Another approach to dynamically defining application routes in Rails engine

engine.rb

module ActionDispatch::Routing
  class Mapper
    def engine_routing
      #define your routes here. You can use all the normal route DSL stuff
      resources :dashboard
    end
  end
end

module OilChange
  class Engine < Rails::Engine
  end
end

gistfile1.txt

module ActionDispatch::Routing
  class Mapper
    def your_routing
      #define your routes here. You can use all the normal route DSL stuff
    end
  end
end