Golang meta.Accessor函数代码示例

// MetaNamespaceIndexFunc is a default index function that indexes based on an object's namespace
func MetaNamespaceIndexFunc(obj interface{}) (string, error) {
	meta, err := meta.Accessor(obj)
	if err != nil {
		return "", fmt.Errorf("object has no meta: %v", err)
	}
	return meta.Namespace(), nil
}

// nameIndexFunc is an index function that indexes based on an object's name
func nameIndexFunc(obj interface{}) ([]string, error) {
	meta, err := meta.Accessor(obj)
	if err != nil {
		return []string{""}, fmt.Errorf("object has no meta: %v", err)
	}
	return []string{meta.Name()}, nil
}

func (r *Reflector) listAndWatch(stopCh <-chan struct{}) {
	var resourceVersion string
	resyncCh, cleanup := r.resyncChan()
	defer cleanup()

	list, err := r.listerWatcher.List()
	if err != nil {
		util.HandleError(fmt.Errorf("%s: Failed to list %v: %v", r.name, r.expectedType, err))
		return
	}
	meta, err := meta.Accessor(list)
	if err != nil {
		util.HandleError(fmt.Errorf("%s: Unable to understand list result %#v", r.name, list))
		return
	}
	resourceVersion = meta.ResourceVersion()
	items, err := runtime.ExtractList(list)
	if err != nil {
		util.HandleError(fmt.Errorf("%s: Unable to understand list result %#v (%v)", r.name, list, err))
		return
	}
	if err := r.syncWith(items); err != nil {
		util.HandleError(fmt.Errorf("%s: Unable to sync list result: %v", r.name, err))
		return
	}
	r.setLastSyncResourceVersion(resourceVersion)

	for {
		w, err := r.listerWatcher.Watch(resourceVersion)
		if err != nil {
			switch err {
			case io.EOF:
				// watch closed normally
			case io.ErrUnexpectedEOF:
				glog.V(1).Infof("%s: Watch for %v closed with unexpected EOF: %v", r.name, r.expectedType, err)
			default:
				util.HandleError(fmt.Errorf("%s: Failed to watch %v: %v", r.name, r.expectedType, err))
			}
			// If this is "connection refused" error, it means that most likely apiserver is not responsive.
			// It doesn't make sense to re-list all objects because most likely we will be able to restart
			// watch where we ended.
			// If that's the case wait and resend watch request.
			if urlError, ok := err.(*url.Error); ok {
				if opError, ok := urlError.Err.(*net.OpError); ok {
					if errno, ok := opError.Err.(syscall.Errno); ok && errno == syscall.ECONNREFUSED {
						time.Sleep(time.Second)
						continue
					}
				}
			}
			return
		}
		if err := r.watchHandler(w, &resourceVersion, resyncCh, stopCh); err != nil {
			if err != errorResyncRequested && err != errorStopRequested {
				util.HandleError(fmt.Errorf("%s: watch of %v ended with: %v", r.name, r.expectedType, err))
			}
			return
		}
	}
}

// GetReference returns an ObjectReference which refers to the given
// object, or an error if the object doesn't follow the conventions
// that would allow this.
func GetReference(obj runtime.Object) (*ObjectReference, error) {
	if obj == nil {
		return nil, ErrNilObject
	}
	if ref, ok := obj.(*ObjectReference); ok {
		// Don't make a reference to a reference.
		return ref, nil
	}
	meta, err := meta.Accessor(obj)
	if err != nil {
		return nil, err
	}
	_, kind, err := Scheme.ObjectVersionAndKind(obj)
	if err != nil {
		return nil, err
	}
	version := versionFromSelfLink.FindStringSubmatch(meta.SelfLink())
	if len(version) < 2 {
		return nil, fmt.Errorf("unexpected self link format: '%v'; got version '%v'", meta.SelfLink(), version)
	}
	return &ObjectReference{
		Kind:            kind,
		APIVersion:      version[1],
		Name:            meta.Name(),
		Namespace:       meta.Namespace(),
		UID:             meta.UID(),
		ResourceVersion: meta.ResourceVersion(),
	}, nil
}

