/pdb_motd

Chef MOTD example cookbook

Primary LanguageRuby

TDD for Chef Cookbooks: Getting Started

Prerequisites:

  • ChefDK: 
    curl https://omnitruck.chef.io/install.sh |
  sudo bash -s -- -c current -P chefdk
eval "$(/opt/chefdk/bin/chef shell-init bash)"
  • git: 
    git clone https://github.com/pburkholder/pdb_motd.git
cd pdb_motd
  • Vagrant

Nordstom's chefDK bootstrap cookbook: https://github.com/Nordstrom/chefdk_bootstrap

curl https://raw.githubusercontent.com/Nordstrom/chefdk_bootstrap/master/bootstrap | bash

Use 'kitchen-dokken' for testing

  • Docker Toolbox, then
docker-machine create --driver virtualbox default
eval "$(docker-machine env default)"
  • In this working dir: 
    chef gem install kitchen-dokken
export KITCHEN_LOCAL_YAML=.kitchen.dokken.yml
kitchen create # should do all the background image downloads, takes a while

Rationale for this cookbook demo:

  • Inductive Learners
  • Examples > Theory
  • Start simple (or even trivial)

User story from Legal:

  • As user connecting via SSH to a node,
  • I expect to see a login message,
  • This system is the property of DevOpsDC

The last developer had a 1/2 completed cookbook:

  • recipes/default.rb with attributes for path, message: 
    file node['motd']['path'] do
  content node['motd']['message']
end
  • Rakefile with test tasks
  • Tests in: 
    spec/unit/recipes/default_spec.rb
test/integration/default/inspec/default_spec.rb

Plan of Attack:

  • Look at the tests; try to understand them
  • Run the test suite
    • if something breaks, fix it
    • repeat until tests pass
  • Do TDD for new ownership with above steps

Plan of Attack:

  • Look at the tests; try to understand them
  • Run the test suite
    • if something breaks, fix it
    • repeat until tests pass
  • Do TDD for new ownership with above steps

Review ChefSpec default_spec.rb

spec/unit/recipes/default_spec.rb

require 'spec_helper'

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

  it 'should create MOTD' do
    expect(chef_run).to render_file('/etc/motd')
      .with_content('Property of DevOpsDC')
  end
end

Review Integration default_spec.rb

test/integration/default/inspec/default_spec

require 'inspec'

describe file('/etc/motd') do
  its(:content) { should match(/Property of DevOpsDC/) }
end

Rake default task:

rake -n
** Invoke default (first_time)
** Invoke cop (first_time)
** Execute (dry run) cop
** Invoke foodcritic (first_time)
** Execute (dry run) foodcritic
** Invoke spec (first_time)
** Execute (dry run) spec
** Execute (dry run) default

Plan of Attack:

  • Look at the tests; try to understand them
  • Run the test suite
    • if something breaks, fix it
    • repeat until tests pass
  • Do TDD for new ownership with above steps

Demo - rake

Demo - rake kitchen

Fixing borked stuff

kitchen login
/opt/chef/embedded/bin/chef-client \
  -z -c /opt/kitchen/client.rb \
  -j /opt/kitchen/dna.json -l warn -F doc

Plan of Attack:

  • Look at the tests; try to understand them
  • Run the test suite
    • if something breaks, fix it
    • repeat until tests pass
  • Do TDD for new ownership with above steps

Demo

Recap: Plan of Attack:

  • Look at the tests; try to understand them
  • Run the test suite
    • if something breaks, fix it
    • repeat until tests pass
  • Do TDD for new content with above steps

Summary:

  • Chef is Ruby
  • We use TDD when developing Ruby, including
    • Rubocop/Foodcritic: style
    • Rspec/ChefSpec: unit testing
    • Test-Kitchen: integration testing

DISCUSSION: Why does Rakefile use shell commands instead of Ruby tasks?

So beginners try each of the commands in isolation, e.g.:

rubocop
rspec
foodcritic .

Fini.

Presentation prerequisites (for OsX)

brew install npm
npm install -g reveal-md
reveal-md README.md