old server httpd.conf:

<VirtualHost *>
    ServerName blah.site.com
    DocumentRoot /home/user/public 
    <Location /access/login>
        AuthUserFile /usr/local/www/.htpasswd
        AuthGroupFile /dev/null
        AuthName "Admin Login"
        AuthType Basic
        require valid-user
    </Location>
</VirtualHost>

access_controller.rb:
class AccessController < ApplicationController
  def login
    session[:logonid] = request.env["REDIRECT_REMOTE_USER"]
    redirect_to :controller=>"main", :action => ""
  end

  def logout
    reset_session()
    redirect_to :controller=>"main", :action => ""
  end
end