nacos-注册源码剖析
一. 根据pom依赖 找到注册主类
- 找到自动装配类
使用nacos注册, 我们都会在pom里添加nacos-discovery依赖
<dependency>
<groupId>com.alibaba.cloudgroupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discoveryartifactId>
dependency>
- 在依赖里找到这个jar包, 再找到spring.factories, 如下
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
com.alibaba.cloud.nacos.discovery.NacosDiscoveryAutoConfiguration,\
com.alibaba.cloud.nacos.ribbon.RibbonNacosAutoConfiguration,\
com.alibaba.cloud.nacos.endpoint.NacosDiscoveryEndpointAutoConfiguration,\
com.alibaba.cloud.nacos.registry.NacosServiceRegistryAutoConfiguration,\
com.alibaba.cloud.nacos.discovery.NacosDiscoveryClientConfiguration,\
com.alibaba.cloud.nacos.discovery.reactive.NacosReactiveDiscoveryClientConfiguration,\
com.alibaba.cloud.nacos.discovery.configclient.NacosConfigServerAutoConfiguration,\
com.alibaba.cloud.nacos.NacosServiceAutoConfiguration
org.springframework.cloud.bootstrap.BootstrapConfiguration=\
com.alibaba.cloud.nacos.discovery.configclient.NacosDiscoveryClientConfigServiceBootstrapConfiguration
- 找到一个Nacos服务注册自动装配类 --> NacosServiceRegistryAutoConfiguration, 接下来从这个类看注册
二. 源码解析NacosServiceRegistryAutoConfiguration
大胆猜测: 看源码之前大致猜想一下, 既然是一个注册的jar, 那么他的业务逻辑起码应该是: 第一步: springIOC初始化后类似dubbo注册一样, 有一个onApplicationEvent触发注册, 第二步: 根据已配置的yml参数, 往nacos注册中心里注册. 也往nacos注册中心留一条服务信息. 这样别的服务才能知道且调用过来. 相当于一个中介角色.
@Configuration(proxyBeanMethods = false)
@EnableConfigurationProperties
@ConditionalOnNacosDiscoveryEnabled
@ConditionalOnProperty(value = "spring.cloud.service-registry.auto-registration.enabled",
matchIfMissing = true)
@AutoConfigureAfter({
AutoServiceRegistrationConfiguration.class,
AutoServiceRegistrationAutoConfiguration.class,
NacosDiscoveryAutoConfiguration.class })
public class NacosServiceRegistryAutoConfiguration {
@Bean
public NacosServiceRegistry nacosServiceRegistry(
NacosDiscoveryProperties nacosDiscoveryProperties) {
return new NacosServiceRegistry(nacosDiscoveryProperties);
}
@Bean
@ConditionalOnBean(AutoServiceRegistrationProperties.class)
public NacosRegistration nacosRegistration(
ObjectProvider<List<NacosRegistrationCustomizer>> registrationCustomizers,
NacosDiscoveryProperties nacosDiscoveryProperties,
ApplicationContext context) {
return new NacosRegistration(registrationCustomizers.getIfAvailable(),
nacosDiscoveryProperties, context);
}
@Bean
@ConditionalOnBean(AutoServiceRegistrationProperties.class)
public NacosAutoServiceRegistration nacosAutoServiceRegistration(
NacosServiceRegistry registry,
AutoServiceRegistrationProperties autoServiceRegistrationProperties,
NacosRegistration registration) {
return new NacosAutoServiceRegistration(registry,
autoServiceRegistrationProperties, registration);
}
}
- NacosRegistration
public class NacosRegistration implements Registration, ServiceInstance {
...
