Redirect non-www requests to www urls in Rails

Question

Simple issue but can't seem to find an answer doing some quick Googling. What's the Rails way of doing this 301 direct (http://x.com/abc > http://www.x.com/abc). A before_filter?

Answer 1

Ideally you'd do this in your web server (Apache, nginx etc.) configuation so that the request doesn't even touch Rails at all.

Add the following before_filter to your ApplicationController:

class ApplicationController < ActionController::Base
  before_filter :add_www_subdomain

  private
  def add_www_subdomain
    unless /^www/.match(request.host)
      redirect_to("#{request.protocol}x.com#{request.request_uri}",
                  :status => 301)
    end
  end
end

If you did want to do the redirect using Apache, you could use this:

RewriteEngine on
RewriteCond %{HTTP_HOST} !^www\.x\.com [NC]
RewriteRule ^(.*)$ http://www.x.com/$1 [R=301,L]

Answer 2

While John's answer is perfectly fine, if you are using Rails >= 2.3 I would suggest to create a new Metal. Rails Metals are more efficient and they offers better performance.

$ ruby script/generate metal NotWwwToWww

Then open the file and paste the following code.

# Allow the metal piece to run in isolation
require(File.dirname(__FILE__) + "/../../config/environment") unless defined?(Rails)

class NotWwwToWww
  def self.call(env)
    if env["HTTP_HOST"] != 'www.example.org'
      [301, {"Content-Type" => "text/html", "Location" => "www.#{env["HTTP_HOST"]}"}, ["Redirecting..."]]
    else
      [404, {"Content-Type" => "text/html"}, ["Not Found"]]
    end
  end
end

Of course, you can customize further the Metal.

If you want to use Apache, here's a few configurations.

Answer 3

I found this article when trying to achieve the opposite (www to root domain redirection). So I wrote the piece of code that redirects all pages from www to the root domain.