Tip of the Week 51 - Acceptance testing on a control-repository using beaker with vagrant and docker

Beaker has become the de-facto standard utility for Puppet code acceptance testing.

Like the figure from The Muppet Show the Puppet tooling “…is a magnet for disaster”. In this specific case we want to find out whether a catalog can be applied to a system successfully. In addition to that the Muppet figure has even more qualification for breaking things: “he routinely experiences mishaps such as being blown up, electrocuted, eaten by large monsters, or afflicted with awkward side effects caused by Dr. Bunsen Honeydew’s experiments. Beaker communicates in a nervous, high-pitched squeak that sounds like “Mee-mee-mee mee”” (quote taken from Wikipedia Beaker Muppet - see link above).

I also like the name for the tool, as we sometimes re-use the “Mee-mee-mee” spelling to a person telling you that something is not working.

Beaker installation

Puppet beaker allows for unattended CI based testing and acts as a frontend for Vagrant, AWS, Google Compute, VMware/Vsphere, Docker and others hypervisors and a puppet apply command. Please see the beaker documentation on hypervisors for additional information on hypervisors.

Within this posting I want to explain how we at example42 use beaker for acceptance testing in control-repositories like PSICK.

Installing beaker is usually done by adding a few lines to your Gemfile:

# Beaker
group :acceptance do
  gem 'beaker'
  gem 'beaker-rspec'
  gem 'beaker-hiera'
  gem 'beaker-puppet_install_helper'
end

All standard beaker hypervisor extensions are a dependency to the beaker gem. Please note that beaker uses the fog libraries for cloud access which causes a long list of dependencies.

Beaker nodesets

Next we need to add node descriptions providing information on operating system and releases to run tests on. These are placed into the spec/acceptance/nodesets/ folder.

Here we usually see the first difference between acceptance tests on control-repositories versus acceptance testing on modules:

Within modules one wants to test, whether the single code base is working as expected on all supported operating systems. For a control-repository one wants to test multiple different system roles on a few operating systems.

Let’s continue testing control-repositories on CentOS 7. The nodeset configuration consists of the following two files:

First we generate the nodeset for testing on docker:

# spec/acceptance/nodesets/default.yml
HOSTS:
  centos7-box:
    platform: el-7-x86_64
    hypervisor: docker
    docker_cmd: '["/usr/sbin/init"]'
    docker_image_commands:
      - 'yum install -y crontabs initscripts iproute openssl sysvinit-tools tar wget which ss'
      - 'systemctl mask [email protected]'
    docker_preserve_image: true
    mount_folders:
      controlrepo:
        host_path: .
        container_path: /tmp/production
        opts: ro
CONFIG:
  type: foss

Now we add the nodeset for testing on vagrant:

# spec/acceptance/nodesets/vagrant.yml
HOSTS:
  centos-7-x64:
    roles:
      - agent
    platform: el-7-x86_64
    box: centos/7
    hypervisor: vagrant
    mount_folders:
      controlrepo:
        host_path: ../../../
        container_path: /tmp/production
        opts: ro
CONFIG:
  type: foss

Beaker running instance preparation

The images we are using do not have puppet agent package installed. Installation and preparation of the started images is configured in the spec/spec_helper_acceptance.rb file:

# spec/spec_helper_acceptance.rb
require 'beaker-rspec'
require 'beaker/puppet_install_helper'

# Instal PC1 puppet 4 agent packages
run_puppet_install_helper

RSpec.configure do |c|
  # Readable test descriptions
  c.formatter = :documentation
  # preare each system after starting the image:
  hosts.each do |host|
    # remove obsolete global hiera.yaml
    on(host, '/usr/bin/test -f /etc/puppetlabs/puppet/hiera.yaml && /bin/rm -f /etc/puppetlabs/puppet/hiera.yaml || echo true')
    # remove existing production environment
    on(host, '/usr/bin/test -d /etc/puppetlabs/code/environments/production && /bin/rm -fr /etc/puppetlabs/code/environments/production || echo true')
    # re-create production environment directory
    on(host, '/usr/bin/test ! -d /etc/puppetlabs/code/environments/production && mkdir -p /etc/puppetlabs/code/environments/production || echo true')
    # copy control-repo
    on(host, 'cp -r /tmp/production/{.git,environment.conf,hiera.yaml,hieradata,manifests,site,modules}  /etc/puppetlabs/code/environments/production/')
  end
end

Beaker serverspec tests

Next one can add serverspec tests for specific roles:

# spec/acceptance/puppetmaster_spec.rb
require 'spec_helper_acceptance'

describe 'puppetmaster' do
  let(:manifest) {
    <<-EOS
      include role::puppetmaster
    EOS
  }
  it 'should run first time with changes and without errors' do
    result = apply_manifest(manifest, :catch_failures => true)
    expect(@result.exit_code).to eq 2
  end
  it 'should run a second time without changes' do
    result = apply_manifest(manifest, :catch_changes => true)
    expect(@result.exit_code).to eq 0
  end
  # here one can add more serverspec tests
end

Now we need to changes the default beaker acceptance testing rake task as we want to run tests on a control-repository.

# Rakefile
# beaker is designed to run all tests on multiple nodes
# we have another use case: run single tests on one host, then next test on new fresh host
Rake::Task[:beaker].clear
RSpec::Core::RakeTask.new(:beaker) do |config|
  puts 'dont use beaker, use beaker_roles:<role> or all_roles instead'
  abort
end

# iterate over acceptance tests and create namespaced rake tasks
namespace :beaker_roles do
  # find all acceptance tests
  Dir.glob("spec/acceptance/*_spec.rb") do |acceptance_test|
    # find role part of file name
    test_name = acceptance_test.split('/').last.split('_spec').first
    RSpec::Core::RakeTask.new(test_name) do |t|
      t.rspec_opts = ['--color']
      t.pattern = acceptance_test
    end
  end
end

Running beaker and acceptance tests

Now we can run the acceptance tests:

bundle exec rake beaker_roles:puppetmaster

This command only uses the default.yml nodeset. If we want to use the vagrant.yml nodeset we must tell beaker to do so by providing an environment variable:

BEAKER_set=vagrant bundle exec rake beaker_roles:puppetmaster

In addition to BEAKER_set there are some other useful environment variables: Usually beaker deletes the container/virtual machine after running tests (even after failed tests). To keep the instance alive just add BEAKER_destroy=no environment variable.

If one needs more information on what is happening during beaker running, it is possible to enable debug mode by specifying BEAKER_debug=true

Happy testing on your control-repository.

example42 wishes everybody a happy Christmas.

Martin Alfke