地道な無停止デプロイ試作品.rb

namespace :app do
  desc 'アプリケーションの再起動'
  task :restart do
    on release_roles :app do
      fullpath_pidfile_default = "#{current_path}/shared/#{fetch :app_pidfile_default}"
      fullpath_pidfile_sub = "#{current_path}/shared/#{fetch :app_pidfile_sub}"
      now_running = nil
      if test "[ -f #{fullpath_pidfile_default} ]"
        now_running = :default
      elsif test "[ -f #{fullpath_pidfile_sub} ]"
        now_running = :sub
      end

      next_running = now_running == :default ? :sub : :default
      next_port = next_running == :default ? (fetch :app_port_default) : (fetch :app_port_sub)
      execute "cd #{current_path}; ( ( nohup ./bin/#{fetch :application} "+
                  "-Dhttp.port=#{next_port} -Dconfig.file=shared/environment.conf "+
                  "-Dpidfile.path=#{next_running == :default ? fullpath_pidfile_default : fullpath_pidfile_sub} "+
                  "&>/dev/null 2>./logs/stderr.log ) & echo $!)"
      sleep 5
      tried = 0
      while test "[ $(curl -i http://localhost:#{next_port}/ -S -s -o /dev/null -w '%{http_code}') -ne 200 ]"
        tried += 1
        raise "MAX RETRY EXCEEDED!" if tried > 10
        sleep 3
      end

      execute "cat #{current_path}/nginx/backend.conf.template | "+
                  "sed -e 's/%HTTP_PORT%/#{next_port}/g' "+
                  "> #{current_path}/nginx/backend.conf"
      sudo "service nginx upgrade"


      if now_running
        tried = 0
        while tried < 10
          sleep 5
          if test "[ \"$(ps aux | grep nginx | grep 'shutting down' | grep -v grep | wc -l)\" -eq 0 ]"
            break
          else
            tried += 1
          end
        end
        execute :kill, "`cat #{now_running == :default ? fullpath_pidfile_default : fullpath_pidfile_sub}`"
      end
    end
  end
end