ChefSpec

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ChefSpec is a unit testing framework for testing Chef cookbooks. ChefSpec makes it easy to write examples and get fast feedback on cookbook changes without the need for virtual machines or cloud servers.

ChefSpec runs your cookbook locally using Chef Solo without actually converging a node. This has two primary benefits:

  • It's really fast!
  • Your tests can vary node attributes, operating systems, and search results to assert behavior under varying conditions.

Important Notes

  • This documentation corresponds to the master branch, which may be unreleased. Please check the README of the latest git tag or the gem's source for your version' documentation!
  • Each resource matcher is self-documented using Yard and has a corresponding aruba test from the examples directory.
  • ChefSpec 3.0 requires Ruby 1.9 or higher!

Writing a Cookbook Example

Given an extremely basic Chef recipe that just installs an operating system package:

package 'foo'

the associated ChefSpec test might look like:

require 'chefspec'

describe 'example::default' do
  let(:chef_run) { ChefSpec::Runner.new.converge(described_recipe) }

  it 'installs foo' do
    expect(chef_run).to install_package('foo')
  end
end

Let's step through this file to see what is happening:

  1. At the top of the spec file we require the chefspec gem. This is required so that our custom matchers are loaded. In larger projects, it is common practice to create a file named "spec_helper.rb" and include ChefSpec and perform other setup tasks in that file.
  2. The describe keyword is part of RSpec and indicates that everything nested beneath is describing the example::default recipe. The convention is to have a separate spec for each recipe in your cookbook.
  3. The let block on creates the ChefSpec:Runner and then does a fake Chef run with the run_list of example::default. Any subsequent examples can then refer to chef_run in order to make assertions about the resources that were created during the mock converge.
  4. The described_recipe macro is a ChefSpec helper method that infers the recipe from the describe block. Alternatively you could specify the recipe directly.
  5. The it block is an example specifying that the foo package is installed. Normally you will have multiple it blocks per recipe, each making a single assertion.

Configuration

ChefSpec exposes a configuration layer at the global level and at the Runner level. The following settings are available:

RSpec.configure do |config|
  # Specify the path for Chef Solo to find cookbooks (default: [inferred from
  # the location of the calling spec file])
  config.cookbook_path = '/var/cookbooks'

  # Specify the path for Chef Solo to find roles (default: [ascending search])
  config.cookbook_path = '/var/cookbooks'

  # Specify the Chef log_level (default: :warn)
  config.log_level = :debug

  # Specify the path to a local JSON file with Ohai data (default: nil)
  config.path = 'ohai.json'

  # Specify the operating platform to mock Ohai data from (default: nil)
  config.platform = 'ubuntu'

  # Specify the operating version to mock Ohai data from (default: nil)
  config.version = '12.04'
end

Values specified at the initalization of the Runner merge and take precedence over the global settings:

# Override only the operating system version (platform is still "ubuntu" from above)
ChefSpec::Runner.new(version: '10.04')

# Use a different operating system platform and version
ChefSpec::Runner.new(platform: 'centos', version: '5.4')

# Specify a different cookbook_path
ChefSpec::Runner.new(cookbook_path: '/var/my/other/path', role_path: '/var/my/roles')

# Add debug log output
ChefSpec::Runner.new(log_level: :debug).converge(described_recipe)

Note: You do not need to specify a platform and version. However, some cookbooks may rely on Ohai data that ChefSpec cannot not automatically generate. Specifying the platform and version keys instructs ChefSpec to load stubbed Ohai attributes from another platform using fauxhai.

Berkshelf

If you are using Berkshelf, simply require chefspec/berkshelf in your spec_helper after requiring chefspec:

# spec_helper.rb
require 'chefspec'
require 'chefspec/berkshelf'

Requiring this file will:

  • Create a temporary working directory
  • Download all the dependencies listed in your Berksfile into the temporary directory
  • Set ChefSpec's cookbook_path to the temporary directory

Librarian

There is not currently librarian integration, but we would welcome a community patch!

Making Assertions

ChefSpec asserts that resource actions have been performed. In general, ChefSpec follows the following pattern:

require 'chefspec'

describe 'example::default' do
  let(:chef_run) { ChefSpec::Runner.new.converge(described_recipe) }

  it 'does something' do
    expect(chef_run).to ACTION_RESOURCE(NAME)
  end
end

where:

  • ACTION - the action on the resource (e.g. install)
  • RESOURCE - the name of the resource (e.g. package)
  • NAME - the name attribute for the resource (e.g. apache2)

Here's a more concrete example:

require 'chefspec'

describe 'example::default' do
  let(:chef_run) { ChefSpec::Runner.new.converge(described_recipe) }

  it 'does something' do
    expect(chef_run).to install_package('apache2')
  end
end

This test is asserting that the Chef run will have a package resource with the name apache2 with an action of install.

