Module attribute constants nil in Elixir
Module attributes in elixir (
@something) can be used as constants and assigned a value, however one must make sure that the value assigned to the constant is available at compile time.
For example when using a constant that loads environment variables if the value is not available in compile time they will resolve to
@salt System.get_env(:your_app_name, "AUTH_SALT")
So either export the environment variables before compiling, or don't use module attributes, instead you can use a function:
defp salt do System.get_env(:your_app_name, "AUTH_SALT") end
- The downside to using a function is that it will be re-evaluated each time.
- The downside of exporting env-vars before compile is that they you might forget and your app will crash in production. You can circumvent that by writing a script for compilation.
You can also call
config.exsbut make sure to run
mix cleanafter doing so since the compiler seems to cache the config compilation.