Headless is a Ruby interface for Xvfb. It allows you to create a headless display straight from Ruby code, hiding some low-level action. It can also capture images and video from the virtual framebuffer.

I created it so I can run Selenium tests in Cucumber without any shell scripting. Even more, you can go headless only when you run tests against Selenium. Other possible uses include pdf generation with wkhtmltopdf, or screenshotting.

Documentation is available at rdoc.info

On Debian/Ubuntu:

sudo apt-get install xvfb
gem install headless

Block mode:

require 'rubygems'
require 'headless'
require 'selenium-webdriver'

Headless.ly do
  driver = Selenium::WebDriver.for :firefox
  driver.navigate.to 'http://google.com'
  puts driver.title 
end

Object mode:

require 'rubygems'
require 'headless'
require 'selenium-webdriver'

headless = Headless.new
headless.start

driver = Selenium::WebDriver.for :firefox
driver.navigate.to 'http://google.com'
puts driver.title

headless.destroy

Running cucumber headless is now as simple as adding a before and after hook in features/support/env.rb:

# change the condition to fit your setup
if Capybara.current_driver == :selenium
  require 'headless'

  headless = Headless.new
  headless.start
end

Video is captured using ffmpeg. You can install it on Debian/Ubuntu via sudo apt-get install ffmpeg or on OS X via brew install ffmpeg. You can capture video continuously or capture scenarios separately. Here is typical use case:

require 'headless'

headless = Headless.new
headless.start

Before do
  headless.video.start_capture
end

After do |scenario|
  if scenario.failed?
    headless.video.stop_and_save("/tmp/#{BUILD_ID}/#{scenario.name.split.join("_")}.mov")
  else
    headless.video.stop_and_discard
  end
end

Images are captured using either the gm utility which is part of graphicsmagick or import utility which is part of imagemagick library. You can install it on Ubuntu via sudo apt-get install graphicsmagick or sudo apt-get install imagemagick respectively. You can call headless.take_screenshot at any time. You have to supply full path to target file. File format is determined by supplied file extension.

It defaults to graphicsmagick but you can pass the options {:image => {:utility => :graphicsmagick}} to pick that utility.

• Igor Afonov - video and screenshot capturing functionality.

© 2011 Leonid Shevtsov, released under the MIT license