Unit Testing with Puppet and RSpec

The Puppet Development Kit doesn’t just set us up to create well-written modules—it also lets us write unit tests for our modules and ensure the changes we expect are being made when we run our Puppet code. This is done through the use of RSpec, a Ruby-based testing framework, and the `rspec-puppet` and `rspec-puppet-facts` plugins. RSpec uses behavior-driven development concepts to check the end state of our code. These tests are written in a human-readable language based on Ruby.

By writing unit tests for our modules, we can ensure we’re putting forth the highest-quality modules and prevent any unexpected production issues. Unit tests essentially work as another layer of protection against poor code, typos, and all the other gremlins that can end up in our modules.

Learning Objectives

Successfully complete this lab by achieving the following learning objectives:

Test That the Required Classes Are Contained

Change to the spec directory of the nginx module:
cd /etc/puppetlabs/code/environments/production/modules/nginx/spec/
Open the classes/nginx_spec.rb file:
sudo vim classes/nginx_spec.rb
Review the existing test. Currently, it is set up to check if the module will compile.

Add unit tests to ensure the desired classes are contained:

describe ‘nginx’ do
on_supported_os.each do |os, os_facts|
context "on #{os}" do
let(:facts) { os_facts }

     it { is_expected.to contain_class('nginx::install') }
     it { is_expected.to contain_class('nginx::config') }
     it { is_expected.to contain_class('nginx::service') }
     it { is_expected.to compile }
   end
 end

end

Test That the `nginx` Package Is Installed

Add the package-based unit test:

it { is_expected.to contain_package('nginx') }

Test That the `nginx` service Is Started, Enabled, and Able to Be Restarted

Add the basic service test:
it { is_expected.to contain_service(‘nginx’) }
Refine the test by adding the required parameter information:
it { is_expected.to contain_service(‘nginx’).with(ensure: ‘running’, enable: true, hasrestart: true) }

Test the Contents of the Static Configuration File

Create a case statement for both distros within the context block:
case os_facts[:osfamily]
when ‘Debian’
when ‘RedHat’
end
Check that the file exists:
case os_facts[:osfamily]
when ‘Debian’
it { is_expected.to contain_file(‘/etc/nginx/nginx.conf’).with_source(‘puppet:///modules/nginx/Debian.conf’) }
when ‘RedHat’
it { is_expected.to contain_file(‘/etc/nginx/nginx.conf’).with_source(‘puppet:///modules/nginx/RedHat.conf’) }
end
Save and exit.
Run the unit test:
sudo pdk test unit

What are Hands-on Labs

Hands-on Labs are real environments created by industry experts to help you learn. These environments help you gain knowledge and experience, practice without compromising your system, test without risk, destroy without fear, and let you learn from your mistakes. Hands-on Labs: practice your skills before delivering in the real world.

Unit Testing with Puppet and RSpec

About this Hands-on Lab

Learning Objectives

Additional Resources

What are Hands-on Labs

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