Does Behaviour Driven Development have a role in the infrastructure world? Enter Behaviour Driven Infrastructure where systems administrators can apply some simple open source tools and BDD principles to make infrastructure management more powerful, more insightful and deliver more value to their customers. The typical enterprise monitoring and configuration management set-up for a website is: - Is the Apache package installed and the appropriate version? - Is the Apache service running? - Can I connect to the HTTP port and is HTML returned? - Multiply this by a few hundred iterations of hosts and types of services and you’re probably looking at your typical Nagios, Puppet, Cfengine, Hyperic set-up. All this monitoring misses something critical though – we’re not actually monitoring that the service does what it should. Yes, it matters whether Apache is installed, the Apache service is running, and you can connect to HTTP but does this actually prove anything about the availability of the service we’re managing and providing for our customers? Nope… We need to demonstrate more than just a check that says the Apache server is up. We need to demonstrate that the service delivered by that infrastructure was available to our customers AND functioning as intended. Enter Behaviour Driven Infrastructure or BDI which applies the principles of Behavioural Driven Development to the management of infrastructure. In this presentation you’ll learn: - How Behaviour Driven Development works - What makes a behavioural test - How to install and use Cucumber to perform BDI - Practical examples of behavioural tests in Cucumber, and - How to integrate BDI into your work flow and your enterprise monitoring and configuration management frameworks.

1. Behaviour
Driven
Infrastructure
Lindsay Holmwood

2. DevOps

3. Behaviour
Driven
Development

4. Behaviour
Driven
Infrastructure?

5. What is a
behavioural test?

6. origins

7. Test Driven Development

8. write test

9. write test
run test

10. write test
run test
test fails

11. write test
run test
test fails
make test pass

12. write test
run test
refactor
test fails
make test pass

13. unit tests

14. input/output
of
functions

15. result = bar(foo)
assert(result, true)

16. xUnit

18. Behavior Driven Development
a reaction to test focus

19. testing the
flow of data
in a system

20. test a
user can
perform a
task

21. make a donation
search for product
checkout cart

22. verifying a
business’s
functional
requirements
are met

23. underlying
implementation is
irrelevant
to the business

24. Business: “assert(bar(foo),true)?”
Tech: “Yes”
Business: “Great”

25. Business: “assert(bar(foo),true)?”
Tech: “Yes”
Business: “Great”

26. Business: “Can I search for things?”
Tech: “Yes”
Business: “Great”

27. function
is important

28. implementation
is not

30. verifying a
business’s
functional
requirements
are met

31. integration tests
acceptance tests

32. “outside-in tests”

33. executable specification

34. written in
spoken language

35. so the business
understands what it is
paying for

37. Enough business
touchy-feely mumbo
jumbo!

38. I thought this was a
Behaviour
Driven
Infrastructure
talk?

39. I thought this was a
Behaviour
Driven
Infrastructure
talk?

41. Infrastructure as code

42. “The ‘Infrastructure’ is an
application, a long running
process with inputs, outputs
and state.”
- Andrew Schafer, 2009
http://bit.ly/he3HBt

43. an abstraction

44. infrastructure
is the
application

45. daemons
are the
libraries

46. configuration management
is the
programming language

47. infrastructure
is
built with code

48. code without tests
is
bad

49. code without tests
evil
is

50. Why?

51. You can’t verify that
your system works.

53. Behaviour
Driven
Infrastructure

54. Taking BDD
principals &
tools

55. Adapting them to
infrastructure
development

57. Show me the
tools!

58. Cucumber

59. Executable format for
software specifications

60. Tool to execute that
specification

62. Terminology

63. feature
is a
module of common functionality

64. Feature: Google search
To increase her knowledge
A user
Needs a search interface
To discover information

65. feature
has many
scenarios

66. Feature: Google search
To increase her knowledge
A user
Needs a search interface
To discover information
Scenario: Home page
When I visit "http://google.com.au/"
And I fill in "q" with "great balls of fire"
Then I should see "great balls of fire"

67. scenario
has many
steps

68. Given

69. When

70. Then

71. And*

73. steps
are like
unit tests

74. they map
to
blocks of code

75. Feature: Google search
To increase her knowledge
A user
Needs a search interface
To discover information
Scenario: Home page
When I visit "http://google.com.au/"
And I fill in "q" with "great balls of fire"
Then I should see "great balls of fire"

76. When /^I visit "([^"]*)"$/ do |location|
# code
end
When /^I fill in "([^"]*)" with "([^"]*)"$/ do |input, value|
# code
end
Then /^I should see "([^"]*)"$/ do |string|
# code
end

