using daemons.

test.rb

# -*- coding: utf-8 -*-

require 'logger'

STDOUT.sync = true
STDERR.sync = true

def get_logger
  ret = Logger.new(File.join(File.dirname(File.expand_path(__FILE__)), 'test.log'))
  ret.level = Logger::INFO
  ret
end

def show_message(str, logger = nil)
  logger = get_logger unless logger
  logger.info str
  puts str
end

# Signal.trap(:HUP) { puts 'SIGHUPを受信' }
Signal.trap(:INT)  { terminate 'SIGINTを受信'  }
Signal.trap(:QUIT) { terminate 'SIGQUITを受信' }
Signal.trap(:KILL) { terminate 'SIGKILLを受信' }
Signal.trap(:TERM) { terminate 'SIGTERMを受信' }
Signal.trap(:INT)  { terminate 'SIGINTを受信'  }
Signal.trap(:QUIT) { terminate 'SIGQUITを受信' }
Signal.trap(:KILL) { terminate 'SIGKILLを受信' }
Signal.trap(:TERM) { terminate 'SIGTERMを受信' }
def terminate(str)
  show_message(str)
  exit 0
end

def my_task(logger)
  show_message('start task', logger)
  sleep 2
  STDOUT.puts "# ----------- stdout #{Time.now}"
  sleep 2
  STDERR.puts "# ----------- stderr #{Time.now}"
  sleep 2
  show_message('end task', logger)
end

def main
  logger = nil
  loop do
    if logger == nil
      logger = get_logger
      show_message('Logging start', logger)
    end
    my_task(logger)
    sleep 2
  end
end

main

testdaemon.rb

# -*- coding: utf-8 -*-

# 開始
#  ruby testdaemon.rb start
# 再起動
#  ruby testdaemon.rb restart
# 終了
#  ruby testdaemon.rb stop
#
require 'rubygems'
require 'daemons'

options = {
  log_output: true,
}
Daemons.run(File.join(File.dirname(File.expand_path(__FILE__)), 'test.rb'), options)

testdaemon_1.rb

ntsitm295139:lib youichikato$ cat testdaemon_1.rb
# -*- coding: utf-8 -*-

# See
#   http://snippets.aktagon.com/snippets/212-how-to-create-a-daemon-process-using-ruby-and-the-daemons-rubygem
#   > How to create a daemon process using Ruby and the daemons RubyGem
#
# 開始
#  ruby testdaemon_1.rb start
# 再起動
#  ruby testdaemon_1.rb restart
# 終了
#  ruby testdaemon_1.rb stop
#
require 'rubygems'
require 'daemons'

file = File.join(File.dirname(File.expand_path(__FILE__)), 'test.rb')

options = {
  log_output: true   # stdout, stderr を test.rb.output に保持する
}

Daemons.run_proc('test.rb', # name of daemon
                 options) do
  exec "ruby #{file}"
end

testdaemon_2.rb

# -*- coding: utf-8 -*-

# See
#   http://snippets.aktagon.com/snippets/212-how-to-create-a-daemon-process-using-ruby-and-the-daemons-rubygem
#   > How to create a daemon process using Ruby and the daemons RubyGem
#
#   http://wokowa.net/blog/archives/88
#   > Rubyのdaemonsでloggerからログ出す方法がよく分からなかった話
#
#   http://stackoverflow.com/questions/11237815/ruby-cant-write-to-logs-in-daemons
#   > What does daemons internally do with my daemons?
#
#   http://stackoverflow.com/questions/12266645/ruby-daemons-soft-stop
#   > Ruby daemons soft stop
#
# 開始
#  ruby testdaemon_2.rb start
# 再起動
#  ruby testdaemon_2.rb restart
# 終了
#  ruby testdaemon_2.rb stop
#
# -----------------------------------------
# task(logger) の処理を繰り返し実行する。
# task 実行中に daemon の stop , restart の指示, kill pid をされても、
# task の処理が途中で中断されることが無い様にした。
#
# $ tail -f test.log や $ tail -f test.rb.output を別コンソールで実行しながら
# damon の stop, resatret, kill pid を行うと様子がよくわかる。
#
# -----------------------------------------
# ruby: ruby 1.9.3p484 (2013-11-22 revision 43786) [i386-darwin9.8.0]
# gem:  daemons (1.1.9)

require 'rubygems'
require 'daemons'
require 'logger'

CWD = File.expand_path(File.dirname(__FILE__))

STDOUT.sync = true
STDERR.sync = true

def task(logger)
  # 時間がかかる処理を定義。
  # 処理の途中で daemon の stop, restart を行いやすくしてある。
  logger.info 'start task'
  sleep 2; STDOUT.puts "# ------- task start #{Time.now}"
  sleep 2; STDOUT.puts "#      -- stdout #{Time.now}"
  sleep 2; STDERR.puts "#      -- stderr #{Time.now}"
  sleep 2; STDOUT.puts "# ------- task end   #{Time.now}"
  logger.info 'fnish task'
end

# ------------------
def get_logger
  ret = Logger.new('test.log')
  ret.level = Logger::INFO
  ret
end

def log_info(logger, str)
  logger = get_logger unless logger
  logger.info str
  logger
end

def show_message(str)
  puts str
  log_info(nil, str)
end

options = {
  log_output: true,   # stdout, stderr を test.rb.output に保持する
  multiple:   false,
  ontop:      false,
  backtrace:  true,
  monitor:    false
}
Daemons.run_proc('test.rb', # name of daemon
                 options) do
  stopped = false
  logger = nil

  Signal.trap(:INT)  { stopped = true; show_message 'SIGINTを受信' }
  Signal.trap(:QUIT) { stopped = true; show_message 'SIGQUITを受信' }
  Signal.trap(:KILL) { stopped = true; show_message 'SIGKILLを受信' }
  Signal.trap(:TERM) { stopped = true; show_message 'SIGTERMを受信' }

  Dir.chdir CWD
  until stopped
    logger = show_message 'Start Daemon' if logger.nil?
    task(logger)
    sleep 2
  end
  show_message 'Finish Daemon'
end