Merge pull request #29439 from matttproud/cleanups_volumeflocker

Automatic merge from submit-queue

volume/flocker: plug time.Ticker resource leak

This commit ensures that `flockerMounter.updateDatasetPrimary` does not leak
running `time.Ticker` instances.  Upon termination of the consuming routine, we
stop the tickers.

```release-note
* flockerMounter.updateDatasetPrimary no longer leaks running time.Ticker instances.
  Upon termination of the consuming routine, we stop the tickers.
```

pkg/volume/flocker/plugin.go

@@ -223,8 +223,10 @@ func (b flockerMounter) updateDatasetPrimary(datasetID, primaryUUID string) erro
 		return err
 	}
 
-	timeoutChan := time.NewTimer(timeoutWaitingForVolume).C
-	tickChan := time.NewTicker(tickerWaitingForVolume).C
+	timeoutChan := time.NewTimer(timeoutWaitingForVolume)
+	defer timeoutChan.Stop()
+	tickChan := time.NewTicker(tickerWaitingForVolume)
+	defer tickChan.Stop()
 
 	for {
 		if s, err := b.client.GetDatasetState(datasetID); err == nil && s.Primary == primaryUUID {
@@ -232,12 +234,12 @@ func (b flockerMounter) updateDatasetPrimary(datasetID, primaryUUID string) erro
 		}
 
 		select {
-		case <-timeoutChan:
+		case <-timeoutChan.C:
 			return fmt.Errorf(
 				"Timed out waiting for the dataset_id: '%s' to be moved to the primary: '%s'\n%v",
 				datasetID, primaryUUID, err,
 			)
-		case <-tickChan:
+		case <-tickChan.C:
 			break
 		}
 	}