Golang Selector.Empty方法代碼示例

// ListPods obtains a list of pods that match selector.
func (k *KubernetesScheduler) ListPods(selector labels.Selector) ([]api.Pod, error) {
	log.V(2).Infof("List pods for '%v'\n", selector)

	k.RLock()
	defer k.RUnlock()

	var result []api.Pod
	for _, task := range k.runningTasks {
		pod := *(task.Pod)

		var l labels.Set = pod.Labels
		if selector.Matches(l) || selector.Empty() {
			result = append(result, *(task.Pod))
		}
	}

	// TODO(nnielsen): Refactor tasks append for the three lists.
	for _, task := range k.pendingTasks {
		pod := *(task.Pod)

		var l labels.Set = pod.Labels
		if selector.Matches(l) || selector.Empty() {
			result = append(result, *(task.Pod))
		}
	}

	// TODO(nnielsen): Wire up check in finished tasks

	log.V(2).Infof("Returning pods: '%v'\n", result)

	return result, nil
}

// WatchControllers begins watching for new, changed, or deleted controllers.
func (registry *EtcdRegistry) WatchControllers(label, field labels.Selector, resourceVersion uint64) (watch.Interface, error) {
	if !field.Empty() {
		return nil, fmt.Errorf("no field selector implemented for controllers")
	}
	return registry.helper.WatchList("/registry/controllers", resourceVersion, func(obj interface{}) bool {
		return label.Matches(labels.Set(obj.(*api.ReplicationController).Labels))
	})
}

// SelectorParam adds the given selector as a query parameter with the name paramName.
func (r *Request) SelectorParam(paramName string, s labels.Selector) *Request {
	if r.err != nil {
		return r
	}
	if s.Empty() {
		return r
	}
	return r.setParam(paramName, s.String())
}

// LabelsSelectorParam adds the given selector as a query parameter
func (r *Request) LabelsSelectorParam(s labels.Selector) *Request {
	if r.err != nil {
		return r
	}
	if s.Empty() {
		return r
	}
	return r.setParam(api.LabelSelectorQueryParam(r.apiVersion), s.String())
}

// WatchEndpoints begins watching for new, changed, or deleted endpoint configurations.
func (r *Registry) WatchEndpoints(label, field labels.Selector, resourceVersion uint64) (watch.Interface, error) {
	if !label.Empty() {
		return nil, fmt.Errorf("label selectors are not supported on endpoints")
	}
	if value, found := field.RequiresExactMatch("ID"); found {
		return r.Watch(makeServiceEndpointsKey(value), resourceVersion)
	}
	if field.Empty() {
		return r.WatchList("/registry/services/endpoints", resourceVersion, tools.Everything)
	}
	return nil, fmt.Errorf("only the 'ID' and default (everything) field selectors are supported")
}

// Watch returns ReplicationController events via a watch.Interface.
// It implements apiserver.ResourceWatcher.
func (rs *RegistryStorage) Watch(label, field labels.Selector, resourceVersion uint64) (watch.Interface, error) {
	if !field.Empty() {
		return nil, fmt.Errorf("no field selector implemented for controllers")
	}
	incoming, err := rs.registry.WatchControllers(resourceVersion)
	if err != nil {
		return nil, err
	}
	return watch.Filter(incoming, func(e watch.Event) (watch.Event, bool) {
		repController := e.Object.(*api.ReplicationController)
		return e, label.Matches(labels.Set(repController.Labels))
	}), nil
}

func (a cachedServiceNamespacer) List(label labels.Selector) (*api.ServiceList, error) {
	if !label.Empty() {
		return nil, fmt.Errorf("label selection on the cache is not currently implemented")
	}
	items, err := a.accessor.store.Index("namespace", &api.Service{ObjectMeta: api.ObjectMeta{Namespace: a.namespace}})
	if err != nil {
		return nil, err
	}
	services := make([]api.Service, 0, len(items))
	for i := range items {
		services = append(services, *items[i].(*api.Service))
	}
	return &api.ServiceList{
		// TODO: set ResourceVersion so that we can make watch work.
		Items: services,
	}, nil
}

// List obtains a list of ReplicationControllers that match selector.
func (rs *REST) List(ctx api.Context, label, field labels.Selector) (runtime.Object, error) {
	if !field.Empty() {
		return nil, fmt.Errorf("field selector not supported yet")
	}
	controllers, err := rs.registry.ListControllers(ctx)
	if err != nil {
		return nil, err
	}
	filtered := []api.ReplicationController{}
	for _, controller := range controllers.Items {
		if label.Matches(labels.Set(controller.Labels)) {
			rs.fillCurrentState(ctx, &controller)
			filtered = append(filtered, controller)
		}
	}
	controllers.Items = filtered
	return controllers, err
}

