I am installing a cedar t&g floor over plywood in a small, 28x21 closet.
Flooring is standard thickness, but will not be nailed because I just don't really see the need.

Do I still need to use a vapor barrier over the plywood despite the small space?
Also, should I glue the boards together?

There is a bit of ventilation since the door was cut in the past to accommodate carpeted flooring.