WordPress Plugin to show the Server Address (IP) in Admin-Bar

dna-ip-to-admin-bar.php

<?php

/**
 * Plugin Name: dna IP to Admin Bar
 * Plugin URI:  https://gist.github.com/dnaber-de/5219882
 * Description: Shows the current Server IP in the Admin Bar. (Requires PHP 5.3)
 * Author:      David Naber
 * Author URI:  http://dnaber.de/
 * Version:     2013.03.22
 * License:     MIT
 * License URI: http://opensource.org/licenses/mit-license.php
 */
namespace dna\ip_to_admin_bar;

if ( ! function_exists( 'add_filter' ) )
	return;

add_action( 'plugins_loaded', array( Plugin::get_instance(), 'init_plugin' ) );

class Plugin {

	/**
	 * the plugin instance
	 *
	 * @var Plugin
	 */
	private static $instance = NULL;

	/**
	 * get the plugin instance
	 *
	 * @return Plugin
	 */
	public static function get_instance() {

		if ( NULL === self::$instance )
			self::$instance = new self;

		return self::$instance;
	}

	/**
	 * hook in
	 *
	 * @wp-hook plugins_loaded
	 */
	public function init_plugin() {

		add_action( 'wp_before_admin_bar_render', array( $this, 'admin_bar' ) );
	}

	/**
	 * add a item to the admin bar
	 *
	 * @wp-hook wp_before_admin_bar_render
	 * @global $wp_admin_bar;
	 * @return
	 */
	public function admin_bar() {

		$server_addrss = $_SERVER[ 'SERVER_ADDR' ];
		$GLOBALS[ 'wp_admin_bar' ]->add_menu(
			array(
				'id'    => 'dna-ip-addr',
				'title' => $server_addrss,
				'href'  => '#'
			)
		);
	}
}