Admin Controller + Subdomain Restriction + Whole URL Glob + Root Route for subdomains, no subdomain, and www subdomain

routes.rb

require 'Subdomain'

CMS::Application.routes.draw do
  
  namespace "admin" do |admin|
    resources :pages # Admin::PagesController Routes
  end
  
  constraints(Subdomain) do
    match '/' => "pages#root" # Route for Root URL for Subdomains
    match '*slug' => 'pages#show' # Route for Page URL for Subdomains
  end
  
  root :to => "pages#index" # Application Root Route

end

subdomain.rb

class Subdomain
  def self.matches?(request)
    request.subdomain.present? && request.subdomain != "www"
  end
end