cucumber-nagios

cucumber-nagios allows you to write high-level behavioural tests of web application, and plug the results into Nagios.

As Bradley Taylor put it: 

“Instead of writing boring monitoring plugins from scratch, 
you can now do behavior driven ops!

Transform from a grumpy, misanthropic sysadmin to a hipster, 
agile developer instantly.”

Quickstart

  1. gem install gemcutter
  2. gem tumble
  3. gem install cucumber-nagios
  4. cucumber-nagios-gen project bunch-o-tests
  5. cd bunch-o-tests
  6. gem bundle
  7. bin/cucumber-nagios-gen feature ebay.com.au bidding
  8. bin/cucumber-nagios features/ebay.com.au/bidding.feature

Setting up a project

To set up a standalone cucumber-nagios project, run:

cucumber-nagios-gen project <project-name>

This will spit out a bunch of files in the directory specified as <project-name>.

Check the README within this directory for specific instructions for managing the project.

Bundling dependencies

Bundling cucumber-nagios's dependencies allows you to drop your cucumber-nagios project to any machine and have it run. This can be useful if you want to develop your tests on one machine, and deploy them to another (like a production Nagios server).

You'll need to bundle your dependencies to use cucumber-nagios.

First you need to make sure the following dependencies are installed:

  • RubyGems
    • bundler08 gem (automatically pulled in by the cucumber-nagios gem)

To bundle your dependencies, within your project directory run:

$ gem bundle

Please note: cucumber-nagios uses bundler08, not bundler. Until the bundler guys sort their shit out, I refuse to release software that uses it.

Deploying to production

Once you've copied your project around, just run the bundler again: 

$ gem bundle

You'll need to have RubyGems and the bundler gem installed on the system you're deploying too. I know, this is not optimal, but hopefully the bundler gem will handle this better in the future.

Writing features

Once you've set up a project, you can use the bin/cucumber-nagios-gen command to generate new features. It takes two arguments: the site you're testing, and feature you're testing: 

bin/cucumber-nagios-gen feature gnome.org navigation

This will spit out two files: 

features/gnome.org/navigation.feature
features/gnome.org/steps/navigation_steps.rb

As for writing features, you'll want to have a read of the Cucumber documentation, however your tests will look something like this:

Feature: google.com.au
  To broaden their knowledge
  A user should be able
  To search for things

  Scenario: Searching for things
    Given I visit "http://www.google.com"
    When I fill in "q" with "wikipedia"
    And I press "Google Search"
    Then I should see "www.wikipedia.org"

There's a collection of steps that will cover most of the things you'll be testing for in features/steps/webrat_steps.rb.

You can write custom steps for testing specific output and behaviour, e.g. in features/smh.com.au/smh.feature: 

Feature: smh.com.au
  It should be up
  And provide links to content

  Scenario: Visiting home page
    When I go to http://smh.com.au/
    Then I should see site navigation
    And there should be a section named "Opinion"

There aren't steps for "Then I should see site navigation", so you have to write one yourself. :-) In features/smh.com.au/steps/smh_steps.rb: 

Then /^I should see site navigation$/ do                                                                    
  doc = Nokogiri::HTML(response.body.to_s)                                                                  
  doc.css("ul#nav li a").size.should > 5                                                                    
end

You can use Nokogiri for testing responses with XPath matchers and CSS selectors.

I suggest you use bin/cucumber directly so you can get better feedback when writing your tests:

bin/cucumber --require features/ features/smh/smh.feature

This will output using the default 'pretty' formatter.

Running

Invoke the Cucumber feature with the cucumber-nagios script: 

bin/cucumber-nagios features/smh.com.au/smh.feature

cucumber-nagios can be run from anywhere: 

/path/to/bin/cucumber-nagios /path/to/features/smh/smh.feature

It should return a standard Nagios-formatted response string: 

Critical: 0, Warning: 0, 2 okay | passed=2, failed=0, total=2

Steps that fail will show up in the "Critical" total, and steps that pass show up in the "okay" total.

The value printed at the end is in Nagios's Performance Data format, so it can be graphed and the like.

Benchmarking

You can benchmark your features if you need to test response times for a set of site interactions: 

Feature: slashdot.com
  To keep the geek masses satisfied
  Slashdot must be responsive

  Scenario: Visiting a responsive front page
    Given I am benchmarking
    When I go to http://slashdot.org/
    Then the elapsed time should be less than 5 seconds

The elapsed time step can be reused multiple times in the same scenario if you need fine grained testing: 

Feature: slashdot.com
  To keep the geek masses satisfied
  Slashdot must be responsive

  Scenario: Visiting news articles
    Given I am benchmarking
    When I go to http://slashdot.org/
    Then the elapsed time should be less than 5 seconds
    When I follow "Login"
    Then the elapsed time should be less than 4 seconds
    When I follow "Contact"
    Then the elapsed time should be less than 7 seconds

AMQP Message Queues

You can test for various conditions on an AMQP message queue.

Feature: github.com
  To make sure the rest of the system is in order
  All our message queues must not be backed up

  Scenario: test queue 2
    Given I have a AMQP server on rabbit.github.com
    And I want to check on the fork queue
    Then it should have less than 400 messages
    Then it should have at least 5 consumers
    Then it should have less than 50 messages per consumer

This has been tested using RabbitMQ but uses the amqp gem which should support other backends. See features/amqp_steps.rb for all the available steps.

Quirks

Failure is an option (exceptions are good)

Exceptions raised within your tests will appear in the failed totals, so you don't need to worry about trying to catch them in your own custom steps.

i.e. if you try fetching a page on a server that is down, or the page returns a 404, the exception raised by Mechanize just gets treated by Cucumber as a test failure.

Using the Steps in another Cucumber suite

If you want to use the steps defined in cucumber-nagios elsewhere, you can require the steps in features/support/env like so:

# All
require 'cucumber/nagios/steps'

# Or one by one
require 'cucumber/nagios/steps/ssh'
require 'cucumber/nagios/steps/ping'

Using the Formatter in another Cucumber suite

cucumber --format Cucumber::Formatter::Nagios features/foo.feature

Version control

It's highly recommend that you store your cucumber-nagios projects in a version control system!

To get up and running with git: 

$ git init
$ git add .
$ git commit -m 'created cucumber-nagios project'

To get up and running with bzr:

$ bzr init
$ bzr add
$ bzr commit -m 'created cucumber-nagios project'

.bzrignore and .gitignores are created when you generate a project.

Testing

The gem is thoroughly tested (with Cucumber, no less). The gem's Cucumber features live in $gemroot/features/, and can be run with: 

$ cucumber --require features/ features/installing.feature
$ cucumber --require features/ features/creating.feature
$ cucumber --require features/ features/using.feature