Merge pull request #36889 from wojtek-t/reuse_fields_and_labels

Automatic merge from submit-queue

Reuse fields and labels

This should significantly reduce memory allocations in apiserver in large cluster.
Explanation:
- every kubelet is refreshing watch every 5-10 minutes (this generally is not causing relist - it just renews watch)
- that means, in 5000-node cluster, we are issuing ~10 watches per second
- since we don't have "watch heartbets", the watch is issued from previously received resourceVersion
- to make some assumption, let's assume pods are evenly spread across pods, and writes for them are evenly spread - that means, that a given kubelet is interested in 1 per 5000 pod changes
- with that assumption, each watch, has to process 2500 (on average) previous watch events
- for each of such even, we are currently computing fields.

This PR is fixing this problem.

pkg/registry/core/configmap/etcd/etcd.go

@@ -43,6 +43,7 @@ func NewREST(opts generic.RESTOptions) *REST {
 		prefix,
 		configmap.Strategy,
 		newListFunc,
+		configmap.GetAttrs,
 		storage.NoTriggerPublisher)
 
 	store := &registry.Store{

pkg/registry/core/configmap/strategy.go

@@ -88,18 +88,20 @@ func ConfigMapToSelectableFields(cfg *api.ConfigMap) fields.Set {
 	return generic.ObjectMetaFieldsSet(&cfg.ObjectMeta, true)
 }
 
+// GetAttrs returns labels and fields of a given object for filtering purposes.
+func GetAttrs(obj runtime.Object) (labels.Set, fields.Set, error) {
+	cfg, ok := obj.(*api.ConfigMap)
+	if !ok {
+		return nil, nil, fmt.Errorf("given object is not a ConfigMap")
+	}
+	return labels.Set(cfg.ObjectMeta.Labels), ConfigMapToSelectableFields(cfg), nil
+}
+
 // MatchConfigMap returns a generic matcher for a given label and field selector.
 func MatchConfigMap(label labels.Selector, field fields.Selector) apistorage.SelectionPredicate {
 	return apistorage.SelectionPredicate{
-		Label: label,
-		Field: field,
-		GetAttrs: func(obj runtime.Object) (labels.Set, fields.Set, error) {
-			cfg, ok := obj.(*api.ConfigMap)
-			if !ok {
-				return nil, nil, fmt.Errorf("given object is not a ConfigMap")
-			}
-
-			return labels.Set(cfg.ObjectMeta.Labels), ConfigMapToSelectableFields(cfg), nil
-		},
+		Label:    label,
+		Field:    field,
+		GetAttrs: GetAttrs,
 	}
 }

pkg/registry/core/controller/etcd/etcd.go

@@ -69,6 +69,7 @@ func NewREST(opts generic.RESTOptions) (*REST, *StatusREST) {
 		prefix,
 		controller.Strategy,
 		newListFunc,
+		controller.GetAttrs,
 		storage.NoTriggerPublisher,
 	)
 

pkg/registry/core/controller/strategy.go

@@ -118,20 +118,23 @@ func ControllerToSelectableFields(controller *api.ReplicationController) fields.
 	return generic.MergeFieldsSets(objectMetaFieldsSet, controllerSpecificFieldsSet)
 }
 
+// GetAttrs returns labels and fields of a given object for filtering purposes.
+func GetAttrs(obj runtime.Object) (labels.Set, fields.Set, error) {
+	rc, ok := obj.(*api.ReplicationController)
+	if !ok {
+		return nil, nil, fmt.Errorf("Given object is not a replication controller.")
+	}
+	return labels.Set(rc.ObjectMeta.Labels), ControllerToSelectableFields(rc), nil
+}
+
 // MatchController is the filter used by the generic etcd backend to route
 // watch events from etcd to clients of the apiserver only interested in specific
 // labels/fields.
 func MatchController(label labels.Selector, field fields.Selector) apistorage.SelectionPredicate {
 	return apistorage.SelectionPredicate{
-		Label: label,
-		Field: field,
-		GetAttrs: func(obj runtime.Object) (labels.Set, fields.Set, error) {
-			rc, ok := obj.(*api.ReplicationController)
-			if !ok {
-				return nil, nil, fmt.Errorf("Given object is not a replication controller.")
-			}
-			return labels.Set(rc.ObjectMeta.Labels), ControllerToSelectableFields(rc), nil
-		},
+		Label:    label,
+		Field:    field,
+		GetAttrs: GetAttrs,
 	}
 }
 

