Progressively read a Jenkins job console output using Groovy

JenkinsTailJobConsole.groovy

def jenkinsBase = // Set to Jenkins base URL
def jenkinsJob =  // Set to Jenkins job name
def address = null
def response = null
def start = 0 // Start at offset 0
def cont = true // This semaphore holds the value of X-More-Data header value
try {
  while (cont == true) { // Loop while X-More-Data value is equal to true
    address = "${jenkinsBase}/job/${jenkinsJob}/lastBuild/logText/progressiveText?start=${start}"
    println("${address}")
    def urlInfo = address.toURL()
    response = urlInfo.openConnection()
    if (response.getResponseCode() != 200) {
    	throw new Exception("Unable to connect to " + address) // Throw an exception to get out of loop if response is anything but 200
  	}
    if (start != response.getHeaderField('X-Text-Size')) { // Print content if the starting offset is not equal the value of X-Text-Size header
      response.getInputStream().getText().eachLine { line ->
        println(line)
      }  
    }
    start = response.getHeaderField('X-Text-Size') // Set new start offset to next byte
    cont = response.getHeaderField('X-More-Data') // Set semaphore to value of X-More-Data field. If this is anything but true, we will fall out of while loop
    sleep(3000) // wait for 3 seconds 
  }
}
catch (Exception ex) {
  println (ex.getMessage()) 
}

This is awesome, thank you!