TraceRequestHttpHeadersFilter overrides all request headers in Spring Cloud Gateway

Oops, I’m not sure it is a bug or question.

I’m trying to integrate Spring Cloud Gateway and Spring Cloud Sleuth. In Spring Boot 2.1.2 and Spring Cloud Greenwich.RELEASE.

I found any of my request Header ‘X-Forward-*’ is missing.

After reading the source code, I found a HeaderFilters in the NettyRoutingFIlter and the TraceRequestHttpHeadersFilter was injected.

But TraceRequestHttpHeadersFilter is so strange. Why is its implementation covered instead of append?

class TraceRequestHttpHeadersFilter extends AbstractHttpHeadersFilter {
    private static final Log log = LogFactory.getLog(TraceRequestHttpHeadersFilter.class);

    static HttpHeadersFilter create(HttpTracing httpTracing) {
        return new TraceRequestHttpHeadersFilter(httpTracing);
    }

    private TraceRequestHttpHeadersFilter(HttpTracing httpTracing) {
        super(httpTracing);
    }

    public HttpHeaders filter(HttpHeaders input, ServerWebExchange exchange) {
        if (log.isDebugEnabled()) {
            log.debug("Will instrument the HTTP request headers");
        }

        Builder builder = exchange.getRequest().mutate();
        Span span = this.handler.handleSend(this.injector, builder);
        if (log.isDebugEnabled()) {
            log.debug("Client span  " + span + " created for the request. New headers are " + builder.build().getHeaders().toSingleValueMap());
        }

        exchange.getAttributes().put(SPAN_ATTRIBUTE, span);
        return new HttpHeaders(builder.build().getHeaders());
    }

    public boolean supports(Type type) {
        return type.equals(Type.REQUEST);
    }
}

ps: Forgive my English, I am still trying to learn it.

[marcingrzejszczak]

Ok, it should be fixed. Please wait for the snapshots and try again.

[martinvisser]

@marcingrzejszczak The input argument is completely ignored in this method in TraceRequestHttpHeadersFilter, so that means that all updated headers, for example the Forwarded header, is removed from this list.