// watchHandler watches w and keeps *resourceVersion up to date.
func (r *Reflector) watchHandler(w watch.Interface, resourceVersion *string, resyncCh <-chan time.Time, stopCh <-chan struct{}) error {
	start := time.Now()
	eventCount := 0

	// Stopping the watcher should be idempotent and if we return from this function there's no way
	// we're coming back in with the same watch interface.
	defer w.Stop()

loop:
	for {
		select {
		case <-stopCh:
			return errorStopRequested
		case <-resyncCh:
			return errorResyncRequested
		case event, ok := <-w.ResultChan():
			if !ok {
				break loop
			}
			if event.Type == watch.Error {
				return apierrs.FromObject(event.Object)
			}
			if e, a := r.expectedType, reflect.TypeOf(event.Object); e != a {
				util.HandleError(fmt.Errorf("%s: expected type %v, but watch event object had type %v", r.name, e, a))
				continue
			}
			meta, err := meta.Accessor(event.Object)
			if err != nil {
				util.HandleError(fmt.Errorf("%s: unable to understand watch event %#v", r.name, event))
				continue
			}
			switch event.Type {
			case watch.Added:
				r.store.Add(event.Object)
			case watch.Modified:
				r.store.Update(event.Object)
			case watch.Deleted:
				// TODO: Will any consumers need access to the "last known
				// state", which is passed in event.Object? If so, may need
				// to change this.
				r.store.Delete(event.Object)
			default:
				util.HandleError(fmt.Errorf("%s: unable to understand watch event %#v", r.name, event))
			}
			*resourceVersion = meta.ResourceVersion()
			r.setLastSyncResourceVersion(*resourceVersion)
			eventCount++
		}
	}

	watchDuration := time.Now().Sub(start)
	if watchDuration < 1*time.Second && eventCount == 0 {
		glog.V(4).Infof("%s: Unexpected watch close - watch lasted less than a second and no items received", r.name)
		return errors.New("very short watch")
	}
	glog.V(4).Infof("%s: Watch close - %v total %v items received", r.name, r.expectedType, eventCount)
	return nil
}

// GetReference returns an ObjectReference which refers to the given
// object, or an error if the object doesn't follow the conventions
// that would allow this.
// TODO: should take a meta.Interface see https://github.com/GoogleCloudPlatform/kubernetes/issues/7127
func GetReference(obj runtime.Object) (*ObjectReference, error) {
	if obj == nil {
		return nil, ErrNilObject
	}
	if ref, ok := obj.(*ObjectReference); ok {
		// Don't make a reference to a reference.
		return ref, nil
	}
	meta, err := meta.Accessor(obj)
	if err != nil {
		return nil, err
	}

	// if the object referenced is actually persisted, we can just get kind from meta
	// if we are building an object reference to something not yet persisted, we should fallback to scheme
	kind := meta.Kind()
	if kind == "" {
		_, kind, err = Scheme.ObjectVersionAndKind(obj)
		if err != nil {
			return nil, err
		}
	}

	// if the object referenced is actually persisted, we can also get version from meta
	version := meta.APIVersion()
	if version == "" {
		selfLink := meta.SelfLink()
		if selfLink == "" {
			if ForTesting_ReferencesAllowBlankSelfLinks {
				version = "testing"
			} else {
				return nil, ErrNoSelfLink
			}
		} else {
			selfLinkUrl, err := url.Parse(selfLink)
			if err != nil {
				return nil, err
			}
			// example paths: /<prefix>/<version>/*
			parts := strings.Split(selfLinkUrl.Path, "/")
			if len(parts) < 3 {
				return nil, fmt.Errorf("unexpected self link format: '%v'; got version '%v'", selfLink, version)
			}
			version = parts[2]
		}
	}

	return &ObjectReference{
		Kind:            kind,
		APIVersion:      version,
		Name:            meta.Name(),
		Namespace:       meta.Namespace(),
		UID:             meta.UID(),
		ResourceVersion: meta.ResourceVersion(),
	}, nil
}

