!!! URGENT !!!

The problem:

The crux of the matter is that I cannot find any way, nor any examples, on how to use the Python 3 runtime in my local dev environment to:

• Upload an image to Google Cloud Storage
• Use the bundled Image service to generate dynamic thumbnails from this image

More info:

The App Engine bundled Images service in the dev server, in the Python 3 runtime, cannot find any images referenced by their blob keys if the image was uploaded to Cloud Storage by the Python 3 runtime (however it works fine if the image was uploaded using the Python 2 runtime).

Expectations:

Using the Python 3 runtime in the dev server, I should be able to upload an image to Cloud Storage, and then use the Images service should find image and return accordingly.

The bundles Images service should be fully supported as shown here.

Steps to reproduce and other information:

I've been migrating from Python 2.7 webapp2 to Python 3 Flask.

I'm currently stuck on trying to get the Python 3 runtime to mimic the Python 2 runtime behaviour when it comes to accessing Google Cloud Storage.

The old Python 2.7 runtime automatically used the local Cloud Storage emulator, but I can only get the Python 3 runtime to save to the cloud based Google Cloud Storage.

This means anything running on local dev that uses the blob key of a Cloud Storage object (e.g. the Images API), is failing.

I tried auto-authenticating with Cloud Storage like this:

from google.cloud import storage
from google.auth.app_engine import Credentials
    
credentials = Credentials()
    
client = storage.Client(credentials=credentials)

but then any call (e.g. stat()) to Cloud Storage would timeout.

So to get the uploads to Cloud Storage to work in the dev server, I instead download a JSON credential file and used this instead:

from google.cloud import storage
from google.auth.app_engine import Credentials

from google.oauth2 import service_account

credentials = service_account.Credentials.from_service_account_file('/file/path.json')

client = storage.Client(credentials=credentials)

I suspect this is the culprit (using JSON file credentials instead of auto-auth), but not sure how to get auto-auth working without timing out.

!!! URGENCY !!!

This has been marked as urgent since the Python 2 runtime will drop from the supported list of runtimes in only a few days!