After almost a year of slow but steady development, the time is soon approaching when you will be able to start writing Jenkins plugins armed with nothing but a simple JRuby environment. To illustrate exactly what this means, we'll study the anatomy of a Ruby plugin, how it works at runtime, and walk through the creation, testing and deploying of an example using nothing put 100% pure Ruby. Finally, beyond the mechanical, we'll discuss why this effort is important for the entire Jenkins community, not just the part of the community that uses Ruby.

1. Ruby Plugins
You’ve come a long way baby

2. Charles Lowell
• cowboyd@github
• cowboyd@twitter
• cowboyd@jenkins-ci

3. What the hell am I
doing here?

4. User Interfaces

5. Lots of Ruby

6. Lot’s of JavaScript

7. Lot’s of Java/C++
+
therubyracer, therubyrhino

8. Bugs!
• Ruby versions (1.8.6,1.8.7,1.9.2, rbx,
jruby, ...)
• CC/libc version
• OS (OSX, ubuntu, rhel)

9. HELL

10. We need a DIESEL
CI solution.

12. Fun Fact: We
actually designed
this logo

14. jenkins.rb 0.1
• rubygem containing jenkins.war
• utility for starting a test jenkins server

15. Dr Nic
• Saw my lightning
talk
• went hog wild on
the gem

16. jenkins.rb 1.0
• create/list/update
jobs from CLI
• create sinatra/rails
jobs in one go
• huge arsenal of
Jenkins Macros

17. Eventually, we wanted
more than macros.

18. Ruby Plugins
Extend Jenkins with nothing but Ruby

19. We need a plan

20. How ‘bout
you do it?
We need a plan

21. Mad Propers!
Kohsuke Kawaguchi

22. Ruby Plugins
See them in action

24. What does it mean for
a plugin to be in Ruby?

25. Language
Ruby.
Duh.

26. API
must “feel” like Ruby, not just scripting Java.

27. Example
“Push” vs “Pull” configuration

28. Java

29. Scripted Java

30. Ruby

31. Tools
They’ve gotta be Ruby too.

32. -Maven -javac
• Rake - build and assembly
• Bundler - dependency management
• jpi - development tools

33. Testing
Yup, also Ruby

34. No solid answers yet
• unit testing?
• mocking builds, jobs, projects?
• fixtures for builds, jobs, projects?

35. How it works

36. How it works
Plugin.java

37. Plugin.java
Jenkins
•
Ruby Runtime Plugin
Small as can
jenkins-ruby-api possibly be
Ruby Plugin A bundled gems
•
plugin ruby code
5 small classes
Ruby Plugin B .....
• will not instantiate
extension points
jenkins-ruby-api
Ruby Plugin C bundled gems
plugin ruby code

38. Plugin.java
Jenkins
•
Ruby Runtime Plugin
every plugin gets
its own scripting
JRuby
Ruby Plugin A
container
Ruby Plugin B .....
• isolation +
JRuby backwards
Ruby Plugin C
compatibility

39. How it works
Plugin.rb

40. Plugin.rb
Jenkins
•
Ruby Runtime Plugin
own copy of API
JRuby
ruby API
Ruby Plugin A bundled gems
extension points • own copy of gems
Ruby Plugin B .....
• Ruby extension
JRuby points detected
Ruby Plugin C
ruby API
bundled gems
and auto-loaded
extension points

41. Plugin.rb
Jenkins
Ruby Runtime Plugin
JRuby
• Library code is
free to vary from
ruby API 1.1
Ruby Plugin A json 1.5, nokogiri 1.8
extension points
plugin to plugin
•
Ruby Plugin B .....
This includes the
plugin API!
JRuby
ruby API 1.3rc5
Ruby Plugin C json 1.6.4
extension points

42. Plugin.rb (API)
• Builder - implement build steps
• Publisher - run build steps after build
complete
• BuildWrapper - decorate a build with
setup/teardown

43. Plugin.rb (API)
• All Ruby extension points are Plain old
Ruby objects (TM)
• Plugin maintains two-way list of proxies to
support this

44. Plugin.rb (API)
Jenkins Ruby Plugin
• All Java Objects
Java Ruby
proxied
•
hudson.model.AbstractBuild Jenkins::Model::Build
All Ruby Objects
wrapped
•
Java Ruby
referential
hudson.tasks.Builder Jenkins::Tasks::Builder integrity
Proxies

45. More Fundamental than
Ruby

46. Supporting Features
• Flexible Descriptor registration
• Pluggable persistence via JRuby Xstream
• Stapler support for pluggable templating

47. Supporting Features
More plugin-provided metadata. Less Java reflection.

48. What works for Ruby...
works for Python

49. What works for Ruby...
works for Python
(in theory)

50. What works for Ruby...
works for Python
(in theory)
but not as magnificently :)

51. What works for Ruby...
works for JavaScript

52. What works for Ruby...
works for Clojure

53. What works for Ruby...
works for Fantom

54. What works for Ruby...
works for X

55. 400+ Plugins
to date

56. 4,000 plugins

57. 4,000 plugins
sooner than you think?

58. Applications?

59. Frameworks?

60. gem install jenkins-plugin

61. Thanks!
• cowboyd@github
• cowboyd@twitter
• cowboyd@jenkins-ci