Is there a way to restrict registrations in firebase

Question

Is there a way to restrict users from registering firebase email/password accounts so that new users can\'t sign up? I have a small app that only a few admins need to have a

Answer 1

@RobDiMarco provided a great answer, but it has a flaw.

The rule root.child('admins').hasChild(auth.uid) will pass, in case auth.uid will be an empty string.

You can test this in Firebase Database Security Simulator, clearing out uid field ({ "provider": "anonymous", "uid": ""}).

This rule root.child('admins').child(auth.uid).val() === true will not pass with an empty uid.