Checkout of Instiki Trunk 1/21/2007.

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

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+require 'optparse'
+require 'net/http'
+require 'uri'
+
+if RUBY_PLATFORM =~ /mswin32/ then abort("Reaper is only for Unix") end
+
+# Instances of this class represent a single running process. Processes may
+# be queried by "keyword" to find those that meet a specific set of criteria.
+class ProgramProcess
+  class << self
+    
+    # Searches for all processes matching the given keywords, and then invokes
+    # a specific action on each of them. This is useful for (e.g.) reloading a
+    # set of processes:
+    #
+    #   ProgramProcess.process_keywords(:reload, "basecamp")
+    def process_keywords(action, *keywords)
+      processes = keywords.collect { |keyword| find_by_keyword(keyword) }.flatten
+
+      if processes.empty?
+        puts "Couldn't find any process matching: #{keywords.join(" or ")}"
+      else
+        processes.each do |process|
+          puts "#{action.capitalize}ing #{process}"
+          process.send(action)
+        end
+      end      
+    end
+
+    # Searches for all processes matching the given keyword:
+    #
+    #   ProgramProcess.find_by_keyword("basecamp")
+    def find_by_keyword(keyword)
+      process_lines_with_keyword(keyword).split("\n").collect { |line|
+        next if line =~ /inq|ps axww|grep|spawn-fcgi|spawner|reaper/
+        pid, *command = line.split
+        new(pid, command.join(" "))
+      }.compact
+    end
+
+    private
+      def process_lines_with_keyword(keyword)
+        `ps axww -o 'pid command' | grep #{keyword}`
+      end
+  end
+
+  # Create a new ProgramProcess instance that represents the process with the
+  # given pid, running the given command.
+  def initialize(pid, command)
+    @pid, @command = pid, command
+  end
+
+  # Forces the (rails) application to reload by sending a +HUP+ signal to the
+  # process.
+  def reload
+    `kill -s HUP #{@pid}`
+  end
+
+  # Forces the (rails) application to gracefully terminate by sending a
+  # +TERM+ signal to the process.
+  def graceful
+    `kill -s TERM #{@pid}`
+  end
+
+  # Forces the (rails) application to terminate immediately by sending a -9
+  # signal to the process.
+  def kill
+    `kill -9 #{@pid}`
+  end
+
+  # Send a +USR1+ signal to the process.
+  def usr1
+    `kill -s USR1 #{@pid}`
+  end
+
+  # Force the (rails) application to restart by sending a +USR2+ signal to the
+  # process.
+  def restart
+    `kill -s USR2 #{@pid}`
+  end
+
+  def to_s #:nodoc:
+    "[#{@pid}] #{@command}"
+  end
+end
+
+OPTIONS = {
+  :action      => "restart",
+  :dispatcher  => File.expand_path(RAILS_ROOT + '/public/dispatch.fcgi')
+}
+
+ARGV.options do |opts|
+  opts.banner = "Usage: reaper [options]"
+
+  opts.separator ""
+
+  opts.on <<-EOF
+  Description:
+    The reaper is used to restart, reload, gracefully exit, and forcefully exit FCGI processes
+    running a Rails Dispatcher. This is commonly done when a new version of the application
+    is available, so the existing processes can be updated to use the latest code.
+
+    The reaper actions are:
+
+    * restart : Restarts the application by reloading both application and framework code
+    * reload  : Only reloads the application, but not the framework (like the development environment)
+    * graceful: Marks all of the processes for exit after the next request
+    * kill    : Forcefully exists all processes regardless of whether they're currently serving a request
+
+    Restart is the most common and default action.
+
+  Examples:
+    reaper # restarts the default dispatcher
+    reaper -a reload
+    reaper -a exit -d /my/special/dispatcher.fcgi
+  EOF
+
+  opts.on("  Options:")
+
+  opts.on("-a", "--action=name", "reload|graceful|kill (default: #{OPTIONS[:action]})", String)  { |v| OPTIONS[:action] = v }
+  opts.on("-d", "--dispatcher=path", "default: #{OPTIONS[:dispatcher]}", String)                 { |v| OPTIONS[:dispatcher] = v }
+
+  opts.separator ""
+
+  opts.on("-h", "--help", "Show this help message.") { puts opts; exit }
+
+  opts.parse!
+end
+
+ProgramProcess.process_keywords(OPTIONS[:action], OPTIONS[:dispatcher])

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

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+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

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

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+require 'optparse'
+
+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
+
+OPTIONS = {
+  :interval => 5.0,
+  :command  => File.expand_path(RAILS_ROOT + '/script/process/spawner'),
+  :daemon   => false
+}
+
+ARGV.options do |opts|
+  opts.banner = "Usage: spinner [options]"
+
+  opts.separator ""
+
+  opts.on <<-EOF
+  Description:
+    The spinner is a protection loop for the spawner, which will attempt to restart any FCGI processes
+    that might have been exited or outright crashed. It's a brute-force attempt that'll just try
+    to run the spawner every X number of seconds, so it does pose a light load on the server.
+
+  Examples:
+    spinner # attempts to run the spawner with default settings every second with output on the terminal
+    spinner -i 3 -d # only run the spawner every 3 seconds and detach from the terminal to become a daemon
+    spinner -c '/path/to/app/script/process/spawner -p 9000 -i 10' -d # using custom spawner
+  EOF
+
+  opts.on("  Options:")
+
+  opts.on("-c", "--command=path",    String) { |v| OPTIONS[:command] = v }
+  opts.on("-i", "--interval=seconds", Float) { |v| OPTIONS[:interval] = v }
+  opts.on("-d", "--daemon")                  { |v| OPTIONS[:daemon] = v }
+
+  opts.separator ""
+
+  opts.on("-h", "--help", "Show this help message.") { puts opts; exit }
+
+  opts.parse!
+end
+
+daemonize if OPTIONS[:daemon]
+
+trap(OPTIONS[:daemon] ? "TERM" : "INT") { exit }
+
+loop do
+  system(OPTIONS[:command])
+  sleep(OPTIONS[:interval])
+end