How to recover Google App Engine's "default service account"

Question

I have mistakenly deleted the default "app engine service account" for my project - {id}@appspot.gserviceaccount.com Is there a way to recover it without resetting/recreating my project on Google Cloud Platform?

Answer 1

Unfortunately at this time, there is no way to recover the default App Engine service account. The solution is as you say creating a new project and redeploying your code there.

Should you wish to see this deletion prevented or default service account recreation made possible in the future, I strongly urge you to file a feature request on the App Engine public issue tracker while providing this example as a business case.

UPDATE: As filed by the OP, a feature request now exists on the App Engine public issue tracker as Issue 13085. Please star this issue to receive updates on its progress.

UPDATE 2: As part of the App Engine Admin API, one can now use the apps.repair API to attempt to address issues of default Cloud Storage buckets and App Engine service accounts. I would recommend trying this API before creating a new project and redeploying. I'm leaving this as an addendum and not the primary solution as it's not guaranteed to solve the issue.

UPDATE 3 It is now possible to undelete service accounts. As per the Undeleting a service account documentation, a service account may be restored if:

The service account was deleted less than 30 days ago

and

There is no existing service account with the same name as the deleted service account.

Answer 2

If you don't know the default service account UniqueID, there is another solution.

Simply disable the App Engine Admin API and enable the same after some time. This will create a new default service account. Please note that this will delete all the associated resources.

(To enable/disable an API: Menu -> API & Services -> Dashboard -> Enable APIs and Services -> Search for that API -> Enable/Disable)