ChefSpec includes matchers for all of Chef's core resources using the above schema. Each resource matcher is self-documented using Yard and has a corresponding cucumber test from the examples directory.

Additionally, ChefSpec includes the following helpful matchers. They are also documented in Yard, but they are included here because they do not follow the "general pattern".

include_recipe

Assert that the Chef run included a recipe from another cookbook

expect(chef_run).to include_recipe('other_cookbook::recipe')
notify

Assert that a resource notifies another in the Chef run

resource = chef_run.template('/etc/foo')
expect(resource).to notify('service[apache2]').to(:restart)
render_file

Assert that the Chef run renders a file (with optional content); this will match cookbook_file, file, and template resources and can also check the resulting content

expect(chef_run).to render_file('/etc/foo')
expect(chef_run).to render_file('/etc/foo').with_content('This is content')
expect(chef_run).to render_file('/etc/foo').with_content(/regex works too.+/)

Additionally, it is possible to assert which Chef phase of execution a resouce is created. Given a resource that is installed at compile time using run_action:

package('apache2').run_action(:install)

You can assert that this package is installed during runtime using the .at_compile_time predicate on the resource matcher:

expect(chef_run).to install_package('apache2').at_compile_time

Simiarly, you can assert that a resource is executed during convergence time:

expect(chef_run).to install_package('apache2').at_converge_time

Since "converge time" is the default behavior for all recipes, this test might be redundant and the predicate could be dropped depending on your situation.

For more complex examples, please see the examples directory or the Yard documentation.

Setting node Attributes

Node attribute can be set when creating the Runner. The initializer yields a block that gives full access to the node object:

describe 'example::default' do
  let(:chef_run) do
    ChefSpec::ChefRunner.new do |node|
      node.set['cookbook']['attribute'] = 'hello'
    end.converge(described_recipe)
  end
end

The node that is returned is actually a Chef::Node object.

To set an attribute within a specific test, set the attribute in the it block and then (re-)converge the node:

describe 'example::default' do
  let(:chef_run) { ChefSpec::ChefRunner.new } # Notice we don't converge here

  it 'performs the action' do
    chef_run.node.set['cookbook']['attribute'] = 'hello'
    chef_run.converge(described_recipe) # The converge happens inside the test

    expect(chef_run).to do_something
  end
end

Stubbing

Command

Given a recipe with shell guard:

template '/tmp/foo.txt' do
  not_if 'grep /tmp/foo.txt text'
end

ChefSpec will raise an error like:

Real commands are disabled. Unregistered command: `grep /tmp/foo.txt text`

You can stub this command with:

 stub_command("grep /tmp/foo.txt text").and_return(true)

============================================================

Just like the error message says, you must stub the command result. This can be done inside a before block or inside the it block, and the stubbing method accepts both a value or Ruby code. If provided a value, the result is static. If provided a Ruby block, the block is evaluated each time the search is called.

describe 'example::default' do
  let(:chef_run) { ChefSpec::ChefRunner.new }

  before do
    stub_command("grep /tmp/foo.txt text").and_return(true)
  end
end
describe 'example::default' do
  let(:chef_run) { ChefSpec::ChefRunner.new }

  before do
    stub_command("grep /tmp/foo.txt text") { rand(50)%2 == 0 }
  end
end

Data Bag & Data Bag Item

Given a recipe that executes a data_bag method:

data_bag('users').each do |user|
  data_bag_item('users', user['id'])
end

ChefSpec will rails an error like:

Real data_bags are disabled. Unregistered data_bag: data_bag(:users)

You can stub this data_bag with:

  stub_data_bag("users").and_return({})

============================================================

Just like the error message says, you must stub the result of the data_bag call. This can be done inside a before block or inside the it block, and the stubbing method accepts both a value or Ruby code. If provided a value, the result is static. If provided a Ruby block, the block is evaluated each time the search is called.

describe 'example::default' do
  let(:chef_run) { ChefSpec::ChefRunner.new }

  before do
    stub_data_bag('users').and_return([])
  end
end
describe 'example::default' do
  let(:chef_run) { ChefSpec::ChefRunner.new }

  before do
    stub_data_bag('users').and_return([
      { id: 'svargo' },
      { id: 'francis' }
    ])

    stub_data_bag_item('users', 'svargo').and_return({ ... })
    stub_data_bag_item('users', 'francis') { (ruby code) }
  end
end

