I've discovered that when I do Google Webmaster Tools --> Fetch as Google on a page on my site (let's call it http://example.com), it shows the static assets (js, css, and images) as Temporarily unreachable.
My static assets are behind an Amazon CloudFront CDN distribution, with the origin being my site, http://example.com. I have CNAMEd the CloudFront to assets.example.com.
That's exactly what is showing as "Temporarily unreachable" - all the css and js hosted at assets.example.com (for example assets.example.com/assets/application.css). The thing is, I can reach all those files just fine. I fear that googlebot is not seeing the js and css of my site, since when I do a Fetch and Render it says "This is how Googlebot saw the page:" and sure enough it's the page as it would look with no css or js.
I went through the responses on this somewhat similar question, but my CloudFront distribution doesn't even have a robots.txt that could be blocking anything, and the response headers when I do a
curl -I on my css & js don't show anything alarming.
What could be causing googlebot to say that my static assets are Temporarily unreachable? Thanks!