func ValidateTableOptions(opts *metav1.TableOptions) field.ErrorList {
 	return allErrs
 }
 
+const MaxSubresourceNameLength = 256
+
 func ValidateManagedFields(fieldsList []metav1.ManagedFieldsEntry, fldPath *field.Path) field.ErrorList {
 	var allErrs field.ErrorList
 	for i, fields := range fieldsList {
@@ -184,6 +186,10 @@ func ValidateManagedFields(fieldsList []metav1.ManagedFieldsEntry, fldPath *fiel
 			allErrs = append(allErrs, field.Invalid(fldPath.Child("fieldsType"), fields.FieldsType, "must be `FieldsV1`"))
 		}
 		allErrs = append(allErrs, ValidateFieldManager(fields.Manager, fldPath.Child("manager"))...)
+
+		if len(fields.Subresource) > MaxSubresourceNameLength {
+			allErrs = append(allErrs, field.TooLong(fldPath.Child("subresource"), fields.Subresource, MaxSubresourceNameLength))
+		}
 	}
 	return allErrs
 }

staging/src/k8s.io/apimachinery/pkg/apis/meta/v1/validation/validation_test.go

@@ -266,6 +266,12 @@ func TestValidateManagedFieldsInvalid(t *testing.T) {
 			Manager:    "field\nmanager",
 			APIVersion: "v1",
 		},
+		{
+			Operation:   metav1.ManagedFieldsOperationApply,
+			FieldsType:  "FieldsV1",
+			APIVersion:  "v1",
+			Subresource: "TooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLongTooLong",
+		},
 	}
 
 	for _, test := range tests {
@@ -291,9 +297,10 @@ func TestValidateMangedFieldsValid(t *testing.T) {
 			APIVersion: "v1",
 		},
 		{
-			Operation:  metav1.ManagedFieldsOperationApply,
-			FieldsType: "FieldsV1",
-			APIVersion: "v1",
+			Operation:   metav1.ManagedFieldsOperationApply,
+			FieldsType:  "FieldsV1",
+			APIVersion:  "v1",
+			Subresource: "scale",
 		},
 		{
 			Operation:  metav1.ManagedFieldsOperationApply,

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

@@ -28,16 +28,18 @@ import (
 type buildManagerInfoManager struct {
 	fieldManager Manager
 	groupVersion schema.GroupVersion
+	subresource  string
 }
 
 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 {
+func NewBuildManagerInfoManager(f Manager, gv schema.GroupVersion, subresource string) Manager {
 	return &buildManagerInfoManager{
 		fieldManager: f,
 		groupVersion: gv,
+		subresource:  subresource,
 	}
 }
 
@@ -61,9 +63,10 @@ func (f *buildManagerInfoManager) Apply(liveObj, appliedObj runtime.Object, mana
 
 func (f *buildManagerInfoManager) buildManagerInfo(prefix string, operation metav1.ManagedFieldsOperationType) (string, error) {
 	managerInfo := metav1.ManagedFieldsEntry{
-		Manager:    prefix,
-		Operation:  operation,
-		APIVersion: f.groupVersion.String(),
+		Manager:     prefix,
+		Operation:   operation,
+		APIVersion:  f.groupVersion.String(),
+		Subresource: f.subresource,
 	}
 	if managerInfo.Manager == "" {
 		managerInfo.Manager = "unknown"

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

@@ -47,7 +47,7 @@ func (*fakeManager) Apply(_, _ runtime.Object, _ Managed, _ string, _ bool) (run
 
 func TestCapManagersManagerMergesEntries(t *testing.T) {
 	f := NewTestFieldManager(schema.FromAPIVersionAndKind("v1", "Pod"),
-		false,
+		"",
 		func(m Manager) Manager {
 			return NewCapManagersManager(m, 3)
 		})
@@ -113,7 +113,7 @@ func TestCapManagersManagerMergesEntries(t *testing.T) {
 
 func TestCapUpdateManagers(t *testing.T) {
 	f := NewTestFieldManager(schema.FromAPIVersionAndKind("v1", "Pod"),
-		false,
+		"",
 		func(m Manager) Manager {
 			return NewCapManagersManager(m, 3)
 		})

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

@@ -66,39 +66,39 @@ type Manager interface {
 // FieldManager updates the managed fields and merge applied
 // configurations.
 type FieldManager struct {
-	fieldManager                         Manager
-	ignoreManagedFieldsFromRequestObject bool
+	fieldManager Manager
+	subresource  string
 }
 
 // NewFieldManager creates a new FieldManager that decodes, manages, then re-encodes managedFields
 // on update and apply requests.
-func NewFieldManager(f Manager, ignoreManagedFieldsFromRequestObject bool) *FieldManager {
-	return &FieldManager{fieldManager: f, ignoreManagedFieldsFromRequestObject: ignoreManagedFieldsFromRequestObject}
+func NewFieldManager(f Manager, subresource string) *FieldManager {
+	return &FieldManager{fieldManager: f, subresource: subresource}
 }
 
