Frontend hardcodes python3

[parente]

Need to make the decision about what language to use server-side after loading the notebook. That, or the server has encode the kernel name in the page template and let the JS echo it back.

I don't know which one is better / worse yet. 💭

[parente]

@jameslmartin want to take a crack at this one next?

Since this was opened, code was added to modify POST /api/kernel requests before they reach the kernel gateway. The fix here would be to get the kernel name (language) from the notebook metadata and replace the {"name" : "kernel_name"} value in the POST request from the frontend with it before it gets proxied to the KG.