@DynamicPropertySource static void propertyOverride(DynamicPropertyRegistry registry) {
    registry.add("zipkin.discovery.eureka.serviceUrl", () -> serviceUrl().url());
  }
Get the serviceUrl of the Eureka container prior to booting Zipkin.
zipkin-server/src/test/java/zipkin2/server/internal/eureka/ITZipkinEureka.java