Using a custom Elixir Library that uses Env variables

config/config.exs in library codebase is not loaded when used as a dependency.

Hi, But I can find it in the installed lib files :

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I am missing something?

It doesn’t matter if it’s there – config files of your dependencies are not used.

Hi LostKobrakai, So how can I make it work ?

You can either move the values into your code or provide app env values (for your app only) via the mix.exs (see vintage_net/mix.exs at main · nerves-networking/vintage_net · GitHub)

The idea is to provide one LIB, but the LIB provide 3 envs (dev, staging and prod) depending on the ENV of the app. How do you think it should be implemented on the LIB side ?

@LostKobrakai how this approche " or provide app env values (for your app only) via the mix.exs "

Can help me get the LIB vars ? you mean I should define the enviromnent in each app that installes the LIB ?

Ideally you should not use the application environment in libraries at all. But answering your question - yes, you should define configuration each time you use dependency.

To add to that, if you decide to rely on the application environment and would still like to rely on some defaults you can do something like the following:

Application.get_env(:test_lib, :dev, your: "default config")

Or a tad more readable:

@default [your: "default config"]

def some_function do
  config = Application.get_env(:test_lib, :dev, @default_config)
  # ...
end

I do something similar in my etag_plug package.

@wolf4earth : Sorry to ask, I’m still beginner but this line will be on the LIB side ?

Application.get_env(:test_lib, :dev, your: "default config")

And this code also ?

@default [your: "default config"]

def some_function do
etc..

When we send the config from the APP to the LIB ?