I have a Python GAE app on a custom domain. When I add login: required to any handler, the site redirects to the app's appspot.com domain instead of my custom domain. The functionality of the site isn't affected, and all handlers and routes continue to work as expected — just on the appspot.com domain instead.
Example snippet from the app.yaml below. mydomain.com works fine with the custom domain, mydomain.com/test and any other handlers redirect to the appspot.com domain after authentication (myapp.appspot.com/test).
- url: /
- url: /test
- url: /.*
Is this a configuration issue with how App Engine is handling the domain, or is this an issue with the redirect used by the login: required setting?