77. When /^I visit "([^"]*)"$/ do |location|
visit(location)
end
When /^I fill in "([^"]*)" with "([^"]*)"$/ do |input, value|
fill_in(input, :with => value)
end
Then /^I should see "([^"]*)"$/ do |string|
response.body.should match(string)
end

78. blocks of code
are like
unit tests

79. ∴ scenario
is a
serial execution
of unit tests

81. Installing

82. $ apt-get install rubygems
$ gem install cucumber

83. Using

84. $ apt-get install rubygems
$ gem install cucumber

85. $ apt-get install rubygems
$ gem install cucumber
$ mkdir -p project/features/steps
$ cd project

86. Testing Workflow

87. write test

88. write test
run test

89. write test
run test
test fails

90. write test
run test
test fails
make test pass

91. write test
run test
refactor
test fails
make test pass

92. $ apt-get install rubygems
$ gem install cucumber
$ mkdir -p project/features/steps
$ cd project
$ vim features/site.feature

93. Feature: Google search
To increase her knowledge
A user
Needs a search interface
To discover information
Scenario: Home page
When I visit "http://google.com.au/"
And I fill in "q" with "great balls of fire"
Then I should see "great balls of fire"

94. $ apt-get install rubygems
$ gem install cucumber
$ mkdir -p project/features/steps
$ cd project
$ vim features/site.feature
$ cucumber features/site.feature
$ vim features/steps/site_steps.rb

95. $ apt-get install rubygems
$ gem install cucumber
$ mkdir -p project/features/steps
$ cd project
$ vim features/site.feature
$ cucumber features/site.feature
$ vim features/steps/site_steps.rb
$ cucumber features/site.feature

97. Implications

98. Continuous
Integration

99. Test server builds

100. Execute tests
on commit
to config management

101. What environments are
the tests run against?

102. UAT?
Staging?
Production?

103. Destructive tests?

104. Fixtures

105. Setup / Teardown
Pattern

106. A/B testing

108. Migration to
config management

110. Continuous Integration
&
Monitoring Systems

111. build deploy
notify test

112. build deploy
notify test

113. notify test

114. We’ve been asking the
wrong questions

115. ping
connect

116. is the host up?
is the service available?

117. n etwork s tack up
other w is e broken
but
is the host up?
is the service available?
misconfiguration, bugs trig
gere d
by user data, hacke d

119. Why should I
care?

120. “Nagios checks
already do this!”

121. Cucumber
provides a framework
to phrase questions

122. Given

123. When

124. Then

125. Lowers the
barrier of entry to
writing good checks

126. Caveat:
You need a firm
grasp of language

127. Feature: Candy Store
Wooooooooo!
Scenario: Lollipops
When I fly to the moon
Then I should see monkeys

128. Feature: Candy Store
Wooooooooo!
Scenario: Lollipops
When I fly to the moon
Then I should see monkeys
o mpletely vali d,
c
co mpletely useless

130. Cucumber
provides a common
specification format
dev & ops can share

131. Cucumber
provides a common
specification format
IT & business can share

132. Duplication of tests

133. Development

134. Production

135. Cucumber features
are librarised tests

136. Same specification

137. Different implementation

139. Where to
from here?

140. Write more code.

141. Patterns.

142. Expand the library
of tests.

143. Explain to your friends,
colleagues, family, pets
these ideas.

144. Discuss!
Thank you.

145. Credits
http://www.flickr.com/photos/51746218@N03/5077975818/
http://www.flickr.com/photos/abrinsky/4981594203/
http://www.flickr.com/photos/andresrueda/3020304543/
http://www.flickr.com/photos/communityfriend/2342578485/
http://www.flickr.com/photos/damienroue/2775342201/
http://www.flickr.com/photos/elsie/3917813380/
http://www.flickr.com/photos/hugo90/5343453489/
http://www.flickr.com/photos/iamphejom/4930805430/
http://www.flickr.com/photos/jiuck/5060618037/
http://www.flickr.com/photos/kusamakura/2435343128/
http://www.flickr.com/photos/laurelfan/100700370/
http://www.flickr.com/photos/littledebbie11/3208631777/
http://www.flickr.com/photos/master-blitzy/1192778834/
http://www.flickr.com/photos/nasacommons/4858567480/
http://www.flickr.com/photos/nhankamer/4703022414/
http://www.flickr.com/photos/normanlowery/4674154988/
http://www.flickr.com/photos/paul_lowry/2266388742/
http://www.flickr.com/photos/pinprick/467320431/
http://www.flickr.com/photos/superciliousness/91346618/
http://www.flickr.com/photos/xaviergp/4003730145/