CODEWITHSUNDEEP
javaspringspring-cloud-sleuth
Stanislav
Stanislav

Reputation: 441

Spring Cloud Sleuth: Propagate traceId to other spring application

I have some spring service that can submit some AWS batch job. This is simple spring batch job that invoke requst to external service. And i want to propagate traceId that generated in my service by including "org.springframework.cloud:spring-cloud-starter-sleuth" lib into classpath , to this job and add "TraceRestTemplateInterceptor" interceptor to external request initilaized with this traceId.

How can i do that? How can i initilaze interceptor which will put existing traceId from application parameter, environment, properties? Or may be need to create some configuration beans?

UPDATE:

Simplified example:

@SpringBootApplication
public class DemoApplication implements CommandLineRunner {
   Logger logger = LoggerFactory.getLogger(DemoApplication.class);

   public static void main(String[] args) {
       SpringApplication.run(DemoApplication.class, args);
   }

   @Bean
   public RestTemplate restTemplate() {
     return new RestTemplate();
   }

   //@Autowired
   //RestTemplate restTemplate;

   @Override
   public void run(String... args) {
       logger.info("Hello, world!");
       //restTemplate.getForObject("some_url", String.class);
   }
}

File application.properties:

 x-b3-traceId=98519d97ce87553d

File build.gradle:

 dependencies {
    implementation('org.springframework.cloud:spring-cloud-starter-sleuth')
 }

Output:

INFO [-,,,] 15048 --- [           main] com.example.demo.DemoApplication         : Hello, world!

First of all, I want to see here traceId which initilized in application.properties. Secondly, when uncomment resttemplate clause, this traceId propagated into request.

Is it possible?

Upvotes: 1

Views: 4909

Answers (4)

Abdelrahman Mahmoud
Abdelrahman Mahmoud

Reputation: 1

As spring sleuth doesn't support Webservicetemplate by default, here is an example of how to use spring cloud sleuth with Webservicetemplate,

if service A sends a request to service B,

At first you'll send the trace id in the header of the sent request by the below code

@Service
public class WebServiceMessageCallbackImpl implements WebServiceMessageCallback {

@Autowired
private Tracer tracer;

public void doWithMessage(WebServiceMessage webServiceMessage) throws TransformerException {
    Span span = tracer.currentSpan();
    String traceId = span.context().traceId();
    SoapMessage soapMessage = (SoapMessage) webServiceMessage;
    SoapHeader header = soapMessage.getSoapHeader();
    StringSource headerSource = new StringSource("<traceId>" + traceId + "</traceId>");
    Transformer transformer = TransformerFactory.newInstance().newTransformer();
    transformer.transform(headerSource, header.getResult());
}
}

then in service B, you'll create an interceptor, then read the trace id from the header of the coming request, then put this trace id in the MDC like in the below code

@Slf4j
@Component
public class HttpInterceptor2 extends OncePerRequestFilter {

private final String traceId = "traceId";
@Autowired
private Tracer tracer;


@Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
        throws ServletException, IOException {


    String payload = new String(request.getInputStream().readAllBytes(), StandardCharsets.UTF_8);

    String traceId = traceId(payload);
    MDC.put("traceId", traceId);

    try {
        chain.doFilter(request, response);
    } finally {
        MDC.remove(traceId);
    }

}

private String traceId(String payload) {
    StringBuilder token = new StringBuilder();

    if (payload.contains(traceId)) {

        int index = payload.indexOf(traceId);

        while (index < payload.length() && payload.charAt(index) != '>') {
            index++;
        }
        index++;

        for (int i = index; ; i++) {
            if (payload.charAt(i) == '<') {
                break;
            }
            token.append(payload.charAt(i));
        }
    }
    if (token.toString().trim().isEmpty()) {
        token.append(traceId());
    }
    return token.toString().trim();

}

private String traceId() {
    Span span = tracer.currentSpan();
    String traceId = span.context().traceId();
    return traceId;
}

}

Upvotes: 0

petronius
petronius

Reputation: 489

You can get the bean:

@Autowired private Tracer tracer;

And get the traceId with

tracer.getCurrentSpan().traceIdString();

Upvotes: 1

Stanislav
Stanislav

Reputation: 441

Resolved this issue only by manually putting into request HEADER key "X-B3-TRACEID" with corresponding value, which is inserted by external application as system property when submits target spring boot application. And manually inserting this key in MDC. Example, this snipet from spring boot application that must get traceId and propagate:

@Bean
public void setTraceIdToMDC(@Value("${x.b3.traceid}") String traceId) {
  MDC.put("x-b3-traceId", traceId);
}

@Bean
public RestTemplate restTemplate() {
    return new RestTemplate();
}

@Bean
public CommandLineRunner commandLineRunnerer(RestTemplate restTemplate, @Value("${x.b3.traceid}") String traceId) {
    return args -> {
        MultiValueMap<String, String> header = new LinkedMultiValueMap<>();
        header.add("X-B3-TRACEID", traceId);

        HttpEntity httpEntity = new HttpEntity(header);

        logger.info("Execute some request"); //<-- prints expected traceId
        restTemplate.exchange("some_url", HttpMethod.GET, httpEntity, String.class);
    };
}

Upvotes: 1

Marcin Grzejszczak
Marcin Grzejszczak

Reputation: 11149

Just add the dependency to the classpath and set rest template as a bean. That's enough.

Upvotes: 0

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