Package io.helidon.webserver.opentracing

Annotation Type Opentraceable

@ClientBinding(configClass=Config.class)
@Documented
@Retention(RUNTIME)
@Target({FIELD,PARAMETER})
public @interface Opentraceable

The Opentraceable provides JAX-RS Client Zipkin integration. The resulting Client or WebTarget propagates the OpenTracing context from the ServerRequest to the remote application.

The idea is that

1. the Client needs to have registered OpentracingClientFilter client filter
2. the tracing context is provided by
   1. the Tracer registered as property OpentracingClientFilter.TRACER_PROPERTY_NAME on the client
   2. additionally, an optional parent SpanContext registered as property OpentracingClientFilter.CURRENT_SPAN_CONTEXT_PROPERTY_NAME
3. when in a context of a server request, it is also possible to provide ServerRequest as a property OpentracingClientFilter.SERVER_REQUEST_PROPERTY_NAME from where the tracing context is injected

Usage:

 // Create the JAX-RS client with registered OpentracingClientFilter:
 Client client = ClientBuilder.newClient(new ClientConfig(OpentracingClientFilter.class));

 // Provide the tracing context; i.e, 'tracer' and optionally 'parentSpan' to the client call:
 Tracer tracer;
 Span parentSpan;

 Response response = client.target("http://localhost:9080")
                           .property(OpentracingClientFilter.TRACER_PROPERTY_NAME, tracer)
                           .property(OpentracingClientFilter.CURRENT_SPAN_PROPERTY_NAME, parentSpan)
                           .request()
                           .get();
 

When using a managed client, the filter gets registered thanks to the Opentraceable annotation:

 class MyResource {
     @Inject ServerRequest request;

     @GET
      public String getText(@Uri("http://remote.server.my:9080") @Opentraceable WebTarget target) {
          Response response = target.property(OpentracingClientFilter.SERVER_REQUEST_PROPERTY_NAME, request)
                                    .request()
                                    .get();
     }
 }
 

See Also:

OpentracingClientFilter