Allow users to disable the fix_notebook call

docs/customize.md

@@ -657,3 +657,11 @@ By default, Voilà's grace period for kernel startup time is 60 seconds. It can
 ```sh
 voila --VoilaExecutor.startup_timeout=60
 ```
+
+## Have voila attempt to solve a best fit kernel spec
+
+By default, Voilà will attempt to resolve a kernel spec to the best fit, based on the available environments. You can disable this functionality as follows:
+
+```py
+c.VoilaConfiguration.attempt_fix_notebook = False
+```

docs/deploy.md

@@ -379,6 +379,7 @@ For more information, you can also follow [the guide on the nginx blog](https://
 ### Using Apache2 as reverse proxy
 
 Apache can also be used to serve voilà. These Apache modules need to be installed and enabled:
+
 - mod_proxy
 - mod_rewrite
 - mod_proxy_http

voila/configuration.py

@@ -211,3 +211,9 @@ def _valid_file_blacklist(self, proposal):
         help="""The dictionary of extension configuration, this dict is passed to the frontend
         through the PageConfig""",
     )
+
+    attempt_fix_notebook = Bool(
+        True,
+        config=True,
+        help="""Whether or not voila should attempt to fix and resolve a notebooks kernelspec metadata""",
+    )

voila/notebook_renderer.py

@@ -312,7 +312,8 @@ async def load_notebook(self, path):
         __, extension = os.path.splitext(model.get("path", ""))
         if model.get("type") == "notebook":
             notebook = model["content"]
-            notebook = await self.fix_notebook(notebook)
+            if self.voila_configuration.attempt_fix_notebook:
+                notebook = await self.fix_notebook(notebook)
             return notebook
         elif extension in self.voila_configuration.extension_language_mapping:
             language = self.voila_configuration.extension_language_mapping[extension]