前言
最近朋友部门接手供方微服务项目过来运维，那套微服务的技术栈是springcloud Netflix，和朋友部门的微服务技术栈刚好匹配。当时朋友部门的想法，既然都是同一套技术体系，那些基础服务治理组件比如注册中心之类，就共用同一套。然而在落地实施的过程中，发现供方提供的微服务项目服务有些serviceId和朋友部门他们已有服务serviceId名字竟然一模一样。这样就有问题了，eureka服务发现是通过serviceId识别
朋友部门的策略是将供方微服务项目serviceId改掉，比如原本serviceId是user，就改成xxx-user。然而调整后，发现供方微服务某些微服务会报错，后面了解到供方仅提供应用层代码，有些核心代码库他们是不提供的。朋友他们部门也考虑要不就替换自己已有服务的serviceId，后边发现可行性也不大，因为朋友他们微服务也对其他部门输出了一些能力，如果改动，就得通知相关方进行改动，这边会涉及到一些沟通成本等非技术性因素。
后边朋友就和我交流了一下方案。首先问题点的本质是serviceId一样引起的吗？乍看一下，好像是这样。我们换个角度考虑这个问题，是不是也可以说是因为隔离性做得不够好导致。于是我就跟朋友说，如果把eureka切换成nacos，对你部门的切换成本大不大。朋友说代码层虽然仅需切换jar和配置即可实现，但是因为版本原因，如果切换，他们也只能用到nacos 1版本的能力。其次他部门对注册中心的性能要求也不高，但对注册中心的稳定性要求比较高，如果切换，他们需要做很多测试方面的工作，仅仅只是因为这个隔离性，他更倾向部署多个eureka。
聊到后面朋友就在吐槽eureka，为啥不能像nacos或者k8s那样搞个namespace来做隔离。基于朋友这个想法，我就跟他说，我帮你扩展一下，让eureka也拥有仿nacos namespace的能力
实现思路
注: 本文以朋友他们公司的微服务版本springcloud Hoxton.SR3来讲解
实现的核心逻辑：利用注册中心都有的元数据，即metaMap，以及配合注册中心具备的服务发现能力进行扩展
核心实现逻辑
1、元数据扩展
a、新建扩展配置类
@ConfigurationProperties(prefix = "eureka.instance.ext")
@Data
@AllArgsConstructor
@NoArgsConstructor
public class EurekaInstanceProperties {
private String namespace = Constant.META_INFO_DEAFULT_NAMESPACE;
private String group = Constant.META_INFO_DEAFULT_GROUP;
private boolean loadBalanceAllowCross;
}b、元数据扩展填充
public class EurekaInstanceSmartInitializingSingleton implements SmartInitializingSingleton, ApplicationContextAware {
private ApplicationContext applicationContext;
@Override
public void afterSingletonsInstantiated() {
EurekaInstanceProperties eurekaInstanceProperties = applicationContext.getBean(EurekaInstanceProperties.class);
EurekaInstanceConfigBean bean = applicationContext.getBean(EurekaInstanceConfigBean.class);
Map metadataMap = bean.getMetadataMap();
metadataMap.put(Constant.META_INFO_KEY_NAMESPACE,eurekaInstanceProperties.getNamespace());
metadataMap.put(Constant.META_INFO_KEY_GROUP,eurekaInstanceProperties.getGroup());
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.applicationContext = applicationContext;
}
}
2、eureka服务端面板改造
a、status.ftlh页面逻辑改造
在项目eureka服务端的src/main/resource目录下新建/templates/eureka文件夹，将eureka原本有的status.ftlh拷贝过来，因为我们要对这个status.ftlh进行改造。而status.ftlh原本位置是放在
在status.ftlh添加如下内容
b、微调EurekaController内容
EurekaController是eureka服务用来面板展示的控制器，可以在eureka的服务端的项目建一个EurekaController一模一样的类，形如
注： 也可以自己自定义一个controller，反正这个controller就是用来页面渲染用的
对如下方法进行微调
org.springframework.cloud.netflix.eureka.server.EurekaController#populateApps微调内容如下
for (InstanceInfo info : app.getInstances()) {
String id = info.getId();
String url = info.getStatusPageUrl();
Map metadata = info.getMetadata();
String group = StringUtils.isEmpty(metadata.get("group")) ? "default" : metadata.get("group");
String namespace = StringUtils.isEmpty(metadata.get("namespace")) ? "default" : metadata.get("namespace");
String metaInfo = url + "_" + namespace + "_" + group;
List> list = instancesByStatus
.computeIfAbsent(status, k -> new ArrayList<>());
list.add(new Pair<>(id, metaInfo));
}
for (Map.Entry>> entry : instancesByStatus
.entrySet()) {
List> value = entry.getValue();
InstanceInfo.InstanceStatus status = entry.getKey();
LinkedHashMap instanceData = new LinkedHashMap<>();
for (Pair p : value) {
LinkedHashMap instance = new LinkedHashMap<>();
instances.add(instance);
instance.put("id", p.first());
