...
Are packages cached inside of CloudFront? What about repository metadata (indexes)?
As of packgecloud:enterprise 2.0.7, with CloudFront enabled, only packages are accessed and cached through CloudFront, repository metadata still goes to S3 using SigV2 signed URLs.
Starting with packagecloud:enterprise 3.0.0, packages and repository metadata will be accessed through CloudFront (to mitigate the June 4, 2019 SigV2 deprecation), but only packages will be cached, repository metadata will be passed-through to ensure Package Managers When CloudFront is enabled, all requests for package files or repository metadata will go through CloudFront. Package files are cached, but repository metadata is written to AWS S3 with a special Cache-Control header so that CloudFront will never cache it. Repository metadata is never cached when it passes through CloudFront to ensure package managers always see the latest generated indexes.
...