Is it possible for an IoT device on Google Cloud Platform to upload a file to the cloud somehow? In this case it's not exactly a telemetry data publishing. A direct access to the bucket could be useful. Either that or access to my AppEngine-based application, but if I upload it to my app (that will in the next step put the file into a bucket), how can I possibly authenticate the device to make sure that the device that sends it to me is actually the device it claims to be?
I managed to solve the problem by passing a Signed URL to the device via the configuration. https://cloud.google.com/storage/docs/access-control/signed-urls