// 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 != nil && 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
}
newResourceVersion := meta.ResourceVersion()
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 = newResourceVersion
r.setLastSyncResourceVersion(newResourceVersion)
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 http://issue.k8s.io/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
}
func objectToVersionedRuntimeObject(obj interface{}) (runtime.Object, uint64, error) {
object, ok := obj.(runtime.Object)
if !ok {
return nil, 0, fmt.Errorf("obj does not implement runtime.Object interface: %v", obj)
}
meta, err := meta.Accessor(object)
if err != nil {
return nil, 0, err
}
resourceVersion, err := parseResourceVersion(meta.ResourceVersion())
if err != nil {
return nil, 0, err
}
return object, resourceVersion, nil
}
// Returns error if ListAndWatch didn't even tried to initialize watch.
func (r *Reflector) ListAndWatch(stopCh <-chan struct{}) error {
var resourceVersion string
resyncCh, cleanup := r.resyncChan()
defer cleanup()
if r.verbose {
glog.Infof("watch %v: listwatch cycle started.", r.name)
defer glog.Infof("watch %v: listwatch cycle exited.", r.name)
}
list, err := r.listerWatcher.List()
if err != nil {
return fmt.Errorf("%s: Failed to list %v: %v", r.name, r.expectedType, err)
}
meta, err := meta.Accessor(list)
if err != nil {
return fmt.Errorf("%s: Unable to understand list result %#v", r.name, list)
}
resourceVersion = meta.ResourceVersion()
items, err := runtime.ExtractList(list)
if err != nil {
return fmt.Errorf("%s: Unable to understand list result %#v (%v)", r.name, list, err)
}
if err := r.syncWith(items, resourceVersion); err != nil {
return fmt.Errorf("%s: Unable to sync list result: %v", r.name, err)
}
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 nil
}
if err := r.watchHandler(w, &resourceVersion, resyncCh, stopCh); err != nil {
if err != errorResyncRequested && err != errorStopRequested {
glog.Warningf("%s: watch of %v ended with: %v", r.name, r.expectedType, err)
}
return nil
}
}
}
// Returns error if ListAndWatch didn't even tried to initialize watch.
func (r *Reflector) ListAndWatch(stopCh <-chan struct{}) error {
var resourceVersion string
resyncCh, cleanup := r.resyncChan()
defer cleanup()
list, err := r.listerWatcher.List()
if err != nil {
return fmt.Errorf("%s: Failed to list %v: %v", r.name, r.expectedType, err)
}
meta, err := meta.Accessor(list)
if err != nil {
return fmt.Errorf("%s: Unable to understand list result %#v", r.name, list)
}
resourceVersion = meta.ResourceVersion()
items, err := runtime.ExtractList(list)
if err != nil {
return fmt.Errorf("%s: Unable to understand list result %#v (%v)", r.name, list, err)
}
if err := r.syncWith(items, resourceVersion); err != nil {
return fmt.Errorf("%s: Unable to sync list result: %v", r.name, err)
}
r.setLastSyncResourceVersion(resourceVersion)
for {
options := api.ListOptions{
ResourceVersion: resourceVersion,
// We want to avoid situations when resyncing is breaking the TCP connection
// - see comment for 'timeoutForWatch()' for more details.
TimeoutSeconds: r.timeoutForWatch(),
}
w, err := r.listerWatcher.Watch(options)
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 nil
}
if err := r.watchHandler(w, &resourceVersion, resyncCh, stopCh); err != nil {
if err != errorResyncRequested && err != errorStopRequested {
glog.Warningf("%s: watch of %v ended with: %v", r.name, r.expectedType, err)
}
return nil
}
if r.canForceResyncNow() {
glog.V(4).Infof("%s: next resync planned for %#v, forcing now", r.name, r.nextResync)
return nil
}
}
}