Where to capture HTTP forwarded proto (original url.scheme)?

[trask]

Forwarded header provide a way to get the original url.schema that was used on the client side.

This is useful data, because often TLS is terminated before it reaches the application server, and so the SERVER span on the application server reports url.scheme of http (unsecured), which can cause users to worry that their traffic is unencrypted.

In #3402 we are now proposing to capture the ip (and optional port) from Forwarded into client.address (and client.port).

It would be nice to capture the proto field (original url.scheme) somewhere at the same time, so that we don't need to re-parse the Forwarded header for it later.

[AlexanderWert]

It would be nice to capture the proto field (original url.scheme) somewhere at the same time, so that we don't need to re-parse the Forwarded header for it later.

How about a new field url.original.scheme (or url.scheme.original). The url.* namespace seems to be a good place for this information since the Forwarded proto describes an aspect of a URL.