具有停止和重启能力的rackup服务器

Question

i'm planning to add some tasks to my capistrano recipes file to give ability for admins to remote start/stop/restart private_pub server. But if for start i can use something like

  desc "Start private_pub server"
  task :start do
    run "cd #{current_path};rackup private_pub.ru -s thin -E production -D"
  end

i cannot find any documentation how to stop or restart rackup server. i see option

  -P, --pid FILE           file to store PID (default: rack.pid)

but maybe use kill command to stop server - not good idea?

Answer 1

I found this while searching for the same solution.

gist.github.com/3197633

basically while starting the process you have it write the pid number to a file in /tmp/pids and then when you go to stop it you read that file and it runs kill -9 ...

Hope it helps.

Answer 2

Your'e correct in that using kill -9 is a bad idea. This can lead to uneccesary loss of data, and as I understand it is recommended to use kill 2 or kill -INT which is equivalent to hitting 'control-c' and should close a normal server for you. I personally have started managing my servers with the God gem by TPW. Here is the script I use for running a local 'geminabox' server, for instance:

God.watch do |w|
w.name = 'gemserver'
    w.dir = '/usr/local/gemserver'
    w.pid_file = "#{ENV['HOME']}/.god/pids/#{w.name}.pid"
    ru = File.expand_path `which rackup`
    w.start = "#{ru} -D #{w.dir}/config.ru -P #{w.pid_file}"
    # w.stop = lambda { Process.kill(3, `lsof -i :9292`.chomp.to_i) }
    w.behavior :clean_pid_file
    w.keepalive
end