Affects: Spring Webflux 5.3.20

Running our app in our kubernetes cluster (or simulating it via spring.main.cloud-platform=kubernetes) or using server.forward-headers-strategy=native produces the wrong scheme when calling ServerWebExchange.getRequest().getURI() when forward headers are present.

This seems to be because ReactorServerHttpRequest uses request.scheme() (which netty fills from X-Forwarded-Proto if present), and combines it with the Host header, where there's no clear correlation between those two headers.

Effectively, the following cURL request:

curl -H "X-Forwarded-Proto: https" -H "X-Forwarded-Host: my-gateway" -H "X-Forwarded-Port: 8181" http://localhost:8080/print-uri

... will return ServerWebExchange.getRequest().getURI() = https://localhost:8080/print-uri, even though the scheme used for the request was HTTP.

Minimal Controller Example: https://github.com/mabako/spring-native-forwarding-headers-webflux/blob/master/src/main/java/com/example/demo/PrintUriController.java