Unexpected attribute app_engine_apis error deploying Python 3 App Engine Flask app

Question

I use Google App Engine standard environemment with Flask Python3 for a current project. This project use as cache the App Engine Memcache (google.appengine.api.memcache).

Currently the cache doesn't work and I think that it's probably because of the dependency on App Engine APIs that need to be enable because when I try to deploy my app (gcloud app deploy) I have this warning: WARNING: There is a dependency on App Engine APIs, but they are not enabled in your app.yaml. Set the app_engine_apis property. WARNING: There is a dependency on App Engine APIs, but they are not enabled in your app.yaml. Set the app_engine_apis property.

My issue is that when I try to set the dependancy in my app.yaml and deploy, I have then this error: Unexpected attribute 'app_engine_apis' for object of type AppInfoExternal.

I also tried with the exact same yaml file than the Google example: https://github.com/googlecodelabs/migrate-python2-appengine/blob/master/mod12b-memcache/app.yaml , it doesn't work.

Here the current app.yaml that I'm trying to use:

runtime: python39
env: standard
app_engine_apis: true

resources:
  cpu: 2
  memory_gb: 4
  disk_size_gb: 15

manual_scaling:
  instances: 2

This issue is almost the same as this question but I couldn't use it to solve my problem: How to deal with `app_engine_apis` warning when updating app.yaml from go114 to go115

Thank you for your help.

Answer 1

Your version of gcloud probably means the app_engine_apis are in the beta version and so you have to do

gcloud beta app deploy

Answer 2

Your Google Cloud SDK is outdated. Per the comments in @NoCommandLine 's answer, your SDK being version 300 is from Jul 2020 whereas the bundled services for 2nd-gen runtimes like Python 3 didn't go into private preview until Jun 2021. They became generally available in Sep 2021 . If you run gcloud components update to get the latest SDK (at the time of this post, it's 410), you should be able to run gcloud app deploy to deploy a Python 3 App Engine app that can access the Memcache bundled service . TL;DR to using bundled services in Python 3:

1. Add app_engine_apis: true to app.yaml
2. Add appengine-python-standard to requirements.txt
3. Import the WSGI wrapper: from google.appengine.api import wrap_wsgi_app
4. Wrap your WSGI object (Flask): app = Flask(__name__); app.wsgi_app = wrap_wsgi_app(app.wsgi_app) app = Flask(__name__); app.wsgi_app = wrap_wsgi_app(app.wsgi_app)
5. Review these instructions , esp. if you're not using Flask
6. Update your Cloud SDK : gcloud components update

NOTE: You no longer need to run pip install -t lib -r requirements.txt to vendor/self-bundle package dependencies... they're now automatically installed for Py3 users (but not Py2 though) when you deploy your app to the cloud.

I recently published a video & codelab (hands-on tutorial) on how to access the bundled services from "Gen2" but realize now I should've mentioned updating your SDK, meaning it covers almost all of the instructions above. :P

For those interested in eventually migrating off Memcache to something more powerful like Redis, I also published content on migrating from Memcache to Cloud Memorystore for Redis , relatively recently as well.