Admin bar menu entry to confirm the website is running on localhost

gistfile1.php

<?php
/*
 * Add a new entry in the admin bar that will display the "LOCL INSTANCE" text.
 * I find this approach especially useful when running remote websites on the
 * localhost server and, because the URL is the same, it's hard to tell which
 * is which. This new menu entry will confirm this is a local instance.
 *
 * Usage: Add this code to your theme's functions.php file
 *
 * Note: Do not forget to remove it when you upload changes to the remote server
 */
add_action('admin_bar_menu', 'wpk_local_adminbar_notice', 100);
function wpk_local_adminbar_notice($wp_admin_bar){
	$args = array(
		'id' => 'custom-notice-local',
		'title' => 'LOCAL INSTANCE',
		'meta' => array(
			'class' => 'custom-notice-class'
		)
	);
	$wp_admin_bar->add_node($args);
}
add_action('admin_head', 'wpk_local_adminbar_notice_styles', 100);
add_action('wp_head', 'wpk_local_adminbar_notice_styles', 100);
function wpk_local_adminbar_notice_styles(){ ?>
	<style type="text/css" id="wpk_local_adminbar_notice_styles">
		#wpadminbar .ab-top-menu .custom-notice-class,
		#wpadminbar .ab-top-menu .custom-notice-class:hover,
		#wpadminbar .ab-top-menu .custom-notice-class:active,
		#wpadminbar .ab-top-menu .custom-notice-class:focus { background: #ffa500 !important; }
		#wpadminbar .ab-top-menu .custom-notice-class:hover div,
		#wpadminbar .ab-top-menu .custom-notice-class:active div,
		#wpadminbar .ab-top-menu .custom-notice-class:focus div,
		#wpadminbar .ab-top-menu .custom-notice-class div { color: #000; cursor: default; background: #ffa500; }
		#wpadminbar .ab-top-menu .custom-notice-class:hover div { color: #000 !important; }
	</style>
<?php }