@Override
  public boolean perform(
      final AbstractBuild<?, ?> build, final Launcher launcher, final BuildListener listener) {

    PrintStream jLogger = listener.getLogger();
    VSphereLogger.vsLogger(jLogger, "Attempting to use server configuration: " + serverName);
    boolean changed = false;

    try {
      Server server = VSpherePlugin.DescriptorImpl.get().getServer(serverName);
      // Need to ensure this server still exists.  If it's deleted
      // and a job is not opened, it will still try to connect
      VSpherePlugin.DescriptorImpl.get().checkServerExistence(server);

      vsphere = VSphere.connect(server);
      changed = markVm(build, launcher, listener);

    } catch (VSphereException e) {
      VSphereLogger.vsLogger(jLogger, e.getMessage());
      e.printStackTrace(jLogger);
    }

    return changed;
  }
 public ListBoxModel doFillServerNameItems() {
   return VSpherePlugin.DescriptorImpl.get().doFillServerItems();
 }