pkg/registry/core/endpoint/etcd/etcd.go

@@ -42,6 +42,7 @@ func NewREST(opts generic.RESTOptions) *REST {
 		prefix,
 		endpoint.Strategy,
 		newListFunc,
+		endpoint.GetAttrs,
 		storage.NoTriggerPublisher,
 	)
 

pkg/registry/core/endpoint/strategy.go

@@ -79,27 +79,21 @@ func (endpointsStrategy) AllowUnconditionalUpdate() bool {
 	return true
 }
 
+// GetAttrs returns labels and fields of a given object for filtering purposes.
+func GetAttrs(obj runtime.Object) (labels.Set, fields.Set, error) {
+	endpoints, ok := obj.(*api.Endpoints)
+	if !ok {
+		return nil, nil, fmt.Errorf("invalid object type %#v", obj)
+	}
+	return endpoints.Labels, EndpointsToSelectableFields(endpoints), nil
+}
+
 // MatchEndpoints returns a generic matcher for a given label and field selector.
 func MatchEndpoints(label labels.Selector, field fields.Selector) pkgstorage.SelectionPredicate {
 	return pkgstorage.SelectionPredicate{
-		Label: label,
-		Field: field,
-		GetAttrs: func(obj runtime.Object) (labels.Set, fields.Set, error) {
-			endpoints, ok := obj.(*api.Endpoints)
-			if !ok {
-				return nil, nil, fmt.Errorf("invalid object type %#v", obj)
-			}
-
-			// Compute fields only if field selectors is non-empty
-			// (otherwise those won't be used).
-			// Those are generally also not needed if label selector does
-			// not match labels, but additional computation of it is expensive.
-			var endpointsFields fields.Set
-			if !field.Empty() {
-				endpointsFields = EndpointsToSelectableFields(endpoints)
-			}
-			return endpoints.Labels, endpointsFields, nil
-		},
+		Label:    label,
+		Field:    field,
+		GetAttrs: GetAttrs,
 	}
 }
 

pkg/registry/core/event/strategy.go

@@ -70,17 +70,20 @@ func (eventStrategy) AllowUnconditionalUpdate() bool {
 	return true
 }
 
+// GetAttrs returns labels and fields of a given object for filtering purposes.
+func GetAttrs(obj runtime.Object) (labels.Set, fields.Set, error) {
+	event, ok := obj.(*api.Event)
+	if !ok {
+		return nil, nil, fmt.Errorf("not an event")
+	}
+	return labels.Set(event.Labels), EventToSelectableFields(event), nil
+}
+
 func MatchEvent(label labels.Selector, field fields.Selector) storage.SelectionPredicate {
 	return storage.SelectionPredicate{
-		Label: label,
-		Field: field,
-		GetAttrs: func(obj runtime.Object) (labels.Set, fields.Set, error) {
-			event, ok := obj.(*api.Event)
-			if !ok {
-				return nil, nil, fmt.Errorf("not an event")
-			}
-			return labels.Set(event.Labels), EventToSelectableFields(event), nil
-		},
+		Label:    label,
+		Field:    field,
+		GetAttrs: GetAttrs,
 	}
 }
 

pkg/registry/core/limitrange/etcd/etcd.go

@@ -42,6 +42,7 @@ func NewREST(opts generic.RESTOptions) *REST {
 		prefix,
 		limitrange.Strategy,
 		newListFunc,
+		limitrange.GetAttrs,
 		storage.NoTriggerPublisher,
 	)
 

pkg/registry/core/limitrange/strategy.go

@@ -85,16 +85,19 @@ func (limitrangeStrategy) Export(api.Context, runtime.Object, bool) error {
 	return nil
 }
 
