perform

# File railties/lib/rails/commands/server/server_command.rb, line 139
      def perform
        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)
          server.start
        end
      end