monit rails rake task

composer.rake

namespace :app do
  desc "排版工作"
  task :composer, [:start, :end] => :environment do |task, args|
    keep_loop = true

    puts "rake app:composer run. I have PID #{Process.pid}"

    `echo "#{Process.pid}" > #{Rails.root}/tmp/composer.pid`
    `echo "#{Process.ppid}" > #{Rails.root}/tmp/composer.ppid`

    def shut_down
      puts "\nShutting down gracefully..."
      keep_loop = false
    end


    # Trap ^C
    Signal.trap("INT") {
      shut_down
      exit
    }

    # Trap `Kill `
    Signal.trap("TERM") {
      shut_down
      exit
    }

    while keep_loop
      puts "\nbegin compose at #{Time.now}"
      begin
        check_and_compose
      rescue => e
        puts e.message
      end

      sleep 10 #seconds
    end

  end # task :composer

  def check_and_compose
    driver = Selenium::WebDriver.for(:remote, :url => Rails.configuration.hejiao.web_driver)

    # set window size using Dimension struct
    target_size = Selenium::WebDriver::Dimension.new(1600, 1000)
    driver.manage.window.size = target_size

    questions = Question.where(need_compose: true).order("id asc")
    puts "#{questions.count} questions need compose"

    questions.each do |q|
      url = q.compose_url
      puts "navigate to #{url}"
      driver.navigate.to url
      max_sleep_seconds = 100
      current_sleep_seconds = 0
      per_sleep_seconds = 5
      keep_waiting = true

      while keep_waiting
        sleep per_sleep_seconds
        current_sleep_seconds += per_sleep_seconds

        question = Question.find(q.id)

        if !question.need_compose
          keep_waiting = false
        else
          keep_waiting = max_sleep_seconds > current_sleep_seconds
          puts "current_sleep_seconds #{current_sleep_seconds}, keep_waiting #{keep_waiting}"
        end
      end

      # save screenshot here for test
      # filename = "/tmp/screenshots/#{q.id}_#{q.axx_id}.png"
      # puts "save_screenshot to #{filename}"
      # driver.save_screenshot(filename)
    end

  end
end

composer.sh

#!/bin/bash
export PATH=$PATH:/home/gsreader/.rvm/rubies/ruby-2.3.3/bin/

case $1 in
   start)
      cd /home/gsreader/site/courseware/current;
      echo $$ > tmp/composer_master.pid
      rake app:composer RAILS_ENV=production
      ;;
    stop)
      cd /home/gsreader/site/courseware/current;
      kill `cat /tmp/composer.ppid`
      kill `cat /tmp/composer.pid`
      kill `cat /tmp/composer_master.pid`
      rm -rf tmp/composer.pid
      ;;
    *)
      echo "usage: composer {start|stop}" ;;
esac
exit 0

monit-rails-rake-task.md

install monit

sudo yum install -y monit

config: https://www.igvita.com/2006/11/07/monit-makes-mongrel-play-nice/

run /usr/local/bin/monit -g composer [stop|start|restart] all

monitrc

check process composer with pidfile /home/gsreader/site/courseware/current/tmp/composer_master.pid
   start program = "/home/gsreader/site/courseware/current/config/composer start"
   stop  program = "/home/gsreader/site/courseware/current/config/composer stop"