String metaInfo = p.second();
String[] metaInfoArr = metaInfo.split("_");
String url = metaInfoArr[0];
instance.put("url", url);
String namespace = metaInfoArr[1];
instance.put("namespace", namespace);
String group = metaInfoArr[2];
instance.put("group", group);
boolean isHref = url != null && url.startsWith("http");
instance.put("isHref", isHref);
}
model.put("apps", apps); c、改造后的面板展示
注： 在eureka的客户端需配形如下配置
3、服务发现改造
a、重写com.netflix.loadbalancer.ServerList
参照eureka的服务发现配置类
@Bean
@ConditionalOnMissingBean
public ServerList ribbonServerList(IClientConfig config,
Provider eurekaClientProvider) {
if (this.propertiesFactory.isSet(ServerList.class, serviceId)) {
return this.propertiesFactory.get(ServerList.class, config, serviceId);
}
DiscoveryEnabledNIWSServerList discoveryServerList = new DiscoveryEnabledNIWSServerList(
config, eurekaClientProvider);
DomainExtractingServerList serverList = new DomainExtractingServerList(
discoveryServerList, config, this.approximateZoneFromHostname);
return serverList;
}
我们可以发现我们仅需改造DiscoveryEnabledNIWSServerList即可
@Slf4j
public class CustomDiscoveryEnabledNIWSServerList extends DiscoveryEnabledNIWSServerList {
private final Provider eurekaClientProvider;
private final EurekaInstanceProperties eurekaInstanceProperties;
public CustomDiscoveryEnabledNIWSServerList(IClientConfig clientConfig, Provider eurekaClientProvider,EurekaInstanceProperties eurekaInstanceProperties) {
this.eurekaClientProvider = eurekaClientProvider;
this.eurekaInstanceProperties = eurekaInstanceProperties;
initWithNiwsConfig(clientConfig);
}
@Override
public List getInitialListOfServers(){
List initialListOfServers = super.getInitialListOfServers();
return selectListOfServersByMetaInfo(initialListOfServers);
}
@Override
public List getUpdatedListOfServers(){
List updatedListOfServers = super.getUpdatedListOfServers();
return selectListOfServersByMetaInfo(updatedListOfServers);
}
private List selectListOfServersByMetaInfo(List discoveryEnabledServerList){
List discoveryEnabledServersByMetaInfo = new ArrayList<>();
if(!CollectionUtils.isEmpty(discoveryEnabledServerList)){
for (DiscoveryEnabledServer discoveryEnabledServer : discoveryEnabledServerList) {
Map metadata = discoveryEnabledServer.getInstanceInfo().getMetadata();
String namespace = metadata.get(Constant.META_INFO_KEY_NAMESPACE);
String group = metadata.get(Constant.META_INFO_KEY_GROUP);
if(eurekaInstanceProperties.getNamespace().equals(namespace) &&
eurekaInstanceProperties.getGroup().equals(group)){
discoveryEnabledServersByMetaInfo.add(discoveryEnabledServer);
}
}
}
if(CollectionUtils.isEmpty(discoveryEnabledServersByMetaInfo) &&
eurekaInstanceProperties.isLoadBalanceAllowCross()){
log.warn("not found enabledServerList in namespace : 【{}】 and group : 【{}】. will select default enabledServerList by isLoadBalanceAllowCross is {}",eurekaInstanceProperties.getNamespace(),eurekaInstanceProperties.getGroup(),eurekaInstanceProperties.isLoadBalanceAllowCross());
return discoveryEnabledServerList;
}
return discoveryEnabledServersByMetaInfo;
}
}
b、配置我们重写后的ServerList
@Configuration
public class EurekaClientAutoConfiguration extends EurekaRibbonClientConfiguration{
@Value("${ribbon.eureka.approximateZoneFromHostname:false}")
private boolean approximateZoneFromHostname = false;
