Cloudfront Function logs

[ispyinternet]

Do you know why event isn't logging?

Seems similar to this persons query:

https://stackoverflow.com/questions/76049017/in-my-lambdaedge-origin-request-function-the-event-parameter-is-empty

But I thought these functions would automatically get setup with service roles that allow logging.

Anyway, I wanted to view the logs to understand why it's necessary to have a viewer-request handler.

Before finding your package, I was running Sveltekit on Cloudfront, using SPA mode (which I still want to do, except for some server routes that I will use your handler for, e.g. /kit/server/* ). I didn't use (need?) a viewer-request, I just needed an origin-request that routed any misses on S3 to the svelte SPA fallback page.

Anyway nice package BTW. Due to the custom setup I need and the fact that my resources are deployed using a code pipeline (not CDK), I will probably end up having to pull out the bits of code I need, hence trying to understand all your moving parts.

[jill64]

Thanks for opening this issue!

First, regarding the issue with CloudFront Functions (a.k.a. CF2) not logging, I have confirmed that this is also happening in the sample case. However, my guess is that this is not a bug, but due to the CF2 specification. CF2 is running on the original runtime based on ECMAScript 5.1 and may not support output beyond the second argument of console.log. I will modify the adapter and see if this is the case.

Secondly, the reason why the CF2 Viewer-Request is needed is that it exists primarily for hostname canonicalisation. When using a custom domain, the application can be accessed by two hostnames.

For example, in the lambda-s3 sample case,

1. https://d1axeq0g4diak1.cloudfront.net
2. https://lambda-s3.adapter-aws.com

the application can be used under either of these hostnames.

In practice, however, it is preferable to normalise all requests to 2 for SEO reasons. To do this, the 1 needs to be converted to 2 by an HTTP redirect before the request passes through CloudFront. This is the need for Viewer-Request.