1.
@filippo
Test Driven Infrastructures

2.
Filippo Liverani
@filippo

3.
agile methods + IT operations?
photo credit: https://www.flickr.com/photos/kalexanderson/6354182139/

4.
1. Test Driven Development
2. Infrastructure as code
3. From theory to practice

5.
Test Driven Development
photo credit: https://www.flickr.com/photos/pagedooley/4308431673/

6.
write a
failing unit
test
make it
pass
refactor

7.
the 3 laws of TDD
photo credit: https://www.flickr.

8.
1
You are not allowed to write
any production code unless it is
to make a failing unit test pass

9.
2
You are not allowed to write any
more of a unit test than is
sufficient to fail

10.
3
You are not allowed to write any
more production code than is
sufficient to pass the one failing
unit test

11.
drives design
small incremental changes
continuous validation
rapid feedback

12.
why it works?
reduces complexity
breaking down a difficult problem into smaller
pieces

13.
listen to the tests
if it’s hard to write
the design is probably wrong

14.
-> Acceptance Test Driven Development
acceptance criteria
examples
definition of done

15.
write a failing
acceptance test

16.
write a failing
acceptance test

17.
write a
failing unit
test
make it
pass
refactor
write a failing
acceptance test

18.
write a
failing unit
test
make it
pass
refactor
write a failing
acceptance test

19.
benefits of TDD
higher code quality
regression test suite
feedback and confidence

20.
more benefits of TDD
implicit acceptance criteria
executable documentation
prevent gold plating

21.
challenges
takes time to learn
requires discipline
changing habits is hard
management does not perceive internal quality

22.
infrastructure as code
photo credit: https://www.flickr.com/photos/mwichary/2348383457/

23.
DevOps
+
virtualization and cloud
->
infrastructure is code too

24.
programmatically configure and provision
everything versioned
business= code repository
+ data backup
+ compute resources

25.
collaboration + automation
knowledge sharing
tooling
power of text

26.
benefits
consistency and repeatability
scalability
testability
maintainability

27.
challenges
spaghetti code
duplication
fear of change
low quality
side effects and chain reactions

28.
TDD can help!

29.
testing what?
Acceptance tests
Prototypes
Exploratory testing
Usability testing
Unit tests
Integration tests
Performance testing
Security testing
Business facing
Technology facing
Supporting
the
team
Critique
Product
credit: Brian Marik

30.
testing what?
Acceptance tests
Prototypes
Exploratory testing
Usability testing
Unit tests
Integration tests
Performance testing
Security testing
Business facing
Technology facing
Supporting
the
team
Critique
Product
credit: Brian Marik

31.
from theory to practice
photo credit: https://www.flickr.com/photos/jurvetson/489257240/

32.
install and start Apache httpd server
exercise

33.
tools needed
git
chefdk
vagrant
virtualbox
(packer)

34.
$ git init httpd-cookbook
$ cd httpd-cookbook

35.
$ chef generate cookbook httpd

36.
Test Kitchen

37.
$ kitchen init --driver=kitchen-vagrant

38.
---
driver:
name: vagrant
provisioner:
name: chef_zero
platforms:
- name: ubuntu-14.04
suites:
- name: default
run_list:
- recipe[httpd::default]
httpd-cookbook/.kitchen.yml

39.
write an acceptance test

40.
require 'spec_helper'
describe service('apache2') do
it { should be_running }
describe port(80) do
it { should be_listening }
end
end
httpd-cookbook/test/integration/server/serverspec/default_spec.
rb

41.
watch it fail

42.
$ kitchen test

43.
Service "apache2"
should be running (FAILED - 1)
Port "80"
should be listening (FAILED - 2)

44.
write a unit test

45.
require 'spec_helper'
describe 'httpd::default' do
let(:chef_run) {
ChefSpec::SoloRunner.converge(described_recipe)
}
it 'installs apache2 package' do
expect(chef_run).to install_package('apache2')
end
end
httpd-cookbook/spec/unit/recipes/default_spec.rb

46.
watch it fail

47.
$ chef exec rspec

48.
F
Failures: 1) httpd::default installs apache2 package
Finished in 0.00957 seconds
1 example, 1 failure

49.
make it pass

50.
package 'apache2' do
action :install
end
httpd-cookbook/recipes/default.rb

51.
$ chef exec rspec

52.
.
Finished in 0.00946 seconds
1 example, 0 failures

53.
refactor

54.
write a unit test

55.
require 'spec_helper'
describe 'httpd::default' do
let(:chef_run) {
ChefSpec::SoloRunner.converge(described_recipe)
}
it 'installs apache2 package' do
expect(chef_run).to install_package('apache2')
end
it 'starts apache2 service' do
expect(chef_run).to start_service('apache2')
end
end
httpd-cookbook/spec/unit/recipes/default_spec.rb

56.
watch it fail

57.
$ chef exec rspec

58.
.F
Failures: 1) httpd::default starts apache2 service
Finished in 0.02133 seconds
2 example, 1 failure

59.
make it pass

60.
package 'apache2' do
action :install
end
service 'apache2' do
action :start
end
httpd-cookbook/recipes/default.rb

61.
$ chef exec rspec

62.
..
Finished in 0.02041 seconds
2 example, 0 failures

63.
refactor

64.
make acceptance test pass

65.
$ kitchen test

66.
Service "apache2"
should be running
Port "80"
should be listening
Finished in 0.09441 seconds
2 example, 0 failures
Finished verifying <default-ubuntu-1404> (0m6.52s).
-----> Kitchen is finished. (0m31.77s)

67.
{
"variables": {
"aws_access_key": null,
"aws_secret_key": null
},
...
packer.json - 1

68.
...
"builders": [{
"type": "amazon-ebs",
"access_key": "{{user `aws_access_key`}}",
"secret_key": "{{user `aws_secret_key`}}",
"region": "eu-west-1",
"ami_virtualization_type": "hvm",
"source_ami": "ami-28ff505f",
"instance_type": "t2.micro",
"ssh_username": "ubuntu",
"ami_name": "httpd"
}]
...
packer.json - 2

69.
...
"provisioners": [
{
"type": "chef-solo",
"cookbook_paths": ["berks-cookbooks"],
"run_list": ["httpd::default"]
}
]
}
packer.json - 3

70.
source 'https://api.berkshelf.com'
cookbook 'httpd', path: './httpd-cookbook'
Berksfile

71.
$ berks vendor
$ packer build
-var 'aws_access_key=YOUR ACCESS KEY'
-var 'aws_secret_key=YOUR SECRET KEY'
packer.json

72.
==> Builds finished. The artifacts of successful
builds are:
--> amazon-ebs: AMIs were created:
eu-west-1: ami-ac3199db

73.
next steps
manage whole stack:
Terraform
Cloudformation
Heat
continuous delivery

74.
TDD is a powerful technique
Treat your infrastructure as code
You can start now

75.
risorse

76.
thank you