如何获取在AWS Lambda中调用的原始URL？

Question

I have a lambda setup with the proxy integration in API Gateway.

I can call my lambda with a URL like https://7kbw9fcfa4.execute-api.us-east-1.amazonaws.com/dev/foo The path here is /dev/foo .

However if I set up CloudFront in front of that, the URL becomes https://a45ex7tnds5r5o.cloudfront.net/foo and the path is /foo .

In both cases I have the same keys in the event variable:

• path contains /foo
• requestContext.path contains /dev/foo

How can I get reliably the actual URL that the client sees in the browser? (both when using Cloudfront and when using API Gateway directly)

Answer 1

You could configure your CloudFront distribution to use a custom header that would be passed to the Lambda function. Then you could determine whether to use path or requestContext.path based on if that CloudFront-only header is present.