 // NewDefaultFieldManager creates a new FieldManager that merges apply requests
 // and update managed fields for other types of requests.
-func NewDefaultFieldManager(typeConverter TypeConverter, objectConverter runtime.ObjectConvertor, objectDefaulter runtime.ObjectDefaulter, objectCreater runtime.ObjectCreater, kind schema.GroupVersionKind, hub schema.GroupVersion, ignoreManagedFieldsFromRequestObject bool, resetFields map[fieldpath.APIVersion]*fieldpath.Set) (*FieldManager, error) {
+func NewDefaultFieldManager(typeConverter TypeConverter, objectConverter runtime.ObjectConvertor, objectDefaulter runtime.ObjectDefaulter, objectCreater runtime.ObjectCreater, kind schema.GroupVersionKind, hub schema.GroupVersion, subresource string, resetFields map[fieldpath.APIVersion]*fieldpath.Set) (*FieldManager, error) {
 	f, err := NewStructuredMergeManager(typeConverter, objectConverter, objectDefaulter, kind.GroupVersion(), hub, resetFields)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create field manager: %v", err)
 	}
-	return newDefaultFieldManager(f, typeConverter, objectConverter, objectCreater, kind, ignoreManagedFieldsFromRequestObject), nil
+	return newDefaultFieldManager(f, typeConverter, objectConverter, objectCreater, kind, subresource), nil
 }
 
 // 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 NewDefaultCRDFieldManager(typeConverter TypeConverter, objectConverter runtime.ObjectConvertor, objectDefaulter runtime.ObjectDefaulter, objectCreater runtime.ObjectCreater, kind schema.GroupVersionKind, hub schema.GroupVersion, ignoreManagedFieldsFromRequestObject bool, resetFields map[fieldpath.APIVersion]*fieldpath.Set) (_ *FieldManager, err error) {
+func NewDefaultCRDFieldManager(typeConverter TypeConverter, objectConverter runtime.ObjectConvertor, objectDefaulter runtime.ObjectDefaulter, objectCreater runtime.ObjectCreater, kind schema.GroupVersionKind, hub schema.GroupVersion, subresource string, resetFields map[fieldpath.APIVersion]*fieldpath.Set) (_ *FieldManager, err error) {
 	f, err := NewCRDStructuredMergeManager(typeConverter, objectConverter, objectDefaulter, kind.GroupVersion(), hub, resetFields)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create field manager: %v", err)
 	}
-	return newDefaultFieldManager(f, typeConverter, objectConverter, objectCreater, kind, ignoreManagedFieldsFromRequestObject), nil
+	return newDefaultFieldManager(f, typeConverter, objectConverter, objectCreater, kind, subresource), nil
 }
 
 // newDefaultFieldManager is a helper function which wraps a Manager with certain default logic.
-func newDefaultFieldManager(f Manager, typeConverter TypeConverter, objectConverter runtime.ObjectConvertor, objectCreater runtime.ObjectCreater, kind schema.GroupVersionKind, ignoreManagedFieldsFromRequestObject bool) *FieldManager {
+func newDefaultFieldManager(f Manager, typeConverter TypeConverter, objectConverter runtime.ObjectConvertor, objectCreater runtime.ObjectCreater, kind schema.GroupVersionKind, subresource string) *FieldManager {
 	return NewFieldManager(
 		NewLastAppliedUpdater(
 			NewLastAppliedManager(
@@ -107,11 +107,11 @@ func newDefaultFieldManager(f Manager, typeConverter TypeConverter, objectConver
 						NewBuildManagerInfoManager(
 							NewManagedFieldsUpdater(
 								NewStripMetaManager(f),
-							), kind.GroupVersion(),
+							), kind.GroupVersion(), subresource,
 						), DefaultMaxUpdateManagers,
 					), objectCreater, kind, DefaultTrackOnCreateProbability,
 				), typeConverter, objectConverter, kind.GroupVersion()),
-		), ignoreManagedFieldsFromRequestObject,
+		), subresource,
 	)
 }
 
@@ -167,7 +167,8 @@ func emptyManagedFieldsOnErr(managed Managed, err error) (Managed, error) {
 func (f *FieldManager) Update(liveObj, newObj runtime.Object, manager string) (object runtime.Object, err error) {
 	// First try to decode the managed fields provided in the update,
 	// This is necessary to allow directly updating managed fields.
-	managed, err := decodeLiveOrNew(liveObj, newObj, f.ignoreManagedFieldsFromRequestObject)
+	isSubresource := f.subresource != ""
+	managed, err := decodeLiveOrNew(liveObj, newObj, isSubresource)
 	if err != nil {
 		return newObj, nil
 	}

