class Rack::Server

Attributes

Public Class Methods

# File lib/rack/server.rb, line 259
def default_middleware_by_environment
  m = Hash.new {|h, k| h[k] = []}
  m["deployment"] = [
    [Rack::ContentLength],
    logging_middleware,
    [Rack::TempfileReaper]
  ]
  m["development"] = [
    [Rack::ContentLength],
    logging_middleware,
    [Rack::ShowExceptions],
    [Rack::Lint],
    [Rack::TempfileReaper]
  ]

  m
end
# File lib/rack/server.rb, line 253
def logging_middleware
  lambda { |server|
    /CGI/.match?(server.server.name) || server.options[:quiet] ? nil : [Rack::CommonLogger, $stderr]
  }
end
# File lib/rack/server.rb, line 277
def middleware
  default_middleware_by_environment
end

Options may include:

  • :app

    a rack application to run (overrides :config and :builder)
    
  • :builder

    a string to evaluate a Rack::Builder from
    
  • :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
    

Additional options for profiling app initialization include:

  • :heapfile

    location for ObjectSpace.dump_all to write the output to
  • :profile_file

    location for CPU/Memory (StackProf) profile output (defaults to a tempfile)
  • :profile_mode

    StackProf profile mode (cpu|wall|object)
    
# File lib/rack/server.rb, line 215
def initialize(options = nil)
  @ignore_options = []

  if options
    @use_default_options = false
    @options = options
    @app = options[:app] if options[:app]
  else
    argv = defined?(SPEC_ARGV) ? SPEC_ARGV : ARGV
    @use_default_options = true
    @options = parse_options(argv)
  end
end

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

# File lib/rack/server.rb, line 167
def self.start(options = nil)
  new(options).start
end

Public Instance Methods

# File lib/rack/server.rb, line 248
def app
  @app ||= options[:builder] ? build_app_from_string : build_app_and_options_from_config
end
# File lib/rack/server.rb, line 234
def default_options
  environment  = ENV['RACK_ENV'] || 'development'
  default_host = environment == 'development' ? 'localhost' : '0.0.0.0'

  {
    environment: environment,
    pid: nil,
    Port: 9292,
    Host: default_host,
    AccessLog: [],
    config: "config.ru"
  }
end
# File lib/rack/server.rb, line 282
def middleware
  self.class.middleware
end
# File lib/rack/server.rb, line 229
def options
  merged_options = @use_default_options ? default_options.merge(@options) : @options
  merged_options.reject { |k, v| @ignore_options.include?(k) }
end
# File lib/rack/server.rb, line 330
def server
  @_server ||= Rack::Handler.get(options[:server])

  unless @_server
    @_server = Rack::Handler.default

    # We already speak FastCGI
    @ignore_options = [:File, :Port] if @_server.to_s == 'Rack::Handler::FastCGI'
  end

  @_server
end
# File lib/rack/server.rb, line 286
def start(&block)
  if options[:warn]
    $-w = true
  end

  if includes = options[:include]
    $LOAD_PATH.unshift(*includes)
  end

  Array(options[:require]).each do |library|
    require library
  end

  if options[:debug]
    $DEBUG = true
    require 'pp'
    p options[:server]
    pp wrapped_app
    pp app
  end

  check_pid! if options[:pid]

  # Touch the wrapped app, so that the config.ru is loaded before
  # daemonization (i.e. before chdir, etc).
  handle_profiling(options[:heapfile], options[:profile_mode], options[:profile_file]) do
    wrapped_app
  end

  daemonize_app if options[:daemonize]

  write_pid if options[:pid]

  trap(:INT) do
    if server.respond_to?(:shutdown)
      server.shutdown
    else
      exit
    end
  end

  server.run(wrapped_app, **options, &block)
end