@RibbonClientName
private String serviceId = "client";;
@Autowired
private PropertiesFactory propertiesFactory;
@Bean
@Primary
public ServerList ribbonServerList(IClientConfig config,
Provider eurekaClientProvider, EurekaInstanceProperties properties) {
if (this.propertiesFactory.isSet(ServerList.class, serviceId)) {
return this.propertiesFactory.get(ServerList.class, config, serviceId);
}
DiscoveryEnabledNIWSServerList discoveryServerList = new CustomDiscoveryEnabledNIWSServerList(
config, eurekaClientProvider,properties);
DomainExtractingServerList serverList = new DomainExtractingServerList(
discoveryServerList, config, this.approximateZoneFromHostname);
return serverList;
}
} c、修改ribbionclient的默认配置
@Configuration(proxyBeanMethods = false)
@EnableConfigurationProperties
@ConditionalOnRibbonAndEurekaEnabled
@AutoConfigureAfter(RibbonAutoConfiguration.class)
@RibbonClients(defaultConfiguration = EurekaClientAutoConfiguration.class)
public class RibbonEurekaAutoConfiguration {
}测试
示例服务：网关、消费者服务、提供者服务、eureka
相关的eureka配置内容如下
1、网关：
网关占用端口：8000
eureka:
instance:
instance-id: ${spring.application.name}:${spring.cloud.client.ip-address}:${spring.application.instance_id:${server.port}}
prefer-ip-address: ${PREFER_IP:true} #是否选择IP注册
# ip-address: ${IP_ADDRESS:localhost} #指定IP地址注册
lease-renewal-interval-in-seconds: 5 #续约更新时间间隔（默认30秒）,使得eureka及时剔除无效服务
lease-expiration-duration-in-seconds: 10 #续约到期时间（默认90秒）
hostname: ${HOSTNAME:${spring.application.name}}
ext:
namespace: dev
group: lybgeek
client:
service-url:
defaultZone: ${EUREKA_CLIENT_SERVICEURL_DEFAULTZONE:http://localhost:8761/eureka/}
#缩短延迟向服务端注册的时间、默认40s
initial-instance-info-replication-interval-seconds: 10
#提高Eureka-Client端拉取Server注册信息的频率,默认30s
registry-fetch-interval-seconds: 52、消费者
消费者1： 占用端口：6614
eureka:
instance:
instance-id: ${spring.application.name}:${spring.cloud.client.ip-address}:${spring.application.instance_id:${server.port}}
prefer-ip-address: ${PREFER_IP:true} #是否选择IP注册
# ip-address: ${IP_ADDRESS:localhost} #指定IP地址注册
lease-renewal-interval-in-seconds: 5 #续约更新时间间隔（默认30秒）,使得eureka及时剔除无效服务
lease-expiration-duration-in-seconds: 10 #续约到期时间（默认90秒）
hostname: ${HOSTNAME:${spring.application.name}}
ext:
group: lybgeek
namespace: dev
client:
service-url:
defaultZone: ${EUREKA_CLIENT_SERVICEURL_DEFAULTZONE:http://localhost:8761/eureka/}
#缩短延迟向服务端注册的时间、默认40s
initial-instance-info-replication-interval-seconds: 10
#提高Eureka-Client端拉取Server注册信息的频率,默认30s
registry-fetch-interval-seconds: 5消费者2： 占用端口：6613
eureka:
instance:
instance-id: ${spring.application.name}:${spring.cloud.client.ip-address}:${spring.application.instance_id:${server.port}}
prefer-ip-address: ${PREFER_IP:true} #是否选择IP注册
# ip-address: ${IP_ADDRESS:localhost} #指定IP地址注册
lease-renewal-interval-in-seconds: 5 #续约更新时间间隔（默认30秒）,使得eureka及时剔除无效服务
lease-expiration-duration-in-seconds: 10 #续约到期时间（默认90秒）
hostname: ${HOSTNAME:${spring.application.name}}
ext:
group: lybgeek6613
namespace: dev
client:
service-url:
defaultZone: ${EUREKA_CLIENT_SERVICEURL_DEFAULTZONE:http://localhost:8761/eureka/}
#缩短延迟向服务端注册的时间、默认40s
initial-instance-info-replication-interval-seconds: 10
#提高Eureka-Client端拉取Server注册信息的频率,默认30s
registry-fetch-interval-seconds: 5控制层示例
@RestController
@RequestMapping("instance")
