Jenkins declarative pipeline - User input parameters - jenkins-pipeline

Question

I've looked for some example of user input parameters using Jenkins declarative pipeline, however all the examples are using the scripted pipelines. Here is a sample of code I'm trying to get working:
pipeline {
agent any
stages {
stage('Stage 1') {
steps {
input id: 'test', message: 'Hello', parameters: [string(defaultValue: '', description: '', name: 'myparam')]
sh "echo ${env}"
}
}
}
}
I can't seem to work out how I can access the myparam variable, it would be great if someone could help me out.
Thanks

Answer 1

When using input, it is very important to use agent none on the global pipeline level, and assign agents to individual stages. Put the input procedures in a separate stage that also uses agent none. If you allocate an agent node for the input stage, that agent executor will remain reserved by this build until a user continues or aborts the build process.
This example should help with using the Input:
def approvalMap // collect data from approval step
pipeline {
agent none
stages {
stage('Stage 1') {
agent none
steps {
timeout(60) { // timeout waiting for input after 60 minutes
script {
// capture the approval details in approvalMap.
approvalMap = input
id: 'test',
message: 'Hello',
ok: 'Proceed?',
parameters: [
choice(
choices: 'apple\npear\norange',
description: 'Select a fruit for this build',
name: 'FRUIT'
),
string(
defaultValue: '',
description: '',
name: 'myparam'
)
],
submitter: 'user1,user2,group1',
submitterParameter: 'APPROVER'
}
}
}
}
stage('Stage 2') {
agent any
steps {
// print the details gathered from the approval
echo "This build was approved by: ${approvalMap['APPROVER']}"
echo "This build is brought to you today by the fruit: ${approvalMap['FRUIT']}"
echo "This is myparam: ${approvalMap['myparam']}"
}
}
}
}
When the input function returns, if it only has a single parameter to return, it returns that value directly. If there are multiple parameters in the input, it returns a map (hash, dictionary), of the values. To capture this value we have to drop to groovy scripting.
It is good practice to wrap your input code in a timeout step so that build don't remain in an unresolved state for an extended time.