+// GetAttrs returns labels and fields of a given object for filtering purposes.
+func GetAttrs(obj runtime.Object) (labels.Set, fields.Set, error) {
+	lr, ok := obj.(*api.LimitRange)
+	if !ok {
+		return nil, nil, fmt.Errorf("given object is not a limit range.")
+	}
+	return labels.Set(lr.ObjectMeta.Labels), LimitRangeToSelectableFields(lr), nil
+}
+
 func MatchLimitRange(label labels.Selector, field fields.Selector) storage.SelectionPredicate {
 	return storage.SelectionPredicate{
-		Label: label,
-		Field: field,
-		GetAttrs: func(obj runtime.Object) (labels.Set, fields.Set, error) {
-			lr, ok := obj.(*api.LimitRange)
-			if !ok {
-				return nil, nil, fmt.Errorf("given object is not a limit range.")
-			}
-			return labels.Set(lr.ObjectMeta.Labels), LimitRangeToSelectableFields(lr), nil
-		},
+		Label:    label,
+		Field:    field,
+		GetAttrs: GetAttrs,
 	}
 }

pkg/registry/core/namespace/etcd/etcd.go

@@ -60,6 +60,7 @@ func NewREST(opts generic.RESTOptions) (*REST, *StatusREST, *FinalizeREST) {
 		prefix,
 		namespace.Strategy,
 		newListFunc,
+		namespace.GetAttrs,
 		storage.NoTriggerPublisher,
 	)
 

pkg/registry/core/namespace/strategy.go

@@ -135,18 +135,21 @@ func (namespaceFinalizeStrategy) PrepareForUpdate(ctx api.Context, obj, old runt
 	newNamespace.Status = oldNamespace.Status
 }
 
+// GetAttrs returns labels and fields of a given object for filtering purposes.
+func GetAttrs(obj runtime.Object) (labels.Set, fields.Set, error) {
+	namespaceObj, ok := obj.(*api.Namespace)
+	if !ok {
+		return nil, nil, fmt.Errorf("not a namespace")
+	}
+	return labels.Set(namespaceObj.Labels), NamespaceToSelectableFields(namespaceObj), nil
+}
+
 // MatchNamespace returns a generic matcher for a given label and field selector.
 func MatchNamespace(label labels.Selector, field fields.Selector) apistorage.SelectionPredicate {
 	return apistorage.SelectionPredicate{
-		Label: label,
-		Field: field,
-		GetAttrs: func(obj runtime.Object) (labels.Set, fields.Set, error) {
-			namespaceObj, ok := obj.(*api.Namespace)
-			if !ok {
-				return nil, nil, fmt.Errorf("not a namespace")
-			}
-			return labels.Set(namespaceObj.Labels), NamespaceToSelectableFields(namespaceObj), nil
-		},
+		Label:    label,
+		Field:    field,
+		GetAttrs: GetAttrs,
 	}
 }
 

pkg/registry/core/node/etcd/etcd.go

@@ -79,6 +79,7 @@ func NewStorage(opts generic.RESTOptions, kubeletClientConfig client.KubeletClie
 		prefix,
 		node.Strategy,
 		newListFunc,
+		node.GetAttrs,
 		node.NodeNameTriggerFunc)
 
 	store := &registry.Store{

pkg/registry/core/node/strategy.go

@@ -144,27 +144,21 @@ func NodeToSelectableFields(node *api.Node) fields.Set {
 	return generic.MergeFieldsSets(objectMetaFieldsSet, specificFieldsSet)
 }
 
