Install a specific plugin on jenkins master via groovy

install-plugin.groovy

// installs single hardcoded plugin
import jenkins.model.*
import java.util.logging.Logger
def logger = Logger.getLogger("")
def installed = false
def initialized = false

def pluginParameter="apache-httpcomponents-client-4-api" // this could be a parameter if we wanted
def plugins = pluginParameter.split()
logger.info("" + plugins)

def instance = Jenkins.getInstance()
def pm = instance.getPluginManager()
def uc = instance.getUpdateCenter()

plugins.each {
  logger.info("[plugins] Checking " + it)
  if (!pm.getPlugin(it)) {
    logger.info("[plugins] Looking UpdateCenter for " + it)
    if (!initialized) {
      uc.updateAllSites()
      initialized = true
    }
    def plugin = uc.getPlugin(it)
    if (plugin) {
      logger.info("Installing " + it)
      def installFuture = plugin.deploy()
      while(!installFuture.isDone()) {
        logger.info("[plugins] Waiting for plugin install: " + it)
        sleep(3000)
      }
      installed = true
    }
  }
}
if (installed) {
  logger.info("Plugins installed, initializing a restart!")
  instance.save()
  instance.restart()
}