Finally found the issue… It seems my CDN is somehow setup to only allow retrieving files with signed URLs and that requires additional configuration to handle. Google Cloud Run will auth with the service account running the instance via token, but this isn’t enough to auth the signed URLs. This is why I was able to upload but not view from the Cloud Run instance.
ERROR: you need a private key to sign credentials.the credentials you are currently using <class 'google.auth.compute_engine.credentials.Credentials'> just contains a token. see Authentication — google-api-core documentation for more details.`
Thank you for the help debugging this, and sorry that it indeed ended up to be a “Doh” moment in my GCS configs. I was finally able to get the error to print out after disabling the DRF Camel Case plugin which was where the exception in my previous message was being thrown from.
All in all, I do think it would be nice if Django would have reported this error in retrieving the file rather than just showing it as null. Even if it were just to be logged as a warning.