Django project deployed to GCP App Engine returns [Errno 30] Read-only file system when uploading an image

[HitLuca]

Tried to look for solutions but I don't seem to have found any, so I'm opening a new issue:
I have a django project which uses a gcp bucket for images upload. Locally it works fine, but when deployed on GCP App Engine and I try to upload an image I get this exception

[Errno 30] Read-only file system: '/workspace/media'

I am confident my env vars are correct and the django-storages library gets set up correctly at startup, but I really can't understand why the backend is trying to access the local filesystem instead of uploading the image. The bucket setup code is below:

if env("USE_BUCKET_AS_MEDIA_FOLDER"):
    # Set "media" folder
    DEFAULT_FILE_STORAGE = "myproject.gcsutils.Media"

    GS_BUCKET_NAME = env("MEDIA_FOLDER_BUCKET_NAME")

    # Add an unique ID to a file name if same file name exists
    GS_FILE_OVERWRITE = False

    GCP_CREDENTIALS = env("GCP_CREDENTIALS")

    GS_CREDENTIALS = service_account.Credentials.from_service_account_info(
        json.loads(GCP_CREDENTIALS)
    )

And here are the contents of myproject.gcsutils.py

from storages.backends.gcloud import GoogleCloudStorage

def Media():
    return GoogleCloudStorage(location="media")

Happy to add any useful details, any help would be very appreciated

[jschneier]

A SpooledTemporaryFile is used as the backing storage which will rollover to disk at a configurable amount. However, the default is to not rollover at all. You haven't set that GS_MAX_MEMORY_SIZE setting, have you?

If not, a larger stack trace would be helpful.

[jschneier]

Need more info.