def builders = [:].asSynchronized()

node('master') {
    stage('Pre-flight') {
        String[] node_names = []

        for (Node node in Hudson.instance.nodes) {
            if (node != null && node.toComputer() != null && node.toComputer().online) {
              node_names += node.getNodeName() 
            }
            node = null
        }

        for (node_name in node_names) {
            def final_node_name = node_name
            
            builders[final_node_name] = {
                node(final_node_name) {
                    timeout(time:5, unit: "MINUTES") {
                        def usage = ''
                        usage = sh(script: "df -h / | tail -n 1 | awk '{print \$5}'", returnStdout: true).trim()
                        println "usage before: ${usage}"
                    
                        sh """#!/bin/bash -x
                        touch ${WORKSPACE}/.dont_remove_workspace
                        sudo find ${WORKSPACE}/.. -mindepth 1 -maxdepth 1 -type d -mmin +180 -print -exec sudo rm -rf {} \\;
                        rm -f ${WORKSPACE}/.dont_remove_workspace
                        """
                        usage = sh(script: "df -h / | tail -n 1 | awk '{print \$5}'", returnStdout: true).trim()
                        println "usage after: ${usage}"
                    }
                }
            }
        }
    }
}


pipeline {
    agent { node { label 'master'} }
    
    triggers { cron('H * * * *')} 
    
    stages{
        stage ('Do the cleanup') {
            steps {
                script {
                    if (builders == [:]) {
                        println "No nodes found"
                        currentBuild.result = 'SUCCESS'
                        return
                    }
                    parallel builders
                }
            }
        }
    }
}