Scope a solution ✅

Add new method to handle the notice for RocketCDN here and the newly created method to the admin_notices filter here.

The method created above should only be displayed based on this conditions here

Then in this file add a new method

public function update_cdn_name( $new_version, $old_version ): void {
		if ( version_compare( $old_version, '3.17.2', '>' ) ) {
			return;
		}
                delete_transient('rocketcdn_status');

		$this->api_client->get_subscription_data();
	}

Add the APiClient as constructor to Subscriber

Finally, add the method created as a callback to wp_rocket_upgrade

Add test, update existing ones.

Estimation

[S]

As the approach is based on the RocketCDN API, the plugin release with this change must happen after this is released: https://github.com/wp-media/rocket-cdn/issues/546
Depending on the delay on the service team side, we might want to take this out of 3.17.2

Removing the 3.17.2 milestone as the RocketCDN API won't be ready for 3.17.2.

We'll display a (success/warning/info) dismissible notice in the WP Rocket plugin settings page

This point is still not handled by this grooming, correct? @Khadreal

It's the notice in WPR is dismissible by default, so I don't think it's needed to cover that again.

I'm not talking about the dismiss, I'm talking about the notice itself, I believe we need to show it in WPR settings along with rocketCDN settings page.
cc @piotrbak

@wordpressfan Yes, the notice should be there.

@DahmaniAdame I think we should display a blue, notification notice. WDYT?

@piotrbak I agree. It's informational and non-critical. Blue will do.

We can use orange if we need a second message later in the process if we notice that the former CNAME is still heavily used.

Grooming to complete with the notice, as pointed out above, before moving it to Grooming to Review.

Everything related to RocketCDN should be handled in RocketCDN classes. The update of the CDN cname can be done in the DataManagerSubscriber class, which already has the API client as a dependency.

We also need to take into account saving the old CDN URL to be able to display it in the notice.

Moving it back to grooming to do.

Grooming

Will take the grooming mentioned above by @Khadreal with some small changes.

Proposed Solution

In this subscriber:

Add a new callback to that array update_cdn_name, this method will be triggered with update action wp_rocket_upgrade, and will save the old cdn url then force reloading subscription data again as below:

public function update_cdn_name( $new_version, $old_version ): void {
	if ( version_compare( $old_version, '3.17.2', '>' ) ) {
		return;
	}
	
	$old_subscription_data = $this->api_client->get_subscription_data();
	
	if ( ! $old_subscription_data['is_active'] || empty( $old_subscription_data['cdn_url'] ) ) {
		return;
	}
	
	update_option( 'rocketcdn_old_url', $old_subscription_data['cdn_url'] );

	delete_transient('rocketcdn_status');

	$this->api_client->get_subscription_data();
}

For showing the notice, We will create a new view file here:

https://github.com/wp-media/wp-rocket/blob/d70151f977efdf2e57a5c6c863ffd8f31a70a905/inc/Engine/CDN/RocketCDN/views

with the notice HTML contents, then we will create a new method here:

To get the old cdn url from the option rocketcdn_old_url mentioned above and the new cdn url, then will call the generate method to show the view file that we created above.

We may need to remove the option rocketcdn_old_url with notice dismiss, also with plugin removal.

Then adjust tests.

Effort

[S]

LGTM