As a Ruby developer, we are responsible for providing unit test harness to support our development. Not only it provides a clean code base, but it also allows you to introduce changes as the needs of your application's supported business over time. Putting the same effort around your application's infrastructure gives the same benefit as well. Being able to support sudden traffic to your application is as important as delivering features to your users. In this talk, I discussed how to treat your Infrastructure as Code with the same test-driven development techniques you do in your application.

1. Treat your servers like your Ruby
App: Infrastructure as Code
2015 March 27-28
Allan Espinosa
Platform as a Service Team
Global Operations Department
Rakuten, Inc.
http://www.rakuten.co.jp/

2. About me
 Allan Espinosa
 Technology Background
 Language Polyglot: Ruby, Node.js, Java, .NET
 Systems Polyglot: Docker, VMWare
 Automation Junkie: Chef, Jenkins
 Job Background
 “Private Heroku”
 Senior Systems Developer
Platform as a Service Team
Global Operations Department
@AllanEspinosa

3. Rakuten, Inc.

4. Agenda
 Audience Demographics
 Typical App TDD
 Introduction to Configuration Management
 Infrastructure as Code
 Evolved App and Infrastructure TDD
 Wrap-up

5. Audience Demographics
 Web application developers?
 Infrastructure engineers?
 Fullstack engineers?
 Unit Tests?
 Test Driven Development?
 Automated/ Push-button deployments?
 Post-deployment end-to-end tests?

6. Infrastructure as Code
 Reproducable servers
 Bring up a lot of servers
 Programmatically add servers to monitor/ load balancer
Server as cattle not pets
Reference: Test Driven Infrastructure with Chef

7. Unmaintained Infrastructure Code
 Where did I install ruby-2.0.0-p589 to?
 Which machines upgraded to ruby-2.1.1-p589?
 Have I upgraded libxml2 for nokogiri?
 Why is database.yml pointing to staging????
 Test and software engineering practices still relevant!
# FIXME:
…
# TODO:
…

8. Typical TDD Cycle
Make the test pass
Refactor
Write a failing test
Application
Ref: K. Beck, Test Driven Development by Example, 2003.

9. Extended TDD with Acceptance Tests
Pass the
unit test
Refactor
Write a failing
unit test
Write Failing
Acceptance Test
Application
Capybara.current_driver = :selenium
Capybara.app_host = ‘http://localhost:8000’
G. Adzic, Specification by Example, 2011.

10. Apply to your Infrastructure
Pass the
unit test
Refactor
Write a failing
unit test
Write Failing
Acceptance Test
Application
+
Servers
Capybara.current_driver = :selenium
Capybara.app_host = ‘http://actual-production.domain

11. Build our infrastructure!
.kitchen.yml
---
provisioner: chef_zero
platforms:
- freebsd-10.1
suites:
- name: app
 Write a failing test
 Test-kitchen
 Plain Minitest
 Make the test pass
 Chef Recipe
 Refactor
 Repeat!
 Roll out to servers
 Pass acceptance test!
test/integration/app/minitest/test_app.rb
class TestApp < Minitest::Unit::TestCase
def test_ruby_is_installed
assert File.exists
‘/usr/local/bin/ruby’, ‘Ruby should be
installed’
end
end

12. Failing Test!
-----> Running minitest test suite
/opt/chef/embedded/bin/ruby -I"/opt/chef/embedded/lib/ruby/2.1.0"
"/opt/chef/embedded/lib/ruby/2.1.0/rake/rake_test_loader.rb"
"/tmp/busser/suites/minitest/test_app.rb"
Run options: --seed 48374
# Running tests:
F
Finished tests in 0.001660s, 602.4866 tests/s, 602.4866 assertions/s.
1) Failure:
AppTest#test_ruby_should_be_installed [/tmp/busser/suites/minitest/test_app.rb:5]:
ruby is not installed
1 tests, 1 assertions, 1 failures, 0 errors, 0 skips
/opt/chef/embedded/lib/ruby/2.1.0/rake/testtask.rb:106:in `block (3 levels) in define':
Command failed with status (1): [ruby -I"/opt/chef/embedded/lib/ruby/2.1.0" "/opt/che
f/embedded/lib/ruby/2.1.0/rake/rake_test_loader.rb" "/tmp/busser/suites/minitest/test_app.rb" ]
(RuntimeError)

13. Build our infrastructure!
.kitchen.yml
---
provisioner: chef_zero
platforms:
- freebsd-10.1
suites:
- name: app
run_list:
- recipe[todo::app]
 Write a failing test
 Test-kitchen
 Plain Minitest
 Make the test pass
 Chef Recipe
 Refactor
 Repeat!
 Roll out to servers
 Pass acceptance test!

14. Build our infrastructure!
recipes/app.rb
execute ‘pkg update’
package ‘ruby’ do
action :install
end
metadata.rb
name ‘todo’
 Write a failing test
 Test-kitchen
 Plain Minitest
 Make the test pass
 Chef Recipe
 Refactor
 Repeat!
 Roll out to servers
 Pass acceptance test!

15. Make the test pass
resolving cookbooks for run list: ["todo::app"]
Synchronizing Cookbooks:
- todo
Compiling Cookbooks...
Converging 2 resources
Recipe: todo::app
* execute[pkg update] action run
- execute pkg update
* package[ruby] action install
- install version 2.0.0.598_2,1 of package ruby
Running handlers:
Running handlers complete
Chef Client finished, 2/2 resources updated in 47.595913304
seconds
Finished converging <app-freebsd-101> (0m55.78s).

16. GREEN! Make the test pass
Run options: --seed 4256
# Running tests:
.
Finished tests in 0.001526s, 655.4072 tests/s, 655.4072
assertions/s.
1 tests, 1 assertions, 0 failures, 0 errors, 0 skips
Finished verifying <app-freebsd-101> (0m2.59s).

17. Conclusion
 Infrastructure express in code
 Leapfrog on software engineering disciplines

18. We’re Hiring!
Search for “Platform as a Service”
http://global.rakuten.com/corp/careers/engineering/

19. Thank you! Questions?