I have an app that sits at exampleapplication.com. It's a rails application sitting on an Apache/Passenger stack.
The app is set up to use subdomain constraints to point to user accounts (e.g. user1.exampleapplication.com).
I want users to be able to point their own domain at their subdomain transparently.
so exampleuser.com points to exampleuser.exampleapplication.com.
I have set up an A record for exampleapplication.com to point to my server. I've set up a DNS zone with A record for exampleuser.com to point to the server.
On which zone to I put the CNAME record?