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

This gem is hosted on gemcutter.org

gem install benotified

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

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           => 'to@example.com',
      :from         => 'from@example.com',
      :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"}

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
  

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