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

@@ -85,14 +85,14 @@ type TestFieldManager struct {
 }
 
 func NewDefaultTestFieldManager(gvk schema.GroupVersionKind) TestFieldManager {
-	return NewTestFieldManager(gvk, false, nil)
+	return NewTestFieldManager(gvk, "", nil)
 }
 
 func NewSubresourceTestFieldManager(gvk schema.GroupVersionKind) TestFieldManager {
-	return NewTestFieldManager(gvk, true, nil)
+	return NewTestFieldManager(gvk, "scale", nil)
 }
 
-func NewTestFieldManager(gvk schema.GroupVersionKind, ignoreManagedFieldsFromRequestObject bool, chainFieldManager func(Manager) Manager) TestFieldManager {
+func NewTestFieldManager(gvk schema.GroupVersionKind, subresource string, chainFieldManager func(Manager) Manager) TestFieldManager {
 	m := NewFakeOpenAPIModels()
 	typeConverter := NewFakeTypeConverter(m)
 	converter := newVersionConverter(typeConverter, &fakeObjectConvertor{}, gvk.GroupVersion())
@@ -118,7 +118,7 @@ func NewTestFieldManager(gvk schema.GroupVersionKind, ignoreManagedFieldsFromReq
 				NewBuildManagerInfoManager(
 					NewManagedFieldsUpdater(
 						NewStripMetaManager(f),
-					), gvk.GroupVersion(),
+					), gvk.GroupVersion(), subresource,
 				), &fakeObjectCreater{gvk: gvk}, gvk, DefaultTrackOnCreateProbability,
 			), typeConverter, objectConverter, gvk.GroupVersion(),
 		),
@@ -127,7 +127,7 @@ func NewTestFieldManager(gvk schema.GroupVersionKind, ignoreManagedFieldsFromReq
 		f = chainFieldManager(f)
 	}
 	return TestFieldManager{
-		fieldManager: NewFieldManager(f, ignoreManagedFieldsFromRequestObject),
+		fieldManager: NewFieldManager(f, subresource),
 		apiVersion:   gvk.GroupVersion().String(),
 		emptyObj:     live,
 		liveObj:      live.DeepCopyObject(),
@@ -1266,7 +1266,7 @@ func TestUpdateViaSubresources(t *testing.T) {
 		},
 	})
 
-	// Check that managed fields cannot be changed via subresources
+	// Check that managed fields cannot be changed explicitly via subresources
 	expectedManager := "fieldmanager_test_subresource"
 	if err := f.Update(obj, expectedManager); err != nil {
 		t.Fatalf("failed to apply object: %v", err)

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

@@ -75,11 +75,15 @@ func printManager(manager string) string {
 	if err := json.Unmarshal([]byte(manager), encodedManager); err != nil {
 		return fmt.Sprintf("%q", manager)
 	}
+	managerStr := fmt.Sprintf("%q", encodedManager.Manager)
+	if encodedManager.Subresource != "" {
+		managerStr = fmt.Sprintf("%s with subresource %q", managerStr, encodedManager.Subresource)
+	}
 	if encodedManager.Operation == metav1.ManagedFieldsOperationUpdate {
 		if encodedManager.Time == nil {
-			return fmt.Sprintf("%q using %v", encodedManager.Manager, encodedManager.APIVersion)
+			return fmt.Sprintf("%s using %v", managerStr, encodedManager.APIVersion)
 		}
-		return fmt.Sprintf("%q using %v at %v", encodedManager.Manager, encodedManager.APIVersion, encodedManager.Time.UTC().Format(time.RFC3339))
+		return fmt.Sprintf("%s using %v at %v", managerStr, encodedManager.APIVersion, encodedManager.Time.UTC().Format(time.RFC3339))
 	}
-	return fmt.Sprintf("%q", encodedManager.Manager)
+	return managerStr
 }

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

@@ -96,6 +96,31 @@ conflicts with "foo" using v1 at 2001-02-03T04:05:06Z:
 				},
 			},
 		},
+		{
+			conflict: merge.Conflicts{
+				merge.Conflict{
+					Manager: `{"manager":"foo","operation":"Update","subresource":"scale","apiVersion":"v1","time":"2001-02-03T04:05:06Z"}`,
+					Path:    fieldpath.MakePathOrDie("spec", "replicas"),
+				},
+			},
+			expected: &errors.StatusError{
+				ErrStatus: metav1.Status{
+					Status: metav1.StatusFailure,
+					Code:   http.StatusConflict,
+					Reason: metav1.StatusReasonConflict,
+					Details: &metav1.StatusDetails{
+						Causes: []metav1.StatusCause{
+							{
+								Type:    metav1.CauseTypeFieldManagerConflict,
+								Message: `conflict with "foo" with subresource "scale" using v1 at 2001-02-03T04:05:06Z`,
+								Field:   ".spec.replicas",
+							},
+						},
+					},
+					Message: `Apply failed with 1 conflict: conflict with "foo" with subresource "scale" using v1 at 2001-02-03T04:05:06Z: .spec.replicas`,
+				},
+			},
+		},
 	}
 	for _, tc := range testCases {
 		actual := internal.NewConflictError(tc.conflict)

