mu-environment-files.php

<?php
/**
 * Plugin Name: Environment Files
 * Description: Load environment-specific config files
 *
 */

if ( 'local' !== VIP_GO_ENV ) {
	if ( file_exists( WPCOM_VIP_PRIVATE_DIR . '/' . VIP_GO_ENV . '-config.php' ) ) {
		require_once( WPCOM_VIP_PRIVATE_DIR . '/' . VIP_GO_ENV . '-config.php' );
	}
} else {
	if ( file_exists( __DIR__ . '/../private/local-config.php' ) ) {
		require_once( __DIR__ . '/../private/local-config.php' );
	}
}