HIVE-29306: GSSException encountered during HMS Ranger authorization

Author: KiranVelumuri

itests/hive-minikdc/src/test/java/org/apache/hive/minikdc/TestRemoteHiveMetaStoreKerberos.java

@@ -107,6 +107,72 @@ public void testThriftMaxMessageSize() throws Throwable {
     cleanUp(dbName, tblName, typeName);
   }
 
+  @Test
+  public void testKerberosProxyUser() throws Exception {
+    String realUserName = "realuser";
+    String realUserPrincipal = miniKDC.getFullyQualifiedUserPrincipal(realUserName);
+
+    // Add the real user principal and generate keytab
+    miniKDC.addUserPrincipal(realUserName);
+
+    // Login real user with valid keytab - this gives us real TGT credentials
+    UserGroupInformation realUserUgi = miniKDC.loginUser(realUserName);
+
+    // Create a proxy user on behalf of the real user
+    String proxyUserName = "proxyuser@" + miniKDC.getKdcConf().getProperty("realm", "EXAMPLE.COM");
+    UserGroupInformation proxyUserUgi = UserGroupInformation.createProxyUser(
+            proxyUserName, realUserUgi);
+
+    proxyUserUgi.doAs(new PrivilegedExceptionAction<Void>() {
+      @Override
+      public Void run() throws Exception {
+        Logger logger = null;
+        StringAppender appender = null;
+        try {
+          UserGroupInformation currentUser = UserGroupInformation.getCurrentUser();
+
+          System.out.println("Real user: " + currentUser.getRealUser().getUserName() +
+                  " (auth:" + currentUser.getRealUser().getAuthenticationMethod() + ")");
+          System.out.println("Proxy user: " + currentUser.getShortUserName() +
+                  " (auth:" + currentUser.getAuthenticationMethod() + ")");
+
+          // Set up log capture to catch "Failed to find any Kerberos tgt" error in logs
+          logger = LoggerFactory.getLogger("org.apache.hadoop.hive.metastore.security");
+          appender = StringAppender.createStringAppender(null);
+          appender.addToLogger(logger.getName(), Level.INFO);
+          appender.start();
+
+          // Attempt to create metastore client connection as Kerberos proxy user
+          // This should work properly (after TUGIAssumingTransport fix)
+          IMetaStoreClient client = new HiveMetaStoreClient(conf);
+
+          // Clean up
+          if (client != null) {
+            client.close();
+          }
+
+          // The test has successfully demonstrated:
+          // 1. Real user has valid Kerberos authentication with real TGT from MiniKdc
+          // 2. Proxy user is properly created with PROXY authentication method
+          // 3. TUGIAssumingTransport fix is working - no "Failed to find any Kerberos tgt" error
+          System.out.println("Successfully verified Kerberos proxy user setup with real KDC");
+
+        } catch (Exception clientException) {
+          // Check the captured logs for the specific "Failed to find any Kerberos tgt" error
+          if (appender.getOutput().contains("Failed to find any Kerberos tgt")) {
+            // This is expected behavior before TUGIAssumingTransport fix
+            Assert.fail("EXPECTED BEFORE FIX: HMS client creation failed with 'Failed to find any Kerberos tgt' error in logs");
+          } else {
+            Assert.fail("Unexpected error (not 'Failed to find any Kerberos tgt'): " + clientException.getMessage());
+          }
+        } finally {
+          appender.removeFromLogger(logger.getName());
+        }
+        return null;
+      }
+    });
+  }
+
   @Override
   protected HiveMetaStoreClient createClient() throws Exception {
     MetastoreConf.setVar(conf, ConfVars.THRIFT_URIS, "thrift://localhost:" + port);

standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/security/TUGIAssumingTransport.java

@@ -45,7 +45,8 @@ public TUGIAssumingTransport(TTransport wrapped, UserGroupInformation ugi) {
    @Override
    public void open() throws TTransportException {
      try {
-       ugi.doAs(new PrivilegedExceptionAction<Void>() {
+       UserGroupInformation loggedInUGI = ugi.getRealUser() != null ?  ugi.getRealUser() : ugi;
+       loggedInUGI.doAs(new PrivilegedExceptionAction<Void>() {
          public Void run() {
            try {
              wrapped.open();