YARN-6989 Ensure timeline service v2 codebase gets UGI from HttpServletRequest in a consistent way. Contributed by Abhishek Modi

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

@@ -269,25 +269,8 @@ public final class TimelineReaderWebServicesUtils {
    * @return UGI.
    */
   public static UserGroupInformation getUser(HttpServletRequest req) {
-    return getCallerUserGroupInformation(req, false);
-  }
-
-  /**
-   * Get UGI from the HTTP request.
-   *
-   * @param hsr HTTP request.
-   * @param usePrincipal if true, use principal name else use remote user name
-   * @return UGI.
-   */
-  public static UserGroupInformation getCallerUserGroupInformation(
-      HttpServletRequest hsr, boolean usePrincipal) {
-
-    String remoteUser = hsr.getRemoteUser();
-    if (usePrincipal) {
-      Principal princ = hsr.getUserPrincipal();
-      remoteUser = princ == null ? null : princ.getName();
-    }
-
+    Principal princ = req.getUserPrincipal();
+    String remoteUser = princ == null ? null : princ.getName();
     UserGroupInformation callerUGI = null;
     if (remoteUser != null) {
       callerUGI = UserGroupInformation.createRemoteUser(remoteUser);

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

@@ -67,7 +67,7 @@ public class TimelineReaderWhitelistAuthorizationFilter implements Filter {
 
     if (isWhitelistReadAuthEnabled) {
       UserGroupInformation callerUGI = TimelineReaderWebServicesUtils
-          .getCallerUserGroupInformation(httpRequest, true);
+          .getUser(httpRequest);
       if (callerUGI == null) {
         String msg = "Unable to obtain user name, user not authenticated";
         throw new AuthorizationException(msg);