Using the Active Choices Parameter plugin is probably the best choice, but if for some reason you can't (or don't want to) use a plugin, you can still achieve dynamic parameters in a Declarative Pipeline.
Here is a sample Jenkinsfile:
def list_wrap() {
sh(script: 'echo choice1 choice2 choice3 choice4 | sed -e "s/ /\\n/g"', , returnStdout: true)
}
pipeline {
agent any
stages {
stage ('Gather Parameters') {
steps {
timeout(time: 30, unit: 'SECONDS') {
script {
properties([
parameters([
choice(
description: 'List of arguments',
name: 'service_name',
choices: 'DEFAULT\n' + list_wrap()
),
booleanParam(
defaultValue: false,
description: 'Whether we should apply changes',
name: 'apply'
)
])
])
}
}
}
}
stage ('Run command') {
when { expression { params.apply == true } }
steps {
sh """
echo choice: ${params.service_name} ;
"""
}
}
}
}
This embeds a script {} in a stage, which calls a function, which runs a shell script on the agent/node of the Declarative Pipeline, and uses the script's output to set the choices for the parameters. The parameters are then available in the next stages.
The gotcha is that you must first run the job with no build parameters in order for Jenkins to populate the parameters, so they're always going to be one run out of date. That's why the Active Choices Parameter plugin is probably a better idea.
You could also combine this with an input command to cause the pipeline to prompt the user for a parameter:
script {
def INPUT_PARAMS = input message: 'Please Provide Parameters', ok: 'Next',
parameters: [
choice(name: 'ENVIRONMENT', choices: ['dev','qa'].join('\n'), description: 'Please select the Environment'),
choice(name: 'IMAGE_TAG', choices: getDockerImages(), description: 'Available Docker Images')]
env.ENVIRONMENT = INPUT_PARAMS.ENVIRONMENT
env.IMAGE_TAG = INPUT_PARAMS.IMAGE_TAG
}
Credit goes to Alex Lashford (https://medium.com/disney-streaming/jenkins-pipeline-with-dynamic-user-input-9f340fb8d9e2) for this method.