It is good practice to make your site available by both www.example.com and example.com URLs. But to prevent the duplication of pages (http://www.example.com/somepage/ and http://example.com/somepage are the same) we should have one version of URL (with WWW or without) and redirect from another version to the chosen one (from www to non-www or vice versa).
Examples:
www.example.com -> example.com
www.example.com/some/some-page -> example.com/some/some-page
www.example.com?some-query-param=value -> example.com?some-query-param=valueRedirect using Rails 3 routes
file config/routes.rb:
Foo::Application.routes.draw do
constraints(host: /^www\./i) do
match '(*any)' => redirect { |params, request|
URI.parse(request.url).tap { |uri| uri.host.sub!(/^www\./i, '') }.to_s
}
end
# other routes
end
Redirect using nginx
If your Rails app is hosted on nginx web server you can make redirect via config file for the server:
server {
listen 80;
server_name www.example.com;
return 301 http://example.com$request_uri;
}
server {
listen 80;
server_name example.com;
...
}
Redirect using Apache
RewriteEngine On
RewriteCond %{HTTP_HOST} ^www.example.com
RewriteRule ^ http://example.com%{REQUEST_URI} [L,R=301]
References:
all code is available here: https://gist.github.com/maxivak/6727458