Preload some mix-dependencies

[fnchooft]

I tried pre-loading some of the mix-install libraries which are used inside a notebook.

The use case is that the a livebook could run inside a closed-network - without access to the "outside" internet - and thus mix would not be able to get library-dependencies (classroom setup / lab setup).

I saw that this could be done - as per nerves ( https://github.com/livebook-dev/nerves_livebook/blob/main/mix.exs) - but my attempt failed.

I tried:

• loading the mix-deps in the livebook by adapting mix.exs
• rebuild as per instructions (mix.dev.setup && MIX_ENV=prod mix escript.build)
• use the "altered/prepped" livebook escripted version.

During execution however, it seems the modules are not getting loaded in the notebook-context and the modules can not be found.

I am getting an:
"** (UndefinedFunctionError) function :module.function/1 is undefined (module :module is not available)"

Kind regards,
Fabian

[josevalim]

Instead of going the Nerves route, what you can do is to install the packages you plan to use on the machines and then set HEX_OFFLINE=1. You can set it either on the machine or at the top of the notebook, via System.put_env/2, before the Mix.install call. This way Hex will use the locally stored information. The cache is stored on ~/.hex, configured the via the HEX_HOME env var, in case you want to copy it between machines.

[fnchooft]

Much more elegant solution - will try this for sure.
Thanks / Obrigado!