Improve the error message when User Default Credentials are not provided

Author: tim-u

google/cloud/dataproc_spark_connect/session.py

@@ -39,6 +39,7 @@
     PermissionDenied,
 )
 from google.api_core.future.polling import POLLING_PREDICATE
+from google.auth.exceptions import DefaultCredentialsError
 from google.cloud.dataproc_spark_connect.client import DataprocChannelBuilder
 from google.cloud.dataproc_spark_connect.exceptions import DataprocSparkConnectException
 from google.cloud.dataproc_spark_connect.pypi_artifacts import PyPiArtifacts
@@ -456,6 +457,15 @@ def create_session_pbar():
                     raise DataprocSparkConnectException(
                         f"Error while creating Dataproc Session: {e.message}"
                     )
+                except DefaultCredentialsError as e:
+                    stop_create_session_pbar_event.set()
+                    if create_session_pbar_thread.is_alive():
+                        create_session_pbar_thread.join()
+                    DataprocSparkSession._active_s8s_session_id = None
+                    DataprocSparkSession._active_session_uses_custom_id = False
+                    raise DataprocSparkConnectException(
+                        f"Error while creating Dataproc Session: {e}"
+                    )
                 except Exception as e:
                     stop_create_session_pbar_event.set()
                     if create_session_pbar_thread.is_alive():

tests/unit/test_session.py

@@ -1487,6 +1487,16 @@ def test_create_session_without_location(self):
         except DataprocSparkConnectException as e:
             self.assertIn("location is not set", str(e))
 
+    def test_create_session_without_application_default_credentials(self):
+        """Tests that an exception is raised when application default credentials is not provided."""
+        os.environ.clear()
+        try:
+            DataprocSparkSession.builder.location("test-region").projectId(
+                "test-project"
+            ).getOrCreate()
+        except DataprocSparkConnectException as e:
+            self.assertIn("Your default credentials were not found", str(e))
+
 
 class DataprocSparkConnectClientTest(unittest.TestCase):