vendor/rails/railties/lib/commands/process/spawner.rb

   1 require 'active_support'
   2 require 'optparse'
   3 require 'socket'
   4 require 'fileutils'
   5
   6 def daemonize #:nodoc:
   7   exit if fork                   # Parent exits, child continues.
   8   Process.setsid                 # Become session leader.
   9   exit if fork                   # Zap session leader. See [1].
  10   Dir.chdir "/"                  # Release old working directory.
  11   File.umask 0000                # Ensure sensible umask. Adjust as needed.
  12   STDIN.reopen "/dev/null"       # Free file descriptors and
  13   STDOUT.reopen "/dev/null", "a" # point them somewhere sensible.
  14   STDERR.reopen STDOUT           # STDOUT/ERR should better go to a logfile.
  15 end
  16
  17 class Spawner
  18   def self.record_pid(name = "#{OPTIONS[:process]}.spawner", id = Process.pid)
  19     FileUtils.mkdir_p(OPTIONS[:pids])
  20     File.open(File.expand_path(OPTIONS[:pids] + "/#{name}.pid"), "w+") { |f| f.write(id) }
  21   end
  22
  23   def self.spawn_all
  24     OPTIONS[:instances].times do |i|
  25       port = OPTIONS[:port] + i
  26       print "Checking if something is already running on #{OPTIONS[:address]}:#{port}..."
  27
  28       begin
  29         srv = TCPServer.new(OPTIONS[:address], port)
  30         srv.close
  31         srv = nil
  32
  33         puts "NO"
  34         puts "Starting dispatcher on port: #{OPTIONS[:address]}:#{port}"
  35
  36         FileUtils.mkdir_p(OPTIONS[:pids])
  37         spawn(port)
  38       rescue
  39         puts "YES"
  40       end
  41     end
  42   end
  43 end
  44
  45 class FcgiSpawner < Spawner
  46   def self.spawn(port)
  47     cmd = "#{OPTIONS[:spawner]} -f #{OPTIONS[:dispatcher]} -p #{port} -P #{OPTIONS[:pids]}/#{OPTIONS[:process]}.#{port}.pid"
  48     cmd << " -a #{OPTIONS[:address]}" if can_bind_to_custom_address?
  49     system(cmd)
  50   end
  51
  52   def self.can_bind_to_custom_address?
  53     @@can_bind_to_custom_address ||= /^\s-a\s/.match `#{OPTIONS[:spawner]} -h`
  54   end
  55 end
  56
  57 class MongrelSpawner < Spawner
  58   def self.spawn(port)
  59     cmd =
  60       "mongrel_rails start -d " +
  61       "-a #{OPTIONS[:address]} " +
  62       "-p #{port} " +
  63       "-P #{OPTIONS[:pids]}/#{OPTIONS[:process]}.#{port}.pid " +
  64       "-e #{OPTIONS[:environment]} " +
  65       "-c #{OPTIONS[:rails_root]} " +
  66       "-l #{OPTIONS[:rails_root]}/log/mongrel.log"
  67
  68     # Add prefix functionality to spawner's call to mongrel_rails
  69     # Digging through mongrel's project subversion server, the earliest
  70     # Tag that has prefix implemented in the bin/mongrel_rails file
  71     # is 0.3.15 which also happens to be the earliest tag listed.
  72     # References: http://mongrel.rubyforge.org/svn/tags
  73     if Mongrel::Const::MONGREL_VERSION.to_f >=0.3 && !OPTIONS[:prefix].nil?
  74       cmd = cmd + " --prefix #{OPTIONS[:prefix]}"
  75     end
  76     system(cmd)
  77   end
  78
  79   def self.can_bind_to_custom_address?
  80     true
  81   end
  82 end
  83
  84
  85 begin
  86   require_library_or_gem 'fcgi'
  87 rescue Exception
  88   # FCGI not available
  89 end
  90
  91 begin
  92   require_library_or_gem 'mongrel'
  93 rescue Exception
  94   # Mongrel not available
  95 end
  96
  97 server = case ARGV.first
  98   when "fcgi", "mongrel"
  99     ARGV.shift
 100   else
 101     if defined?(Mongrel)
 102       "mongrel"
 103     elsif RUBY_PLATFORM !~ /(:?mswin|mingw)/ && !silence_stderr { `spawn-fcgi -version` }.blank? && defined?(FCGI)
 104       "fcgi"
 105     end
 106 end
 107
 108 case server
 109   when "fcgi"
 110     puts "=> Starting FCGI dispatchers"
 111     spawner_class = FcgiSpawner
 112   when "mongrel"
 113     puts "=> Starting mongrel dispatchers"
 114     spawner_class = MongrelSpawner
 115   else
 116     puts "Neither FCGI (spawn-fcgi) nor Mongrel was installed and available!"
