How do I create an admin subdomain to manage subdomains in Rails - ruby-on-rails

Question

I am using AuthLogic and the subdomain method that dhh covered in this blog post, everything is working great, and as expected. What I'm trying to figure out is how to create a subdomain like 'admin' or 'host' that will have a user authenticated from AuthLogic (this may be trivial and unnecessary to mention) that will manage the subdomains. So basically, all subdomains will act normally, except admin.site.com which will go to its own controller and layout..
dhh suggested just throwing in an exception to redirect, but I'm not sure where that goes, it didnt seem that simple to me, any ideas?
EDIT
I think that the fact I am using AuthLogic is important here, because the subdomain logic isnt forwarding users anywhere, once authenticated AuthLogic sends the user to /account - so my question may be related to how do I tell AuthLogic to a different spot if the user is a root user, logging into the admin subdomain..
Here is the code we have implemented thus far
Company Model
class Company < ActiveRecord::Base
has_many :users
has_many :brands, :dependent => :destroy
validates_presence_of :name, :phone, :subdomain
validates_format_of :subdomain, :with => /^[A-Za-z0-9-]+$/, :message => 'The subdomain can only contain alphanumeric characters and dashes.', :allow_blank => true
validates_uniqueness_of :subdomain, :case_sensitive => false
validates_exclusion_of :format, :in => %w( support blog billing help api www host admin manage ryan jeff allie), :message => "Subdomain {{value}} is not allowed."
before_validation :downcase_subdomain
protected
def downcase_subdomain
self.subdomain.downcase! if attribute_present?("subdomain")
end
end
SubdomainCompanies Module
module SubdomainCompanies
def self.included( controller )
controller.helper_method(:company_domain, :company_subdomain, :company_url, :company_account, :default_company_subdomain, :default_company_url)
end
protected
# TODO: need to handle www as well
def default_company_subdomain
''
end
def company_url( company_subdomain = default_company_subdomain, use_ssl = request.ssl? )
http_protocol(use_ssl) + company_host(company_subdomain)
end
def company_host( subdomain )
company_host = ''
company_host << subdomain + '.'
company_host << company_domain
end
def company_domain
company_domain = ''
company_domain << request.domain + request.port_string
end
def company_subdomain
request.subdomains.first || ''
end
def default_company_url( use_ssl = request.ssl? )
http_protocol(use_ssl) + company_domain
end
def current_company
Company.find_by_subdomain(company_subdomain)
end
def http_protocol( use_ssl = request.ssl? )
(use_ssl ? "https://" : "http://")
end
end
Application Controller
class ApplicationController < ActionController::Base
include SubdomainCompanies
rescue_from 'Acl9::AccessDenied', :with => :access_denied
helper :all # include all helpers, all the time
protect_from_forgery # See ActionController::RequestForgeryProtection for details
helper_method :current_user_session, :current_user, :current_company_name
filter_parameter_logging :password, :password_confirmation
before_filter :check_company_status
protected
def public_site?
company_subdomain == default_company_subdomain
end
def current_layout_name
public_site? ? 'public' : 'login'
end
def check_company_status
unless company_subdomain == default_company_subdomain
# TODO: this is where we could check to see if the account is active as well (paid, etc...)
redirect_to default_company_url if current_company.nil?
end
end
end

Answer 1

Look into subdomain-fu which allows you to route to different controllers and actions based on the subdomain. I have done a Railscasts Episode on the subject.
It might looks something like this.
# in routes.rb
map.manage_companies '', :controller => 'companies', :action => 'index', :conditions => { :subdomain => "admin" }
This will need to be high enough up in the routes list so nothing else is matched before it.

Answer 2

FOR RAILS 2.3: You can download a full example app (with a step-by-step tutorial) showing how to implement an admin subdomain, a main domain, and multiple user subdomains using the Devise gem for authentication and the subdomain-routes gem for managing subdomains. Here's the link: subdomain authentication for Rails 2.3.
FOR RAILS 3: Here's a complete example implementation of Rails 3 subdomains with authentication (along with a detailed tutorial). It's much easier to do this in Rails 3 than in Rails 2 (no plugin required).