registry pattern

registry.rb

module Registry
  class << self
    
    def logger
      # some default logger...
    end

    def server
      # some server
    end
  end
end

class MyHttpApplication
  def initialize(opts = {})
    @logger = opts.fetch(:logger) { Registry.logger() }
    @server = opts.fetch(:server) { Registry.server() }
  end
end

MyHttpApplication.new(server: Unicorn.new()).main()