By Daniel Spilker, CoreMedia Learn how to use the Gradle JPI plugin to enable a 100% Groovy plugin development environment. We will delve into Groovy as the primary programming language, Spock for writing tests and Gradle as the build system.

1. Plugin Development with Gradle and Groovy
Daniel Spilker – CoreMedia AG

2. #jenkinsconf
Plugin Development – It‘s Your Choice
• Build Tool
– Maven, Gradle, …
• Programming Language
– Java, Groovy, Ruby, Python, …
• Testing
– JUnit, Spock, …

3. #jenkinsconf
Plugin Development – It‘s Your Choice
• Build Tool
– Maven, Gradle, …
• Programming Language
– Java, Groovy, Ruby, Python, …
• Testing
– JUnit, Spock, …

4. #jenkinsconf
Gradle JPI Plugin

5. #jenkinsconf
Gradle JPI Plugin
• Builds the Jenkins plugin file (HPI / JPI)
• Can be combined with other Gradle plugins
• Hooks into the standard Gradle tasks
• Recommended prerequisites
– Java 7
– Gradle 2.3

6. #jenkinsconf
Example
buildscript { … }
apply plugin: 'org.jenkins-ci.jpi'
group = 'org.jenkins-ci.plugins'
version = '0.0.1-SNAPSHOT'
description = 'A description of your plugin'
jenkinsPlugin {
coreVersion = '1.580'
displayName = 'Hello World'
url = 'http://wiki.jenkins-ci.org/display/JENKINS/Hello+World'
gitHubUrl = 'https://github.com/jenkinsci/hello-world-plugin'
developers { … }
}

7. #jenkinsconf
Directory Structure
hello-world-plugin
+---build.gradle
---src
+---main
| +---groovy
| ---resources
---test
+---groovy
---resources

8. #jenkinsconf
Gradle Tasks
• gradle server
– Start a Jenkins instance with the plugin installed for
manual testing
• gradle jpi
– Build the Jenkins plugin file
• gradle publish
– Deploy your plugin to the Jenkins Maven repository to
be included in the Update Center

9. #jenkinsconf
Further Information
• Documentation
https://wiki.jenkins-ci.org/display/JENKINS/Gradle+JPI+Plugin
• Issue Tracker
https://issues.jenkins-ci.org/browse/JENKINS/component/16321
• Jenkins Developer Mailing List
https://groups.google.com/forum/#!forum/jenkinsci-dev
• Example
https://github.com/jenkinsci/job-dsl-plugin

10. #jenkinsconf
Groovy

11. #jenkinsconf
Groovy
• All documentation and examples about plugin
development with Java also apply to Groovy
• Jenkins comes with Groovy 1.8

12. #jenkinsconf
Example
class HelloWorldBuilder extends Builder {
final String name
@DataBoundConstructor
HelloWorldBuilder(String name) { … }
@Override
boolean perform(…) {
listener.logger.println("Hello, ${name}!")
true
}
}

13. #jenkinsconf
Further Information
• Groovy
http://www.groovy-lang.org/
http://www.groovy-lang.org/groovy-weekly.html
http://glaforge.appspot.com/article/groovy-presentations-at-conferences
• Developing Plugins
https://wiki.jenkins-ci.org/display/JENKINS/Extend+Jenkins
• Example
https://github.com/jenkinsci/hello-world-groovy-plugin

14. #jenkinsconf
Spock Framework

15. #jenkinsconf
Spock Framework
• Spock 0.7 must be used due to Groovy 1.8 constraint
• Gradle dependency declaration
dependencies {
testCompile 'org.spockframework:spock-core:0.7-groovy-1.8'
}
• The Jenkins test harness can be used
@Rule
JenkinsRule jenkinsRule = new JenkinsRule()

16. #jenkinsconf
Example
class ExampleSpec extends Specification {
@Rule
JenkinsRule jenkinsRule = new JenkinsRule()
def 'some example test'() {
setup:
FreeStyleProject job = jenkinsRule.createFreeStyleProject('seed')
when:
FreeStyleBuild freeStyleBuild = job.scheduleBuild2(0).get()
then:
freeStyleBuild.result == SUCCESS
}
}

17. #jenkinsconf
Further Information
• Documentation
http://docs.spockframework.org/
• Testing plugins
https://wiki.jenkins-ci.org/display/JENKINS/Unit+Test

18. #jenkinsconf
Summary – It‘s Your Choice
• Build Tool
– Maven, Gradle, …
• Programming Language
– Java, Groovy, Ruby, Python, …
• Views
– Jelly, Groovy
• Testing
– JUnit, Spock, …

19. #jenkinsconf
Thank You
Daniel Spilker
daniel.spilker@coremedia.com
@daspilker
We‘re hiring
www.coremedia.com
@CoreMediaMinds