Ways to use Lambda@Edge - Amazon CloudFront

Ways to use Lambda@Edge

There are many uses for Lambda@Edge processing with your Amazon CloudFront distribution. For example:

  • A Lambda function can inspect cookies and rewrite URLs so that users see different versions of a site for A/B testing.

  • CloudFront can return different objects to viewers based on the device they're using by checking the User-Agent header, which includes information about the devices. For example, CloudFront can return different images based on the screen size of their device. Similarly, the function could consider the value of the Referer header and cause CloudFront to return the images to bots that have the lowest available resolution.

  • Or you could check cookies for other criteria. For example, on a retail website that sells clothing, if you use cookies to indicate which color a user chose for a jacket, a Lambda function can change the request so that CloudFront returns the image of a jacket in the selected color.

  • A Lambda function can generate HTTP responses when CloudFront viewer request or origin request events occur.

  • A function can inspect headers or authorization tokens, and insert a header to control access to your content before CloudFront forwards the request to your origin.

  • A Lambda function can also make network calls to external resources to confirm user credentials, or fetch additional content to customize a response.

For more ideas, including example code, see Lambda@Edge example functions.

For a procedure that shows you how to set up Lambda@Edge in the console, see Tutorial: Create a basic Lambda@Edge function.