perform method

perform.rb

def perform
  extract_environment_option_from_argument
  set_application_directory!
  prepare_restart
  Rails::Server.new(server_options).tap do |server|
    # Require application after server sets environment to propagate
    # the --environment option.
    require APP_PATH
    Dir.chdir(Rails.application.root)
    if server.serveable?
      print_boot_information(server.server, server.served_url)
      after_stop_callback = -> { say "Exiting" unless options[:daemon] }
      server.start(after_stop_callback)
    else
      say rack_server_suggestion(using)
    end
  end
end