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ChefSpec

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Use ChefSpec to simulate the convergence of resources on a node:

  • Is an extension of RSpec, a behavior-driven development (BDD) framework for Ruby
  • Is the fastest way to test resources and recipes

ChefSpec is a framework that tests resources and recipes as part of a simulated Chef Infra Client run. ChefSpec tests execute very quickly. When used as part of the cookbook authoring workflow, ChefSpec tests are often the first indicator of problems that may exist within a cookbook.

Run ChefSpec

ChefSpec is packaged as part of Chef Workstation. To run ChefSpec:

chef exec rspec

Unit Tests

RSpec is a behavior-driven development (BDD) framework that uses a natural language domain-specific language (DSL) to quickly describe scenarios in which systems are being tested. RSpec allows a scenario to be set up, and then executed. The results are compared to a set of defined expectations.

ChefSpec is built on the RSpec DSL.

Syntax

The syntax of RSpec-based tests should follow the natural language descriptions of RSpec itself. The tests themselves should create an English-like sentence: “The sum of one plus one equals two, and not three.” For example:

describe '1 plus 1' do
  it 'equals 2' do
    a = 1
    b = 1
    sum = a + b
    expect(sum).to eq(2)
    expect(sum).not_to eq(3)
  end
end

where:

  • describe creates the testing scenario: 1 plus 1
  • it is a block that defines a list of parameters to test, along with parameters that define the expected outcome
  • describe and it should have human readable descriptions: “one plus one equals two”
  • a, b, and sum define the testing scenario: a equals one, b equals one, the sum of one plus equals two
  • expect() defines the expectation: the sum of one plus one equals two—expect(sum).to eq(2)—and does not equal three–expect(sum).not_to eq(3)
  • .to tests the results of the test for true; .not_to tests the result of the test for false; a test passes when the results of the test are true

context

RSpec-based tests may contain context blocks. Use context blocks within describe blocks to define “tests within tests”. Each context block is tested individually. All context blocks within a describe block must be true for the test to pass. For example:

describe 'math' do
  context 'when adding 1 + 1' do
    it 'equals 2' do
      expect(sum).to eq(2)
    end
  end

  context 'when adding 2 + 2' do
    it 'equals 4' do
      expect(sum).to eq(4)
    end
  end
end

where each context block describes a different testing scenario: “The sum of one plus one to equal two, and also the sum of two plus two to equal four.” A context block is useful to handle platform-specific scenarios. For example, “When on platform A, test for foo; when on platform B, test for bar.” For example:

describe 'cookbook_name::recipe_name' do

  context 'when on Debian' do
    it 'equals 2' do
      a = 1
      b = 1
      sum = a + b
      expect(sum).to eq(2)
    end
  end

  context 'when on Ubuntu' do
    it 'equals 2' do
      expect(1 + 1).to eq(2)
    end
  end

  context 'when on Windows' do
    it 'equals 3' do
      expect(1 + 2).to eq(3)
    end
  end

end

let

RSpec-based tests may contain let statements within a context block.Use let statements to create a symbol, assign it a value, and then use it elsewhere in the context block. For example:

describe 'Math' do
  context 'when adding 1 + 1' do
    let(:sum) { 1 + 1 }

    it 'equals 2' do
      expect(sum).to eq(2)
    end
  end

  context 'when adding 2 + 2' do
    let(:sum) do
      2 + 2
    end

    it 'equals 4' do
      expect(sum).to eq(4)
    end
  end
end

where:

  • The first let statement creates the :sum symbol, and then assigns it the value of one plus one. The expect statement later in the test uses sum to test that one plus one equals two
  • The second let statement creates the :sum symbol, and then assigns it the value of two plus two. The expect statement later in the test uses sum to test that two plus two equals four

Require ChefSpec

A ChefSpec unit test must contain the following statement at the top of the test file:

require 'chefspec'

