fix: allow for inf spec and server override to be passed (#4769)

* fix: allow for just inf spec and server overide to pass

* fix formatting

Author: samruds

src/sagemaker/serve/builder/model_builder.py

@@ -881,8 +881,8 @@ def _build_for_model_server(self):  # pylint: disable=R0911, R1710
         if self.model_metadata:
             mlflow_path = self.model_metadata.get(MLFLOW_MODEL_PATH)
 
-        if not self.model and not mlflow_path:
-            raise ValueError("Missing required parameter `model` or 'ml_flow' path")
+        if not self.model and not mlflow_path and not self.inference_spec:
+            raise ValueError("Missing required parameter `model` or 'ml_flow' path or inf_spec")
 
         if self.model_server == ModelServer.TORCHSERVE:
             return self._build_for_torchserve()

tests/unit/sagemaker/serve/builder/test_model_builder.py

@@ -147,7 +147,7 @@ def test_model_server_override_djl_without_model_or_mlflow(self, mock_serve_sett
         )
         self.assertRaisesRegex(
             Exception,
-            "Missing required parameter `model` or 'ml_flow' path",
+            "Missing required parameter `model` or 'ml_flow' path or inf_spec",
             builder.build,
             Mode.SAGEMAKER_ENDPOINT,
             mock_role_arn,
@@ -168,12 +168,26 @@ def test_model_server_override_torchserve_with_model(
 
         mock_build_for_ts.assert_called_once()
 
+    @patch("sagemaker.serve.builder.model_builder._ServeSettings")
+    @patch("sagemaker.serve.builder.model_builder.ModelBuilder._build_for_torchserve")
+    def test_model_server_override_torchserve_with_inf_spec(
+        self, mock_build_for_ts, mock_serve_settings
+    ):
+        mock_setting_object = mock_serve_settings.return_value
+        mock_setting_object.role_arn = mock_role_arn
+        mock_setting_object.s3_model_data_url = mock_s3_model_data_url
+
+        builder = ModelBuilder(model_server=ModelServer.TORCHSERVE, inference_spec="some value")
+        builder.build(sagemaker_session=mock_session)
+
+        mock_build_for_ts.assert_called_once()
+
     @patch("sagemaker.serve.builder.model_builder._ServeSettings")
     def test_model_server_override_torchserve_without_model_or_mlflow(self, mock_serve_settings):
         builder = ModelBuilder(model_server=ModelServer.TORCHSERVE)
         self.assertRaisesRegex(
             Exception,
-            "Missing required parameter `model` or 'ml_flow' path",
+            "Missing required parameter `model` or 'ml_flow' path or inf_spec",
             builder.build,
             Mode.SAGEMAKER_ENDPOINT,
             mock_role_arn,