+// GetAttrs returns labels and fields of a given object for filtering purposes.
+func GetAttrs(obj runtime.Object) (labels.Set, fields.Set, error) {
+	nodeObj, ok := obj.(*api.Node)
+	if !ok {
+		return nil, nil, fmt.Errorf("not a node")
+	}
+	return labels.Set(nodeObj.ObjectMeta.Labels), NodeToSelectableFields(nodeObj), nil
+}
+
 // MatchNode returns a generic matcher for a given label and field selector.
 func MatchNode(label labels.Selector, field fields.Selector) pkgstorage.SelectionPredicate {
 	return pkgstorage.SelectionPredicate{
-		Label: label,
-		Field: field,
-		GetAttrs: func(obj runtime.Object) (labels.Set, fields.Set, error) {
-			nodeObj, ok := obj.(*api.Node)
-			if !ok {
-				return nil, nil, fmt.Errorf("not a node")
-			}
-
-			// Compute fields only if field selectors is non-empty
-			// (otherwise those won't be used).
-			// Those are generally also not needed if label selector does
-			// not match labels, but additional computation of it is expensive.
-			var nodeFields fields.Set
-			if !field.Empty() {
-				nodeFields = NodeToSelectableFields(nodeObj)
-			}
-			return labels.Set(nodeObj.ObjectMeta.Labels), nodeFields, nil
-		},
+		Label:       label,
+		Field:       field,
+		GetAttrs:    GetAttrs,
 		IndexFields: []string{"metadata.name"},
 	}
 }

pkg/registry/core/persistentvolume/etcd/etcd.go

@@ -43,6 +43,7 @@ func NewREST(opts generic.RESTOptions) (*REST, *StatusREST) {
 		prefix,
 		persistentvolume.Strategy,
 		newListFunc,
+		persistentvolume.GetAttrs,
 		storage.NoTriggerPublisher,
 	)
 

pkg/registry/core/persistentvolume/strategy.go

@@ -95,18 +95,21 @@ func (persistentvolumeStatusStrategy) ValidateUpdate(ctx api.Context, obj, old r
 	return validation.ValidatePersistentVolumeStatusUpdate(obj.(*api.PersistentVolume), old.(*api.PersistentVolume))
 }
 
+// GetAttrs returns labels and fields of a given object for filtering purposes.
+func GetAttrs(obj runtime.Object) (labels.Set, fields.Set, error) {
+	persistentvolumeObj, ok := obj.(*api.PersistentVolume)
+	if !ok {
+		return nil, nil, fmt.Errorf("not a persistentvolume")
+	}
+	return labels.Set(persistentvolumeObj.Labels), PersistentVolumeToSelectableFields(persistentvolumeObj), nil
+}
+
 // MatchPersistentVolume returns a generic matcher for a given label and field selector.
 func MatchPersistentVolumes(label labels.Selector, field fields.Selector) storage.SelectionPredicate {
 	return storage.SelectionPredicate{
-		Label: label,
-		Field: field,
-		GetAttrs: func(obj runtime.Object) (labels.Set, fields.Set, error) {
-			persistentvolumeObj, ok := obj.(*api.PersistentVolume)
-			if !ok {
-				return nil, nil, fmt.Errorf("not a persistentvolume")
-			}
-			return labels.Set(persistentvolumeObj.Labels), PersistentVolumeToSelectableFields(persistentvolumeObj), nil
-		},
+		Label:    label,
+		Field:    field,
+		GetAttrs: GetAttrs,
 	}
 }
 

pkg/registry/core/persistentvolumeclaim/etcd/etcd.go

@@ -43,6 +43,7 @@ func NewREST(opts generic.RESTOptions) (*REST, *StatusREST) {
 		prefix,
 		persistentvolumeclaim.Strategy,
 		newListFunc,
+		persistentvolumeclaim.GetAttrs,
 		storage.NoTriggerPublisher,
 	)
 

pkg/registry/core/persistentvolumeclaim/strategy.go

@@ -95,18 +95,21 @@ func (persistentvolumeclaimStatusStrategy) ValidateUpdate(ctx api.Context, obj,
 	return validation.ValidatePersistentVolumeClaimStatusUpdate(obj.(*api.PersistentVolumeClaim), old.(*api.PersistentVolumeClaim))
 }
 
+// GetAttrs returns labels and fields of a given object for filtering purposes.
+func GetAttrs(obj runtime.Object) (labels.Set, fields.Set, error) {
+	persistentvolumeclaimObj, ok := obj.(*api.PersistentVolumeClaim)
+	if !ok {
+		return nil, nil, fmt.Errorf("not a persistentvolumeclaim")
+	}
+	return labels.Set(persistentvolumeclaimObj.Labels), PersistentVolumeClaimToSelectableFields(persistentvolumeclaimObj), nil
+}
+
 // MatchPersistentVolumeClaim returns a generic matcher for a given label and field selector.
 func MatchPersistentVolumeClaim(label labels.Selector, field fields.Selector) storage.SelectionPredicate {
 	return storage.SelectionPredicate{
-		Label: label,
-		Field: field,
-		GetAttrs: func(obj runtime.Object) (labels.Set, fields.Set, error) {
-			persistentvolumeclaimObj, ok := obj.(*api.PersistentVolumeClaim)
-			if !ok {
-				return nil, nil, fmt.Errorf("not a persistentvolumeclaim")
-			}
-			return labels.Set(persistentvolumeclaimObj.Labels), PersistentVolumeClaimToSelectableFields(persistentvolumeclaimObj), nil
-		},
+		Label:    label,
+		Field:    field,
+		GetAttrs: GetAttrs,
 	}
 }
 

pkg/registry/core/pod/etcd/etcd.go

@@ -69,6 +69,7 @@ func NewStorage(opts generic.RESTOptions, k client.ConnectionInfoGetter, proxyTr
 		prefix,
 		pod.Strategy,
 		newListFunc,
+		pod.GetAttrs,
 		pod.NodeNameTriggerFunc,
 	)
 

pkg/registry/core/pod/strategy.go

@@ -155,27 +155,21 @@ func (podStatusStrategy) ValidateUpdate(ctx api.Context, obj, old runtime.Object
 	return validation.ValidatePodStatusUpdate(obj.(*api.Pod), old.(*api.Pod))
 }
 
+// GetAttrs returns labels and fields of a given object for filtering purposes.
+func GetAttrs(obj runtime.Object) (labels.Set, fields.Set, error) {
+	pod, ok := obj.(*api.Pod)
+	if !ok {
+		return nil, nil, fmt.Errorf("not a pod")
+	}
+	return labels.Set(pod.ObjectMeta.Labels), PodToSelectableFields(pod), nil
+}
+
 // MatchPod returns a generic matcher for a given label and field selector.
 func MatchPod(label labels.Selector, field fields.Selector) storage.SelectionPredicate {
 	return storage.SelectionPredicate{
-		Label: label,
-		Field: field,
-		GetAttrs: func(obj runtime.Object) (labels.Set, fields.Set, error) {
-			pod, ok := obj.(*api.Pod)
-			if !ok {
-				return nil, nil, fmt.Errorf("not a pod")
-			}
-
-			// Compute fields only if field selectors is non-empty
-			// (otherwise those won't be used).
-			// Those are generally also not needed if label selector does
-			// not match labels, but additional computation of it is expensive.
-			var podFields fields.Set
-			if !field.Empty() {
-				podFields = PodToSelectableFields(pod)
-			}
-			return labels.Set(pod.ObjectMeta.Labels), podFields, nil
-		},
+		Label:       label,
+		Field:       field,
+		GetAttrs:    GetAttrs,
 		IndexFields: []string{"spec.nodeName"},
 	}
 }

pkg/registry/core/podtemplate/etcd/etcd.go

@@ -42,6 +42,7 @@ func NewREST(opts generic.RESTOptions) *REST {
 		prefix,
 		podtemplate.Strategy,
 		newListFunc,
+		podtemplate.GetAttrs,
 		storage.NoTriggerPublisher,
 	)
 

pkg/registry/core/podtemplate/strategy.go

@@ -86,16 +86,19 @@ func PodTemplateToSelectableFields(podTemplate *api.PodTemplate) fields.Set {
 	return nil
 }
 
