In my opinion, including Lager is outside the scope of Exometer. We're trying to include Exometer in an existing Elixir application which uses the Elixir's Logger. Getting Lager included just because of Exometer adds a lot of overhead and makes configuring logging much more complex (we either have to disable Lager or make it somehow send messages to the Elixir logging framework).

I see three possible solutions:

1. Exclude logging completely from Exometer
2. Use error_logger (which is picked up by Lager and Elixir's Logger anyway)
3. Make logging/events inside Exometer be handled by a user defined callback module