god.unicorn.rb

rack_env   = "staging"
app_root   = "/data/cloud/current"
owner      = "atmos"
home      = "/home/#{owner}"
instance_id = "i-XXXXXXXX"
socket_path = "/var/run/engineyard/unicorn_cloud.sock"

port   = "master"
inline = "#{home}/.ruby_inline/unicorn-#{port}"

God.watch do |w|
  w.name     = "unicorn-#{port}"
  w.group    = 'unicorn'
  w.uid      = owner
  w.gid      = owner
  w.interval = 30.seconds
  w.log      = "#{app_root}/log/unicorn.#{port}.log"
  w.dir      = app_root
  w.env      = {"INSTANCE_ID" => instance_id, "GOD_WATCH" => w.name, "RACK_ENV" => rack_env, "HOME" => home, "INLINEDIR" => inline}
  w.start    = "bundle exec unicorn -l #{socket_path} -c #{app_root}/config/unicorn.rb #{app_root}/config.ru -D"
  w.pid_file = "#{app_root}/tmp/pids/unicorn.pid"

  w.behavior(:clean_pid_file)

  # retart if memory gets too high
  w.transition(:up, :restart) do |on|
    on.condition(:memory_usage) do |c|
      c.above = 350.megabytes
      c.times = 2
    end
  end

  # 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
      c.interval = 5.seconds
    end

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

  # start if process is not running
  w.transition([:up], :start) do |on|
    on.condition(:process_running) do |c|
      c.running = false
    end
  end
end