Jenkins cascading parameters using Active Choice Parameter Plugin and Groovy

Hey Net-Heads!!

Of late, I have been working on CICD pipelines (though not as colorful pipelines as in the pic :))and have come across a task to build a job with parameters that provisions dynamic population of drop down list on selection of another drop down value.

Jenkins do not outline in-built plugins to support this feature. I started searching for options and found this Active Choice Parameter Plugin.

In this post, we will establish an approach to implement the cascading feature using a Jenkinsfile (Declarative Pipeline)

Behind the scenes:

Download and Install Active Choice Plugin: Jenkin’s plugin manager is the hot-spot to upgrade/install/uninstall required plugins. Navigate to Plugin Manager and click on Download now and install after restart to install the plugin.

Jenkin’s Plugin Manager UI

Using a Jenkinsfile…

Let’s toss around a rendering example:

Active Choice Reactive Parameter — Jenkins UI

In the example above the value options for the ‘Items’ parameter get updated when the ‘Categories’ parameter changes.

Creating a Jenkinsfile:

#!/usr/bin/env groovy
// Define variables
List category_list = ["\"Select:selected\"","\"Vegetables\"","\"Fruits\""]
List fruits_list = ["\"Select:selected\"","\"apple\"","\"banana\"","\"mango\""]
List vegetables_list = ["\"Select:selected\"","\"potato\"","\"tomato\"","\"broccoli\""]
List default_item = ["\"Not Applicable\""]
String categories = buildScript(category_list)
String vegetables = buildScript(vegetables_list)
String fruits = buildScript(fruits_list)
String items = populateItems(default_item,vegetables_list,fruits_list)
// Methods to build groovy scripts to populate data
String buildScript(List values){
  return "return $values"
}
String populateItems(List default_item, List vegetablesList, List fruitsList){
return """if(Categories.equals('Vegetables')){
     return $vegetablesList
     }
     else if(Categories.equals('Fruits')){
     return $fruitsList
     }else{
     return $default_item
     }
     """
}
// Properties step to set the Active choice parameters via 
// Declarative Scripting
properties([
    parameters([
        [$class: 'ChoiceParameter', choiceType: 'PT_SINGLE_SELECT',   name: 'Categories', script: [$class: 'GroovyScript', fallbackScript: [classpath: [], sandbox: false, script: 'return ["ERROR"]'], script: [classpath: [], sandbox: false,
        script:  categories]]],
[$class: 'CascadeChoiceParameter', choiceType: 'PT_SINGLE_SELECT',name: 'Items', referencedParameters: 'Categories', script: [$class: 'GroovyScript', fallbackScript: [classpath: [], sandbox: false, script: 'return ["error"]'], script: [classpath: [], sandbox: false, script: items]]]
    ])
])
pipeline {
    agent any
stages {
   stage('Build'){
    steps {
       echo 'Building..'
      }
    }
   }
}

We are ready with the script. Now, It’s showtime!!!

Click on the video to know how to use the pipeline script and simulate the above rendering example:

Thank you for reading!!
Stay tuned for more productionised solutions!!!

Happy Coding!!!

Interested to read more stories, you are always welcome to have a look at my writings here:

GeminiD - Medium