Trying to understand GOD rb

Question

I'm facing few confusion with GOD documentation

Firstly my configuration script look like this

DIRECTORY = "/Users/joshianiket22/myProject/god_script"
God.pid_file_directory = DIRECTORY
God.watch do |w|
  w.name = "mess"
  w.start = "ruby /Users/joshianiket22/myProject/god_script/simple.rb"
  w.pid_file =  File.join(DIRECTORY,'simple.pid')
  puts File.join(DIRECTORY,'simple.pid')
  w.stop = "ruby -e 'puts \"#{DateTime.now}\"'"
  w.log = File.join(DIRECTORY,'god.log')
  w.behavior(:clean_pid_file)
  w.interval = 10.seconds
   w.start_if do |start| 
    start.condition(:process_running) do |c| 
      puts "Inside start condition"
      c.interval = 5.seconds 
      c.running = false
    end 
  end 
end

Confusion 1 : GOD PID FILE DILEMMA

In GOD documentation it mention

Now I have clear I have set the pid_file and pid_file_directory yet the PID is no where to be seen in that directory that is define in my configuration

FYI, started GOD with sudo so assuming directory would be writable by GOD

Confusion 2: START_IF CONDITION

Now That how one define a start_if condition now I not able to understand the use case for this. Also word condition what conditions to set of conditions

• Is :process_running a set of condition?, if yes what are other set of condition for start_if

• Also what does the attributes inside the do block suppose to do? and when would they be executed?

  More precisely I referring to c.running = false ( what it does internal and what other list of attributes are available on start_if)

Confusion 3 (start/stop/restart command)

Now given my configuration file which has a start command written in it, now is it also required to write a stop and restart command as well in configuration

so that when run the following

sudo god stop mess
sudo god restart mess

they would get executed

Assuming I don't write them

• what would happen if run them ?

• Will GOD will eventually Kill the running process when stop command i.e sudo god stop mess' is executed? or restart the running process when restart command i.esudo god restart mess` is executed"?

Can anyone share light on it

Confusion 4 (Whether or whether not to daemonize the process):

According to GOD documentation

Now Consider I explicitly put by process to background inside GOD something like

w.start = "ruby /Users/joshianiket22/myProject/god_script/simple.rb &" 

what would happen in such case

• Will GOD monitor them for stop and restart command ?

So daemonizing your process inside GOD (in start command ) can be consider a valid approach assuming that GOD know that the process has gone in background and it react to all command start / stop / restart command on that process when run against GOD ?

like

sudo god stop mess
sudo god restart mess

Can anyone put some light on this as well

So here are list of question extracted from above

• Why isn't the pid_file_directory syntax working?

• if :process_running is a set of conditions what other conditions does start_if contains also what c.running = false (internally do)

• Is it necessary to write/define stop and restart in God configuration

• If the process is explicity move to background will GOD still monitor it for command like stop|restart etc

Answer 1

Partially answer some part of my question

Question: Is it necessary to write/define stop and restart in God configuration

Answer Well not really you can define your own command but if in case you dont define there is default lambda for stop and restart

Straight from GOD documentation

Question: If the process is explicity move to background will GOD still monitor it for command like stop|restart etc

Answer: Answer is YES and NO , No because if you dont give GOD the pid file to monitor it will not monitor the process running in background

Again from GOD documentation

Question: If :process_running is a set of conditions what other conditions does start_if contains also what c.running = false (internally do)

Answer: Well I will answer this question in 2 parts

• What other conditions does start_if contains ?

  Ans: Well the best place to look that is under conditions directory of god check over here there is process_running condition also exists

• What c.running = false (internally do)?

  Ans: Well c.running is internally used to check (the check is perform with respect to process id and running variable) whether a process was running prior when god start so if the process i.e(c.running = true) is running and the pid file pointed has the corrected all work well but if the c.running = true and pid monitored is different or does not exist it keep looping hence it advisable to use c.running = true only if the process was already running and correct pid_file (with correct pid in it is) is define in god file . One can check that over here

Note: Accepting my answer since only one question is left and I believe it was mostly not working because of my wrong doing (i.e the pid wasn't getting stored in desired directory) :) Rest all question are answered by me.