BeNotified

Description

This library monitors your programs or resources and notifies you by email or log if anything goes wrong.

Installation

This gem is hosted on gemcutter.org

gem install benotified

Usage

require 'be_notified'

BeNotified::Monitor.new do
	alert_when "Something went wrong" do
		# Put your code here 
		# Return true if something went wrong 
		# or false if everything was fine
	end
end

This library can be used in two different ways:

First: Run it from crontab to monitor some resources, for exmaple:

BeNotified::Monitor.new do
	alert_when "Staging server is down" do
		host_not_available?("staging.example.com")
	end
end

or

BeNotified::Monitor.new do
	alert_when "Log file does not exist" do
		File.exists?('/var/log/messages') == false
	end
end

Second: Wrap your program around it and be informed when something goes wrong. I will use imaginary program called db_updater as an example:

BeNotified::Monitor.new do
	alert_when "Db was not updated" do
		# Require your program here
		require 'db_updater'
	
		# Get the count of the records before run
		count_before_run = DBUpdater::Update::Record.all.count
	
		# Run your application
		DBUpdater::Update.run
	
		# Get the count after the run
		count_after_run = DBUpdater::Update::Record.all.count
	
		# Now decide if anything went wrong
		count_after_run == count_before_run
	end
end

Configuration file

Options can be set up in the three different ways:

First: By default program will log to standard output.

Second: Define properties directly in the code. An example of setting logging and email notification:

BeNotified::Monitor.new do
	custom_options = {
		:notifier_type  => [BeNotified::Notifiers::Log, BeNotified::Notifiers::Email]
    :email => {
      :smtp_address => 'localhost',
      :smtp_port    => 25,
      :domain       => 'example.com',
      :username     => 'login',
      :password     => 'pass',
      :to           => '[email protected]',
      :from         => '[email protected]',
      :subject      => 'The Subject'
    }
  }

	# Make sure you merge the options
	configuration(custom_options)
end

Third: Create a file .be_notified in your home directory. It stores the configuration in JSON format. An example of setting application to log to the file:

{"logger_file":"/tmp/benotified.log"}

Helper Methods

This library is shipped with some helper methods that can be used to monitor resources:

• host_not_alive? - checks if a given host if alive or not

    alert_when "Staging server is down" do
    	host_not_available?("staging.example.com")
    end
  

• number_of_files - checks the number of files in a given directory

    alert_when "Number of files on the desktop is greater then 50" do
    	number_of_files("/Users/dominik/Desktop") > 50
    end
  

• program_running? - checks if a given program is running

    alert_when "Application server is not running" do
    	! program_running?("jboss")
    end
  

• size_of_file - checks the size of a given file in GB, MB or KB

    alert_when "JBoss log file is bigger then 1GB" do
    	size_of_file("/usr/local/jboss/server/default/log/server.log") > 1.GB
    end
  

How to contribute

1. Revise the code and suggest improvements / changes
2. Write more helper methods
3. Add new ways of notifying user