examples/events.god

   1 # This example shows how you might keep a local development Rails server up
   2 # and running on your Mac.
   3
   4 # Run with:
   5 # god -c /path/to/events.god
   6
   7 RAILS_ROOT = ENV['GOD_TEST_RAILS_ROOT']
   8
   9 %w{3002}.each do |port|
  10   God.watch do |w|
  11     w.name = "local-#{port}"
  12     w.interval = 5.seconds
  13     w.start = "mongrel_rails start -p #{port} -P #{RAILS_ROOT}/log/mongrel.#{port}.pid -c #{RAILS_ROOT} -d"
  14     w.stop = "mongrel_rails stop -P #{RAILS_ROOT}/log/mongrel.#{port}.pid -c #{RAILS_ROOT}"
  15     w.pid_file = File.join(RAILS_ROOT, "log/mongrel.#{port}.pid")
  16     w.log = File.join(RAILS_ROOT, "log/commands.#{port}.log")
  17
  18     # clean pid files before start if necessary
  19     w.behavior(:clean_pid_file)
  20
  21     # determine the state on startup
  22     w.transition(:init, { true => :up, false => :start }) do |on|
  23       on.condition(:process_running) do |c|
  24         c.running = true
  25       end
  26     end
  27
  28     # determine when process has finished starting
  29     w.transition([:start, :restart], :up) do |on|
  30       on.condition(:process_running) do |c|
  31         c.running = true
  32       end
  33
  34       # failsafe
  35       on.condition(:tries) do |c|
  36         c.times = 8
  37         c.within = 2.minutes
  38         c.transition = :start
  39       end
  40     end
  41
  42     # start if process is not running
  43     w.transition(:up, :start) do |on|
  44       on.condition(:process_exits)
  45     end
  46
  47     # restart if memory or cpu is too high
  48     w.transition(:up, :restart) do |on|
  49       on.condition(:memory_usage) do |c|
  50         c.interval = 20
  51         c.above = 50.megabytes
  52         c.times = [3, 5]
  53       end
  54
  55       on.condition(:cpu_usage) do |c|
  56         c.interval = 10
  57         c.above = 10.percent
  58         c.times = 5
  59       end
  60
  61       on.condition(:http_response_code) do |c|
  62         c.host = 'localhost'
  63         c.port = port
  64         c.path = '/'
  65         c.code_is = 500
  66         c.timeout = 10.seconds
  67         c.times = [3, 5]
  68       end
  69     end
  70
  71     # lifecycle
  72     w.lifecycle do |on|
  73       on.condition(:flapping) do |c|
  74         c.to_state = [:start, :restart]
  75         c.times = 5
  76         c.within = 1.minute
  77         c.transition = :unmonitored
  78         c.retry_in = 10.minutes
  79         c.retry_times = 5
  80         c.retry_within = 2.hours
  81       end
  82     end
  83   end
  84 end