VPC Network error when configuring App Engine for Google Tag Manager Server Side

Question

I'm trying to set up ServerSide Google Tag Manager, which is a service that runs on GCP App Engine.

The setup is done with a few Cloud Shell commands, which are describede here: https://developers.google.com/tag-platform/tag-manager/server-side/script-user-guide#create_a_tagging_server_or_reconfigure_an_existing_tagging_server

However, when I did it originally (even as GCP project owner), I got this error:

I was advised that, to solve this, I needed to manually create a VPC Network called default. So I did exactly, that, with the default network settings.

When I ran the App Engine setup commands again, I got further, but ran into a new error:

ERROR: (gcloud.app.deploy) Error Response: [3] Flex operation projects/projectid/regions/europe-west1/operations/f7d7489b-f4ef-4b8b-ac26-b9b945d3ebfc error [INVALID_ARGUMENT]: An internal error occurred while processing task /app-engine-flex/insert_flex_deployment/flex_create_resources>2022-05-12T09:17:00.642Z6448.wa.0: 'subnetwork_name' must be specified for custom mode network 'default'.

I tried the setup commands with and without a defined subnetwork in the new VPC network I created. The same error persisted regardless.

I have not been able to find any solution to this online so far, so hoping that someone here will be able to assist.

Thanks in advance! Simon

Answer 1

The answer to this was that the default service in the app engine (Services in the left-hand menu in the app engine console) failed to automatically create the VPC- and subnetworks.

By manually recreating the defaultapp engine service, the correct VPC networks and subnetworks were created, and the problem was solved.