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herokuelixirproductioncowboyplug

Elixir with Plug and Cowboy: Disable nice error messages

I am using heroku-buildpack-elixir to deploy an application to Heroku. My application consists of a simple Plug/Cowboy setup. I noticed that when unhandled exceptions occur, a nice error message appears, showing the stack trace and the lines of code where the error appeared.

This is ok for development environments, however on production environments I do not want my code to be visible to visitors. How can I disable or override the default behaviour?

I tried setting the MIX_ENV environment variable to prod in Heroku with no effect.

Solution

  • wrap the Plug.Debugger statement in an if clause. Running in prod environment no longer show errors as html pages. source

      if Mix.env == :dev do
    use Plug.Debugger, otp_app: :my_app
  end