WordPress - Add Basic Auth to Remote Requests

functions.php

/**
 * function to filter the remote request arguments to ensure we are passing
 * http auth headers when remotely calling from staging or dev environments
 * only used if HOST of requested URL matches the site's home HOST and if the auth
 * exists
 *
 * @param array $_the_args The existing arguments passed with the request.
 * @param string $_the_url The URL being requested.
 * 
 */
if( ! function_exists( 'remote_auth_filter' ) ) {

	function remote_auth_filter( $_the_args, $_the_url ) {

		// parse the passed URL
		$_url = wp_parse_url( $_the_url, PHP_URL_HOST );

		// now get the site's home url and parse it for the host as well
		$_home = wp_parse_url( get_site_url( ), PHP_URL_HOST );

		// we only want to do this if the url requested, and the site hom url match
		if( $_url === $_home ) {

			// check if we have basic auth
			if( isset( $_SERVER["HTTP_AUTHORIZATION"] ) ) {
			
				// add it to our arguments as it is
				$_the_args['headers']['Authorization'] = $_SERVER["HTTP_AUTHORIZATION"];

			}

		}

		// return them
		return $_the_args;

	}

}

// now hook into the proper filter
add_filter( 'http_request_args', 'remote_auth_filter', PHP_INT_MAX, 2 );