RFC7239 Forwarded Header

[AndrewBurian]

RFC7239 specifies a new official header Forwarded to replace the somewhat haphazard collection of X-Forwarded-* headers. I think this should be implemented and provided to help spread adoption and standardize the headers onto something more sane.

Ideally I think it should be in Go's Reverse Proxy since they are in the best position to kickstart adoption and Oxy and Traefik will benefit automatically. However, the only issue discussing it though was lukewarm and abandonded. I am going to attempt to restart that discussion, but assuming the lead time on that is going to be ages, perhaps Oxy should write it itself for now.

If Oxy implemented it, it would be a fairly straightforward addition to the forward rewrite logic, and the RFC specifies guideline on producing a Forwarded header in the presence of X-Forwarded-For.