Jenkins dynamic paramters based on groovy method - jenkins

Question

I am trying to do the below things as part of Jenkins pipeline dsl.
I have a yaml file where i store all my static values.
I created a pipeline job which should show 2 parameters.
a)region : northamerica/europe
b)environment : this should come based on the region selected.
I am defining the 2 functions outside of the pipeline so that i can use them during the parameters section.
Syntax:
#!/usr/bin/env groovy
def yaml_file = "JenkinsFiles/environments.yaml"
def getRegions() {
def var_regions = []
yaml_settings.environments.each { key, value -> var_regions.add(key) }
return var_regions
}
def getEnvironments(String region) {
def var_envs = []
yaml_settings.environments."${region}".non_prod.each { key, value -> var_envs.add("\"" + key + "\"") }
return var_envs
}
environment {
yaml_settings = {}
}
pipeline {
agent
{
node
{
label 'docker'
}
}
stages {
stage('Prepare') {
steps{
script{
yaml_settings = readYaml file: "${yaml_file}"
list_regions = getRegions()
properties([
parameters([
choice(choices: list_regions , description: 'Please select region to deploy', name: 'REGION'),
[$class: 'CascadeChoiceParameter', choiceType: 'PT_SINGLE_SELECT', description: 'Please select environment to deploy', filterLength: 1, filterable: false, name: 'ACP_ENVIRONMENTS', randomName: 'choice-parameter-deploy-env', referencedParameters: 'REGION', script: [$class: 'GroovyScript', fallbackScript: [classpath: [], sandbox: false, script: ''], script: [classpath: [], sandbox: true, script: """
envs = getEnvironments($REGION)
return $envs
"""]]]])])}}}}}
Issue:
The getEnvironments method is not returning the value into the variable and its not getting effected in the parameter. But $region value is coming into though.I can do if else based on the reference parameter and get the value but i dont want to use if else coz i will get many values down the line.
HELP APPRECIATED!!

Answer 1

As with many other questions, the issue here is that Jenkins needs to know the parameters before it executes your pipeline. Once the pipeline is running, the parameters have already been defined, and any change to the parameters won't impact this build.
You may want to take a look at the ActiveChoice plugin to address this.