nacos官方地址:https://nacos.io/zh-cn/
大家可以看一下nacos的中文手册以及官方源码,博主就不带领大家快速入门 了,官方文档中都有而且非常标准,比其他博客写的好多了并且还是实时更新的。
先看一下博主给大家画的流程图,掌握一下大概的基本流程,好理解,博主给大家讲源码:
https://www.processon.com/view/link/5f7e895be0b34d0711f65178
nacos最主要的功能就是服务注册及发现,那它到底是如何实现的呢?博主用的springboot开发的,所以直接就去找nacos的jar包下的spring.factories,这是每个要自动注入的服务jar的必备文件,我们来看一下
里面有很多的自动配置类,我们只看一下NacosServiceRegistryAutoConfiguration,该类主要做的是服务注册的相关事宜,如果大家第一次看源码的话不知道该如何下手,最笨的方法就是一个一个看。总会找到的,最好要找名字看起来就像自己找的,因为这是阿里巴巴开发的,他们是有java开发规范的,要做到见名知意。
1 /**
2 * @author xiaojing
3 * @author <a href="mailto:mercyblitz@gmail.com">Mercy</a>
4 */
5 @Configuration(proxyBeanMethods = false)
6 @EnableConfigurationProperties
7 @ConditionalOnNacosDiscoveryEnabled
8 @ConditionalOnProperty(value = "spring.cloud.service-registry.auto-registration.enabled",
9 matchIfMissing = true)
10 @AutoConfigureAfter({ AutoServiceRegistrationConfiguration.class,
11 AutoServiceRegistrationAutoConfiguration.class,
12 NacosDiscoveryAutoConfiguration.class })
13 public class NacosServiceRegistryAutoConfiguration {
14
15 @Bean
16 public NacosServiceRegistry nacosServiceRegistry(
17 NacosDiscoveryProperties nacosDiscoveryProperties) {
18 return new NacosServiceRegistry(nacosDiscoveryProperties);
19 }
20
21 @Bean
22 @ConditionalOnBean(AutoServiceRegistrationProperties.class)
23 public NacosRegistration nacosRegistration(
24 NacosDiscoveryProperties nacosDiscoveryProperties,
25 ApplicationContext context) {
26 return new NacosRegistration(nacosDiscoveryProperties, context);
27 }
28
29 @Bean
30 @ConditionalOnBean(AutoServiceRegistrationProperties.class)
31 public NacosAutoServiceRegistration nacosAutoServiceRegistration(
32 NacosServiceRegistry registry,
33 AutoServiceRegistrationProperties autoServiceRegistrationProperties,
34 NacosRegistration registration) {
35 //这里才是自动注入的类,我们需要进去看一下
36 return new NacosAutoServiceRegistration(registry,
37 autoServiceRegistrationProperties, registration);
38 }
39
40 }
1 public class NacosAutoServiceRegistration
2 extends AbstractAutoServiceRegistration<Registration> {
3
4 private static final Logger log = LoggerFactory
5 .getLogger(NacosAutoServiceRegistration.class);
6
7 private NacosRegistration registration;
8
9 public NacosAutoServiceRegistration(ServiceRegistry<Registration> serviceRegistry,
10 AutoServiceRegistrationProperties autoServiceRegistrationProperties,
11 NacosRegistration registration) {
12 super(serviceRegistry, autoServiceRegistrationProperties);
13 this.registration = registration;
14 }
15
16 @Deprecated
17 public void setPort(int port) {
18 getPort().set(port);
19 }
20
21 @Override
22 protected NacosRegistration getRegistration() {
23 if (this.registration.getPort() < 0 && this.getPort().get() > 0) {
24 this.registration.setPort(this.getPort().get());
25 }
26 Assert.isTrue(this.registration.getPort() > 0, "service.port has not been set");
27 return this.registration;
28 }
29
30 @Override
31 protected NacosRegistration getManagementRegistration() {
32 return null;
33 }
34
35 @Override
36 protected void register() {
37 if (!this.registration.getNacosDiscoveryProperties().isRegisterEnabled()) {
38 log.debug("Registration disabled.");
39 return;
40 }
41 if (this.registration.getPort() < 0) {
42 this.registration.setPort(getPort().get());
43 }
44 super.register();
45 }
46
47 @Override
48 protected void registerManagement() {
49 if (!this.registration.getNacosDiscoveryProperties().isRegisterEnabled()) {
50 return;
51 }
52 super.registerManagement();
53
54 }
55
56 @Override
57 protected Object getConfiguration() {
58 return this.registration.getNacosDiscoveryProperties();
59 }
60
61 @Override
62 protected boolean isEnabled() {
63 return this.registration.getNacosDiscoveryProperties().isRegisterEnabled();
64 }
65
66 @Override
67 @SuppressWarnings("deprecation")
68 protected String getAppName() {
69 String appName = registration.getNacosDiscoveryProperties().getService();
70 return StringUtils.isEmpty(appName) ? super.getAppName() : appName;
71 }
72
73 }
看到这里,大家可能有点懵,我应该找那个方法呢?大家可以看一下构造器中,引用了父类,当我们看到父类的时候,发现父类实现了ApplicationListener,这个类大家不陌生,系统会自动执行其onApplicationEvent而正好我们的类实现了这个方法,最后我们发现了应该看register() 方法,大家可以来看看这个方法的实现
1 @Override
2 public void register(Registration registration) {
3
4 if (StringUtils.isEmpty(registration.getServiceId())) {
5 log.warn("No service to register for nacos client...");
6 return;
7 }
8 //看到这两个参数,大家看过nacos文档就知道这两个参数要干啥用了
9 String serviceId = registration.getServiceId();
10 String group = nacosDiscoveryProperties.getGroup();
11 //要发送的实例对象,具体的属性,大家可以看看这个方法
12 Instance instance = getNacosInstanceFromRegistration(registration);
13
14 try {
15 //走这里,是真正的注册服务
16 namingService.registerInstance(serviceId, group, instance);
17 log.info("nacos registry, {} {} {}:{} register finished", group, serviceId,
18 instance.getIp(), instance.getPort());
19 }
20 catch (Exception e) {
21 log.error("nacos registry, {} register failed...{},", serviceId,
22 registration.toString(), e);
23 // rethrow a RuntimeException if the registration is failed.