Search

Because ChecSpec is a unit-testing framework, it is recommended that all third-party API calls be mocked or stubbed. ChefSpec exposes a helpful RSpec macro for stubbing search results in your tests. If you converge a Chef recipe that implements a search call, ChefSpec will throw an error like:

Real searches are disabled. Unregistered search: search(:node, 'name:hello')

You can stub this search with:

  stub_search(:node, 'name:hello') {  }

============================================================

Just like the error message says, you must stub the search result. This can be done inside a before block or inside the it block, and the stubbing method accepts both a value or Ruby code. If provided a value, the result is static. If provided a Ruby block, the block is evaluated each time the search is called.

describe 'example::default' do
  let(:chef_run) { ChefSpec::ChefRunner.new }

  before do
    stub_search(:node, 'name:hello').and_return([])
  end
end
describe 'example::default' do
  let(:chef_run) { ChefSpec::ChefRunner.new }

  before do
    stub_search(:node, 'name:hello') { (ruby_code) }
  end
end

Mocking Out Environments

If you want to mock out node.chef_environment, you'll need to use RSpec mocks/stubs twice:

let(:chef_run) do
  ChefSpec::Runner.new do |node|
    # Create a new environment (you could also use a different :let block or :before block)
    env = Chef::Environment.new
    env.name 'staging'

    # Stub the node to return this environment
    node.stub(:chef_environment).and_return(env.name)

    # Stub any calls to Environment.load to return this environment
    Chef::Environment.stub(:load).and_return(env)
  end.converge('cookbook::recipe')
end

There is probably a better/easier way to do this. If you have a better solution, please open an issue or Pull Request so we can make this less painful :)

Testing LWRPs

ChefSpec overrides all providers to take no action (otherwise it would actually converge your system). This means that the steps inside your LWRP are not actually executed. If an LWRP performs actions, those actions are never executed or added to the resource collection.

In order to run the actions exposed by your LWRP, you have to explicitly tell the Runner to step into it:

require 'chefspec'

describe 'foo::default' do
  let(:chef_run) { ChefSpec::Runner.new(step_into: ['my_lwrp']).converge('foo::default') }

  it 'installs the foo package through my_lwrp' do
    expect(chef_run).to install_package('foo')
  end
end

Please read the caveats on custom LWRPs in the wiki before testing your LWRPs!

You should never step_into an LWRP unless you are testing it. Never step_into an LWRP from another cookbook!

Packaging Custom Matchers

ChefSpec exposes the ability for cookbook authors to package custom matchers inside a cookbook so that other developers may take advantage of them in testing. This is done by creating a special library file in the cookbook named matchers.rb:

# cookbook/libraries/matchers.rb

if defined?(ChefSpec)
  def my_custom_matcher(resource_name)
    ChefSpec::Matchers::ResourceMatcher.new(resource, action, resource_name)
  end
end
  1. The entire contents of this file must be wrapped with the conditional clause checking if ChefSpec is defined.
  2. Each matcher is actually a top-level method. The above example corresponds to the following RSpec test: ruby expect(chef_run).to my_custom_matcher('...')

  3. ChefSpec::Matchers::ResourceMatcher accepts three parameters:

    1. The name of the resource to find in the resource collection (i.e. the name of the LWRP).
    2. The action that resource should receive.
    3. The value of the name attribute of the resource to find. (This is typically proxied as the value from the matcher definition.)

ChefSpec's built-in ResourceMatcher should satisfy most common use cases for packaging a custom matcher with your LWRPs. However, if your cookbook is extending Chef core or is outside of the scope of a traditional "resource", you may need to create a custom matcher. For more information on custom matchers in RSpec, please watch the Railscast on Custom Matchers or look at some of the other custom matchers in ChefSpec's source code.

Example

Suppose I have a cookbook named "motd" with a resource/provider "message".

# motd/resources/message.rb
actions :write
default_action :write

attribute :message, name_attribute: true
# motd/providers/message.rb
action :write do
  # ...
end

Chef will dynamically build the motd_message LWRP at runtime that can be used in the recipe DSL:

motd_message 'my message'

You can package a custom ChefSpec matcher with the motd cookbook by including the following code in libraries/matcher.rb:

# motd/libraries/matcher.rb
if defined?(ChefSpec)
  def write_motd_message(message)
    ChefSpec::Matchers::ResourceMatcher.new(:motd_message, :write, message)
  end
end

Other developers can write RSpec tests against your LWRP in their cookbooks:

expect(chef_run).to write_motd_message('my message')

Don't forget to include documentation in your cookbook's README noting the custom matcher and it's API!