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

@@ -213,7 +213,11 @@ func sortEncodedManagedFields(encodedManagedFields []metav1.ManagedFieldsEntry)
 		if p.Manager != q.Manager {
 			return p.Manager < q.Manager
 		}
-		return p.APIVersion < q.APIVersion
+
+		if p.APIVersion != q.APIVersion {
+			return p.APIVersion < q.APIVersion
+		}
+		return p.Subresource < q.Subresource
 	})
 
 	return encodedManagedFields, nil

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

@@ -258,6 +258,15 @@ func TestRoundTripManagedFields(t *testing.T) {
           f:storage: {}
   manager: foo
   operation: Update
+`,
+		`- apiVersion: v1
+  fieldsType: FieldsV1
+  fieldsV1:
+    f:spec:
+      f:replicas: {}
+  manager: foo
+  operation: Update
+  subresource: scale
 `,
 	}
 
@@ -313,6 +322,18 @@ time: "2001-02-03T04:05:06Z"
 `,
 			expected: "{\"manager\":\"foo\",\"operation\":\"Apply\"}",
 		},
+		{
+			managedFieldsEntry: `
+apiVersion: v1
+fieldsV1:
+  f:apiVersion: {}
+manager: foo
+operation: Apply
+subresource: scale
+time: "2001-02-03T04:05:06Z"
+`,
+			expected: "{\"manager\":\"foo\",\"operation\":\"Apply\",\"subresource\":\"scale\"}",
+		},
 	}
 
 	for _, test := range tests {
@@ -462,6 +483,19 @@ func TestSortEncodedManagedFields(t *testing.T) {
 				{Manager: "c", Operation: metav1.ManagedFieldsOperationUpdate, Time: &metav1.Time{time.Date(2000, time.January, 0, 0, 0, 0, 1, time.UTC)}},
 			},
 		},
+		{
+			name: "entries with subresource field",
+			managedFields: []metav1.ManagedFieldsEntry{
+				{Manager: "a", Operation: metav1.ManagedFieldsOperationApply, Subresource: "status"},
+				{Manager: "a", Operation: metav1.ManagedFieldsOperationApply, Subresource: "scale"},
+				{Manager: "a", Operation: metav1.ManagedFieldsOperationApply},
+			},
+			expected: []metav1.ManagedFieldsEntry{
+				{Manager: "a", Operation: metav1.ManagedFieldsOperationApply},
+				{Manager: "a", Operation: metav1.ManagedFieldsOperationApply, Subresource: "scale"},
+				{Manager: "a", Operation: metav1.ManagedFieldsOperationApply, Subresource: "status"},
+			},
+		},
 	}
 
 	for _, test := range tests {

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

@@ -27,7 +27,7 @@ import (
 
 func TestLastAppliedUpdater(t *testing.T) {
 	f := NewTestFieldManager(schema.FromAPIVersionAndKind("apps/v1", "Deployment"),
-		false,
+		"",
 		func(m Manager) Manager {
 			return NewLastAppliedUpdater(m)
 		})

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

@@ -27,7 +27,7 @@ import (
 )
 
 func TestNoManagedFieldsUpdateDoesntUpdateTime(t *testing.T) {
-	f := NewTestFieldManager(schema.FromAPIVersionAndKind("v1", "Pod"), false, nil)
+	f := NewTestFieldManager(schema.FromAPIVersionAndKind("v1", "Pod"), "", nil)
 
 	obj := &unstructured.Unstructured{Object: map[string]interface{}{}}
 	if err := yaml.Unmarshal([]byte(`{

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

@@ -42,7 +42,7 @@ func (f *fakeObjectCreater) New(_ schema.GroupVersionKind) (runtime.Object, erro
 }
 
 func TestNoUpdateBeforeFirstApply(t *testing.T) {
-	f := NewTestFieldManager(schema.FromAPIVersionAndKind("v1", "Pod"), false, func(m Manager) Manager {
+	f := NewTestFieldManager(schema.FromAPIVersionAndKind("v1", "Pod"), "", func(m Manager) Manager {
 		return NewSkipNonAppliedManager(
 			m,
 			&fakeObjectCreater{gvk: schema.GroupVersionKind{Version: "v1", Kind: "Pod"}},
@@ -82,7 +82,7 @@ func TestNoUpdateBeforeFirstApply(t *testing.T) {
 }
 
 func TestUpdateBeforeFirstApply(t *testing.T) {
-	f := NewTestFieldManager(schema.FromAPIVersionAndKind("v1", "Pod"), false, func(m Manager) Manager {
+	f := NewTestFieldManager(schema.FromAPIVersionAndKind("v1", "Pod"), "", func(m Manager) Manager {
 		return NewSkipNonAppliedManager(
 			m,
 			&fakeObjectCreater{gvk: schema.GroupVersionKind{Version: "v1", Kind: "Pod"}},

