Hack to Learn

Many, if not most, Rails applications require an administration interface, which allows a certain group of users to perform maintenance and administration tasks on the application and its underlying data.

Sometimes it is beneficial to move the administration interface to its own server. However, most applications do not use a separate project for the administration interface. It can be done that way but then you need to share models between two projects.

I accomplished this by having the project code on multiple servers, and configuring one of those servers to host the admin interface, which is simply a set of controllers within the main application:

app/controllers/admin

So, I setup a before_filter that simply forces a redirect based on the request URI. In other words if the URI begins with /admin we force a redirect to the server hosting the admin interface like this:

  def check_and_redirect_admin_domain
    if ['production'].include?(ENV['RAILS_ENV'])
      using_dot_biz = (request.host =~ /\.biz$/)
      if !using_dot_biz && request.request_uri =~ /^\/admin/
        full_url = request.protocol + request.host
        full_url += ':' + request.port.to_s if request.port
        full_url += request.request_uri
        full_url.gsub!(/\.com/, '.biz')
        redirect_to full_url and return false
      end
    end
  end

Our administration interface is hosted on a .biz domain, while our application is hosted on the .com domain. First we check to see if the environment is running on production. If it is, check if we are already on the .biz domain, or if it is being requested directly by the user. If it is not, and the requested URI begins with /admin, we build and execute our redirect.

This effectively partitions our application so the admin interface runs on a different server. We also setup separate mongrel instances and a separate database connection which uses one of the DB mirrors.