Allow for separate code gen app config (#7)

* Allow for seperate code gen app.config while retaining the helm chart generated config

servicex_codegen/__init__.py

@@ -57,8 +57,11 @@ def create_app(test_config=None, provided_translator=None):
 
     if test_config:
         app.config.from_mapping(test_config)
-    elif 'APP_CONFIG_FILE' in os.environ:
-        app.config.from_envvar('APP_CONFIG_FILE')
+    else:
+        if 'APP_CONFIG_FILE' in os.environ:
+            app.config.from_envvar('APP_CONFIG_FILE')
+        if 'CODEGEN_CONFIG_FILE' in os.environ:
+            app.config.from_envvar('CODEGEN_CONFIG_FILE')
 
     with app.app_context():
         translator = provided_translator

servicex_codegen/post_operation.py

@@ -90,11 +90,12 @@ def post(self):
                     body["code"], cache_path=tempdir)
 
                 zip_data = self.stream_generated_code(generated_code_result)
-                # code gen transformer returns the default transformer image mentioned in the config file
+                # code gen transformer returns the default transformer image mentioned in
+                # the config file
                 transformer_image = current_app.config.get("TRANSFORMER_SCIENCE_IMAGE")
-                # Send the response back to you-know-what.
 
-                # MultipartEncoder library takes multiple types of data fields and merge them into a multipart mime data type
+                # MultipartEncoder library takes multiple types of data fields and merge
+                # them into a multipart mime data type
                 m = MultipartEncoder(
                     fields={'transformer_image': transformer_image,
                             'zip_data': zip_data}