Auto-rotation of logs in Elixir

By default, a Phoenix app will configure the built-in logger to an unlimited size.

Technically, the configuration defaults to the values set in Erlang’s logger_std_h module.

Fortunately, Elixir allows you to use a keyword list in the config to override these settings.

config :logger, :default_handler,
  config: [
    file: ~c"system.log",
    max_no_bytes: 10_000_000,
    max_no_files: 5
  ]

This allows you to easy rotate on file size (in this case 10M bytes.)