Read interactive input in Jenkins pipeline into shell script

Question

I have pipeline with input which is correctly echoing i.e. 'Destroy: true' but not in the next echo inside 'sh' script. I tried ${destroyCluster} or $destroyCluster there but no difference , echo shows empty

script {   
        def destroyCluster = input(
             id: 'destroyCluster', message: 'Destroy cluster ?', 
             parameters: [[$class: 'BooleanParameterDefinition', defaultValue: false, description: 'Destroy cluster', name: 'destroy'],
                        ]
                    )
echo ("Destroy: "+ destroyCluster)
sh '''
    echo "${destroyCluster}"
'''

question from:https://stackoverflow.com/questions/65849558/read-interactive-input-in-jenkins-pipeline-into-shell-script

Answer 1

The problem here is you need to either interpolate the Groovy variable within Groovy if you are passing it to the shell step method for interpretation, or use it as a first class expression within Groovy.

Showing examples for both of these possibilities:

script {   
  def destroyCluster = input(
    id: 'destroyCluster',
    message: 'Destroy cluster ?', 
    parameters: [[$class: 'BooleanParameterDefinition',
                  defaultValue: false,
                  description: 'Destroy cluster',
                  name: 'destroy']])
  
  echo "Destroy: ${destroyCluster}" // proper Groovy interpolation
  print destroyCluster // first class expression

If nothing is still output to standard out in the Jenkins Pipeline logs, then destroyCluster is a void type method and does not return anything. In that case, you will be unable to assign and utilize its return value.