Examples

The ChefSpec repo on github has an impressive collection of examples. For all of the core Chef Infra Client resources, for guards, attributes, multiple actions, and so on. Take a look at those examples and use them as a starting point for building your own unit tests. Some of them are included below, for reference here.

file Resource

Recipe

file '/tmp/explicit_action' do
  action :delete
end

file '/tmp/with_attributes' do
  user 'user'
  group 'group'
  backup false
  action :delete
end

file 'specifying the identity attribute' do
  path   '/tmp/identity_attribute'
 action :delete
end

Unit Test

require 'chefspec'

describe 'file::delete' do
  let(:chef_run) { ChefSpec::SoloRunner.new(platform: 'ubuntu', version: '20.04').converge(described_recipe) }

  it 'deletes a file with an explicit action' do
    expect(chef_run).to delete_file('/tmp/explicit_action')
    expect(chef_run).to_not delete_file('/tmp/not_explicit_action')
  end

  it 'deletes a file with attributes' do
    expect(chef_run).to delete_file('/tmp/with_attributes').with(backup: false)
    expect(chef_run).to_not delete_file('/tmp/with_attributes').with(backup: true)
  end

  it 'deletes a file when specifying the identity attribute' do
    expect(chef_run).to delete_file('/tmp/identity_attribute')
  end
end

template Resource

Recipe

template '/tmp/default_action'

template '/tmp/explicit_action' do
  action :create
end

template '/tmp/with_attributes' do
  user 'user'
  group 'group'
  backup false
end

template 'specifying the identity attribute' do
  path '/tmp/identity_attribute'
end

Unit Test

require 'chefspec'

describe 'template::create' do
  let(:chef_run) { ChefSpec::SoloRunner.new(platform: 'ubuntu', version: '20.04').converge(described_recipe) }

  it 'creates a template with the default action' do
    expect(chef_run).to create_template('/tmp/default_action')
    expect(chef_run).to_not create_template('/tmp/not_default_action')
  end

  it 'creates a template with an explicit action' do
    expect(chef_run).to create_template('/tmp/explicit_action')
  end

  it 'creates a template with attributes' do
    expect(chef_run).to create_template('/tmp/with_attributes').with(
      user: 'user',
      group: 'group',
      backup: false,
    )

    expect(chef_run).to_not create_template('/tmp/with_attributes').with(
      user: 'bacon',
      group: 'fat',
      backup: true,
    )
  end

  it 'creates a template when specifying the identity attribute' do
    expect(chef_run).to create_template('/tmp/identity_attribute')
  end
end

package Resource

Recipe

package 'explicit_action' do
  action :remove
end

package 'with_attributes' do
  version '1.0.0'
  action :remove
end

package 'specifying the identity attribute' do
  package_name 'identity_attribute'
  action :remove
end

Unit Test

require 'chefspec'

describe 'package::remove' do
  let(:chef_run) { ChefSpec::SoloRunner.new(platform: 'ubuntu', version: '20.04').converge(described_recipe) }

  it 'removes a package with an explicit action' do
    expect(chef_run).to remove_package('explicit_action')
    expect(chef_run).to_not remove_package('not_explicit_action')
  end

  it 'removes a package with attributes' do
    expect(chef_run).to remove_package('with_attributes').with(version: '1.0.0')
    expect(chef_run).to_not remove_package('with_attributes').with(version: '1.2.3')
  end

  it 'removes a package when specifying the identity attribute' do
    expect(chef_run).to remove_package('identity_attribute')
  end
end

chef_gem Resource

Recipe

chef_gem 'default_action'

chef_gem 'explicit_action' do
  action :install
end

chef_gem 'with_attributes' do
  version '1.0.0'
end

chef_gem 'specifying the identity attribute' do
  package_name 'identity_attribute'
end

