Known Issues in the App Engine Flexible Environment

Region ID

The REGION_ID is a code that Google assigns based on the region you select when you create your app. Including REGION_ID.r in App Engine URLs is optional for existing apps and will soon be required for all new apps.

To ensure a smooth transition, we are slowly updating App Engine to use region IDs. If we haven't updated your Google Cloud project yet, you won't see a region ID for your app. Since the ID is optional for existing apps, you don't need to update URLs or make other changes once the region ID is available for your existing apps.

Learn more about region IDs.

For a full list of known issues or to report a new issue, see the issue tracker.

  • After you deploy your application with gcloud app deploy, you might need to wait 1-2 minutes before your application starts serving at https://PROJECT_ID.REGION_ID.r.appspot.com. Until then, you might see HTTP 503 errors.

  • You cannot use the App Engine flexible environment if the organization policy on your project restricts access to external IPs, for example:

    • The effective policy for constraints/compute.vmExternalIpAccess is set to DENY_ALL.
    • The effective policy for constraints/compute.vmExternalIpAccess is set to whitelist only specific VM instances.

    These constraints are not automatically detected, and deployments might time out and fail. You can check the organization policy for your project by running the command gcloud beta resource-manager org-policies describe compute.vmExternalIpAccess --project=my-project --effective.