Possible to join existing local kernels with hydrogen?

[mrchrisadams]

Hi there,

I might have missed this earlier, but is it possible to use Hydrogen just like another client to connect to an existing Jupyter Kernel?

If I start a Jupyter notebook session like so:

jupyter notebook

I can join that same kernel from the console with:

jupyter console --existing

This means I can define variables or methods , in one session, and then call them from the other, which can be handy for all kinds of reasons. Is it possible to do the same with Hydrogen too, so I can send code I write in Atom the same kernel?

This gist here mentioned in issue #38 makes me think it can, but I don't yet understand what kernelspecs are with Jupyter, and how to use them.

The way hydrogen works is... if it doesn't find a running kernel around (on the local machine), then it opens up a process, but the good thing is that it actually looks for kernelspecs before it does that! which is why this method works.

For my use case, I don't need to speak to any remote machines.

FWIW, I tried going the other way (as in start a kernel from Atom with hydrogen run and join it from a console with jupyter console --existing, with no joy.)

Thanks for making such an awesome package BTW 👍

[willwhitney]

You should be able to join a kernel that was started by Hydrogen, but not (currently) vice versa. Located in <hydrogen_install_directory>/kernel-configs you will find the configurations that Hydrogen builds to launch its kernels. If you launch a kernel by running some code in Hydrogen, you can then run jupyter console --existing <hydrogen-dir>/kernel-configs/kernel-<blah>.json on the config file that Hydrogen created, thus connecting a console session to your running kernel.

[oztalha]

Yes. I was able to connect to a kernel that was started by jupyter notebook command.
In the package settings in atom, simply set your kernel gateway like this:

[{"name": "my local","options":{"baseUrl":"http://localhost:8888/","token":"0ce3d02e994b89d5ea4dec15ac9c5805b6ed3cd31b275127"}}]