How to Integration Test spring-cloud-netflix & Feign, using WireMock

I use Spring-Cloud-Netflix for communication between micro services. Let's say I have two services, Foo and Bar, and Foo consumes one of Bar's REST endpoints. I use an interface annotated with @FeignClient:

@FeignClient
public interface BarClient {
  @RequestMapping(value = "/some/url", method = "POST")
  void bazzle(@RequestBody BazzleRequest);
}

Then I have a service class SomeService in Foo, which calls the BarClient.

@Component
public class SomeService {
    @Autowired
    BarClient barClient;

    public String doSomething() {
      try {
        barClient.bazzle(new BazzleRequest(...));
        return "so bazzle my eyes dazzle";
      } catch(FeignException e) {
        return "Not bazzle today!";
      }

    }
}

Now, to make sure the communication between services works, I want to build a test that fires a real HTTP request against a fake Bar server, using WireMock. The test should make sure that feign correctly decodes the service response and reports it to SomeService.

public class SomeServiceIntegrationTest {

    @Autowired SomeService someService;

    @Test
    public void shouldSucceed() {
      stubFor(get(urlEqualTo("/some/url"))
        .willReturn(aResponse()
            .withStatus(204);

      String result = someService.doSomething();

      assertThat(result, is("so bazzle my eyes dazzle"));
    }

    @Test
    public void shouldFail() {
      stubFor(get(urlEqualTo("/some/url"))
        .willReturn(aResponse()
            .withStatus(404);

      String result = someService.doSomething();

      assertThat(result, is("Not bazzle today!"));
    }
}

How can I successfully inject such a WireMock server into Eureka, so that Feign is able to find it and communicate with it?

Use Spring's RestTemplate instead of feign. RestTemplate is also able to resolve service names via eureka, so you can do something like this:

@Component
public class SomeService {
   @Autowired
   RestTemplate restTemplate;

   public String doSomething() {
     try {
       restTemplate.postForEntity("http://my-service/some/url", 
                                  new BazzleRequest(...), 
                                  Void.class);
       return "so bazzle my eyes dazzle";
     } catch(HttpStatusCodeException e) {
       return "Not bazzle today!";
     }
   }
}

This is way easier testable with Wiremock than feign.