start offline jenkins slaves

start_off_slaves.groovy

import hudson.model.*
import hudson.node_monitors.*
import hudson.slaves.*
import java.util.concurrent.*
 
jenkins = Hudson.instance
 
import javax.mail.internet.*;
import javax.mail.*
import javax.activation.*
 
def getEnviron(computer) {
   def env
   def thread = Thread.start("Getting env from ${computer.name}", { env = computer.environment })
   thread.join(2000)
   if (thread.isAlive()) thread.interrupt()
   env
}
 
def slaveAccessible(computer) {
    getEnviron(computer)?.get('PATH') != null
}
 
 
def numberOfflineNodes = 0
def numberNodes = 0
for (slave in jenkins.slaves) {
    def computer = slave.computer
    numberNodes ++
    println ""
    if (computer.offline) {
        numberOfflineNodes ++
        println "${computer.name}"
        println('\tcomputer.isOffline: ' + slave.getComputer().isOffline()); 
        println('\tcomputer.isTemporarilyOffline: ' + slave.getComputer().isTemporarilyOffline());
        println('\tcomputer.getOfflineCause: ' + slave.getComputer().getOfflineCause());
        println('\tcomputer.offline: ' + computer.offline); 
        println('\tattempting to online slave...'); 
        computer.connect(true)
    }
}
println ("Number of Offline Nodes: " + numberOfflineNodes)
println ("Number of Nodes: " + numberNodes)