Writing Custom Matchers

If you are testing a cookbook that does not package it's LWRP matchers, you can create your own following the same pattern as above. Create a file at spec/support/matchers.rb and add your resource matchers:

# spec/support/matchers.rb
def my_custom_matcher(resource_name)
  ChefSpec::Matchers::ResourceMatcher.new(:resource, :action, resource_name)
end

Please use this as a temporary solution. Consider sending a Pull Request to the LWRP author(s) packaging the custom resource matchers (see previous section).

Expecting Exceptions

In Chef 11, custom formatters were introduced and ChefSpec uses a custom formatter to supress Chef Client output. In the event of a convergence failure, ChefSpec will output the error message from the run to help you debug:

================================================================================
Recipe Compile Error in apt_package/recipes/install.rb
================================================================================

RuntimeError
------------
RuntimeError

Cookbook Trace:
---------------
  .../apt_package/recipes/install.rb:1:in `from_file'
  .../apt_package/spec/install_spec.rb:4:in `block (2 levels) in <top (required)>'
  .../apt_package/spec/install_spec.rb:7:in `block (2 levels) in <top (required)>'

Relevant File Content:
----------------------
.../apt_package/recipes/install.rb:

  1>> raise RuntimeError
  2:
  3:  apt_package 'default_action'

This output is automatically silenced when using RSpec's raise_error matcher:

let(:chef_run) { ChefSpec::Runner.new.converge('cookbook::recipe') }

it 'raises an error' do
  expect {
    chef_run
  }.to raise_error
end

You can also assert that a particular error was raised. If the error matches the given type, the output is suppressed. If not, the test fails and the entire stack trace is presented.

let(:chef_run) { ChefSpec::Runner.new.converge('cookbook::recipe') }

it 'raises an error' do
  expect {
    chef_run
  }.to raise_error(RuntimeError)
end

Testing Roles

Even though ChefSpec is cookbook-centric, you can still converge multiple recipes and roles in a single ChefSpec::Runner instance. Given a cookbook "bacon" with a default recipe:

# cookbooks/bacon/recipes/default.rb
package 'foo'

and a default attributes file:

# cookbooks/bacon/attributes/default.rb
default['bacon']['temperature'] = 200

and a role "breakfast":

# roles/breakfast.rb
default_attributes(
  'bacon' => {
    'temperature' => 150 # NOTE: This is different from the default value
  }
)
run_list([
  'recipe[bacon::default]'
])

You can test that the role is appropriately applied by telling the ChefSpec::Runner to converge on the role instead of a recipe:

let(:chef_run) { ChefSpec::Runner.new.converge('role[breakfast]') }

Assert that the run_list is properly expanded:

expect(chef_run).to include_recipe('bacon::default')

Assert that the correct attribute is used:

expect(runner.node['bacon']['temperature']).to eq(150)

NOTE: If your roles live somewhere outside of the expected path, you must set RSpec.config.role_path to point to the directory containing your roles before invoking the #converge method!

RSpec.configure do |config|
  config.role_path = '/var/my/roles' # global setting
end

# - OR -

ChefSpec::Runner.new(role_path: '/var/my/roles') # local setting

Using Chef Zero

Warning: This is not an officially supported pathway at this time. Please use at your own risk:

ChefZero is an in-memory chef server from Jon Keiser. With ChefZero you can completely bypass the search and data bag stubbing requirements, as now it provides a full Chef Server in memory. You should only create one instance of a Chef Zero server, so it's best to do so in your spec_helper.rb:

require 'chefspec'

require 'chef_zero/server'
server = ChefZero::Server.new(port: 4000)
server.start_background

at_exit do
  server.stop if server.running?
end

You can also populate pre-baked node data (for example all the nodes from staging environment) which in turn will dictate the outcome of your search calls. This will be slower than the first two methods and also requires more memory. See the ChefZero documentation for more details.

Videos

Development

  1. Fork the repository from GitHub.
  2. Clone your fork to your local machine:

    $ git clone git@github.com:USER/chefspec.git
    
  3. Create a git branch

    $ git checkout -b my_bug_fix
    
  4. Write tests

  5. Make your changes/patches/fixes, committing appropiately

  6. Run the tests: bundle exec rake

  7. Push your changes to GitHub

  8. Open a Pull Request

ChefSpec is on Travis CI which tests against multiple Chef and Ruby versions.

If you are contributing, please see the Contributing Guidelines for more information.

License

MIT - see the accompanying LICENSE file for details.