we're using Google App Engine and Cloud SQL for a django web app. We want to run migrations during the build; however, GAE uses Container Registry to build the app, and Container Registry not authenticated to access Cloud SQL. So, as expected, the migrations fail to due to a rejected connection.
How does someone authorize Container Registry to access Cloud SQL?
When you say:
GAE uses Container Registry to build the app, and Container Registry not authenticated to access Cloud SQL.
I assume that you mean:
GAE uses Container Builder to build the app, and the Container Builder Service Account is not authenticated to access Cloud SQL.
Assuming that's what you need, this document explains how to use IAM to grant additional permissions to the Service Account: https://cloud.google.com/container-builder/docs/how-to/service-account-permissions
If you are in fact asking a different question, please clarify, including an example that demonstrates the problem you are having.