public class InstanceInfoController {
@InstancePort
private String port;
@InstanceName
private String instanceName;
@Autowired
private InstanceServiceFeign instanceServiceFeign;
@GetMapping("list")
public List list(){
List instanceInfos = new ArrayList<>();
InstanceInfo comsumeInstanceInfo = InstanceInfo.builder()
.port(port).name(instanceName).build();
instanceInfos.add(comsumeInstanceInfo);
InstanceInfo providerInstanceInfo = null;
try {
providerInstanceInfo = instanceServiceFeign.getInstanceInfo();
instanceInfos.add(providerInstanceInfo);
} catch (Exception e) {
e.printStackTrace();
}
return instanceInfos;
}
} 3、提供者
提供者1： 占用端口:6605
eureka:
instance:
instance-id: ${spring.application.name}:${spring.cloud.client.ip-address}:${spring.application.instance_id:${server.port}}
prefer-ip-address: ${PREFER_IP:true} #是否选择IP注册
# ip-address: ${IP_ADDRESS:localhost} #指定IP地址注册
lease-renewal-interval-in-seconds: 5 #续约更新时间间隔（默认30秒）,使得eureka及时剔除无效服务
lease-expiration-duration-in-seconds: 10 #续约到期时间（默认90秒）
hostname: ${HOSTNAME:${spring.application.name}}
ext:
namespace: dev
group: lybgeek
client:
service-url:
defaultZone: ${EUREKA_CLIENT_SERVICEURL_DEFAULTZONE:http://localhost:8761/eureka/}
#缩短延迟向服务端注册的时间、默认40s
initial-instance-info-replication-interval-seconds: 10
#提高Eureka-Client端拉取Server注册信息的频率,默认30s
registry-fetch-interval-seconds: 5提供者2： 占用端口:6604
eureka:
instance:
instance-id: ${spring.application.name}:${spring.cloud.client.ip-address}:${spring.application.instance_id:${server.port}}
prefer-ip-address: ${PREFER_IP:true} #是否选择IP注册
# ip-address: ${IP_ADDRESS:localhost} #指定IP地址注册
lease-renewal-interval-in-seconds: 5 #续约更新时间间隔（默认30秒）,使得eureka及时剔除无效服务
lease-expiration-duration-in-seconds: 10 #续约到期时间（默认90秒）
hostname: ${HOSTNAME:${spring.application.name}}
ext:
namespace: dev
group: lybgeek6613
client:
service-url:
defaultZone: ${EUREKA_CLIENT_SERVICEURL_DEFAULTZONE:http://localhost:8761/eureka/}
#缩短延迟向服务端注册的时间、默认40s
initial-instance-info-replication-interval-seconds: 10
#提高Eureka-Client端拉取Server注册信息的频率,默认30s
registry-fetch-interval-seconds: 5控制层示例
@RestController
@RequestMapping(InstanceServiceFeign.PATH)
public class InstanceServiceFeignImpl implements InstanceServiceFeign {
@InstancePort
private String port;
@InstanceName
private String instanceName;
@Override
public InstanceInfo getInstanceInfo() {
return InstanceInfo.builder()
.name(instanceName).port(port).build();
}
}
访问eureka面板
通过网关访问会发现不管访问多少次，网关只能命中namespace为dev、group为lybgeek的服务，说明隔离效果生效
当我们的服务和其他服务不属于同个namespace或者group时，可以通过配置load-balance-allow-cross: true，实现跨namespace和group访问。配置形如下
eureka:
instance:
instance-id: ${spring.application.name}:${spring.cloud.client.ip-address}:${spring.application.instance_id:${server.port}}
prefer-ip-address: ${PREFER_IP:true} #是否选择IP注册
# ip-address: ${IP_ADDRESS:localhost} #指定IP地址注册
lease-renewal-interval-in-seconds: 5 #续约更新时间间隔（默认30秒）,使得eureka及时剔除无效服务
lease-expiration-duration-in-seconds: 10 #续约到期时间（默认90秒）
hostname: ${HOSTNAME:${spring.application.name}}
ext:
namespace: dev
group: lybgeek123
load-balance-allow-cross: true
我们再通过网关访问一下
观察控制台，会发现出现警告
总结
本文主要是仿造nacos的一些思路，对eureka进行扩展。其实注册中心的功能大同小异，尤其集成springcloud后，基本上都有固定套路了。本文只是实现eureka 服务发现隔离的一种方式，也可以通过eureka本身的zone和region，通过自定义负载均衡策略来实现。最后eureka instance其实也有namespace的属性，只是在springcloud集成，被忽略了