Unit Test

require 'chefspec'

describe 'chef_gem::install' do
  let(:chef_run) { ChefSpec::SoloRunner.new(platform: 'ubuntu', version: '20.04').converge(described_recipe) }

  it 'installs a chef_gem with the default action' do
    expect(chef_run).to install_chef_gem('default_action')
    expect(chef_run).to_not install_chef_gem('not_default_action')
  end

  it 'installs a chef_gem with an explicit action' do
    expect(chef_run).to install_chef_gem('explicit_action')
  end

  it 'installs a chef_gem with attributes' do
    expect(chef_run).to install_chef_gem('with_attributes').with(version: '1.0.0')
    expect(chef_run).to_not install_chef_gem('with_attributes').with(version: '1.2.3')
  end

  it 'installs a chef_gem when specifying the identity attribute' do
    expect(chef_run).to install_chef_gem('identity_attribute')
  end
end

directory Resource

Recipe

directory '/tmp/default_action'

directory '/tmp/explicit_action' do
  action :create
end

directory '/tmp/with_attributes' do
  user 'user'
  group 'group'
end

directory 'specifying the identity attribute' do
  path '/tmp/identity_attribute'
end

Unit Test

require 'chefspec'

describe 'directory::create' do
  let(:chef_run) { ChefSpec::SoloRunner.new(platform: 'ubuntu', version: '20.04').converge(described_recipe) }

  it 'creates a directory with the default action' do
    expect(chef_run).to create_directory('/tmp/default_action')
    expect(chef_run).to_not create_directory('/tmp/not_default_action')
  end

  it 'creates a directory with an explicit action' do
    expect(chef_run).to create_directory('/tmp/explicit_action')
  end

  it 'creates a directory with attributes' do
    expect(chef_run).to create_directory('/tmp/with_attributes').with(
      user: 'user',
      group: 'group',
    )

    expect(chef_run).to_not create_directory('/tmp/with_attributes').with(
      user: 'bacon',
      group: 'fat',
    )
  end

  it 'creates a directory when specifying the identity attribute' do
    expect(chef_run).to create_directory('/tmp/identity_attribute')
  end
end

Guards

Recipe

service 'true_guard' do
  action  :start
  only_if { 1 == 1 }
end

service 'false_guard' do
  action :start
  not_if { 1 == 1 }
end

service 'action_nothing_guard' do
  action :nothing
end

Unit Test

require 'chefspec'

describe 'guards::default' do
  let(:chef_run) { ChefSpec::SoloRunner.new(platform: 'ubuntu', version: '20.04').converge(described_recipe) }

  it 'includes resource that have guards that evaluate to true' do
    expect(chef_run).to start_service('true_guard')
  end

  it 'excludes resources that have guards evaluated to false' do
    expect(chef_run).to_not start_service('false_guard')
  end

  it 'excludes resource that have action :nothing' do
    expect(chef_run).to_not start_service('action_nothing_guard')
  end
end

include_recipe Method

Recipe

include_recipe 'include_recipe::other'

Unit Test

require 'chefspec'

describe 'include_recipe::default' do
  let(:chef_run) { ChefSpec::SoloRunner.new(platform: 'ubuntu', version: '20.04').converge(described_recipe) }

  it 'includes the `other` recipe' do
    expect(chef_run).to include_recipe('include_recipe::other')
  end

  it 'does not include the `not` recipe' do
    expect(chef_run).to_not include_recipe('include_recipe::not')
  end
end

Multiple Actions

Recipe

service 'resource' do
  action :start
end

service 'resource' do
  action :nothing
end

Unit Test

require 'chefspec'

describe 'multiple_actions::sequential' do
  let(:chef_run) { ChefSpec::SoloRunner.new(platform: 'ubuntu', version: '20.04', log_level: :fatal).converge(described_recipe) }

  it 'executes both actions' do
    expect(chef_run).to start_service('resource')
  end

  it 'does not match other actions' do
    expect(chef_run).to_not disable_service('resource')
  end
end

More Information

For more information about ChefSpec:

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