Merge pull request #33899 from MrHohn/fix_config_test

Automatic merge from submit-queue

Fix #33784, IN_CREATE event does not guarantee file content written

Fixed #33784.

The CREATE inotify event [here](https://github.com/kubernetes/kubernetes/blob/master/pkg/kubelet/config/file_linux_test.go#L275) is triggered by os.OpenFile(), however the content would be written by the following f.Write(). It will fail if the program try to process the event in between.

IN_CREAE event is triggered by open(2), mkdir(2), link(2), symlink(2), bind(2), but not all of them will guarantee the content is written ([ref](http://man7.org/linux/man-pages/man7/inotify.7.html)). <s>Hence we should not respond to IN_CREATE event for pod creation. I believe listen on IN_MODIFY and IN_MOVED_TO would be sufficient for pod addition&update.

Would like to see the Jenkins test results for further evaluation.

@Random-Liu

pkg/kubelet/config/file_linux_test.go

@@ -261,32 +261,13 @@ func watchFileAdded(watchDir bool, t *testing.T) {
 				testCase.writeToFile(dirName, fileName, t)
 			}
 
-			if watchDir {
-				defer func() {
-					// Remove the file
-					deleteFile(dirName, fileName, ch, t)
-				}()
-			}
-
 			go addFile()
 
-			if watchDir {
+			// For !watchDir: expect an update by SourceFile.resetStoreFromPath().
-				// expect an update by CREATE inotify event
+			// For watchDir: expect at least one update from CREATE & MODIFY inotify event.
+			// Shouldn't expect two updates from CREATE & MODIFY because CREATE doesn't guarantee file written.
+			// In that case no update will be sent from CREATE event.
 			expectUpdate(t, ch, testCase)
-				// expect an update by MODIFY inotify event
-				expectUpdate(t, ch, testCase)
-
-				from := fileName
-				fileName = fileName + "_ch"
-				go changeFileName(dirName, from, fileName, t)
-				// expect an update by MOVED_FROM inotify event cause changing file name
-				expectEmptyUpdate(t, ch)
-				// expect an update by MOVED_TO inotify event cause changing file name
-				expectUpdate(t, ch, testCase)
-			} else {
-				// expect an update by SourceFile.resetStoreFromPath()
-				expectUpdate(t, ch, testCase)
-			}
 		}()
 	}
 }