[PP-1] S3 Access Denied Request has expired - getExternalUrl() cached beyond presign timeout

Hopefully 🌱 [Meta] Allow StreamWrapper's to provide cacheability metadata Active can fix this.

can you leverage this? https://www.drupal.org/project/cache_control_override →

RE:CCO

I do not believe so.

Firstly because there is currently no ability to even provide metadata for caching from a StreamWrapper, meaning there is nothing to bubble up to CCO.

Secondly:
IIRC CCO has known problems that can only be solved by Core fixing its metadata handling problems

I found a workaround for this that is good enough for my own needs. Basically, you need to user alter hooks to add cachebility metadata at the entity level. In my case, I wanted to add a max-age to a node when it had a file field with a presigned url that was set to expire.

This could be simplified. I had two different fields I had to take into account. Posting for posterity:

/**
 * Implements hook_node_load().
 */
function mymodule_node_load($entities) {
  $map = [
    // node-type => s3 key.
    'song' => [
      's3_key' => 'songs',
      // We only override the max-age if one of the file fields in actually populated.
      'required_fields' => ['field_song_audio', 'field_song_archive'],
    ],
    'firmware_release' => [
      's3_key' => 'firmware-releases',
      'required_fields' => ['field_firmware_archive'],
    ]
  ];

  foreach ($entities as $entity) {
    if ($entity->getEntityTypeId() == 'node' && in_array($entity->getType(), array_keys($map))) {
      if (!shouldOverrideCacheHeaders($map, $entity)) {
        continue;
      }

      $config = \Drupal::config('s3fs.settings');
      if ($config->get('presigned_urls')) {
        $presigned_urls = getPresignedUrls($config->get('presigned_urls'));
        $s3_key = $map[$entity->getType()]['s3_key'];
        foreach ($presigned_urls as $blob => $timeout) {
          if (preg_match("^$blob^", $s3_key)) {
            $cachebility_metadata = new CacheableMetadata();
            $cachebility_metadata->setCacheMaxAge((int) $timeout);
            $entity->addCacheableDependency($cachebility_metadata);
            break;
          }
        }
      }
    }
  }
}

/**
 * @param $map
 * @param $entity
 *
 * @return bool
 */
function shouldOverrideCacheHeaders($map, $entity): bool {
  foreach ($map[$entity->getType()]['required_fields'] as $field_name) {
    if (!$entity->{$field_name}->isEmpty()) {
      return TRUE;
    }
  }

  return FALSE;
}

/**
 * @param string $presigned_urls_config
 *
 * @return array
 * @see \Drupal\s3fs\StreamWrapper\S3fsStream->__construct())
 */
function getPresignedUrls(string $presigned_urls_config): array {
  $presigned_urls = [];
  foreach (explode(PHP_EOL, $presigned_urls_config) as $line) {
    $blob = trim($line);
    if ($blob) {
      if (preg_match('/(.*)\|(.*)/', $blob, $matches)) {
        $blob = $matches[2];
        $timeout = $matches[1];
        $presigned_urls[$blob] = $timeout;
      }
      else {
        $presigned_urls[$blob] = 60;
      }
    }
  }
  return $presigned_urls;
}