I have a Spring Boot application, with Webflux, that receives requests from a Kong server. I receive these requests via a generic RestController and handle they differently based on the request's path. But recently, after I upgraded the Spring Boot's version from 3.3.8 to 3.4.2, the path I'm getting isn't what I expect for the same request.
GenericController.java
@PostMapping(value = "**", produces = MediaType.APPLICATION_JSON_VALUE)
public Mono<ResponseEntity<byte[]>> genericPost(
@RequestBody byte[] body,
@RequestHeader HttpHeaders headers,
ServerHttpRequest request) {
log.trace("> getURI {}", request.getURI());
log.trace("> getPath {}", request.getPath());
Spring Boot 3.3.8
> getURI https://my-external-host.kong.com/
> getPath /
Spring Boot 3.4.2
> getURI https://my-external-host.kong.com/v1/api/service/
> getPath /v1/api/service/
The Kong service is configured with "strip_path: true", so the Spring Boot application is receiving the request at /. This can be verified with Spring Boot version 3.3.8. But it seems ServerHttpRequest is showing info from the external request only.
How can I get the internal request info using Spring Boot 3.4.2?
Additional information Here some headers (same for both versions) that may be useful to understand what's happening:
[Host:"my-internal-service:8080",
Connection:"keep-alive",
X-Forwarded-For:"xxx.xxx.xxx.xxx, xxx.xxx.xxx.xxx",
X-Forwarded-Proto:"https",
X-Forwarded-Host:"my-external-host.kong.com",
X-Forwarded-Port:"443",
X-Forwarded-Path:"/v1/api/service",
X-Forwarded-Prefix:"/v1/api/service",
X-Real-IP:"xxx.xxx.xxx.xxx"]
I think this is related to this particular change in Reactor Netty.
Previously Reactor Netty was not supporting this HTTP header and now it does. Note, it was supporting already the other "X-Forwarded-*" headers (host, port, etc). This is a behavior change, but you should know that you would have seen that behavior in the past already if you were using Tomcat of the Spring Framework Forwarded filters.
Spring Boot enables the "native" forwarded headers strategy for applications deployed on the cloud (Cloud Foundry, Kubernetes, etc) because a lot of platforms rely on internal proxies and those headers for routing and load balancing. If your application is not meant to handle Forwarded headers in the first place, because you are not behind a proxy or a CDN, then you should set "server.forward-headers-strategy=none".