Standalone node start command customization

[petrkozorezov]

It would be convenient to be able to customize command how to start standalone node.
In my case, I would like to start node with additional packages installed for specific notebooks. For example, I would like to add rust and cargo when I need to compile explorer with custom flags, such as AVX-512.

[josevalim]

How have you installed Livebook? If you are using the Desktop version, you can set env vars in a script file. You can also set anything in the setup cell before Mix.install. So why would you need to customize the runtime? Can you provide more info?

[petrkozorezov]

Mmm, I forgot to mention about Nix (m.b. spellcheck corrector removed it). This case is about Nix shell.
I have Livebook installed on Linux with Nix installed, and I can create ad hoc shell with additional packages installed.

For example I can create shell with cargo (and rustc) and elixir v15

λ nix-shell -p cargo elixir_1_15 --command iex
this path will be fetched (155.29 MiB download, 723.23 MiB unpacked):
  /nix/store/1cigjjw5zrds5avjnrz9c8wq9llg2van-cargo-1.77.2
  /nix/store/7awq9xc34wajgca41cmd7n4kdj9hwm6l-rustc-1.77.2
  /nix/store/avw2a8m8cwc7igqj3v346c6873mlfj8c-rustc-wrapper-1.77.2
  /nix/store/lz88wzn825h1j830gq94ws582bji1i2v-elixir-1.15.7
copying path '/nix/store/7awq9xc34wajgca41cmd7n4kdj9hwm6l-rustc-1.77.2' from 'https://cache.nixos.org'...
copying path '/nix/store/avw2a8m8cwc7igqj3v346c6873mlfj8c-rustc-wrapper-1.77.2' from 'https://cache.nixos.org'...
copying path '/nix/store/1cigjjw5zrds5avjnrz9c8wq9llg2van-cargo-1.77.2' from 'https://cache.nixos.org'...
copying path '/nix/store/lz88wzn825h1j830gq94ws582bji1i2v-elixir-1.15.7' from 'https://cache.nixos.org'...
Erlang/OTP 25 [erts-13.2.2.9] [source] [64-bit] [smp:16:16] [ds:16:16:10] [async-threads:1] [jit:ns]

Interactive Elixir (1.15.7) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)>

This is very convenient way to have custom reproducible environments.

I can't do this in any way (as I know) now without control over node starting process. Mb you can suggest any other way.

My goal is to have different system packages environments for each specific notebook.

[josevalim]

The problem with doing that is that the notebooks themselves then are not reproducible, because the information of the environment they run on is elsewhere. Ideally the best way would be to customize and set this up within the notebook itself.

[petrkozorezov]

Ideally the best way would be to customize and set this up within the notebook itself.

Sure, but I don't know how to do this in a general. I can propose a such solution for nix, but it will be just for nix and not for all. And 'standalone' node run command customization can help to solve this problem in a specific way without breaking anything else.

One of the goals nix based tools like devenv is to create reproducible environment anywhere (like it docker does, but without any kind of virtualization).

[jonatanklosko]

@petrkozorezov you can use System.cmd or System.shell in the setup cell to install anything, and you can also alter the PATH programmatically.

[petrkozorezov]

@jonatanklosko

1. I don't know a way to do this by nix just for current shell without touching global profile
2. It will be impossible to pin/change erlang/elixir version.