How was cdn.seomoz.org configured?

[mcglynn]

The SEOmoz CDN appears to have a "pull zone" that is set to the root of the domain, such that any static file can be addressed from either subdomain:

http://www.seomoz.org/q/moz_nav_assets/images/logo.png

http://cdn.seomoz.org/q/moz_nav_assets/images/logo.png

The risk of this configuration is that web pages (not just images/CSS/JS) also get cached and served by the CDN. I won't put the URL here for fear of Google indexing it, but if you replace the 'www' in the URL below with 'cdn', you'll see a cached copy of the original:

http://www.seomoz.org/ugc/the-greatest-attribution-ever-graphed

The worst-case scenario is that the homepage gets indexed. But this doesn't happen here:

http://cdn.seomoz.org/

That URL issues a 301 redirect back to the canonical www subdomain. As it should.

Here's my question: how was that done?

Because maxcdn.com can't do it. If you set a "pull zone" to your entire domain, they'll cache your homepage and everything else. googlebot has a field day with that; it will reindex your entire site off the CDN.

Maybe the SEOmoz CDN provider (CloudFront) allows specific URLs to be blocked? Or do you detect the CloudFront IPs and serve them a 301 (which they'd proxy out to anyone requesting cdn.seomoz.org)?

One solution is to create a pull zone that points to a folder, like example.com/images... but this doesn't help a complex site that has cacheable content in multiple places (do you Wordpress users really store ALL your static content under /wp-content/ ?).

Or, as suggested above, dynamically detect requests from the CDN's proxy servers, and give them a 301 for any HTML-page request. This gets complex quickly, and is both prone to breakage and very difficult to regression-test.

Properly retrofitting a complex site to use a CDN, without creating a half-dozen new CDN subdomains, does not appear to be easy.

[DiamondJewelryEmpire]

its a SEOmoz secret...