Why TDD Works for Sysadmins - Presented 2014-11-14 at LISA in Seattle.

1. Garrett Honeycutt
gh@learnpuppet.com
learnpuppet.com
@learnpuppet
Garrett Honeycutt
gh@learnpuppet.com
learnpuppet.com
@learnpuppet

4. TDD?

5. Why Test?

8. DEVELOPERS!
DEVELOPERS!
DEVELOPERS!
DEVELOPERS!
DEVELOPERS!
DEVELOPERS!
DEVELOPERS!
DEVELOPERS!
DEVELOPERS!
DEVELOPERS!

17. Why Test
First?

24. What to
Test?

28. Tooling

38. require 'spec_helper'
!
describe package('httpd') do
it { should be_installed }
end
!
describe service('httpd') do
it { should be_enabled }
it { should be_running }
end
!
describe port(80) do
it { should be_listening }
end

39. $ rake spec
!
Package "httpd"
should be installed
!
Service "httpd"
should be enabled
should be running
!
Port "80"
should be listening
!
4 examples, 0 failures

43. Monitoring

45. $ ping -c1 example.com
PING example.com (93.184.216.119): 56
data bytes
64 bytes from 93.184.216.119: icmp_seq=0
ttl=58 time=4.947 ms
!
--- example.com ping statistics ---
1 packets transmitted, 1 packets
received, 0.0% packet loss
round-trip min/avg/max/stddev =
4.947/4.947/4.947/0.000 ms

46. $ curl example.com -I
HTTP/1.1 200 OK
Accept-Ranges: bytes
Cache-Control: max-age=604800
Content-Type: text/html
Date: Thu, 13 Nov 2014 03:52:15 GMT
Etag: "359670651"
Expires: Thu, 20 Nov 2014 03:52:15 GMT
Last-Modified: Fri, 09 Aug 2013 23:54:35
GMT
Server: ECS (pae/3796)
X-Cache: HIT
x-ec-custom-error: 1
Content-Length: 1270

48. write tests
(which fail)

49. just enough
code to pass

50. refactor

51. Garrett Honeycutt
gh@learnpuppet.com
learnpuppet.com
@learnpuppet