How the use of Groovy language can help you manage your Jenkins instance and extend its functionality. Presentation given at Jenkins User Conference Israel 2015

1. Jenkins World Tour 2015
Tel Aviv, Israel July 2015
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2. #jenkinsconf
Grooving with the Butler
Anton Weiss, (otomato)
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3. #jenkinsconf
About me
Ant(on) Weiss
DevOps Evangelist&Enabler, CI/CD/ALM
Expert
now at PrimaryData Inc.
ant.weiss@gmail.com
twitter: @antweiss
http://otomato.link3

4. #jenkinsconf
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GROOVY

5. #jenkinsconf
The Groovy Language
• Easy to learn and use
• Compiles to JVM bytecode
• Dynamic, optionally-typed
• Fully interoperates with Java
• Provides scripting capabilities
• Allows DSL authoring
• Meta-programming
• Functional programming
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6. #jenkinsconf
Hello , groovy world!
def sayHello(name) {
println("Hello $name!")
}
def name = 'world'
sayHello(name)
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7. #jenkinsconf
Groovy use in Jenkins
• Perform Maintenance Tasks
• Extend Functionality (instead of writing a full-fledged
plugin)
• Retrieve Information
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8. #jenkinsconf
Get into the Groove!
• Groovy to Manage your Jenkins
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9. #jenkinsconf
Jenkins Script Console
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10. #jenkinsconf
Jenkins Script Console
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import jenkins.model.*
import hudson.plugins.git.*
Hudson.instance.items.each() { job ->
def SCM = job.getScm()
if(SCM instanceof GitSCM ) {
def url = SCM.userRemoteConfigs[0].url
println url
new_url = url.replaceAll(/antweiss/, "otomato")
SCM.userRemoteConfigs[0].url = new_url
job.save()
}
}

11. #jenkinsconf
Jenkins Script Console
• No version control for scripts
• Requires manual editing to change values
Solution:
• Jenkins Scriptler Plugin
https://wiki.jenkins-
ci.org/display/JENKINS/Scriptler+Plugin
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12. #jenkinsconf
Go on grooving!
• Grooving with Parameters!
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13. #jenkinsconf
Groovy for Dynamic Parameters
• Retrieve parameter values dynamically:
• from Jenkins itself
• from external data sources:
• e.g: SCM, DB, file system
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14. #jenkinsconf
Groovy for Parameters - Example
• Retrieve a list of successful builds of a project:
import jenkins.model.*
job = Jenkins.instance.getItem(jobname)
job.getBuilds().each() { build ->
if ( build.result.toString() == "SUCCESS")
{
println build.number
}
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15. #jenkinsconf
Groovy for Dynamic Parameters
• Use with:
• Dynamic Parameter Plugin (+Scriptler)
• Extended Choice Parameter Plugin
• Extensible Choice Parameter Plugin
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16. #jenkinsconf
Groovier Yet!
• Grooving with Build Steps!
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17. #jenkinsconf
Groovy Build Steps
• Jenkins Groovy Plugin
• run regular groovy scripts
• run “system groovy scripts” :
• inside Jenkins master JVM
• schedule maintenance scripts
• extend functionality:
• build.setDescription(build.buildVariables.get(‘VERSION_NUM'))
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18. #jenkinsconf
Go on grooving!
• Grooving after Builds!
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19. #jenkinsconf
Groovy Post-Build Plugin
• Provides ‘manager’ object
• Provides log parser methods:
logContains(regexp)
getLogMatcher(regexp) - returns a
java.util.regex.Matcher
• Provides decorator methods:
manager.addShortText(“$manager.getEnvVariable('DD_VERSION')}")
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20. #jenkinsconf
Groovy Post-Build Plugin
def exit_status = manager.getEnvVariable("EXIT_FLAG")
def SETUP_NAME=manager.getEnvVariable("name")
switch (exit_status) {
case "0":
manager.buildSuccess()
break
case "9":
manager.buildUnstable()
manager.addBadge("delete.gif", "release setup", “http://my.server.com:8080/view/integration/job/drms-release-
setup/parambuild/?name=$SETUP_NAME”)
manager.createSummary("orange-square.png").appendText("<b>Setup name:</b> $SETUP_NAME", false,
false, false, "grey")
break
default:
manager.buildFailure()
}
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21. #jenkinsconf
Groovy Emails
• Using Groovy with Email-ext plugin
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+

22. #jenkinsconf
Groovy Emails
• In ‘Recipient List’ field:
• ${SCRIPT, script=“upstream_committers.groovy”}
• For email templates:
• ${SCRIPT, template="groovy-html1.template"}
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23. #jenkinsconf
Still want a plugin?
• The Groovy Way to Write Jenkins Plugins
• by Shiran Rubin (jfrog)
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24. #jenkinsconf
Footer
Divider Slide
Thanks and Be Groovy!!!
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