Get a list of env vars available in a job …

By visiting a specific url every Jenkins instance has:

https://<jenkins url>/env-vars.html

Starter Jenkinsfile

pipeline {
    agent any
    docker {
        image "maven:3.6.3-jdk-8"
        label "docker"
    }

    parameters {
        string(name: "", default: "", description: "")
        choice(name: "", choices: ["yes", "no"], description: "")
    }

    stages {
        stage("Checkout Code") {
            when {
            } 
            steps {
                script {
                }
            }
        }
    }
    
    post {
        always {
        }
    }
}