Checkout of Instiki Trunk 1/21/2007.

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

@@ -0,0 +1,94 @@
+require 'optparse'
+require 'socket'
+
+def daemonize #:nodoc:
+  exit if fork                   # Parent exits, child continues.
+  Process.setsid                 # Become session leader.
+  exit if fork                   # Zap session leader. See [1].
+  Dir.chdir "/"                  # Release old working directory.
+  File.umask 0000                # Ensure sensible umask. Adjust as needed.
+  STDIN.reopen "/dev/null"       # Free file descriptors and
+  STDOUT.reopen "/dev/null", "a" # point them somewhere sensible.
+  STDERR.reopen STDOUT           # STDOUT/ERR should better go to a logfile.
+end
+
+def spawn(port)
+  print "Checking if something is already running on port #{port}..."
+  begin
+    srv = TCPServer.new('0.0.0.0', port)
+    srv.close
+    srv = nil
+    print "NO\n "
+    print "Starting FCGI on port: #{port}\n  "
+    system("#{OPTIONS[:spawner]} -f #{OPTIONS[:dispatcher]} -p #{port}")
+  rescue
+    print "YES\n"
+  end
+end
+				    
+def spawn_all
+  OPTIONS[:instances].times { |i| spawn(OPTIONS[:port] + i) }
+end
+
+OPTIONS = {
+  :environment => "production",
+  :spawner     => '/usr/bin/env spawn-fcgi',
+  :dispatcher  => File.expand_path(RAILS_ROOT + '/public/dispatch.fcgi'),
+  :port        => 8000,
+  :instances   => 3,
+  :repeat      => nil
+}
+
+ARGV.options do |opts|
+  opts.banner = "Usage: spawner [options]"
+
+  opts.separator ""
+
+  opts.on <<-EOF
+  Description:
+    The spawner is a wrapper for spawn-fcgi that makes it easier to start multiple FCGI
+    processes running the Rails dispatcher. The spawn-fcgi command is included with the lighttpd 
+    web server, but can be used with both Apache and lighttpd (and any other web server supporting
+    externally managed FCGI processes).
+
+    You decide a starting port (default is 8000) and the number of FCGI process instances you'd 
+    like to run. So if you pick 9100 and 3 instances, you'll start processes on 9100, 9101, and 9102.
+
+    By setting the repeat option, you get a protection loop, which will attempt to restart any FCGI processes
+    that might have been exited or outright crashed. 
+
+  Examples:
+    spawner               # starts instances on 8000, 8001, and 8002
+    spawner -p 9100 -i 10 # starts 10 instances counting from 9100 to 9109
+    spawner -p 9100 -r 5  # starts 3 instances counting from 9100 to 9102 and attempts start them every 5 seconds
+  EOF
+
+  opts.on("  Options:")
+
+  opts.on("-p", "--port=number",      Integer, "Starting port number (default: #{OPTIONS[:port]})")                { |v| OPTIONS[:port] = v }
+  opts.on("-i", "--instances=number", Integer, "Number of instances (default: #{OPTIONS[:instances]})")            { |v| OPTIONS[:instances] = v }
+  opts.on("-r", "--repeat=seconds",   Integer, "Repeat spawn attempts every n seconds (default: off)")             { |v| OPTIONS[:repeat] = v }
+  opts.on("-e", "--environment=name", String,  "test|development|production (default: #{OPTIONS[:environment]})")  { |v| OPTIONS[:environment] = v }
+  opts.on("-s", "--spawner=path",     String,  "default: #{OPTIONS[:spawner]}")                                    { |v| OPTIONS[:spawner] = v }
+  opts.on("-d", "--dispatcher=path",  String,  "default: #{OPTIONS[:dispatcher]}") { |dispatcher| OPTIONS[:dispatcher] = File.expand_path(dispatcher) }
+
+  opts.separator ""
+
+  opts.on("-h", "--help", "Show this help message.") { puts opts; exit }
+
+  opts.parse!
+end
+
+ENV["RAILS_ENV"] = OPTIONS[:environment]
+
+if OPTIONS[:repeat]
+  daemonize
+  trap("TERM") { exit }
+
+  loop do
+    spawn_all
+    sleep(OPTIONS[:repeat])
+  end
+else
+  spawn_all
+end