README

WACK CloudFront Invalidation is a WordPress plugin that helps you to run invalidation on CloudFront after a post is published or updated.

It is designed to work with the WACK Stack, but can be used with any WordPress installation that uses CloudFront as a CDN.

How it works

This plugin listens to the save_post action and sends an invalidation request to CloudFront when a post is published or updated.

Installation

• Requires PHP 8.1 or later
• Requires WordPress 6.7 or later
• Requires Composer

Using Composer

composer require kodansha/wack-cloudfront-invalidation

Note

This plugin is not available on the WordPress.org plugin repository. The only installation method currently available is through Composer.

Configuration

AWS credentials

WACK CloudFront Invalidation uses AWS SDK for PHP to send invalidation requests to CloudFront, so you need to configure AWS credentials. Please refer to the AWS SDK for PHP documentation for more information on how to set up credentials.

CloudFront Distribution ID

Specify the CloudFront Distribution ID to be invalidated using the WACK_CF_INV_DISTRIBUTION_ID constant.

Add the following to your wp-config.php file or somewhere similar:

define('WACK_CF_INV_DISTRIBUTION_ID', 'YOUR_CLOUDFRONT_DISTRIBUTION_ID');

Note

Currently, only the CloudFront Distribution ID specified by the WACK_CF_INV_DISTRIBUTION_ID constant will be targeted, and it's not possible to specify more than one CloudFront Distribution.

Invalidation Path Settings

After installing the WACK CloudFront Invalidation plugin, a settings page is added to the WordPress admin menu under WACK Stack > WACK CF Inv.

In this settings page, you can configure CloudFront invalidation paths for each post type.

Important

To specify multiple paths, list them separated by line breaks. Empty lines will be ignored.

wack_cf_inv_{post_type}_paths filter

This plugin allows you to customize the CloudFront invalidation paths per post type using a filter.

The following filter is applied before issuing a CloudFront invalidation:

$paths = apply_filters('wack_cf_inv_' . $post->post_type . '_paths', $paths, $post);

• {post_type}: Replace with your custom post type (e.g., post, news, etc.).
• $paths: Array of paths determined by the post type and the plugin settings.
• $post: The WP_Post object being processed.

Example

To add the homepage (/) to the invalidation paths for the post post type, add the following to your theme’s functions.php or a custom plugin:

add_filter('wack_cf_inv_post_paths', function($paths, $post) {
    $paths[] = '/';
    return $paths;
}, 10, 2);

This filter allows you to modify or extend the list of paths to be invalidated for each post type, providing flexible cache control.

Tip

If you want to modify or extend the list of paths for the news post type, use wack_cf_inv_news_paths instead of wack_cf_inv_post_paths.

Tips

WACK_CF_INV_DRY_RUN constant

If the WACK_CF_INV_DRY_RUN constant is defined and set to true, the actual CloudFront invalidation execution will be skipped, and only log output will be performed.

You can use this for testing behavior in development environments.

WACK Log integration

If you have the WACK Log plugin installed, various logs from WACK CloudFront Invalidation will be output to standard output using WACK Log.