title: spring-cloud-sleuth with opentracing
body: <p>I'm using the latest milestone of spring-cloud-sleuth and I can't seem to get traces emitted through opentracing. I have a <code>Tracer</code> bean defined and spring boot seems to acknowledge that, but no traces are being emitted.</p>
  
  <p>Is there a way to check if spring-cloud-sleuth is aware of the Tracer bean?</p>
  
  <p><strong><em>update</em></strong></p>
  
  <p>I did see the merged documentation and have a <code>Tracer</code> instance on the bean, as defined below:</p>
  
  <pre><code>@Bean(name = "tracer")
  @Primary
  public Tracer lightstepTracer() throws MalformedURLException {
      Options opt = lightstepOptionsBuilder.build();
      log.info("Instantiating LightStep JRETracer.");
      return new JRETracer(opt);
  }
  </code></pre>
  
  <p>I'm not explicitly importing the OpenTracing APIs, because the LightStep tracer pulls that in transitively, but I can try doing that.</p>
  
  <p>I've also explicitly enabled OpenTracing support in my application.yml file.</p>
  
  <pre><code>sleuth:
    opentracing:
      enabled: true
  </code></pre>