simple dynamic robots.txt

gistfile1.rb

require 'robots_txt_generator'
AppName::Application.routes.draw do
  [snip]
  match '/robots.txt' => RobotsTxtGenerator

end


class RobotsTxtGenerator
  # Disallow everything for all other environments.
  def self.call(env)
    body = if Rails.env.production?
      body    = 'Sitemap: http://s3.amazonaws.com/degreestory-production/sitemaps/sitemap.xml.gz'
    else
      "User-agent: *\nDisallow: /"
    end 


    headers = { 
      'Content-Type'  => 'text/plain'
    }   

    [200, headers, [body]]
  rescue Errno::ENOENT
    headers = { 'Content-Type' => 'text/plain' }
    body    = '# A robots.txt is not configured'

    [404, headers, [body]]
  end 
end