Force WP Engine SSL

force-wpengine-ssl.php

<?php
/**
 * Plugin Name: Force WP Engine SSL
 * Description: Prevent WP Engine's Staging & Development environments from loading via http
 * Version:     1.0
 * Author:      Patrick Haney
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License version 2, as published by the
 * Free Software Foundation. You may NOT assume that you can use any other
 * version of the GPL.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.
 *
 * Based on Bill Erickson's work: https://www.billerickson.net/force-ssl-on-wpengine/
 *
 * @package    ForceWPEngineSSL
 * @since      1.0.0
 * @copyright  Copyright (c) 2019, Patrick Haney
 * @license    GPL-2.0+
 */

function force_wpengine_ssl() {
    if( !is_ssl() && strpos( home_url(), 'wpengine' ) ) {
        wp_redirect( 'https://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'], 301 );
        exit();
    }
}
add_action( 'template_redirect', 'force_wpengine_ssl' );