// @PostConstruct初始化前这个时间断 执行该方法 可以看出来主要作用是 判断是否yml中有参数 往metadata中set
@PostConstruct
public void init() {
Map<String, String> metadata = nacosDiscoveryProperties.getMetadata();
Environment env = context.getEnvironment();
String endpointBasePath = env.getProperty(MANAGEMENT_ENDPOINT_BASE_PATH);
if (!StringUtils.isEmpty(endpointBasePath)) {
metadata.put(MANAGEMENT_ENDPOINT_BASE_PATH, endpointBasePath);
}
Integer managementPort = ManagementServerPortUtils.getPort(context);
if (null != managementPort) {
metadata.put(MANAGEMENT_PORT, managementPort.toString());
String contextPath = env
.getProperty("management.server.servlet.context-path");
String address = env.getProperty("management.server.address");
if (!StringUtils.isEmpty(contextPath)) {
metadata.put(MANAGEMENT_CONTEXT_PATH, contextPath);
}
if (!StringUtils.isEmpty(address)) {
metadata.put(MANAGEMENT_ADDRESS, address);
}
}
if (null != nacosDiscoveryProperties.getHeartBeatInterval()) {
metadata.put(PreservedMetadataKeys.HEART_BEAT_INTERVAL,
nacosDiscoveryProperties.getHeartBeatInterval().toString());
}
if (null != nacosDiscoveryProperties.getHeartBeatTimeout()) {
metadata.put(PreservedMetadataKeys.HEART_BEAT_TIMEOUT,
nacosDiscoveryProperties.getHeartBeatTimeout().toString());
}
if (null != nacosDiscoveryProperties.getIpDeleteTimeout()) {
metadata.put(PreservedMetadataKeys.IP_DELETE_TIMEOUT,
nacosDiscoveryProperties.getIpDeleteTimeout().toString());
}
customize(registrationCustomizers, this);
}
...
}
- AbstractAutoServiceRegistration
public abstract class AbstractAutoServiceRegistration<R extends Registration>
implements AutoServiceRegistration, ApplicationContextAware,
ApplicationListener<WebServerInitializedEvent> {
...
// 看到了这个方法 就知道是spring加载完成后要做的事情
@Override
@SuppressWarnings("deprecation")
public void onApplicationEvent(WebServerInitializedEvent event) {
bind(event);
}
@Deprecated
public void bind(WebServerInitializedEvent event) {
ApplicationContext context = event.getApplicationContext();
if (context instanceof ConfigurableWebServerApplicationContext) {
if ("management".equals(((ConfigurableWebServerApplicationContext) context)
.getServerNamespace())) {
return;
}
}
// CAS
this.port.compareAndSet(0, event.getWebServer().getPort());
this.start();
}
...
// 主执行方法在这里
public void start() {
if (!isEnabled()) {
if (logger.isDebugEnabled()) {
logger.debug("Discovery Lifecycle disabled. Not starting");
}
return;
}
// only initialize if nonSecurePort is greater than 0 and it isn't already running
// because of containerPortInitializer below
if (!this.running.get()) {
this.context.publishEvent(
new InstancePreRegisteredEvent(this, getRegistration()));
// 这个register就会调用到第三个@Bean的NacosServiceRegistry里面的register方法
// 接下来看NacosServiceRegistry的register方法实现
register();
if (shouldRegisterManagement()) {
registerManagement();
}
this.context.publishEvent(
new InstanceRegisteredEvent<>(this, getConfiguration()));
this.running.compareAndSet(false, true);
}
}
...
}
- NacosServiceRegistry
public class NacosServiceRegistry implements ServiceRegistry<Registration> {
...
@Override
public void register(Registration registration) {
if (StringUtils.isEmpty(registration.getServiceId())) {
log.warn("No service to register for nacos client...");
return;
}
// 1. 核心NamingService 主要看这个service的实例化
NamingService namingService = namingService();
String serviceId = registration.getServiceId();
String group = nacosDiscoveryProperties.getGroup();
Instance instance = getNacosInstanceFromRegistration(registration);
try {
// 调用实例化出来的namingService 的注册方法 http形式通知到nacos注册中心
namingService.registerInstance(serviceId, group, instance);
log.info("nacos registry, {} {} {}:{} register finished", group, serviceId,
instance.getIp(), instance.getPort());
}
catch (Exception e) {
log.error("nacos registry, {} register failed...{},", serviceId,
registration.toString(), e);
// rethrow a RuntimeException if the registration is failed.
// issue : https://github.com/alibaba/spring-cloud-alibaba/issues/1132
rethrowRuntimeException(e);
}
}
...