// WatchEndpoints begins watching for new, changed, or deleted endpoint configurations.
func (r *Registry) WatchEndpoints(ctx api.Context, label labels.Selector, field fields.Selector, resourceVersion string) (watch.Interface, error) {
	version, err := tools.ParseWatchResourceVersion(resourceVersion, "endpoints")
	if err != nil {
		return nil, err
	}
	if !label.Empty() {
		return nil, fmt.Errorf("label selectors are not supported on endpoints")
	}
	if value, found := field.RequiresExactMatch("name"); found {
		key, err := makeServiceEndpointsKey(ctx, value)
		if err != nil {
			return nil, err
		}
		return r.Watch(key, version), nil
	}
	if field.Empty() {
		return r.WatchList(makeServiceEndpointsListKey(ctx), version, tools.Everything)
	}
	return nil, fmt.Errorf("only the 'ID' and default (everything) field selectors are supported")
}

// WatchServices begins watching for new, changed, or deleted service configurations.
func (r *Registry) WatchServices(ctx api.Context, label labels.Selector, field fields.Selector, resourceVersion string) (watch.Interface, error) {
	version, err := storage.ParseWatchResourceVersion(resourceVersion, "service")
	if err != nil {
		return nil, err
	}
	if !label.Empty() {
		return nil, fmt.Errorf("label selectors are not supported on services")
	}
	if value, found := field.RequiresExactMatch("name"); found {
		key, err := makeServiceKey(ctx, value)
		if err != nil {
			return nil, err
		}
		// TODO: use generic.SelectionPredicate
		return r.Watch(key, version, storage.Everything)
	}
	if field.Empty() {
		return r.WatchList(makeServiceListKey(ctx), version, storage.Everything)
	}
	return nil, fmt.Errorf("only the 'name' and default (everything) field selectors are supported")
}

// Watch returns ReplicationController events via a watch.Interface.
// It implements apiserver.ResourceWatcher.
func (rs *REST) Watch(ctx api.Context, label, field labels.Selector, resourceVersion string) (watch.Interface, error) {
	if !field.Empty() {
		return nil, fmt.Errorf("no field selector implemented for controllers")
	}
	incoming, err := rs.registry.WatchControllers(ctx, resourceVersion)
	if err != nil {
		return nil, err
	}
	// TODO(lavalamp): remove watch.Filter, which is broken. Implement consistent way of filtering.
	// TODO(lavalamp): this watch method needs a test.
	return watch.Filter(incoming, func(e watch.Event) (watch.Event, bool) {
		repController, ok := e.Object.(*api.ReplicationController)
		if !ok {
			// must be an error event-- pass it on
			return e, true
		}
		match := label.Matches(labels.Set(repController.Labels))
		if match {
			rs.fillCurrentState(ctx, repController)
		}
		return e, match
	}), nil
}

// WatchControllers begins watching for new, changed, or deleted controllers.
func (r *Registry) WatchControllers(ctx api.Context, label, field labels.Selector, resourceVersion string) (watch.Interface, error) {
	if !field.Empty() {
		return nil, fmt.Errorf("field selectors are not supported on replication controllers")
	}
	version, err := tools.ParseWatchResourceVersion(resourceVersion, "replicationControllers")
	if err != nil {
		return nil, err
	}
	key := makeControllerListKey(ctx)
	return r.WatchList(key, version, func(obj runtime.Object) bool {
		controller, ok := obj.(*api.ReplicationController)
		if !ok {
			// Must be an error: return true to propagate to upper level.
			return true
		}
		match := label.Matches(labels.Set(controller.Labels))
		if match {
			pods, _ := r.ListPods(ctx, labels.Set(controller.Spec.Selector).AsSelector())
			controller.Status.Replicas = len(pods.Items)
		}
		return match
	})
}

// WatchRoutes begins watching for new, changed, or deleted route configurations.
func (registry *Etcd) WatchRoutes(ctx kapi.Context, label labels.Selector, field fields.Selector, resourceVersion string) (watch.Interface, error) {
	if !label.Empty() {
		return nil, fmt.Errorf("label selectors are not supported on routes yet")
	}

	version, err := storage.ParseWatchResourceVersion(resourceVersion, "pod")
	if err != nil {
		return nil, err
	}

	if value, found := field.RequiresExactMatch("ID"); found {
		key, err := makeRouteKey(ctx, value)
		if err != nil {
			return nil, err
		}
		return registry.Watch(key, version, storage.Everything)
	}

	if field.Empty() {
		key := kubeetcd.MakeEtcdListKey(ctx, RoutePath)
		return registry.WatchList(key, version, storage.Everything)
	}
	return nil, fmt.Errorf("only the 'ID' and default (everything) field selectors are supported")
}

// List satisfies the RESTStorage interface.
func (rs *REST) List(ctx api.Context, label, field labels.Selector) (runtime.Object, error) {
	if !label.Empty() || !field.Empty() {
		return nil, errors.NewBadRequest("label/field selectors are not supported on endpoints")
	}
	return rs.registry.ListEndpoints(ctx)
}

// List satisfies the RESTStorage interface.
func (rs *Storage) List(selector labels.Selector) (interface{}, error) {
	if !selector.Empty() {
		return nil, errors.New("label selectors are not supported on endpoints")
	}
	return rs.registry.ListEndpoints()
}