Bedrock Multisite WP_CONTENT_URL

When using Bedrock in a WordPress multisite setup, media URLs point to the main site’s domain (eg. example.com/app/uploads/sites/2/2022/10/image.jpg). You can change the media domain to the subsite’s domain (eg. subsite.example.com/app/uploads/sites/2/2022/10/image.jpg) by updating config/application.php.

Replace

Config::define('WP_CONTENT_URL', Config::get('WP_HOME') . Config::get('CONTENT_DIR'));

by

if (isset($_SERVER['HTTP_HOST'])) {
    $protocol    = isset($_SERVER['HTTPS']) ? 'https' : 'http';
    $webrootHost = $protocol . '://' . $_SERVER['HTTP_HOST'];
    Config::define('WP_CONTENT_URL', $webrootHost . Config::get('CONTENT_DIR'));
} else {
    Config::define('WP_CONTENT_URL', Config::get('WP_HOME') . Config::get('CONTENT_DIR'));
}