// 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
}
gvk := obj.GetObjectKind().GroupVersionKind()
// 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 := gvk.Kind
if len(kind) == 0 {
// TODO: this is wrong
gvks, _, err := Scheme.ObjectKinds(obj)
if err != nil {
return nil, err
}
kind = gvks[0].Kind
}
// An object that implements only List has enough metadata to build a reference
var listMeta meta.List
objectMeta, err := meta.Accessor(obj)
if err != nil {
listMeta, err = meta.ListAccessor(obj)
if err != nil {
return nil, err
}
} else {
listMeta = objectMeta
}
// if the object referenced is actually persisted, we can also get version from meta
version := gvk.GroupVersion().String()
if len(version) == 0 {
selfLink := listMeta.GetSelfLink()
if len(selfLink) == 0 {
return nil, ErrNoSelfLink
}
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]
}
// only has list metadata
if objectMeta == nil {
return &ObjectReference{
Kind: kind,
APIVersion: version,
ResourceVersion: listMeta.GetResourceVersion(),
}, nil
}
return &ObjectReference{
Kind: kind,
APIVersion: version,
Name: objectMeta.GetName(),
Namespace: objectMeta.GetNamespace(),
UID: objectMeta.GetUID(),
ResourceVersion: objectMeta.GetResourceVersion(),
}, nil
}
// ListAndWatch first lists all items and get the resource version at the moment of call,
// and then use the resource version to watch.
// It returns error if ListAndWatch didn't even try to initialize watch.
func (r *Reflector) ListAndWatch(stopCh <-chan struct{}) error {
glog.V(3).Infof("Listing and watching %v from %s", r.expectedType, r.name)
var resourceVersion string
resyncCh, cleanup := r.resyncChan()
defer cleanup()
// Explicitly set "0" as resource version - it's fine for the List()
// to be served from cache and potentially be delayed relative to
// etcd contents. Reflector framework will catch up via Watch() eventually.
options := api.ListOptions{ResourceVersion: "0"}
list, err := r.listerWatcher.List(options)
if err != nil {
return fmt.Errorf("%s: Failed to list %v: %v", r.name, r.expectedType, err)
}
listMetaInterface, err := meta.ListAccessor(list)
if err != nil {
return fmt.Errorf("%s: Unable to understand list result %#v: %v", r.name, list, err)
}
resourceVersion = listMetaInterface.GetResourceVersion()
items, err := meta.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)
resyncerrc := make(chan error, 1)
go func() {
for {
select {
case <-resyncCh:
case <-stopCh:
return
}
glog.V(4).Infof("%s: next resync planned for %#v, forcing now", r.name, r.nextResync)
if err := r.store.Resync(); err != nil {
resyncerrc <- err
return
}
cleanup()
resyncCh, cleanup = r.resyncChan()
}
}()
for {
timemoutseconds := int64(minWatchTimeout.Seconds() * (rand.Float64() + 1.0))
options = api.ListOptions{
ResourceVersion: resourceVersion,
// We want to avoid situations of hanging watchers. Stop any wachers that do not
// receive any events within the timeout window.
TimeoutSeconds: &timemoutseconds,
}
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:
utilruntime.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, resyncerrc, stopCh); err != nil {
if err != errorStopRequested {
glog.Warningf("%s: watch of %v ended with: %v", r.name, r.expectedType, err)
}
return nil
}
}
}