I'm using Cloud Run for the backend of a project I'm working on, in part due to its generous free tier (2 million requests per month, free). But the services require some secret values (database password, Oauth secret key, etc.), so I have followed the Google recommendation to store these values in Google Secret Manager and load them as environment variables through Cloud Run.
However, the free tier of Secret Manager is much more restrictive, at only 10,000 free access operations per month. If cloud run spins up a container for nearly every request, it seems as though it must access secrets at approximately this rate too, drastically reducing the free tier quota.
So my question is, how should I set up the environment variables for my Cloud Run instance without destroying the free tier that made the platform so attractive in the first place? Simply putting the database password etc. in the environment variables seems like a bad idea, but it's unclear to me how much of a security risk that actually poses given that the project is a student website that doesn't contain any sensitive personal information in the database, and also given that a user with administrative access to the Google Cloud console could access the secret values from secret manager anyway.