Fauxhai

Fauxhai is a gem for mocking out ohai data in your chef testing. Fauxhai is community supported, so we need your help to populate our dataset. Here's an example for testing my "awesome_cookbook" on Ubuntu:

Fauxhai finally stable! Pull Requests are still welcome though :)

require 'chefspec'

describe 'awesome_cookbook::default' do
  before do
    Fauxhai.mock(platform: 'ubuntu', version: '12.04')
  end

  it 'should install awesome' do
    @runner = ChefSpec::ChefRunner.new.converge('tmpreaper::default')
    @runner.should install_package 'awesome'
  end
end

Alternatively, you can pull "real" ohai data from an existing server:

require 'chefspec'

describe 'awesome_cookbook::default' do
  before do
    Fauxhai.fetch(host: 'server01.example.com')
  end

  it 'should install awesome' do
    @runner = ChefSpec::ChefRunner.new.converge('tmpreaper::default')
    @runner.should install_package 'awesome'
  end
end

Fauxhai supports ChefSpec and rspec-chef. In order to prevent polluting the README, only ChefSpec examples will be provided. However, there is an extensive README for each testing framework in the examples directory.

Important Note

Fauxhai ships with a command line tool - fauxhai. This is not the same as Fauxhai.mock. Running fauxhai on a machine effectively runs ohai, but then sanitizes the data, removing/replacing things like:

  • users
  • ssh keys
  • usernames in paths
  • sensitive system information

fauxhai should only be used by developers wishing to submit a new json file.

Usage

Fauxhai provides a bunch of default attributes so that you don't need to mock out your entire infastructure to write a simple test. That being said, not all configurations will suit your needs. Because of that, Fauxhai provides two ways to configure your mocks:

Overriding

Fauxhai.mock will also accept a block with override attributes that are merged with all the default attributes. For example, the default Ubutnu 12.04 mock uses Ruby 1.9.3. Maybe your system is using ree, and you want to verify that the cookbooks work with that data as well:

require 'chefspec'

describe 'awesome_cookbook::default' do
  before do
    Fauxhai.mock(platform: 'ubuntu', version: '12.04') do |node|
      node['languages']['ruby']['version'] = 'ree'
    end
  end

  it 'should install awesome' do
    @runner = ChefSpec::ChefRunner.new.converge('tmpreaper::default')
    @runner.should install_package 'awesome'
  end
end

The node block variable allows you to set any Ohai attribute on the mock that you want. This provides an easy way to manage your environments. If you find that you are overridding attributes like OS or platform, you should see the section on Contributing.

Fetching

Alternatively, if you do not want to mock the data, Fauxhai provides a fetch mechanism for collecting "real" ohai data from a remote server or local file. Maybe you want to test against the fully-replicated environment for a front-facing server in your pool. Just pass in the url option instead of a platform:

The fetch method supports all the same options as the Net-SSH command, such as :user, :password, :key_file, etc.

The fetch method will cache the JSON file in a temporary path on your local machine. Similar to gems like VCR, this allows fauxhai to use the cached copy, making your test suite run faster. You can optionally force a cache miss by passing the :force_cache_miss => true option to the fetch initializer. Because this is real data, there may be a security concern. Secure your laptop accordingly.

require 'chefspec'

describe 'awesome_cookbook::default' do
  before do
    Fauxhai.fetch(host: 'server01.example.com')
  end

  it 'should install awesome' do
    @runner = ChefSpec::ChefRunner.new.converge('tmpreaper::default')
    @runner.should install_package 'awesome'
  end
end

This will ssh into the machine (you must have authorization to run sudo ohai on that machine), download a copy of the ohai output, and optionally cache that data inside the test directory (speeding up future tests).

Overriding + Fetching

As you might expect, you can combine overriding and fetching like so:

require 'chefspec'

describe 'awesome_cookbook::default' do
  before do
    Fauxhai.fetch(host: 'server01.example.com') do |node|
      node['languages']['ruby']['version'] = 'ree'
    end
  end

  it 'should install awesome' do
    @runner = ChefSpec::ChefRunner.new.converge('tmpreaper::default')
    @runner.should install_package 'awesome'
  end
end

Fixturing

If you want to use fauxhai as "fixture" data, you can store real JSON in your project and use the :path option:

require 'chefspec'

describe 'awesome_cookbook::default' do
  before do
    Fauxhai.mock(path: 'fixtures/my_node.json')
  end
end

Overriding + Fixturing

You can also change specific attributes in your fixture:

require 'chefspec'

describe 'awesome_cookbook::default' do
  before do
    Fauxhai.mock(path: 'fixtures/my_node.json') do |node|
      node['languages']['ruby']['version'] = 'ree'
    end
  end
end

Testing Multiple Versions

It's a common use case to test multiple version of the same operating system. Here's a simple example to get your started. This is more rspec-related that fauxhai related, but here ya go:

require 'chefspec'

describe 'awesome_cookbook::default' do
  ['12.04', '11.06', '10.04'].each do |version|
    context "on Ubuntu #{version}" do
      before do
        Fauxhai.mock(platform: 'ubuntu', version: version)
      end

      it 'should install awesome' do
        @runner = ChefSpec::ChefRunner.new.converge('tmpreaper::default')
        @runner.should install_package 'awesome'
      end
    end
  end
end

Contributing

Fauxhai is community-maintained and updated. Aside from the initial files, all of the ohai system mocks have been created by the community. If you have a system that you think would benefit the community, here's how you get it into fauxhai:

  1. Build a system to your liking (on a virtual machine, for example)
  2. Install chef, ohai, and fauxhai

  3. Run the following at the command line:

    sudo fauxhai > /tmp/fauxhai.json

  4. This will create a file /tmp/fauxhai.json

  5. Copy the contents of this file to your local development machine (using scp or sftp, for example)

  6. Clone and bundle this repo:

    git clone git@github.com:customink/fauxhai.git
cd fauxhai
bundle

  7. Create a new branch named add_[platform]_[version] (e.g. add_ubuntu_12_04) without dashes and dots replaced with underscores. Be sure to use the official version number, not a package name (e.g. '12_04', not 'precise') if avaliable:

    Ubuntu Precise, 12.04       add_ubuntu_12_04
Ubuntu Lucid, 11.5          add_ubuntu_11_5
OSX Lion, 10.7.4            add_osx_10_7_4
Windows XP                  add_windows_xp

    Q: Is there a reason for this super-specific naming convention?

    A: No, but it helps in tracking problems and analyzing pull requests. Ultimately it just ensures your pull request is merged as quickly as possible.

  8. Create a new json file in fauxhai/platforms/[os]/[version].json (e.g. fauxhai/platforms/ubuntu/12.04.json)

  9. Copy-paste the contents of the file from Step 4 into this file and save

  10. Verify the installation was successful by doing the following:

    irb -rubygems -rfauxhai
Fauxhai.mock('platform: [os], version:  [version]') # e.g. Fauxhai.mock(platform: 'ubuntu', version: '12.04')

    As long as that does not throw an error, you're good to go!

  11. Submit a pull request on github