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

@@ -607,7 +607,7 @@ func (a *APIInstaller) registerResourceHandlers(path string, storage rest.Storag
 			a.group.Creater,
 			fqKindToRegister,
 			reqScope.HubGroupVersion,
-			isSubresource,
+			subresource,
 			resetFields,
 		)
 		if err != nil {

test/integration/apiserver/apply/apply_test.go

@@ -2920,3 +2920,509 @@ spec:
 		t.Errorf("object has unexpected managedFields: %v", managed)
 	}
 }
+
+func TestRenamingAppliedFieldManagers(t *testing.T) {
+	defer featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, genericfeatures.ServerSideApply, true)()
+
+	_, client, closeFn := setup(t)
+	defer closeFn()
+
+	// Creating an object
+	podBytes := []byte(`{
+		"apiVersion": "v1",
+		"kind": "Pod",
+		"metadata": {
+			"name": "just-a-pod",
+			"labels": {
+				"a": "one"
+			}
+		},
+		"spec": {
+			"containers": [{
+				"name":  "test-container-a",
+				"image": "test-image-one"
+			}]
+		}
+	}`)
+	_, err := client.CoreV1().RESTClient().
+		Patch(types.ApplyPatchType).
+		Namespace("default").
+		Param("fieldManager", "multi_manager_one").
+		Resource("pods").
+		Name("just-a-pod").
+		Body(podBytes).
+		Do(context.TODO()).
+		Get()
+	if err != nil {
+		t.Fatalf("Failed to apply: %v", err)
+	}
+	_, err = client.CoreV1().RESTClient().
+		Patch(types.ApplyPatchType).
+		Namespace("default").
+		Param("fieldManager", "multi_manager_two").
+		Resource("pods").
+		Name("just-a-pod").
+		Body([]byte(`{"apiVersion":"v1","kind":"Pod","metadata":{"labels":{"b":"two"}}}`)).
+		Do(context.TODO()).
+		Get()
+	if err != nil {
+		t.Fatalf("Failed to apply: %v", err)
+	}
+
+	pod, err := client.CoreV1().Pods("default").Get(context.TODO(), "just-a-pod", metav1.GetOptions{})
+	if err != nil {
+		t.Fatalf("Failed to get object: %v", err)
+	}
+	expectedLabels := map[string]string{
+		"a": "one",
+		"b": "two",
+	}
+	if !reflect.DeepEqual(pod.Labels, expectedLabels) {
+		t.Fatalf("Expected labels to be %v, but got %v", expectedLabels, pod.Labels)
+	}
+
+	managedFields := pod.GetManagedFields()
+	for i := range managedFields {
+		managedFields[i].Manager = "multi_manager"
+	}
+	pod.SetManagedFields(managedFields)
+
+	obj, err := client.CoreV1().RESTClient().
+		Put().
+		Namespace("default").
+		Resource("pods").
+		Name("just-a-pod").
+		Body(pod).
+		Do(context.TODO()).
+		Get()
+	if err != nil {
+		t.Fatalf("Failed to update: %v", err)
+	}
+
+	accessor, err := meta.Accessor(obj)
+	if err != nil {
+		t.Fatalf("Failed to get meta accessor for object: %v", err)
+	}
+	managedFields = accessor.GetManagedFields()
+	if len(managedFields) != 1 {
+		t.Fatalf("Expected object to have 1 managed fields entry, got: %d", len(managedFields))
+	}
+	entry := managedFields[0]
+	if entry.Manager != "multi_manager" || entry.Operation != "Apply" || string(entry.FieldsV1.Raw) != `{"f:metadata":{"f:labels":{"f:b":{}}}}` {
+		t.Fatalf(`Unexpected entry, got: %v`, entry)
+	}
+}
+
+func TestRenamingUpdatedFieldManagers(t *testing.T) {
+	defer featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, genericfeatures.ServerSideApply, true)()
+
+	_, client, closeFn := setup(t)
+	defer closeFn()
+
+	// Creating an object
+	podBytes := []byte(`{
+		"apiVersion": "v1",
+		"kind": "Pod",
+		"metadata": {
+			"name": "just-a-pod"
+		},
+		"spec": {
+			"containers": [{
+				"name":  "test-container-a",
+				"image": "test-image-one"
+			}]
+		}
+	}`)
+	_, err := client.CoreV1().RESTClient().
+		Patch(types.ApplyPatchType).
+		Namespace("default").
+		Param("fieldManager", "first").
+		Resource("pods").
+		Name("just-a-pod").
+		Body(podBytes).
+		Do(context.TODO()).
+		Get()
+	if err != nil {
+		t.Fatalf("Failed to create object: %v", err)
