# File src/ruby_supportlib/phusion_passenger/config/list_instances_command.rb, line 38
      def run
        parse_options
        instances = AdminTools::InstanceRegistry.new.list
        if @options[:json]
          print_json(instances)
        elsif instances.empty?
          print_no_instances_running
        else
          print_instances(instances)
        end
      end