Options may include:

• :app

    a rack application to run (overrides :config)
  

• :config

    a rackup configuration file path to load (.ru)
  

• :environment

    this selects the middleware that will be wrapped around
    your application. Default options available are:
      - development: CommonLogger, ShowExceptions, and Lint
      - deployment: CommonLogger
      - none: no extra middleware
    note: when the server is a cgi server, CommonLogger is not included.
  

• :server

    choose a specific Rack::Handler, e.g. cgi, fcgi, webrick
  

• :daemonize

    if true, the server will daemonize itself (fork, detach, etc)
  

• :pid

    path to write a pid file after daemonize
  

• :Host

    the host address to bind to (used by supporting Rack::Handler)
  

• :Port

    the port to bind to (used by supporting Rack::Handler)
  

• :AccessLog

    webrick access log options (or supporting Rack::Handler)
  

• :debug

    turn on debug output ($DEBUG = true)
  

• :warn

    turn on warnings ($-w = true)
  

• :include

    add given paths to $LOAD_PATH
  

• :require

    require the given libraries
  

Start a new rack server (like running rackup). This will parse ARGV and provide standard ARGV rackup options, defaulting to load ‘config.ru’.

Providing an options hash will prevent ARGV parsing and will not include any default options.

This method can be used to very easily launch a CGI application, for example:

 Rack::Server.start(
   :app => lambda do |e|
     [200, {'Content-Type' => 'text/html'}, ['hello world']]
   end,
   :server => 'cgi'
 )

Further options available here are documented on Rack::Server#initialize