InitialTraceIdFilter.java

@Component
@Slf4j
public class TraceIdFilter implements WebFilter {

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
        Map<String, String> headers = exchange.getRequest().getHeaders().toSingleValueMap();
      
        var traceId = "";
        if (headers.containsKey("X-B3-TRACEID")) {
            traceId = headers.get("X-B3-TRACEID");
            MDC.put("X-B3-TraceId", traceId);
        } else if (!exchange.getRequest().getURI().getPath().contains("/actuator")) {
            log.warn("TRACE_ID not present in header: {}", exchange.getRequest().getURI());
        }

        return chain.filter(exchange);

    }


}