Spring Cloud discovery для нескольких версий служб

Это трюк для взлома приборной панели Эврики. Добавьте этот аспект AspectJ (поскольку InstanceInfo, используемый в EurekaController, не является Spring Bean) в проект @EnableEurekaServer:

@Configuration
@Aspect
public class EurekaDashboardVersionLabeler {

    @Value("${eureka.instance.metadata.keys.version:instanceBuildVersion}")
    private String versionMetadataKey;

    @Around("execution(public * com.netflix.appinfo.InstanceInfo.getId())")
    public String versionLabelAppInstances(ProceedingJoinPoint jp) throws Throwable {
        String instanceId = (String) jp.proceed();
        for (StackTraceElement ste : Thread.currentThread().getStackTrace()) {
            // limit to EurekaController#populateApps in order to avoid side effects
            if (ste.getClassName().contains("EurekaController")) {
                InstanceInfo info = (InstanceInfo) jp.getThis();
                String version = info.getMetadata().get(versionMetadataKey);
                if (StringUtils.hasText(version)) {
                    return String.format("%s [%s]", instanceId, version);
                }
                break;
            }
        }
        return instanceId;
    }

    @Bean("post-construct-labeler")
    public EurekaDashboardVersionLabeler init() {
        return EurekaDashboardVersionLabeler.aspectOf();
    }

    private static EurekaDashboardVersionLabeler instance = new EurekaDashboardVersionLabeler();
    /** Singleton pattern used by LTW then Spring */
    public static EurekaDashboardVersionLabeler aspectOf() {
        return instance;
    }
}

Вы также должны добавить зависимость, не предусмотренную starters:

<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-eureka-server</artifactId>
    </dependency>
    <dependency>
        <groupId>org.aspectj</groupId>
        <artifactId>aspectjrt</artifactId>
        <scope>runtime</scope>
    </dependency>
</dependencies>

И активировать LTW a runtime с помощью VM arg, конечно:

-javaagent:D:\.m2\repository\org\aspectj\aspectjweaver\1.8.9\aspectjweaver-1.8.9.jar

Сервис 1 регистры v1 и v2 С Эврикой

Служба 2 обнаруживает и отправляет запросы к службе 1 ' s v1 и v2, используя различные ленточные клиенты

Я получил эту демо-версию для работы и буду писать о ней в блоге в ближайшие пару дней.

Http://tech.asimio.net/2017/03/06/Multi-version-Service-Discovery-using-Spring-Cloud-Netflix-Eureka-and-Ribbon.html

Идея I далее следовало для RestTemplate использовать другой Ribbon клиент для каждой версии, потому что каждый клиент имеет свой собственный ServerListFilter.

---

Служба 1

Применение.yml

...
eureka:
  client:
    registerWithEureka: true
    fetchRegistry: true
    serviceUrl:
      defaultZone: http://localhost:8000/eureka/
  instance:
    hostname: ${hostName}
    statusPageUrlPath: ${management.context-path}/info
    healthCheckUrlPath: ${management.context-path}/health
    preferIpAddress: true
    metadataMap:
      instanceId: ${spring.application.name}:${server.port}

---
spring:
   profiles: v1
eureka:
  instance:
    metadataMap:
      versions: v1

---
spring:
   profiles: v1v2
eureka:
  instance:
    metadataMap:
      versions: v1,v2
...

---

Служба 2

Применение.yml

...
eureka:
  client:
    registerWithEureka: false
    fetchRegistry: true
    serviceUrl:
      defaultZone: http://localhost:8000/eureka/

demo-multiversion-registration-api-1-v1:
   ribbon:
     # Eureka vipAddress of the target service
     DeploymentContextBasedVipAddresses: demo-multiversion-registration-api-1
     NIWSServerListClassName: com.netflix.niws.loadbalancer.DiscoveryEnabledNIWSServerList
     # Interval to refresh the server list from the source (ms)
     ServerListRefreshInterval: 30000

demo-multiversion-registration-api-1-v2:
   ribbon:
     # Eureka vipAddress of the target service
     DeploymentContextBasedVipAddresses: demo-multiversion-registration-api-1
     NIWSServerListClassName: com.netflix.niws.loadbalancer.DiscoveryEnabledNIWSServerList
     # Interval to refresh the server list from the source (ms)
     ServerListRefreshInterval: 30000
...

