Ugly non threadsafe way of routing a subdomain to a controller

router.rb

class SupportSubdomain
  
  def self.subdomain
    @@request.subdomain.to_sym rescue :not_found
  end
  
  def self.matches?(request)
    @@request = request
    request.path_parameters[:controller] = request.subdomain
    Rails.logger.info request.path_parameters[:controller]
    request.subdomain.presence
  end
end
Subroutes::Application.routes.draw do
  c = Class.new SupportSubdomain
  
  constraints(c) do
    controller c.subdomain do
      match "(:action)"
    end
  end
end