Comment 12 for bug 1739646

Per comment 3:

> I'm not sure about the feasibility and the ability to detect if we're using the default value *or* if it was manually added by the deployed in the config.

I think there might be a recent-ish feature in oslo.config that will allow us to know this, but we probably can't rely on that since it wouldn't be in older versions of oslo.config on stable branches.

Also, this bug came back to mind because I think another (public) bug reported is a duplicate of essentially the same issue:

https://bugs.launchpad.net/nova/+bug/1758278