Address comments: watch.Until return private error errWatchClosed on channel closed

staging/src/k8s.io/apimachinery/pkg/util/wait/wait.go

@@ -129,9 +129,6 @@ func Jitter(duration time.Duration, maxFactor float64) time.Duration {
 // ErrWaitTimeout is returned when the condition exited without success.
 var ErrWaitTimeout = errors.New("timed out waiting for the condition")
 
-// ErrChannelClosed is returned when the watch channel is closed.
-var ErrChannelClosed = errors.New("watch channel closed")
-
 // ConditionFunc returns true if the condition is satisfied, or an error
 // if the loop should be aborted.
 type ConditionFunc func() (done bool, err error)

staging/src/k8s.io/apimachinery/pkg/watch/until.go

@@ -17,6 +17,7 @@ limitations under the License.
 package watch
 
 import (
+	"errors"
 	"time"
 
 	"k8s.io/apimachinery/pkg/util/wait"
@@ -28,6 +29,9 @@ import (
 // from false to true).
 type ConditionFunc func(event Event) (bool, error)
 
+// errWatchClosed is returned when the watch channel is closed before timeout in Until.
+var errWatchClosed = errors.New("watch closed before Until timeout")
+
 // Until reads items from the watch until each provided condition succeeds, and then returns the last watch
 // encountered. The first condition that returns an error terminates the watch (and the event is also returned).
 // If no event has been received, the returned event will be nil.
@@ -61,7 +65,7 @@ func Until(timeout time.Duration, watcher Interface, conditions ...ConditionFunc
 			select {
 			case event, ok := <-ch:
 				if !ok {
-					return lastEvent, wait.ErrChannelClosed
+					return lastEvent, errWatchClosed
 				}
 				lastEvent = &event