 117     exit(0)
 118 end
 119
 120
 121
 122 OPTIONS = {
 123   :environment => "production",
 124   :spawner     => '/usr/bin/env spawn-fcgi',
 125   :dispatcher  => File.expand_path(RELATIVE_RAILS_ROOT + '/public/dispatch.fcgi'),
 126   :pids        => File.expand_path(RELATIVE_RAILS_ROOT + "/tmp/pids"),
 127   :rails_root  => File.expand_path(RELATIVE_RAILS_ROOT),
 128   :process     => "dispatch",
 129   :port        => 8000,
 130   :address     => '0.0.0.0',
 131   :instances   => 3,
 132   :repeat      => nil,
 133   :prefix      => nil
 134 }
 135
 136 ARGV.options do |opts|
 137   opts.banner = "Usage: spawner [platform] [options]"
 138
 139   opts.separator ""
 140
 141   opts.on <<-EOF
 142   Description:
 143     The spawner is a wrapper for spawn-fcgi and mongrel that makes it
 144     easier to start multiple processes running the Rails dispatcher. The
 145     spawn-fcgi command is included with the lighttpd web server, but can
 146     be used with both Apache and lighttpd (and any other web server
 147     supporting externally managed FCGI processes). Mongrel automatically
 148     ships with with mongrel_rails for starting dispatchers.
 149
 150     The first choice you need to make is whether to spawn the Rails
 151     dispatchers as FCGI or Mongrel. By default, this spawner will prefer
 152     Mongrel, so if that's installed, and no platform choice is made,
 153     Mongrel is used.
 154
 155     Then decide a starting port (default is 8000) and the number of FCGI
 156     process instances you'd like to run. So if you pick 9100 and 3
 157     instances, you'll start processes on 9100, 9101, and 9102.
 158
 159     By setting the repeat option, you get a protection loop, which will
 160     attempt to restart any FCGI processes that might have been exited or
 161     outright crashed.
 162
 163     You can select bind address for started processes. By default these
 164     listen on every interface. For single machine installations you would
 165     probably want to use 127.0.0.1, hiding them form the outside world.
 166
 167      Examples:
 168        spawner               # starts instances on 8000, 8001, and 8002
 169                              # using Mongrel if available.
 170        spawner fcgi          # starts instances on 8000, 8001, and 8002
 171                              # using FCGI.
 172        spawner mongrel -i 5  # starts instances on 8000, 8001, 8002,
 173                              # 8003, and 8004 using Mongrel.
 174        spawner -p 9100 -i 10 # starts 10 instances counting from 9100 to
 175                              # 9109 using Mongrel if available.
 176        spawner -p 9100 -r 5  # starts 3 instances counting from 9100 to
 177                              # 9102 and attempts start them every 5
 178                              # seconds.
 179        spawner -a 127.0.0.1  # starts 3 instances binding to localhost
 180   EOF
 181
 182   opts.on("  Options:")
 183
 184   opts.on("-p", "--port=number",      Integer, "Starting port number (default: #{OPTIONS[:port]})")                { |v| OPTIONS[:port] = v }
 185
 186   if spawner_class.can_bind_to_custom_address?
 187     opts.on("-a", "--address=ip",     String,  "Bind to IP address (default: #{OPTIONS[:address]})")                { |v| OPTIONS[:address] = v }
 188   end
 189
 190   opts.on("-p", "--port=number",      Integer, "Starting port number (default: #{OPTIONS[:port]})")                { |v| OPTIONS[:port] = v }
 191   opts.on("-i", "--instances=number", Integer, "Number of instances (default: #{OPTIONS[:instances]})")            { |v| OPTIONS[:instances] = v }
 192   opts.on("-r", "--repeat=seconds",   Integer, "Repeat spawn attempts every n seconds (default: off)")             { |v| OPTIONS[:repeat] = v }
 193   opts.on("-e", "--environment=name", String,  "test|development|production (default: #{OPTIONS[:environment]})")  { |v| OPTIONS[:environment] = v }
 194   opts.on("-P", "--prefix=path",      String,  "URL prefix for Rails app. [Used only with Mongrel > v0.3.15]: (default: #{OPTIONS[:prefix]})")         { |v| OPTIONS[:prefix] = v }
 195   opts.on("-n", "--process=name",     String,  "default: #{OPTIONS[:process]}")                                    { |v| OPTIONS[:process] = v }
 196   opts.on("-s", "--spawner=path",     String,  "default: #{OPTIONS[:spawner]}")                                    { |v| OPTIONS[:spawner] = v }
 197   opts.on("-d", "--dispatcher=path",  String,  "default: #{OPTIONS[:dispatcher]}") { |dispatcher| OPTIONS[:dispatcher] = File.expand_path(dispatcher) }
 198
 199   opts.separator ""
 200
 201   opts.on("-h", "--help", "Show this help message.") { puts opts; exit }
 202
 203   opts.parse!
 204 end
 205
 206 ENV["RAILS_ENV"] = OPTIONS[:environment]
 207
 208 if OPTIONS[:repeat]
 209   daemonize
 210   trap("TERM") { exit }
 211   spawner_class.record_pid
 212
 213   loop do
 214     spawner_class.spawn_all
 215     sleep(OPTIONS[:repeat])
 216   end
 217 else
 218   spawner_class.spawn_all
 219 end