How do I redirect without www using Rails 3 / Rack?

Question

I understand there are a lot of questions that answer this. I\'m familiar with .htaccess and nginx.conf methods, but I do not have access to such t

Answer 1

Nothing wrong with the approaches above, but there are also a couple of gems that provide Rack middleware to do this.

I like the way that they keep this behaviour separate from the app itself, but it's not a particularly strong argument either way. I also use middleware to do this when working with Sinatra, so prefer to use a technique that I can use on apps built from Rails and/or Sinatra (I often run Nesta embedded in Rails).

Anyway, here they are:

• https://github.com/cwninja/rack-force_domain
• https://github.com/tylerhunt/rack-canonical-host

The first is simpler (and the one I've been using) while the second offers a couple more features (that I'm yet to need, but appreciate).

Answer 2

In Ruby on Rails 4, removing www. from any URL whilst maintaining the pathname can be achieved simply by using:

# config/routes.rb

constraints subdomain: 'www' do
  get ':any', to: redirect(subdomain: nil, path: '/%{any}'), any: /.*/
end

In contrast, adding www. to the beginning of any URL that doesn't already have it can be achieved by:

# config/routes.rb

constraints subdomain: false do
  get ':any', to: redirect(subdomain: 'www', path: '/%{any}'), any: /.*/
end

Answer 3

If you want to redirect from the top-level domain (TLD) to the www subdomain, use this code:

constraints :subdomain => '' do
  match '(*any)' => redirect { |p, req| req.url.sub('//', '//www.') }
end

Note: This code the use of sub, not gsub, because sub replaces the first occurrence of the double-slashes where gsub would replace all double-slashes.