Delete topics with a certain prefix name from Google PubSub

deleteUnusedTopics.php

<?php

require_once __DIR__ . '/../vendor/autoload.php';

## Delete all topics and subscriptions with name having prefix: `gcloud_testing_`
use Google\Cloud\PubSub\PubSubClient;

$client = new PubSubClient();
$topics = $client->topics();

$countTopic = 0;
$countSubscription = 0;
foreach ($topics as $topic) {
    if (str_contains($topic->name(), 'gcloud_testing_')) {
        $countTopic += 1;
        echo $topic->name() . "\n";
        // Delete all subscriptions in the topic
        $subscriptions = iterator_to_array($topic->subscriptions());
        foreach ($subscriptions as $subscription) {
            $countSubscription += 1;
            if (str_contains($subscription->name(), 'gcloud_testing_')) {
                $subscription->delete();
            }
        }
        $topic->delete();
    }
}
echo "Deleted $countTopic topics and $countSubscription subscriptions.\n";