fix(data-imports): map DeltaLake object-store access errors to an actionable message

products/warehouse_sources/backend/models/table.py

@@ -71,6 +71,9 @@
 ExtractErrors = {
     "The AWS Access Key Id you provided does not exist": "The Access Key you provided does not exist",
     "Access Denied: while reading key:": "Access was denied when reading the provided file",
+    # DeltaLake-kernel object_store errors (Delta-format tables, e.g. all warehouse_sources synced
+    # tables) use a different vocabulary than ClickHouse's native S3 errors above.
+    "The operation lacked the necessary privileges to complete": "Access was denied when reading the provided file",
     "Could not list objects in bucket": "Access was denied to the provided bucket",
     "file is empty": "The provided file contains no data",
     "The specified key does not exist": "The provided file doesn't exist in the bucket",

products/warehouse_sources/backend/tests/test_table.py

@@ -111,6 +111,23 @@ def test_transient_errors_without_message_are_reraised_untouched(self, err: Exce
             DataWarehouseTable()._safe_expose_ch_error(err)
         assert exc_info.value is err
 
+    def test_delta_kernel_permission_error_gets_actionable_message(self) -> None:
+        # Delta-format tables (the default for every warehouse_sources synced table) read via
+        # ClickHouse's DeltaLake kernel, whose object_store errors use different wording than
+        # the native ClickHouse S3 errors above. Without a matching ExtractErrors entry this
+        # fell through to the generic fallback message regardless of the actual cause.
+        delta_kernel_error = ServerException(
+            "DB::Exception: Received DeltaLake kernel error ObjectStoreError: Error interacting with "
+            "object store: The operation lacked the necessary privileges to complete for path "
+            "team_2_mysql_x/dw_table/_delta_log/_last_checkpoint: Error performing GET "
+            "http://objectstorage:19000/data-warehouse/team_2_mysql_x/dw_table/_delta_log/_last_checkpoint "
+            "- Server returned non-2xx status code: 403 Forbidden: AccessDenied",
+            code=742,  # DELTA_KERNEL_ERROR
+        )
+
+        with pytest.raises(Exception, match="Access was denied when reading the provided file"):
+            DataWarehouseTable()._safe_expose_ch_error(delta_kernel_error)
+
 
 class TestRunChdbQuery:
     def test_hung_query_is_killed_and_raises_instead_of_blocking(self) -> None: