CDN URL到根文件夹/防止重复内容？

Question

For a image gallery I have to install a CDN Domain.

Default Domain:

http://www.example.com
Apache folder: /html/mywebsite

CDN Domain:

http://cdn.example.com
Apache folder: /html/mywebsite

The CDN Domain need the same Apache folder for url rewrite reasons etc.

Problem:

http://cdn.example.com
and
http://www.example.com

open the same website and this is bad. I cant rewrite (301) from cdn to www because I have to serve the images from the CDN. Also I cant use a 403:

RewriteCond %{HTTP_HOST} ^cdn\.example\.com$ [NC]
RewriteRule .* / [F]

because image urls from the cdn

http://cdn.example.com/images/test.jpg

get also a 403. Is it possible to make a 403 only for the root folder and not for subfolders or do you have a better idea?

btw. robots.txt is also bad, because images from the cdn should be indexed. A htaccess solution would be great.

Answer 1

If you only want the root (and any documents in the root) of cdn.example.com to go to www.example.com and each domain uses a separate VirtualHost, you can use something as simple as

RedirectMatch permanent ^/?(.+\.php)$ http://www.example.com/$1

in the VirtualHost container for cdn.example.com. Obviously, you can tweak the regular expression to match your site's files.

See the Apache docs for some reasons why this is preferable to using mod_rewrite. It's simpler, easier to maintain, and in many cases will result in better performance.