+	}
+
+	_, err = client.CoreV1().RESTClient().
+		Patch(types.MergePatchType).
+		Namespace("default").
+		Param("fieldManager", "multi_manager_one").
+		Resource("pods").
+		Name("just-a-pod").
+		Body([]byte(`{"metadata":{"labels":{"a":"one"}}}`)).
+		Do(context.TODO()).
+		Get()
+	if err != nil {
+		t.Fatalf("Failed to update: %v", err)
+	}
+	_, err = client.CoreV1().RESTClient().
+		Patch(types.MergePatchType).
+		Namespace("default").
+		Param("fieldManager", "multi_manager_two").
+		Resource("pods").
+		Name("just-a-pod").
+		Body([]byte(`{"metadata":{"labels":{"b":"two"}}}`)).
+		Do(context.TODO()).
+		Get()
+	if err != nil {
+		t.Fatalf("Failed to update: %v", err)
+	}
+
+	pod, err := client.CoreV1().Pods("default").Get(context.TODO(), "just-a-pod", metav1.GetOptions{})
+	if err != nil {
+		t.Fatalf("Failed to get object: %v", err)
+	}
+	expectedLabels := map[string]string{
+		"a": "one",
+		"b": "two",
+	}
+	if !reflect.DeepEqual(pod.Labels, expectedLabels) {
+		t.Fatalf("Expected labels to be %v, but got %v", expectedLabels, pod.Labels)
+	}
+
+	managedFields := pod.GetManagedFields()
+	for i := range managedFields {
+		managedFields[i].Manager = "multi_manager"
+	}
+	pod.SetManagedFields(managedFields)
+
+	obj, err := client.CoreV1().RESTClient().
+		Put().
+		Namespace("default").
+		Resource("pods").
+		Name("just-a-pod").
+		Body(pod).
+		Do(context.TODO()).
+		Get()
+	if err != nil {
+		t.Fatalf("Failed to update: %v", err)
+	}
+
+	accessor, err := meta.Accessor(obj)
+	if err != nil {
+		t.Fatalf("Failed to get meta accessor for object: %v", err)
+	}
+	managedFields = accessor.GetManagedFields()
+	if len(managedFields) != 2 {
+		t.Fatalf("Expected object to have 2 managed fields entries, got: %d", len(managedFields))
+	}
+	entry := managedFields[1]
+	if entry.Manager != "multi_manager" || entry.Operation != "Update" || string(entry.FieldsV1.Raw) != `{"f:metadata":{"f:labels":{"f:b":{}}}}` {
+		t.Fatalf(`Unexpected entry, got: %v`, entry)
+	}
+}
+
+func TestDroppingSubresourceField(t *testing.T) {
+	defer featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, genericfeatures.ServerSideApply, true)()
+
+	_, client, closeFn := setup(t)
+	defer closeFn()
+
+	// Creating an object
+	podBytes := []byte(`{
+		"apiVersion": "v1",
+		"kind": "Pod",
+		"metadata": {
+			"name": "just-a-pod"
+		},
+		"spec": {
+			"containers": [{
+				"name":  "test-container-a",
+				"image": "test-image-one"
+			}]
+		}
+	}`)
+	_, err := client.CoreV1().RESTClient().
+		Patch(types.ApplyPatchType).
+		Namespace("default").
+		Param("fieldManager", "first").
+		Resource("pods").
+		Name("just-a-pod").
+		Body(podBytes).
+		Do(context.TODO()).
+		Get()
+	if err != nil {
+		t.Fatalf("Failed to create object: %v", err)
+	}
+
+	_, err = client.CoreV1().RESTClient().
+		Patch(types.ApplyPatchType).
+		Namespace("default").
+		Param("fieldManager", "label_manager").
+		Resource("pods").
+		Name("just-a-pod").
+		Body([]byte(`{"apiVersion":"v1","kind":"Pod","metadata":{"labels":{"a":"one"}}}`)).
+		Do(context.TODO()).
+		Get()
+	if err != nil {
+		t.Fatalf("Failed to apply: %v", err)
+	}
+	_, err = client.CoreV1().RESTClient().
+		Patch(types.ApplyPatchType).
+		Namespace("default").
+		Param("fieldManager", "label_manager").
+		Resource("pods").
+		Name("just-a-pod").
+		SubResource("status").
+		Body([]byte(`{"apiVersion":"v1","kind":"Pod","metadata":{"labels":{"b":"two"}}}`)).
+		Do(context.TODO()).
+		Get()
+	if err != nil {
+		t.Fatalf("Failed to apply: %v", err)
+	}
+
+	pod, err := client.CoreV1().Pods("default").Get(context.TODO(), "just-a-pod", metav1.GetOptions{})
+	if err != nil {
+		t.Fatalf("Failed to get object: %v", err)
+	}
