在响应中注入跟踪标头

如何解决在响应中注入跟踪标头

我已将 Sleuth 集成添加到应用程序中。现在日志显示了 traceId 和 spanId。

INFO [AppName,5dd62861a751e1b0,true]

我可以发送带有开放跟踪标头的 HTTP 请求

X-B3-TraceId
X-B3-SpanId

跟踪器使用的，我可以在日志中看到。 但是我想在响应中返回它们。

我有过滤器，我想在响应中添加这些标头

public class RequestResponseFilter implements Filter {

    private final Tracer tracer;
    private final Injector<HttpServletResponse> tracingInjector;
    
    public RequestResponseFilter(final Tracing tracing,final Tracer tracer) {
        this.tracer = tracer;
        this.tracingInjector = tracing.propagation().injector(HttpServletResponse::addHeader);
    }

    @Override
    public void doFilter(final ServletRequest request,final ServletResponse response,final FilterChain chain) throws IOException,ServletException {

        final HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        final HttpServletResponse httpServletResponse = (HttpServletResponse) response;

        ....

        // inject tracing header
        Span currentSpan = tracer.currentSpan();
        tracingInjector.inject(currentSpan.context(),httpServletResponse);

        chain.doFilter(httpServletRequest,httpServletResponse);
    }
}

但它们并没有以我预期的方式添加。在回复中我看到

b3: 5dd62861a751e1b0,5dd62861a751e1b0-1

怎么了？

解决方法

如果您查看文档，您将如何自定义 HTTP 服务器跨度 - https://docs.spring.io/spring-cloud-sleuth/docs/current/reference/html/howto.html#how-to-cutomize-http-server-spans 因为您可以访问 HttpServletResponse 和 TraceContext，您可以检索跟踪 ID / span id 并将其放入响应中。

侦探 3.x

@Configuration(proxyBeanMethods = false)
public static class ServerParserConfiguration {

    @Bean(name = HttpServerRequestParser.NAME)
    HttpRequestParser myHttpRequestParser() {
        return (request,context,span) -> {
            // Span customization
            span.tag("ServerRequest","Tag");
            Object unwrap = request.unwrap();
            if (unwrap instanceof HttpServletRequest) {
                HttpServletRequest req = (HttpServletRequest) unwrap;
                // Span customization
                span.tag("ServerRequestServlet",req.getMethod());
            }
        };
    }

    @Bean(name = HttpServerResponseParser.NAME)
    HttpResponseParser myHttpResponseParser() {
        return (response,span) -> {
            // Span customization
            span.tag("ServerResponse","Tag");
            Object unwrap = response.unwrap();
            if (unwrap instanceof HttpServletResponse) {
                HttpServletResponse resp = (HttpServletResponse) unwrap;
                // Span customization
                span.tag("ServerResponseServlet",String.valueOf(resp.getStatus()));
            }
        };
    }

}

Sleuth 2.x（几乎完全相同）-https://docs.spring.io/spring-cloud-sleuth/docs/2.2.x/reference/html/#data-policy