CODEWITHSUNDEEP
rubymonitoringmonit
Tom
Tom

Reputation: 34366

Monitor ruby processes with Monit

I have a bunch of Ruby scripts which are long running, I'd like to ensure that every 30 seconds or so these are up.

I normally start the commands by simply ruby script-name.rb

How can I configure monit to look after these scripts?

Update: I tried to follow this method to create a wrapper script which would then launch the ruby process but it did not seem to create the .pid file and typing './wrapper-script stop' did nothing :/

Should I write the pid inside ruby or use a wrapper script to create the pid necessary for monit?

Upvotes: 13

Views: 9670

Answers (7)

Kelvin
Kelvin

Reputation: 1

Add this line to your ruby script yourapp.rb, that creates a pid file named yourapp.pid

File.open('/somepath/yourapp.pid', 'w') {|f| f.write Process.pid }

Configure Monit to check for the pid in /etc/monit/conf.d/yourapp

check process yourapp with pidfile /somepath/yourapp.pid

Upvotes: 0

Eki Eqbal
Eki Eqbal

Reputation: 6057

Modify the file :

/etc/init.d/skeleton

You will need to slightly modify it, and then :

chmod +x /etc/init.d/process_name 
sudo update-rc.d process_name defaults
sudo /etc/init.d/process_name (start| stop| reload )

Now just use Monit with the pid at /var/run/process.pid

start location : sudo /etc/init.d/process start

stop location : sudo /etc/init.d/process stop

Cheers

Upvotes: 1

Flyounet
Flyounet

Reputation: 115

(Surely out of subject but) as it is about ruby, why don't you use : http://god.rubyforge.org/ ?

Upvotes: 0

Maurício Linhares
Maurício Linhares

Reputation: 40333

You don't need to write a wrapper script or try any kind of black magic, just use the Daemons library and you're done.

Imagine that you have a class Worker that has a method "run" that enters an infinite loop reading from a socket or anything like that, here's how you'd write your Daemons wrapper:

# this is file my_worker_control.rb
require 'rubygems'
require 'daemons'
require 'worker'

Daemons.run_proc(:app_name => 'my_worker', :dir_mode => :system, :log_output => true ) do
  Worker.run
end

Once the script is done, just call it from your command line or an init.d script:

my_worker_control.rb run|start|stop|restart

This config will generate a "my_worker.pid" file under "/var/run" and you can use monit to watch over the process by using this file.

Upvotes: 4

yawn
yawn

Reputation: 8214

As an alternative (to monit), have a look at bluepill.

Upvotes: 0

cam
cam

Reputation: 14222

Writing the pid file in your ruby script may be easiest for you (just open a file and write $$ in it). That said, the wrapper script approach should work fine. Does your script have permission to write to a file in /var/run (or wherever you are putting the pidfile)?

Upvotes: 0

Michael Kohl
Michael Kohl

Reputation: 66837

The Monit Wiki has a lot of configuration examples:

http://mmonit.com/wiki/Monit/ConfigurationExamples

Just pick a simple one and modify it according to your needs.

Update: the wrapper script should create the pid for you in this line:

echo $$ > /var/run/xyz.pid;

Did you adapt the script to your needs? Is it executable (chmod +x)? Does it have write permissions for the destination? Maybe post the wrapper you are trying to use so I can help you more.

Upvotes: 6

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