Применение.java

...
@SpringBootApplication(scanBasePackages = {
    "com.asimio.api.multiversion.demo2.config",
    "com.asimio.api.multiversion.demo2.rest"
})
@EnableDiscoveryClient
public class Application {

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

AppConfig.java (смотрите, как имя клиента Ribbon совпадает с ключом Ribbon, найденным в применение.yml

...
@Configuration
@RibbonClients(value = {
    @RibbonClient(name = "demo-multiversion-registration-api-1-v1", configuration = RibbonConfigDemoApi1V1.class),
    @RibbonClient(name = "demo-multiversion-registration-api-1-v2", configuration = RibbonConfigDemoApi1V2.class)
})
public class AppConfig {

    @Bean(name = "loadBalancedRestTemplate")
    @LoadBalanced
    public RestTemplate loadBalancedRestTemplate() {
        return new RestTemplate();
    }
}

RibbonConfigDemoApi1V1.java

...
public class RibbonConfigDemoApi1V1 {

    private DiscoveryClient discoveryClient;

    @Bean
    public ServerListFilter<Server> serverListFilter() {
        return new VersionedNIWSServerListFilter<>(this.discoveryClient, RibbonClientApi.DEMO_REGISTRATION_API_1_V1);
    }

    @Autowired
    public void setDiscoveryClient(DiscoveryClient discoveryClient) {
        this.discoveryClient = discoveryClient;
    }
}

RibbonConfigDemoApi1V2.java аналогична, но использует RibbonClientApi.DEMO_REGISTRATION_API_1_V2

RibbonClientApi.java

...
public enum RibbonClientApi {

    DEMO_REGISTRATION_API_1_V1("demo-multiversion-registration-api-1", "v1"),

    DEMO_REGISTRATION_API_1_V2("demo-multiversion-registration-api-1", "v2");

    public final String serviceId;
    public final String version;

    private RibbonClientApi(String serviceId, String version) {
        this.serviceId = serviceId;
        this.version = version;
    }
}

VersionedNIWSServerListFilter.java

...
public class VersionedNIWSServerListFilter<T extends Server> extends DefaultNIWSServerListFilter<T> {

    private static final String VERSION_KEY = "versions";

    private final DiscoveryClient discoveryClient;
    private final RibbonClientApi ribbonClientApi;

    public VersionedNIWSServerListFilter(DiscoveryClient discoveryClient, RibbonClientApi ribbonClientApi) {
        this.discoveryClient = discoveryClient;
        this.ribbonClientApi = ribbonClientApi;
    }

    @Override
    public List<T> getFilteredListOfServers(List<T> servers) {
        List<T> result = new ArrayList<>();
        List<ServiceInstance> serviceInstances = this.discoveryClient.getInstances(this.ribbonClientApi.serviceId);
        for (ServiceInstance serviceInstance : serviceInstances) {
            List<String> versions = this.getInstanceVersions(serviceInstance);
            if (versions.isEmpty() || versions.contains(this.ribbonClientApi.version)) {
                result.addAll(this.findServerForVersion(servers, serviceInstance));
            }
        }
        return result;
    }

    private List<String> getInstanceVersions(ServiceInstance serviceInstance) {
        List<String> result = new ArrayList<>();
        String rawVersions = serviceInstance.getMetadata().get(VERSION_KEY);
        if (StringUtils.isNotBlank(rawVersions)) {
            result.addAll(Arrays.asList(rawVersions.split(",")));
        }
        return result;
    }
...

AggregationResource.java

...
@RestController
@RequestMapping(value = "/aggregation", produces = "application/json")
public class AggregationResource {

    private static final String ACTORS_SERVICE_ID_V1 = "demo-multiversion-registration-api-1-v1";
    private static final String ACTORS_SERVICE_ID_V2 = "demo-multiversion-registration-api-1-v2";

    private RestTemplate loadBalancedRestTemplate;

    @RequestMapping(value = "/v1/actors/{id}", method = RequestMethod.GET)
    public com.asimio.api.multiversion.demo2.model.v1.Actor findActorV1(@PathVariable(value = "id") String id) {
        String url = String.format("http://%s/v1/actors/{id}", ACTORS_SERVICE_ID_V1);
        return this.loadBalancedRestTemplate.getForObject(url, com.asimio.api.multiversion.demo2.model.v1.Actor.class, id);
    }

    @RequestMapping(value = "/v2/actors/{id}", method = RequestMethod.GET)
    public com.asimio.api.multiversion.demo2.model.v2.Actor findActorV2(@PathVariable(value = "id") String id) {
        String url = String.format("http://%s/v2/actors/{id}", ACTORS_SERVICE_ID_V2);
        return this.loadBalancedRestTemplate.getForObject(url, com.asimio.api.multiversion.demo2.model.v2.Actor.class, id);
    }

    @Autowired
    public void setLoadBalancedRestTemplate(RestTemplate loadBalancedRestTemplate) {
        this.loadBalancedRestTemplate = loadBalancedRestTemplate;
    }
}