// MetaNamespaceKeyFunc is a convenient default KeyFunc which knows how to make
// keys for API objects which implement meta.Interface.
// The key uses the format: <namespace>/<name>
func MetaNamespaceKeyFunc(obj interface{}) (string, error) {
	meta, err := meta.Accessor(obj)
	if err != nil {
		return "", fmt.Errorf("object has no meta: %v", err)
	}
	if len(meta.Namespace()) > 0 {
		return meta.Namespace() + "/" + meta.Name(), nil
	}
	return meta.Name(), nil
}

func fuzzInternalObject(t *testing.T, forVersion string, item runtime.Object, seed int64) runtime.Object {
	fuzzerFor(t, forVersion, rand.NewSource(seed)).Fuzz(item)

	j, err := meta.Accessor(item)
	if err != nil {
		t.Fatalf("Unexpected error %v for %#v", err, item)
	}
	j.SetKind("")
	j.SetAPIVersion("")

	return item
}

// MetaNamespaceKeyFunc is a convenient default KeyFunc which knows how to make
// keys for API objects which implement meta.Interface.
// The key uses the format <namespace>/<name> unless <namespace> is empty, then
// it's just <name>.
//
// TODO: replace key-as-string with a key-as-struct so that this
// packing/unpacking won't be necessary.
func MetaNamespaceKeyFunc(obj interface{}) (string, error) {
	if key, ok := obj.(ExplicitKey); ok {
		return string(key), nil
	}
	meta, err := meta.Accessor(obj)
	if err != nil {
		return "", fmt.Errorf("object has no meta: %v", err)
	}
	if len(meta.Namespace()) > 0 {
		return meta.Namespace() + "/" + meta.Name(), nil
	}
	return meta.Name(), nil
}

// syncWith replaces the store's items with the given list.
func (r *Reflector) syncWith(items []runtime.Object) error {
	found := map[string]interface{}{}
	for _, item := range items {
		meta, err := meta.Accessor(item)
		if err != nil {
			return fmt.Errorf("unexpected item in list: %v", err)
		}
		found[meta.Name()] = item
	}

	r.store.Replace(found)
	return nil
}

// watchHandler watches w and keeps *resourceVersion up to date.
func (r *Reflector) watchHandler(w watch.Interface, resourceVersion *string, exitWatch <-chan time.Time) error {
	start := time.Now()
	eventCount := 0
loop:
	for {
		select {
		case <-exitWatch:
			w.Stop()
			return errorResyncRequested
		case event, ok := <-w.ResultChan():
			if !ok {
				break loop
			}
			if event.Type == watch.Error {
				return apierrs.FromObject(event.Object)
			}
			if e, a := r.expectedType, reflect.TypeOf(event.Object); e != a {
				glog.Errorf("expected type %v, but watch event object had type %v", e, a)
				continue
			}
			meta, err := meta.Accessor(event.Object)
			if err != nil {
				glog.Errorf("unable to understand watch event %#v", event)
				continue
			}
			switch event.Type {
			case watch.Added:
				r.store.Add(event.Object)
			case watch.Modified:
				r.store.Update(event.Object)
			case watch.Deleted:
				// TODO: Will any consumers need access to the "last known
				// state", which is passed in event.Object? If so, may need
				// to change this.
				r.store.Delete(event.Object)
			default:
				glog.Errorf("unable to understand watch event %#v", event)
			}
			*resourceVersion = meta.ResourceVersion()
			eventCount++
		}
	}

	watchDuration := time.Now().Sub(start)
	if watchDuration < 1*time.Second && eventCount == 0 {
		glog.V(4).Infof("Unexpected watch close - watch lasted less than a second and no items received")
		return errors.New("very short watch")
	}
	glog.V(4).Infof("Watch close - %v total %v items received", r.expectedType, eventCount)
	return nil
}

