YARN-8591. [ATSv2] NPE while checking for entity acl in non-secure cluster. Contributed by Rohith Sharma K S.

(cherry picked from commit 63e08ec071852640babea9e39780327a0907712a)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/reader/TimelineReaderWebServices.java

@@ -3532,7 +3532,8 @@ public class TimelineReaderWebServices {
   static boolean checkAccess(TimelineReaderManager readerManager,
       UserGroupInformation ugi, String entityUser) {
     if (isDisplayEntityPerUserFilterEnabled(readerManager.getConfig())) {
-      if (!validateAuthUserWithEntityUser(readerManager, ugi, entityUser)) {
+      if (ugi != null && !validateAuthUserWithEntityUser(readerManager, ugi,
+          entityUser)) {
         String userName = ugi.getShortUserName();
         String msg = "User " + userName
             + " is not allowed to read TimelineService V2 data.";

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/test/java/org/apache/hadoop/yarn/server/timelineservice/reader/TestTimelineReaderWebServicesBasicAcl.java

@@ -88,6 +88,10 @@ public class TestTimelineReaderWebServicesBasicAcl {
     Assert.assertFalse(TimelineReaderWebServices
         .validateAuthUserWithEntityUser(manager, null, user1));
 
+    // true because ugi is null
+    Assert.assertTrue(
+        TimelineReaderWebServices.checkAccess(manager, null, user1));
+
     // incoming ugi is admin asking for entity owner user1
     Assert.assertTrue(
         TimelineReaderWebServices.checkAccess(manager, adminUgi, user1));