jupyter: add ijavascript kernel

[schneefux]

Motivation for this change

Added the IJavascript Jupyter Notebook kernel to the (so far unmerged) pull request #33673 by @aborsu

I added a javascript kernel to pkgs/development/misc/jupyterKernels/default.nix which requires the package nodePackages.ijavascript.

Following the steps of the npm packaging documentation, I added the ijavascript package to pkgs/development/node-packages/node-packages-v6.json and added build input overrides in pkgs/development/node-packages/default-v6.nix because the package depends on node-gyp and zeromq.
Then I ran the generate.sh script. Unfortunately it generated a huge diff of the node-packages-v?.nix files.

I tested the updated module with this configuration:

  services.jupyter = {
    enable = true;
    port = 8465;
    notebookDir = "/var/www/jupyter";
    password = "'sha1:1b961dc713fb:88483270a63e57d18d43cf337e629539de1436ba'"; # test
  };

  services.nginx = {
    enable = true;
    virtualHosts = {
        "jupyter.mydomain.org" = {
                locations = {
                        "/" = {
                                proxyPass = "http://localhost:8465";
                                proxyWebsockets = true;
                        };
                };
        };
   };
};

Both python3 and javascript notebooks run fine.

Note that proxyWebsockets = true is required else the browser will fail to connect to the notebook. I discovered it by enabling debug logging in the nixos jupyter service.
NPM dependencies for the notebook need to be installed into the notebookDir.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option build-use-sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.

[Mic92]

The diff is fine, there is no sane way to handle the complexity of npm modules.

[aborsu]

I'm glad to see it works with another language.
Just got me thinking, if we start adding a lot of different kernels, we might want to make them disabled by default and add an override flag to make them enabled?

[schneefux]

I upgraded it to a Node 8 package because a user probably wants the latest feature in the REPL.

Just got me thinking, if we start adding a lot of different kernels, we might want to make them disabled by default and add an override flag to make them enabled?

Agreed, but I lack the Nix knowledge to know how.

[FRidh]

This needs to be rebased. If you still want to get this in, please open a new PR.