// ExtractFieldPathAsString extracts the field from the given object
// and returns it as a string.  The object must be a pointer to an
// API type.
//
// Currently, this API is limited to supporting the fieldpaths:
//
// 1.  metadata.name - The name of an API object
// 2.  metadata.namespace - The namespace of an API object
func ExtractFieldPathAsString(obj interface{}, fieldPath string) (string, error) {
	accessor, err := meta.Accessor(obj)
	if err != nil {
		return "", nil
	}

	switch fieldPath {
	case "metadata.name":
		return accessor.Name(), nil
	case "metadata.namespace":
		return accessor.Namespace(), nil
	}

	return "", fmt.Errorf("Unsupported fieldPath: %v", fieldPath)
}

func (r *Reflector) listAndWatch(stopCh <-chan struct{}) {
	var resourceVersion string
	resyncCh, cleanup := r.resyncChan()
	defer cleanup()

	list, err := r.listerWatcher.List()
	if err != nil {
		glog.Errorf("Failed to list %v: %v", r.expectedType, err)
		return
	}
	meta, err := meta.Accessor(list)
	if err != nil {
		glog.Errorf("Unable to understand list result %#v", list)
		return
	}
	resourceVersion = meta.ResourceVersion()
	items, err := runtime.ExtractList(list)
	if err != nil {
		glog.Errorf("Unable to understand list result %#v (%v)", list, err)
		return
	}
	if err := r.syncWith(items); err != nil {
		glog.Errorf("Unable to sync list result: %v", err)
		return
	}
	r.setLastSyncResourceVersion(resourceVersion)

	for {
		w, err := r.listerWatcher.Watch(resourceVersion)
		if err != nil {
			switch err {
			case io.EOF:
				// watch closed normally
			case io.ErrUnexpectedEOF:
				glog.V(1).Infof("Watch for %v closed with unexpected EOF: %v", r.expectedType, err)
			default:
				glog.Errorf("Failed to watch %v: %v", r.expectedType, err)
			}
			return
		}
		if err := r.watchHandler(w, &resourceVersion, resyncCh, stopCh); err != nil {
			if err != errorResyncRequested {
				glog.Errorf("watch of %v ended with: %v", r.expectedType, err)
			}
			return
		}
	}
}

func (r *Reflector) listAndWatch() {
	var resourceVersion string

	list, err := r.listerWatcher.List()
	if err != nil {
		glog.Errorf("Failed to list %v: %v", r.expectedType, err)
		return
	}
	meta, err := meta.Accessor(list)
	if err != nil {
		glog.Errorf("Unable to understand list result %#v", list)
		return
	}
	resourceVersion = meta.ResourceVersion()
	items, err := runtime.ExtractList(list)
	if err != nil {
		glog.Errorf("Unable to understand list result %#v (%v)", list, err)
		return
	}
	err = r.syncWith(items)
	if err != nil {
		glog.Errorf("Unable to sync list result: %v", err)
		return
	}

	for {
		w, err := r.listerWatcher.Watch(resourceVersion)
		if err != nil {
			switch err {
			case io.EOF:
				// watch closed normally
			case io.ErrUnexpectedEOF:
				glog.V(1).Infof("Watch for %v closed with unexpected EOF: %v", r.expectedType, err)
			default:
				glog.Errorf("Failed to watch %v: %v", r.expectedType, err)
			}
			return
		}
		if err := r.watchHandler(w, &resourceVersion); err != nil {
			glog.Errorf("watch of %v ended with error: %v", r.expectedType, err)
			return
		}
	}
}

func TestTypes(t *testing.T) {
	for kind := range api.Scheme.KnownTypes("") {
		// Try a few times, since runTest uses random values.
		for i := 0; i < *fuzzIters; i++ {
			item, err := api.Scheme.New("", kind)
			if err != nil {
				t.Errorf("Couldn't make a %v? %v", kind, err)
				continue
			}
			if _, err := meta.Accessor(item); err != nil {
				t.Logf("%s is not a TypeMeta and cannot be round tripped: %v", kind, err)
				continue
			}
			runTest(t, v1beta1.Codec, item)
			runTest(t, v1beta2.Codec, item)
			runTest(t, api.Codec, item)
		}
	}
}