+// GetAttrs returns labels and fields of a given object for filtering purposes.
+func GetAttrs(obj runtime.Object) (labels.Set, fields.Set, error) {
+	pt, ok := obj.(*api.PodTemplate)
+	if !ok {
+		return nil, nil, fmt.Errorf("given object is not a pod template.")
+	}
+	return labels.Set(pt.ObjectMeta.Labels), PodTemplateToSelectableFields(pt), nil
+}
+
 func MatchPodTemplate(label labels.Selector, field fields.Selector) storage.SelectionPredicate {
 	return storage.SelectionPredicate{
-		Label: label,
-		Field: field,
-		GetAttrs: func(obj runtime.Object) (labels.Set, fields.Set, error) {
-			pt, ok := obj.(*api.PodTemplate)
-			if !ok {
-				return nil, nil, fmt.Errorf("given object is not a pod template.")
-			}
-			return labels.Set(pt.ObjectMeta.Labels), PodTemplateToSelectableFields(pt), nil
-		},
+		Label:    label,
+		Field:    field,
+		GetAttrs: GetAttrs,
 	}
 }

pkg/registry/core/resourcequota/etcd/etcd.go

@@ -43,6 +43,7 @@ func NewREST(opts generic.RESTOptions) (*REST, *StatusREST) {
 		prefix,
 		resourcequota.Strategy,
 		newListFunc,
+		resourcequota.GetAttrs,
 		storage.NoTriggerPublisher,
 	)
 

pkg/registry/core/resourcequota/strategy.go

@@ -98,18 +98,21 @@ func (resourcequotaStatusStrategy) ValidateUpdate(ctx api.Context, obj, old runt
 	return validation.ValidateResourceQuotaStatusUpdate(obj.(*api.ResourceQuota), old.(*api.ResourceQuota))
 }
 
+// GetAttrs returns labels and fields of a given object for filtering purposes.
+func GetAttrs(obj runtime.Object) (labels.Set, fields.Set, error) {
+	resourcequotaObj, ok := obj.(*api.ResourceQuota)
+	if !ok {
+		return nil, nil, fmt.Errorf("not a resourcequota")
+	}
+	return labels.Set(resourcequotaObj.Labels), ResourceQuotaToSelectableFields(resourcequotaObj), nil
+}
+
 // MatchResourceQuota returns a generic matcher for a given label and field selector.
 func MatchResourceQuota(label labels.Selector, field fields.Selector) storage.SelectionPredicate {
 	return storage.SelectionPredicate{
-		Label: label,
-		Field: field,
-		GetAttrs: func(obj runtime.Object) (labels.Set, fields.Set, error) {
-			resourcequotaObj, ok := obj.(*api.ResourceQuota)
-			if !ok {
-				return nil, nil, fmt.Errorf("not a resourcequota")
-			}
-			return labels.Set(resourcequotaObj.Labels), ResourceQuotaToSelectableFields(resourcequotaObj), nil
-		},
+		Label:    label,
+		Field:    field,
+		GetAttrs: GetAttrs,
 	}
 }
 

pkg/registry/core/secret/etcd/etcd.go

@@ -42,6 +42,7 @@ func NewREST(opts generic.RESTOptions) *REST {
 		prefix,
 		secret.Strategy,
 		newListFunc,
+		secret.GetAttrs,
 		storage.NoTriggerPublisher,
 	)
 

pkg/registry/core/secret/strategy.go

@@ -94,18 +94,21 @@ func (s strategy) Export(ctx api.Context, obj runtime.Object, exact bool) error
 	return nil
 }
 