// 2. 去nacosServiceManager里 拿namingService 接下来去看nacosServiceManager这个类
private NamingService namingService() {
return nacosServiceManager
.getNamingService(nacosDiscoveryProperties.getNacosProperties());
}
}
- NacosServiceManager
public class NacosServiceManager {
...
public NamingService getNamingService(Properties properties) {
if (Objects.isNull(this.namingService)) {
// 1. 看如何构建的
buildNamingService(properties);
}
return namingService;
}
...
private NamingService buildNamingService(Properties properties) {
if (Objects.isNull(namingService)) {
// sync 锁资源 避免重复build
synchronized (NacosServiceManager.class) {
if (Objects.isNull(namingService)) {
namingService = createNewNamingService(properties);
}
}
}
return namingService;
}
...
private NamingService createNewNamingService(Properties properties) {
try {
// 2. 源码包下api目录下, NamingFactory的createNamingService方法
return createNamingService(properties);
}
catch (NacosException e) {
throw new RuntimeException(e);
}
}
...
}
- NamingFactory
public class NamingFactory{
...
public static NamingService createNamingService(Properties properties) throws NacosException {
try {
Class<?> driverImplClass = Class.forName("com.alibaba.nacos.client.naming.NacosNamingService");
Constructor constructor = driverImplClass.getConstructor(Properties.class);
// 这里会实例化出NaocsNamingService
NamingService vendorImpl = (NamingService) constructor.newInstance(properties);
return vendorImpl;
} catch (Throwable e) {
throw new NacosException(NacosException.CLIENT_INVALID_PARAM, e);
}
}
}
- NaocsNamingService
public class NaocsNamingService{
...
@Override
public void registerInstance(String serviceName, String groupName, Instance instance) throws NacosException {
// 检查参数的有效性
NamingUtils.checkInstanceIsLegal(instance);
String groupedServiceName = NamingUtils.getGroupedName(serviceName, groupName);
// 是否为临时的也就是AP架构
// nacos支持CAP里的两种架构 一种是AP架构存在内存的数据 另一种是CP架构 持久化到磁盘的
if (instance.isEphemeral()) {
// 构建心跳实体
BeatInfo beatInfo = beatReactor.buildBeatInfo(groupedServiceName, instance);
// 添加到ScheduledThreadPoolExecutor里 定时发送心跳
beatReactor.addBeatInfo(groupedServiceName, beatInfo);
}
// proxy的注册逻辑 接下来去NamingProxy看
serverProxy.registerService(groupedServiceName, groupName, instance);
}
...
}
- NamingProxy
public class NamingProxy{
...
public void registerService(String serviceName, String groupName, Instance instance) throws NacosException {
NAMING_LOGGER.info("[REGISTER-SERVICE] {} registering service {} with instance: {}", namespaceId, serviceName,
instance);
final Map<String, String> params = new HashMap<String, String>(16);
params.put(CommonParams.NAMESPACE_ID, namespaceId);
params.put(CommonParams.SERVICE_NAME, serviceName);
params.put(CommonParams.GROUP_NAME, groupName);
params.put(CommonParams.CLUSTER_NAME, instance.getClusterName());
params.put("ip", instance.getIp());
params.put("port", String.valueOf(instance.getPort()));
params.put("weight", String.valueOf(instance.getWeight()));
params.put("enable", String.valueOf(instance.isEnabled()));
params.put("healthy", String.valueOf(instance.isHealthy()));
params.put("ephemeral", String.valueOf(instance.isEphemeral()));
params.put("metadata", JacksonUtils.toJson(instance.getMetadata()));
// UtilAndComs.nacosUrlInstance
// public static String nacosUrlInstance = nacosUrlBase + "/instance";
// nacosTemplate http形式 调用nacos注册中心的注册api
// 就此注册到nacos注册中心上去了
reqApi(UtilAndComs.nacosUrlInstance, params, HttpMethod.POST);
}
...
}
PS: 这里只是介绍了client的注册逻辑, nacos server主要是对外提供了一套api来实现注册与实例查询相关, 官网: https://nacos.io/en-us/docs/open-api.html