Log the error message in case module is not compatible with mxnet

Author: nikhil-sk

src/sagemaker_mxnet_serving_container/handler_service.py

@@ -41,11 +41,6 @@ class HandlerService(DefaultHandlerService):
     Based on: https://github.com/awslabs/multi-model-server/blob/master/docs/custom_service.md
 
     """
-    def __init__(self):
-        # self._service = None
-        transformer = Transformer(default_inference_handler=DefaultMXNetInferenceHandler())
-        super(HandlerService, self).__init__(transformer=transformer)
-
     @staticmethod
     def _user_module_transformer(model_dir=environment.model_dir):
         try:
@@ -83,5 +78,10 @@ def initialize(self, context):
         else:
             os.environ[PYTHON_PATH_ENV] = code_dir_path
 
-        self._service = self._user_module_transformer(model_dir)
+        try:
+            self._service = self._user_module_transformer(model_dir)
+        except ValueError as e:
+             logging.error(f"Error determining model. {str(e)}. For non-mxnet models, consider using pytorch-inference DLC that leverages TorchServe.")
+             raise
+
         super(HandlerService, self).initialize(context)