A module to implement retrieving of secrets.

Allows you to implement secrets access via your method or choice at runtime.

Example

defmodule MyApp.GetSecret do
  use AshAuthentication.Secret

  def secret_for([:authentication, :strategies, :oauth2, :client_id], MyApp.User, _opts), do: Application.fetch_env(:my_app, :oauth_client_id)
  def secret_for([:authentication, :strategies, :oauth2, :client_secret], MyApp.User, _opts), do: Application.fetch_env(:my_app, :oauth_client_secret)
end

defmodule MyApp.Accounts.User do
  use Ash.Resource,
    extensions: [AshAuthentication],
    domain: MyApp.Accounts

  authentication do
    strategies do
      oauth2 do
        client_id MyApp.GetSecret
        client_secret MyApp.GetSecret
      end
    end
  end
end

You can also implement it directly as a function:

defmodule MyApp.User do
   use Ash.Resource,
    extensions: [AshAuthentication],
    domain: MyApp.Accounts

  authentication do
    strategies do
      oauth2 do
        client_id fn _secret, _resource ->
          Application.fetch_env(:my_app, :oauth_client_id)
        end
      end
    end
  end
end

Secret name

Because you may wish to reuse this module for a number of different providers and resources, the first argument passed to the callback is the "secret name", it contains the "path" to the option being set. The path is made up of a list containing the DSL path to the secret.