Question

I am building a RoR3 site that generates a microsite for each client. At this moment they enter to their microsite using the url http://www.site.com/clientid , but I want to register their own domain programatically, so they will enter to http://www.clientid.com and they will be redirected to my server. Is there any way to do that?

Answer 1

Have the client point the domain to your IP using the DNS management interface of the registrar. (More technically this would result in the creation of an A record or an AAAA record but this is not your concern).
Once the DNS is propagated, entering www.clientid.com in the browser will make a request to your server (your rails app). There you can selectively serve content based on the domain.

class ApplicationController
  before_filter do
    @current_account = Account.find_by_domain(request.domain)
  end
end