snippet.rb

God.watch do |w|
  w.name = "mongod"
  w.interval = 30.seconds
  w.start = "rake -f #{RAILS_ROOT}/Rakefile mongodb:start"
  w.stop = "killall mongod"
  w.env = { "RAILS_ENV" => "development" }
  w.uid = 'rails'
  w.gid = 'rails'
  w.pid_file = File.join(RAILS_ROOT, 'config/mongod.lock')

  # clean pid files before start if necessary
  w.behavior(:clean_pid_file)

  # determine the state on startup
  w.transition(:init, { true => :up, false => :start }) do |on|
    on.condition(:process_running) do |c|
      c.running = true
    end
  end

  # determine when process has finished starting
  w.transition([:start, :restart], :up) do |on|
    on.condition(:process_running) do |c|
      c.running = true
    end

    # failsafe
    on.condition(:tries) do |c|
      c.times = 5
      c.transition = :start
    end
  end

  # start if process is not running
  w.transition(:up, :start) do |on|
    on.condition(:process_exits)
  end
end