在运行此Jenkinsfile时，它将提示用户选择要构建的环境。用户可以选择"pre"或"prod"，然后Jenkins将相应地构建所选的环境。如果用户没有提供选项参数，则Jenkins将默认构建"pre"环境。

pipeline {
agent any

parameters {
choice(name: 'BUILD_ENVIRONMENT',
choices: ['pre', 'prod'],
description: 'Select environment to build')
}

stages {
stage('Build') {
steps {
if("${params.BUILD_ENVIRONMENT}" == "prod") {
echo 'Building production environment...'
// Add build commands for production environment
} else {
echo 'Building pre-production environment...'
// Add build commands for pre-production environment
}
}
}
}
post {
always {
echo 'Build finished'
}
}
}