Prevent rails' file server from serving index.html

You can prevent rails' file server from serving index.html, while continuing to serve other files from the public directory by changing the index_name:

class Application
  config.public_file_server.index_name = "other-index.html"
end

Rails.application.routes.draw do
  get :dashboard, to: "application#dashboard"
  root to: redirect("/dashboard")
end

Visiting the root path / will no longer serve public/index.html if you define another route for /