I\'m using Devise in a Rails 3 app, but in this case, a user must be created by an existing user, who determines what permissions he/she will have.
Because of this, I
Instead of searching for a hard solution. I used the below approaches.
Delete the sign_up form from page (path devise/registrations/new.html.erb) and replace it with custom info.
Redirect the incoming traffic to some other page. Like below in routes.rb
get "/users/sign_up", to: redirect('/')
post "/users/sign_up", to: redirect('/')
Make sure to write it before devise_for :users