A simple class to trigger Google Cloud Functions.

google_cloud_functions.php

<?php

// Exit if accessed directly.
defined( 'ABSPATH' ) || exit;

if ( ! class_exists( 'Google_Cloud_Functions' ) ) {

	/**
	 * Google Cloud Functions
	 */
	class Google_Cloud_Functions {

		/**
		 * __construct function.
		 *
		 * @access public
		 * @return void
		 */
		public function __construct() {

		}

		/**
		 * Trigger Google Cloud Function.
		 * @param  string $region        Region.
		 * @param  string $project       Project.
		 * @param  string $function_name Function Name.
		 * @param  array  $body          Body.
		 * @return mixed                Results or error.
		 */
		public function trigger( string $region = '', string $project = '', string $function_name = '', $body = '', bool $cache = false, bool $debug = false ) {

			// Missing Valid Region.
			if( empty( $region ) ) {
				return new WP_Error( 'missing-region', __( "Please provide a valid Google Cloud Region (https://cloud.google.com/compute/docs/regions-zones/).", "google-cloud-functions" ) );
			}

			// Missing Valid Project.
			if( empty( $project ) ) {
				return new WP_Error( 'missing-project', __( 'Please provide a valid project name.', 'google-cloud-functions' ) );
			}

			// Missing Valid Function Name.
			if( empty( $function_name ) ) {
				return new WP_Error( 'missing-function-name', __( 'Please provide a valid function name.', 'google-cloud-functions' ) );
			}

			// Define Function URL.
			$function_url = esc_url( 'https://' . $region .'-' . $project . '.cloudfunctions.net/' . $function_name );

			// Use a Cached Response.
			if( true === $cache ) {
				$cache_name = 'gcf_cache_' . md5( $function_url );
				$response = get_transient( $cache_name );
				if( false === $response ) {
					$response = wp_remote_post( $function_url, array( 'body' => $body ) );
					set_transient( $cache_name, $response );
				}
			} else {
				$response = wp_remote_post( $function_url, array( 'body' => $body ) );
			}

			// Debug Response.
			if ( true === $debug ) {
				error_log( print_r( $response ) );
			}

			// Display Error.
			if( is_wp_error( $response ) ) {
    		return $response->get_error_message();
			}

			// Return Response.
			return wp_remote_retrieve_body( $response );

		}
	}
}