Merge pull request #66906 from tnozicka/rename-until

Automatic merge from submit-queue (batch tested with PRs 67071, 66906, 66722, 67276, 67039). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

#50102 Task 1: Move apimachinery/pkg/watch.Until into client-go/tools/watch.UntilWithoutRetry

**What this PR does / why we need it**:
This is a split off from https://github.com/kubernetes/kubernetes/pull/50102 to go in smaller pieces.

Moves `apimachinery/pkg/watch.Until` into `client-go/tools/watch.UntilWithoutRetry` and adds context so it is cancelable.

**Release note**:
```release-note
NONE
```

**Dev release note**:
```dev-release-note
`apimachinery/pkg/watch.Until` has been moved to `client-go/tools/watch.UntilWithoutRetry`.
While switching please consider using the new `client-go/tools/watch.UntilWithSync` or `client-go/tools/watch.Until`.
```

/cc @smarterclayton @kubernetes/sig-api-machinery-pr-reviews
/milestone v1.12
/priority important-soon
/kind bug
(bug after the main PR which is this split from)

Kubernetes-commit: b6f0aed056ab94fef0b6f54e1ca1d66a5fc228b3

vendor/k8s.io/apimachinery/pkg/runtime/scheme.go

@@ -70,7 +70,7 @@ type Scheme struct {
 	defaulterFuncs map[reflect.Type]func(interface{})
 
 	// converter stores all registered conversion functions. It also has
-	// default coverting behavior.
+	// default converting behavior.
 	converter *conversion.Converter
 
 	// versionPriority is a map of groups to ordered lists of versions for those groups indicating the

vendor/k8s.io/client-go/tools/cache/listwatch.go

@@ -28,6 +28,7 @@ import (
 	"k8s.io/apimachinery/pkg/watch"
 	restclient "k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/pager"
+	watchtools "k8s.io/client-go/tools/watch"
 )
 
 // ListerWatcher is any object that knows how to perform an initial list and start a watch on a resource.
@@ -116,7 +117,7 @@ func (lw *ListWatch) Watch(options metav1.ListOptions) (watch.Interface, error)
 // ListWatchUntil checks the provided conditions against the items returned by the list watcher, returning wait.ErrWaitTimeout
 // if timeout is exceeded without all conditions returning true, or an error if an error occurs.
 // TODO: check for watch expired error and retry watch from latest point?  Same issue exists for Until.
-func ListWatchUntil(timeout time.Duration, lw ListerWatcher, conditions ...watch.ConditionFunc) (*watch.Event, error) {
+func ListWatchUntil(timeout time.Duration, lw ListerWatcher, conditions ...watchtools.ConditionFunc) (*watch.Event, error) {
 	if len(conditions) == 0 {
 		return nil, nil
 	}
@@ -178,8 +179,10 @@ func ListWatchUntil(timeout time.Duration, lw ListerWatcher, conditions ...watch
 		return nil, err
 	}
 
-	evt, err := watch.Until(timeout, watchInterface, remainingConditions...)
-	if err == watch.ErrWatchClosed {
+	ctx, cancel := watchtools.ContextWithOptionalTimeout(context.Background(), timeout)
+	defer cancel()
+	evt, err := watchtools.UntilWithoutRetry(ctx, watchInterface, remainingConditions...)
+	if err == watchtools.ErrWatchClosed {
 		// present a consistent error interface to callers
 		err = wait.ErrWaitTimeout
 	}

vendor/k8s.io/client-go/tools/watch/until.go

@@ -17,38 +17,39 @@ limitations under the License.
 package watch
 
 import (
+	"context"
 	"errors"
 	"time"
 
+	"github.com/golang/glog"
 	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/apimachinery/pkg/watch"
 )
 
 // ConditionFunc returns true if the condition has been reached, false if it has not been reached yet,
 // or an error if the condition cannot be checked and should terminate. In general, it is better to define
 // level driven conditions over edge driven conditions (pod has ready=true, vs pod modified and ready changed
 // from false to true).
-type ConditionFunc func(event Event) (bool, error)
+type ConditionFunc func(event watch.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")
+// ErrWatchClosed is returned when the watch channel is closed before timeout in UntilWithoutRetry.
+var ErrWatchClosed = errors.New("watch closed before UntilWithoutRetry timeout")
 
-// Until reads items from the watch until each provided condition succeeds, and then returns the last watch
+// UntilWithoutRetry 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.
 // Conditions are satisfied sequentially so as to provide a useful primitive for higher level composition.
-// A zero timeout means to wait forever.
-func Until(timeout time.Duration, watcher Interface, conditions ...ConditionFunc) (*Event, error) {
+// Waits until context deadline or until context is canceled.
+//
+// Warning: Unless you have a very specific use case (probably a special Watcher) don't use this function!!!
+// Warning: This will fail e.g. on API timeouts and/or 'too old resource version' error.
+// Warning: You are most probably looking for a function *Until* or *UntilWithSync* below,
+// Warning: solving such issues.
+// TODO: Consider making this function private to prevent misuse when the other occurrences in our codebase are gone.
+func UntilWithoutRetry(ctx context.Context, watcher watch.Interface, conditions ...ConditionFunc) (*watch.Event, error) {
 	ch := watcher.ResultChan()
 	defer watcher.Stop()
-	var after <-chan time.Time
-	if timeout > 0 {
-		after = time.After(timeout)
-	} else {
-		ch := make(chan time.Time)
-		defer close(ch)
-		after = ch
-	}
-	var lastEvent *Event
+	var lastEvent *watch.Event
 	for _, condition := range conditions {
 		// check the next condition against the previous event and short circuit waiting for the next watch
 		if lastEvent != nil {
@@ -69,7 +70,6 @@ func Until(timeout time.Duration, watcher Interface, conditions ...ConditionFunc
 				}
 				lastEvent = &event
 
-				// TODO: check for watch expired error and retry watch from latest point?
 				done, err := condition(event)
 				if err != nil {
 					return lastEvent, err
@@ -78,10 +78,25 @@ func Until(timeout time.Duration, watcher Interface, conditions ...ConditionFunc
 					break ConditionSucceeded
 				}
 
-			case <-after:
+			case <-ctx.Done():
 				return lastEvent, wait.ErrWaitTimeout
 			}
 		}
 	}
 	return lastEvent, nil
 }
+
+// ContextWithOptionalTimeout wraps context.WithTimeout and handles infinite timeouts expressed as 0 duration.
+func ContextWithOptionalTimeout(parent context.Context, timeout time.Duration) (context.Context, context.CancelFunc) {
+	if timeout < 0 {
+		// This should be handled in validation
+		glog.Errorf("Timeout for context shall not be negative!")
+		timeout = 0
+	}
+
+	if timeout == 0 {
+		return context.WithCancel(parent)
+	}
+
+	return context.WithTimeout(parent, timeout)
+}