24 // issue : https://github.com/alibaba/spring-cloud-alibaba/issues/1132
25 rethrowRuntimeException(e);
26 }
27 }
1 @Override
2 public void registerInstance(String serviceName, String groupName, Instance instance) throws NacosException {
3 //是否是临时的,这个参数默认是临时实例,这个是临时或者是否持久很重要,先记住
4 if (instance.isEphemeral()) {
5 //填写各种心跳信息,毕竟服务需要往nacos发送心跳,nacos才能知道该服务是否还存活
6 BeatInfo beatInfo = new BeatInfo();
7 beatInfo.setServiceName(NamingUtils.getGroupedName(serviceName, groupName));
8 beatInfo.setIp(instance.getIp());
9 beatInfo.setPort(instance.getPort());
10 beatInfo.setCluster(instance.getClusterName());
11 beatInfo.setWeight(instance.getWeight());
12 beatInfo.setMetadata(instance.getMetadata());
13 beatInfo.setScheduled(false);
14 beatInfo.setPeriod(instance.getInstanceHeartBeatInterval());
15 //看一下客服端是如何发送心跳
16 beatReactor.addBeatInfo(NamingUtils.getGroupedName(serviceName, groupName), beatInfo);
17 }
18 //注册服务
19 serverProxy.registerService(NamingUtils.getGroupedName(serviceName, groupName), groupName, instance);
20 }
1 @Override
2 public void run() {
3 if (beatInfo.isStopped()) {
4 return;
5 }
6 long nextTime = beatInfo.getPeriod();
7 try {
8 //会调用nacos服务端的/instance/beat接口
9 JSONObject result = serverProxy.sendBeat(beatInfo, BeatReactor.this.lightBeatEnabled);
10 long interval = result.getIntValue("clientBeatInterval");
11 boolean lightBeatEnabled = false;
12 if (result.containsKey(CommonParams.LIGHT_BEAT_ENABLED)) {
13 lightBeatEnabled = result.getBooleanValue(CommonParams.LIGHT_BEAT_ENABLED);
14 }
15 BeatReactor.this.lightBeatEnabled = lightBeatEnabled;
16 if (interval > 0) {
17 nextTime = interval;
18 }
19 int code = NamingResponseCode.OK;
20 if (result.containsKey(CommonParams.CODE)) {
21 code = result.getIntValue(CommonParams.CODE);
22 }
23 //如果找不到服务,则进行注册服务
24 if (code == NamingResponseCode.RESOURCE_NOT_FOUND) {
25 Instance instance = new Instance();
26 instance.setPort(beatInfo.getPort());
27 instance.setIp(beatInfo.getIp());
28 instance.setWeight(beatInfo.getWeight());
29 instance.setMetadata(beatInfo.getMetadata());
30 instance.setClusterName(beatInfo.getCluster());
31 instance.setServiceName(beatInfo.getServiceName());
32 instance.setInstanceId(instance.getInstanceId());
33 instance.setEphemeral(true);
34 try {
35 //该方法封装好参数后,会调用/instance接口
36 serverProxy.registerService(beatInfo.getServiceName(),
37 NamingUtils.getGroupName(beatInfo.getServiceName()), instance);
38 } catch (Exception ignore) {
39 }
40 }
41 } catch (NacosException ne) {
42 NAMING_LOGGER.error("[CLIENT-BEAT] failed to send beat: {}, code: {}, msg: {}",
43 JSON.toJSONString(beatInfo), ne.getErrCode(), ne.getErrMsg());
44
45 }
46 //定时线程池不会一直循环进行调用,所以每次执行完之后会继续添加定时任务进行发送心跳
47 executorService.schedule(new BeatTask(beatInfo), nextTime, TimeUnit.MILLISECONDS);
48 }
看完发送心跳的方法,我们该看注册服务的方法了:serverProxy.registerService(NamingUtils.getGroupedName(serviceName, groupName), groupName, instance);其实就是发送心跳后,找不到服务时调用的/instance接口。
到此,我们的服务就会注册到nacos服务端中,客户端的代码就是如此,还是挺简单的,我们下一篇就会带大家走进服务端的代码。
原创声明:本文系作者授权腾讯云开发者社区发表,未经许可,不得转载。
如有侵权,请联系 cloudcommunity@tencent.com 删除。
原创声明:本文系作者授权腾讯云开发者社区发表,未经许可,不得转载。
如有侵权,请联系 cloudcommunity@tencent.com 删除。