flysystem_gcs_cors

Field type behavior

This module intentionally alters Drupal's core file and image field type definitions when it is enabled. The altered classes keep the core storage shape and field semantics, but adjust upload validation for fields whose uri_scheme is backed by a Flysystem GCS configuration. Those GCS-backed fields can accept uploads larger than PHP's normal upload limit because the browser uploads the object directly to GCS instead of streaming the file through PHP.

The behavior is site-wide because Drupal upload validators are resolved from the field item class, not only from the selected widget. Non-GCS file and image fields still use PHP's upload limit. GCS-backed fields still respect a field's configured max_filesize when one is set.

Files up to 5 GiB use the existing signed POST policy upload. Larger files use a signed GCS resumable upload session and are sent from the browser in 32 MiB chunks. The module-wide default maximum upload size is 10 GB. Site builders can raise it as high as GCS's 5 TiB object limit, and individual fields can still set a smaller max_filesize.

For resumable uploads, the bucket CORS policy must allow POST and PUT and must expose the Location and Range response headers. Re-save the module's CORS settings form after updating to apply those headers to the selected bucket.

Site builders should enable this module only when the site expects core file or image fields that use a GCS-backed Flysystem scheme to participate in this direct-upload behavior. Custom field type replacements or other modules that also alter the core file or image field classes can conflict with this module and should be reviewed before enabling both modules together.

Testing locally

The CI tests that run on pull requests in GitHub leverage the docker images built in islandora/islandora_ci. The CI tests a wide range of PHP and Drupal version combinations. You can run these same tests locally if you have docker installed.

Run the default suite with:

make test

Override the Drupal version, PHP version, or PHPUnit test suite as needed:

make test DRUPAL_VERSION=11.3 PHP_VERSION=8.3
make test TEST_SUITE=FunctionalJavascript

The test target will:

• create the ci-default Docker network if needed
• start a chromedriver container if one is not already running
• run the Islandora CI container with this module mounted read-only

Stop the background chromedriver container with:

make test-stop