+	expectedLabels := map[string]string{
+		"a": "one",
+		"b": "two",
+	}
+	if !reflect.DeepEqual(pod.Labels, expectedLabels) {
+		t.Fatalf("Expected labels to be %v, but got %v", expectedLabels, pod.Labels)
+	}
+
+	managedFields := pod.GetManagedFields()
+	if len(managedFields) != 3 {
+		t.Fatalf("Expected object to have 3 managed fields entries, got: %d", len(managedFields))
+	}
+	if managedFields[1].Manager != "label_manager" || managedFields[1].Operation != "Apply" || managedFields[1].Subresource != "" {
+		t.Fatalf(`Unexpected entry, got: %v`, managedFields[1])
+	}
+	if managedFields[2].Manager != "label_manager" || managedFields[2].Operation != "Apply" || managedFields[2].Subresource != "status" {
+		t.Fatalf(`Unexpected entry, got: %v`, managedFields[2])
+	}
+
+	for i := range managedFields {
+		managedFields[i].Subresource = ""
+	}
+	pod.SetManagedFields(managedFields)
+
+	obj, err := client.CoreV1().RESTClient().
+		Put().
+		Namespace("default").
+		Resource("pods").
+		Name("just-a-pod").
+		Body(pod).
+		Do(context.TODO()).
+		Get()
+	if err != nil {
+		t.Fatalf("Failed to update: %v", err)
+	}
+
+	accessor, err := meta.Accessor(obj)
+	if err != nil {
+		t.Fatalf("Failed to get meta accessor for object: %v", err)
+	}
+	managedFields = accessor.GetManagedFields()
+	if len(managedFields) != 2 {
+		t.Fatalf("Expected object to have 2 managed fields entries, got: %d", len(managedFields))
+	}
+	entry := managedFields[1]
+	if entry.Manager != "label_manager" || entry.Operation != "Apply" || string(entry.FieldsV1.Raw) != `{"f:metadata":{"f:labels":{"f:b":{}}}}` {
+		t.Fatalf(`Unexpected entry, got: %v`, entry)
+	}
+}
+
+func TestDroppingSubresourceFromSpecField(t *testing.T) {
+	defer featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, genericfeatures.ServerSideApply, true)()
+
+	_, client, closeFn := setup(t)
+	defer closeFn()
+
+	// Creating an object
+	podBytes := []byte(`{
+		"apiVersion": "v1",
+		"kind": "Pod",
+		"metadata": {
+			"name": "just-a-pod"
+		},
+		"spec": {
+			"containers": [{
+				"name":  "test-container-a",
+				"image": "test-image-one"
+			}]
+		}
+	}`)
+	_, err := client.CoreV1().RESTClient().
+		Patch(types.ApplyPatchType).
+		Namespace("default").
+		Param("fieldManager", "first").
+		Resource("pods").
+		Name("just-a-pod").
+		Body(podBytes).
+		Do(context.TODO()).
+		Get()
+	if err != nil {
+		t.Fatalf("Failed to create object: %v", err)
+	}
+
+	_, err = client.CoreV1().RESTClient().
+		Patch(types.MergePatchType).
+		Namespace("default").
+		Param("fieldManager", "manager").
+		Resource("pods").
+		Name("just-a-pod").
+		Body([]byte(`{"metadata":{"labels":{"a":"two"}}}`)).
+		Do(context.TODO()).
+		Get()
+	if err != nil {
+		t.Fatalf("Failed to update: %v", err)
+	}
+
+	_, err = client.CoreV1().RESTClient().
+		Patch(types.MergePatchType).
+		Namespace("default").
+		Param("fieldManager", "manager").
+		Resource("pods").
+		SubResource("status").
+		Name("just-a-pod").
+		Body([]byte(`{"status":{"phase":"Running"}}`)).
+		Do(context.TODO()).
+		Get()
+	if err != nil {
+		t.Fatalf("Failed to apply: %v", err)
+	}
+
+	pod, err := client.CoreV1().Pods("default").Get(context.TODO(), "just-a-pod", metav1.GetOptions{})
+	if err != nil {
+		t.Fatalf("Failed to get object: %v", err)
+	}
+	expectedLabels := map[string]string{"a": "two"}
+	if !reflect.DeepEqual(pod.Labels, expectedLabels) {
+		t.Fatalf("Expected labels to be %v, but got %v", expectedLabels, pod.Labels)
+	}
+	if pod.Status.Phase != v1.PodRunning {
+		t.Fatalf("Expected phase to be %q, but got %q", v1.PodRunning, pod.Status.Phase)
+	}
+
+	managedFields := pod.GetManagedFields()
+	if len(managedFields) != 3 {
