Possible to use with Ecto? about confex HOT 5 CLOSED

Hi.

Ecto has init callback, we use it in all our projects with Confex:

defmodule MyApp do
  use Ecto.Repo, otp_app: :my_app

  @doc """
  Dynamically loads the repository configuration from the environment variables.
  """
  def init(_, config) do
    url = System.get_env("DATABASE_URL")
    config = if url, do: Ecto.Repo.Supervisor.parse_url(url), else: Confex.process_env(config)

    unless config[:database] do
      raise "Set DB_NAME environment variable!"
    end

    unless config[:username] do
      raise "Set DB_USER environment variable!"
    end

    unless config[:password] do
      raise "Set DB_PASSWORD environment variable!"
    end

    unless config[:hostname] do
      raise "Set DB_HOST environment variable!"
    end

    unless config[:port] do
      raise "Set DB_PORT environment variable!"
    end

    {:ok, config}
  end
end

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@dropfen I've added this sample to README.md, thanks using Confex 👍

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@AndrewDryga I just saw it, will try it out ASAP. I guess, I just had the aha moment, for how it works and so on. Let me express:

• The config.exs is compiled at build time, so there is no way to pass values at runtime
• So, we use callbacks/config-handlers where we are checking the compiled-in configs, and load them if they are missing from Confex (its System.get_env under the hood)

Still missing point:

• how to handle other libs, where we do not have callbacks? Like guardian for example, or whatever xyz-lib

Thank you Andrew!

Boris

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Thanks Andrew, it worked! 👍

from confex.

Unfortunately It's a question that should be pointed to libraries developers. Usually you have one of few options:

1. You can define default config in confix.ex, and pass overrides in supervisor args (when adding external supervisor to your app's supervision tree);
2. Lib can provide callbacks;
3. Some libs have their own {:system, ..} tuples implementation.

If you using something that don't have those options, only way for you is to replace ENV variables via REPLACE_OS_VARS=true. You can read more about it at Distillery docs.

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