// finishRequest makes a given resultFunc asynchronous and handles errors returned by the response.
// Any api.Status object returned is considered an "error", which interrupts the normal response flow.
func finishRequest(timeout time.Duration, fn resultFunc) (result runtime.Object, err error) {
// these channels need to be buffered to prevent the goroutine below from hanging indefinitely
// when the select statement reads something other than the one the goroutine sends on.
ch := make(chan runtime.Object, 1)
errCh := make(chan error, 1)
panicCh := make(chan interface{}, 1)
go func() {
// panics don't cross goroutine boundaries, so we have to handle ourselves
defer utilruntime.HandleCrash(func(panicReason interface{}) {
// Propagate to parent goroutine
panicCh <- panicReason
})
if result, err := fn(); err != nil {
errCh <- err
} else {
ch <- result
}
}()
select {
case result = <-ch:
if status, ok := result.(*metav1.Status); ok {
return nil, errors.FromObject(status)
}
return result, nil
case err = <-errCh:
return nil, err
case p := <-panicCh:
panic(p)
case <-time.After(timeout):
return nil, errors.NewTimeoutError("request did not complete within allowed duration", 0)
}
}
// Error returns the error executing the request, nil if no error occurred.
// If the returned object is of type Status and has Status != StatusSuccess, the
// additional information in Status will be used to enrich the error.
// See the Request.Do() comment for what errors you might get.
func (r Result) Error() error {
// if we have received an unexpected server error, and we have a body and decoder, we can try to extract
// a Status object.
if r.err == nil || !errors.IsUnexpectedServerError(r.err) || len(r.body) == 0 || r.decoder == nil {
return r.err
}
// attempt to convert the body into a Status object
// to be backwards compatible with old servers that do not return a version, default to "v1"
out, _, err := r.decoder.Decode(r.body, &schema.GroupVersionKind{Version: "v1"}, nil)
if err != nil {
glog.V(5).Infof("body was not decodable (unable to check for Status): %v", err)
return r.err
}
switch t := out.(type) {
case *metav1.Status:
// because we default the kind, we *must* check for StatusFailure
if t.Status == metav1.StatusFailure {
return errors.FromObject(t)
}
}
return r.err
}
// Get returns the result as an object, which means it passes through the decoder.
// If the returned object is of type Status and has .Status != StatusSuccess, the
// additional information in Status will be used to enrich the error.
func (r Result) Get() (runtime.Object, error) {
if r.err != nil {
// Check whether the result has a Status object in the body and prefer that.
return nil, r.Error()
}
if r.decoder == nil {
return nil, fmt.Errorf("serializer for %s doesn't exist", r.contentType)
}
// decode, but if the result is Status return that as an error instead.
out, _, err := r.decoder.Decode(r.body, nil, nil)
if err != nil {
return nil, err
}
switch t := out.(type) {
case *metav1.Status:
// any status besides StatusSuccess is considered an error.
if t.Status != metav1.StatusSuccess {
return nil, errors.FromObject(t)
}
}
return out, nil
}
// Into stores the result into obj, if possible. If obj is nil it is ignored.
// If the returned object is of type Status and has .Status != StatusSuccess, the
// additional information in Status will be used to enrich the error.
func (r Result) Into(obj runtime.Object) error {
if r.err != nil {
// Check whether the result has a Status object in the body and prefer that.
return r.Error()
}
if r.decoder == nil {
return fmt.Errorf("serializer for %s doesn't exist", r.contentType)
}
out, _, err := r.decoder.Decode(r.body, nil, obj)
if err != nil || out == obj {
return err
}
// if a different object is returned, see if it is Status and avoid double decoding
// the object.
switch t := out.(type) {
case *metav1.Status:
// any status besides StatusSuccess is considered an error.
if t.Status != metav1.StatusSuccess {
return errors.FromObject(t)
}
}
return nil
}
// watchHandler watches w and keeps *resourceVersion up to date.
func (r *Reflector) watchHandler(w watch.Interface, resourceVersion *string, errc chan error, 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 err := <-errc:
return err
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 {
utilruntime.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 {
utilruntime.HandleError(fmt.Errorf("%s: unable to understand watch event %#v", r.name, event))
continue
}
newResourceVersion := meta.GetResourceVersion()
switch event.Type {
case watch.Added:
err := r.store.Add(event.Object)
if err != nil {
utilruntime.HandleError(fmt.Errorf("%s: unable to add watch event object (%#v) to store: %v", r.name, event.Object, err))
}
case watch.Modified:
err := r.store.Update(event.Object)
if err != nil {
utilruntime.HandleError(fmt.Errorf("%s: unable to update watch event object (%#v) to store: %v", r.name, event.Object, err))
}
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.
err := r.store.Delete(event.Object)
if err != nil {
utilruntime.HandleError(fmt.Errorf("%s: unable to delete watch event object (%#v) from store: %v", r.name, event.Object, err))
}
default:
utilruntime.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
}