+		t.Fatalf("Expected object to have 3 managed fields entries, got: %d", len(managedFields))
+	}
+	if managedFields[1].Manager != "manager" || managedFields[1].Operation != "Update" || managedFields[1].Subresource != "" {
+		t.Fatalf(`Unexpected entry, got: %v`, managedFields[1])
+	}
+	if managedFields[2].Manager != "manager" || managedFields[2].Operation != "Update" || managedFields[2].Subresource != "status" {
+		t.Fatalf(`Unexpected entry, got: %v`, managedFields[2])
+	}
+
+	for i := range managedFields {
+		managedFields[i].Subresource = ""
+	}
+	pod.SetManagedFields(managedFields)
+
+	obj, err := client.CoreV1().RESTClient().
+		Put().
+		Namespace("default").
+		Resource("pods").
+		Name("just-a-pod").
+		Body(pod).
+		Do(context.TODO()).
+		Get()
+	if err != nil {
+		t.Fatalf("Failed to update: %v", err)
+	}
+
+	accessor, err := meta.Accessor(obj)
+	if err != nil {
+		t.Fatalf("Failed to get meta accessor for object: %v", err)
+	}
+	managedFields = accessor.GetManagedFields()
+	if len(managedFields) != 2 {
+		t.Fatalf("Expected object to have 2 managed fields entries, got: %d", len(managedFields))
+	}
+	entry := managedFields[1]
+	if entry.Manager != "manager" || entry.Operation != "Update" || string(entry.FieldsV1.Raw) != `{"f:status":{"f:phase":{}}}` {
+		t.Fatalf(`Unexpected entry, got: %v`, entry)
+	}
+}
+
+func TestSubresourceField(t *testing.T) {
+	defer featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, genericfeatures.ServerSideApply, true)()
+
+	_, client, closeFn := setup(t)
+	defer closeFn()
+
+	// Creating a deployment
+	deploymentBytes := []byte(`{
+		"apiVersion": "apps/v1",
+		"kind": "Deployment",
+		"metadata": {
+			"name": "deployment",
+			"labels": {"app": "nginx"}
+		},
+		"spec": {
+			"replicas": 3,
+			"selector": {
+				"matchLabels": {
+					 "app": "nginx"
+				}
+			},
+			"template": {
+				"metadata": {
+					"labels": {
+						"app": "nginx"
+					}
+				},
+				"spec": {
+					"containers": [{
+						"name":  "nginx",
+						"image": "nginx:latest"
+					}]
+				}
+			}
+		}
+	}`)
+	_, err := client.CoreV1().RESTClient().
+		Patch(types.ApplyPatchType).
+		AbsPath("/apis/apps/v1").
+		Namespace("default").
+		Resource("deployments").
+		Name("deployment").
+		Param("fieldManager", "manager").
+		Body(deploymentBytes).Do(context.TODO()).Get()
+	if err != nil {
+		t.Fatalf("Failed to apply object: %v", err)
+	}
+
+	_, err = client.CoreV1().RESTClient().
+		Patch(types.MergePatchType).
+		AbsPath("/apis/apps/v1").
+		Namespace("default").
+		Resource("deployments").
+		SubResource("status").
+		Name("deployment").
+		Body([]byte(`{"status":{"unavailableReplicas":32}}`)).
+		Param("fieldManager", "manager").
+		Do(context.TODO()).
+		Get()
+	if err != nil {
+		t.Fatalf("Failed to update status: %v", err)
+	}
+
+	// TODO (nodo): add test for "scale" once we start tracking managed fields (#82046)
+
+	deployment, err := client.AppsV1().Deployments("default").Get(context.TODO(), "deployment", metav1.GetOptions{})
+	if err != nil {
+		t.Fatalf("Failed to get object: %v", err)
+	}
+
+	managedFields := deployment.GetManagedFields()
+	if len(managedFields) != 2 {
+		t.Fatalf("Expected object to have 3 managed fields entries, got: %d", len(managedFields))
+	}
+	if managedFields[0].Manager != "manager" || managedFields[0].Operation != "Apply" || managedFields[0].Subresource != "" {
+		t.Fatalf(`Unexpected entry, got: %v`, managedFields[0])
+	}
+	if managedFields[1].Manager != "manager" ||
+		managedFields[1].Operation != "Update" ||
+		managedFields[1].Subresource != "status" ||
+		string(managedFields[1].FieldsV1.Raw) != `{"f:status":{"f:unavailableReplicas":{}}}` {
+		t.Fatalf(`Unexpected entry, got: %v`, managedFields[1])
+	}
+}