Amazon CloudFront自定义源配置

Question

I'd like CloudFront to first search S3 for a file, defaulting to my custom server if the image is not found. Is this possible?

Answer 1

Unfortunately CloudFront does not have a flexible fallback mechanism.

Depending on your specific use case, you could use an alternate approach where you configure CloudFront to pass all traffic trough your custom server and configure the server to proxy the request to S3 by default and, if that fails, to serve a local copy of the file.

It's also possible that, instead of actually proxying the content from S3, you just configure your server to redirect to the S3 object if it exists, to reduce the traffic that goes trough your server.

Another approach, that could possibly apply if you have a CloudFront distribution dedicated to serving images, is to set your S3 bucket as the distribution's origin and configure a custom error page for 404 errors to serve a default image that's also hosted on S3. For this approach, see:

http://aws.typepad.com/aws/2013/09/custom-error-pages-and-responses-for-amazon-cloudfront.html

Answer 2

You could to try and set it up as a reverse proxy. I haven't tested it, but it falls back to your domain if the asset is missing. Who knows what the 'break' would be that you would need a fallback. But this would help in a number of cases, such as a new admin accidentally deleting your cloudfront bucket.