+// GetAttrs returns labels and fields of a given object for filtering purposes.
+func GetAttrs(obj runtime.Object) (labels.Set, fields.Set, error) {
+	secret, ok := obj.(*api.Secret)
+	if !ok {
+		return nil, nil, fmt.Errorf("not a secret")
+	}
+	return labels.Set(secret.Labels), SelectableFields(secret), nil
+}
+
 // Matcher returns a generic matcher for a given label and field selector.
 func Matcher(label labels.Selector, field fields.Selector) apistorage.SelectionPredicate {
 	return apistorage.SelectionPredicate{
-		Label: label,
-		Field: field,
-		GetAttrs: func(obj runtime.Object) (labels.Set, fields.Set, error) {
-			secret, ok := obj.(*api.Secret)
-			if !ok {
-				return nil, nil, fmt.Errorf("not a secret")
-			}
-			return labels.Set(secret.Labels), SelectableFields(secret), nil
-		},
+		Label:    label,
+		Field:    field,
+		GetAttrs: GetAttrs,
 	}
 }
 

pkg/registry/core/service/etcd/etcd.go

@@ -43,6 +43,7 @@ func NewREST(opts generic.RESTOptions) (*REST, *StatusREST) {
 		prefix,
 		service.Strategy,
 		newListFunc,
+		service.GetAttrs,
 		storage.NoTriggerPublisher,
 	)
 

pkg/registry/core/service/strategy.go

@@ -101,17 +101,20 @@ func (svcStrategy) Export(ctx api.Context, obj runtime.Object, exact bool) error
 	return nil
 }
 
+// GetAttrs returns labels and fields of a given object for filtering purposes.
+func GetAttrs(obj runtime.Object) (labels.Set, fields.Set, error) {
+	service, ok := obj.(*api.Service)
+	if !ok {
+		return nil, nil, fmt.Errorf("Given object is not a service")
+	}
+	return labels.Set(service.ObjectMeta.Labels), ServiceToSelectableFields(service), nil
+}
+
 func MatchServices(label labels.Selector, field fields.Selector) apistorage.SelectionPredicate {
 	return apistorage.SelectionPredicate{
-		Label: label,
-		Field: field,
-		GetAttrs: func(obj runtime.Object) (labels.Set, fields.Set, error) {
-			service, ok := obj.(*api.Service)
-			if !ok {
-				return nil, nil, fmt.Errorf("Given object is not a service")
-			}
-			return labels.Set(service.ObjectMeta.Labels), ServiceToSelectableFields(service), nil
-		},
+		Label:    label,
+		Field:    field,
+		GetAttrs: GetAttrs,
 	}
 }
 

pkg/registry/core/serviceaccount/etcd/etcd.go

@@ -42,6 +42,7 @@ func NewREST(opts generic.RESTOptions) *REST {
 		prefix,
 		serviceaccount.Strategy,
 		newListFunc,
+		serviceaccount.GetAttrs,
 		storage.NoTriggerPublisher,
 	)
 

pkg/registry/core/serviceaccount/strategy.go

@@ -77,18 +77,21 @@ func (strategy) AllowUnconditionalUpdate() bool {
 	return true
 }
 
+// GetAttrs returns labels and fields of a given object for filtering purposes.
+func GetAttrs(obj runtime.Object) (labels.Set, fields.Set, error) {
+	sa, ok := obj.(*api.ServiceAccount)
+	if !ok {
+		return nil, nil, fmt.Errorf("not a serviceaccount")
+	}
+	return labels.Set(sa.Labels), SelectableFields(sa), nil
+}
+
 // Matcher returns a generic matcher for a given label and field selector.
 func Matcher(label labels.Selector, field fields.Selector) apistorage.SelectionPredicate {
 	return apistorage.SelectionPredicate{
-		Label: label,
-		Field: field,
-		GetAttrs: func(obj runtime.Object) (labels.Set, fields.Set, error) {
-			sa, ok := obj.(*api.ServiceAccount)
-			if !ok {
-				return nil, nil, fmt.Errorf("not a serviceaccount")
-			}
-			return labels.Set(sa.Labels), SelectableFields(sa), nil
-		},
+		Label:    label,
+		Field:    field,
+		GetAttrs: GetAttrs,
 	}
 }