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.”


  1. gem install cucumber-nagios
  2. cucumber-nagios-gen project bunch-o-tests
  3. cd bunch-o-tests
  4. bundle install
  5. cucumber-nagios-gen feature bidding
  6. bin/cucumber-nagios features/


Install the gem with:

gem install cucumber-nagios

This will add the cucumber-nagios-gen command to your path, and make the shipped cucumber-nagios steps available to other projects using Cucumber.

Windows users - you need to download and install the Ruby Installer and the development kit, otherwise gem install cucumber-nagios will fail.

Setting up a project

After installing the cucumer-nagios gem, set up a standalone project with:

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 on any machine and have it run. This solves the case of developing your checks on your local machine, and deploying them on a production monitoring server.

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

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

Then to bundle your dependencies, within your project directory run:

$ bundle install

Writing features

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

cucumber-nagios-gen feature navigation

This will spit out two files:


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

  To broaden their knowledge
  A user should be able
  To search for things

  Scenario: Searching for things
    When I go to ""
    And I fill in "q" with "wikipedia"
    And I press "Google Search"
    Then I should see ""

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/

  It should be up
  And provide links to content

  Scenario: Visiting home page
    When I go to
    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/

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

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.


Invoke the Cucumber feature with the cucumber-nagios script:

bin/cucumber-nagios features/

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.


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

  To keep the geek masses satisfied
  Slashdot must be responsive

  Scenario: Visiting a responsive front page
    Given I am benchmarking
    When I go to
    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:

  To keep the geek masses satisfied
  Slashdot must be responsive

  Scenario: Visiting news articles
    Given I am benchmarking
    When I go to
    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.

  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
    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.

Deploying to production

As per the install instructions above, make sure you have RubyGems and the bundler gem installed.

Once you've copied your project to your monitoring server, just run bundler again:

$ bundle install


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 shipped with cucumber-nagios elsewhere, you can require them by adding the following line to features/support/env.rb like so:

require 'cucumber/nagios/steps'

Or just require the steps you care about:

require 'cucumber/nagios/steps/ssh'
require 'cucumber/nagios/steps/ping'

Using the Formatter in another Cucumber suite

Once installed as a gem, the cucumber-nagios formatter is available in any other Cucumber test suite:

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

Version control

It's strongly 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'

.gitignore is created when you generate a project.


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

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


See the HACKING file.