gluster-web-interface/app/controllers/application_controller.rb

class ApplicationController < ActionController::Base
    # Prevent CSRF attacks by raising an exception.
    # For APIs, you may want to use :null_session instead.
    # protect_from_forgery with: :exception
    include ApplicationHelper
    include HomeHelper
    include VolumeHelper
    include NodeHelper

    def require_login
        unless user_signed_in?
            flash[:error] = "Please, Login required to use the service."
            redirect_to "/users/sign_in" # halts request cycle
        end
    end
end