How to define almost global variable and almost top level method in Rails

# app/models/application_container.rb require 'singleton' class ApplicationContainer include Singleton end 

# app/controllers/application_controler.rb class ApplicationController < ActionController::Base delegate_missing_to :container cattr_accessor :container, default: ApplicationContainer.instance end 

# app/models/application_record.rb class ApplicationRecord < ActiveRecord::Base self.abstract_class = true delegate_missing_to :container cattr_accessor :container, default: ApplicationContainer.instance end