Soul网关学习Zookeeper数据同步01
2021年1月20日大约 5 分钟Soul
启动 soul-admin、soul-bootstrap， 使用 zookeeper 同步数据到网关
一、配置环境
1、soul-admin 服务配置，需要重启服务
soul-admin/src/main/resources/application.yml
soul:
sync:
zookeeper:
url: localhost:2181
sessionTimeout: 5000
connectionTimeout: 20002、soul-bootstrap 网关服务配置，需要重启
soul-bootstrap/pom.xml
<!--soul data sync start use zookeeper-->
<dependency>
<groupId>org.dromara</groupId>
<artifactId>soul-spring-boot-starter-sync-data-zookeeper</artifactId>
<version>${project.version}</version>
</dependency>soul-bootstrap/src/main/resources/application-local.yml
soul:
sync:
zookeeper:
url: localhost:2181
sessionTimeout: 5000
connectionTimeout: 2000二、启动服务
1、 启动 zookeeper
zookeeper ./bin/zkServer.sh start
/usr/bin/java
ZooKeeper JMX enabled by default
Using config: /Documents/soft/zookeeper/bin/../conf/zoo.cfg
Starting zookeeper ... STARTED2、soul-admin 网关后台服务启动，服务启动后可以看到发起的 ZooKeeper 请求调用
2021-01-20 17:34:48.752 INFO 64500 --- [-localhost:2181] org.I0Itec.zkclient.ZkEventThread : Starting ZkClient event thread.
2021-01-20 17:34:48.761 INFO 64500 --- [ main] org.apache.zookeeper.ZooKeeper : Client environment:zookeeper.version=3.5.6-c11b7e26bc554b8523dc929761dd28808913f091, built on 10/08/2019 20:18 GMT
2021-01-20 17:34:48.761 INFO 64500 --- [ main] org.apache.zookeeper.ZooKeeper : Client environment:host.name=10.7.254.31
2021-01-20 17:34:48.761 INFO 64500 --- [ main] org.apache.zookeeper.ZooKeeper : Client environment:java.version=1.8.0_261
2021-01-20 17:34:48.761 INFO 64500 --- [ main] org.apache.zookeeper.ZooKeeper : Client environment:java.vendor=Oracle Corporation
......
2021-01-20 17:34:48.806 INFO 64500 --- [localhost:2181)] org.apache.zookeeper.ClientCnxn : Opening socket connection to server localhost/0:0:0:0:0:0:0:1:2181. Will not attempt to authenticate using SASL (unknown error)
2021-01-20 17:34:48.826 INFO 64500 --- [localhost:2181)] org.apache.zookeeper.ClientCnxn : Socket connection established, initiating session, client: /0:0:0:0:0:0:0:1:58214, server: localhost/0:0:0:0:0:0:0:1:2181
2021-01-20 17:34:48.857 INFO 64500 --- [localhost:2181)] org.apache.zookeeper.ClientCnxn : Session establishment complete on server localhost/0:0:0:0:0:0:0:1:2181, sessionid = 0x1000b5e22f50001, negotiated timeout = 5000
2021-01-20 17:34:48.861 INFO 64500 --- [ain-EventThread] org.I0Itec.zkclient.ZkClient : zookeeper state changed (SyncConnected)3、soul-bootstrap 网关服务启动，服务启动后可以看到发起的 ZooKeeper 请求调用
2021-01-20 17:35:58.996 INFO 64583 --- [ main] s.b.s.d.z.ZookeeperSyncDataConfiguration : you use zookeeper sync soul data.......
2021-01-20 17:35:59.003 INFO 64583 --- [-localhost:2181] org.I0Itec.zkclient.ZkEventThread : Starting ZkClient event thread.
......
2021-01-20 17:35:59.012 INFO 64583 --- [ main] org.apache.zookeeper.ZooKeeper : Client environment:user.home=/Users/liquan
2021-01-20 17:35:59.012 INFO 64583 --- [ main] org.apache.zookeeper.ZooKeeper : Client environment:os.memory.total=310MB
2021-01-20 17:35:59.018 INFO 64583 --- [ main] org.apache.zookeeper.ZooKeeper : Initiating client connection, connectString=localhost:2181 sessionTimeout=5000 watcher=org.I0Itec.zkclient.ZkClient@114a5e0
2021-01-20 17:35:59.121 INFO 64583 --- [localhost:2181)] org.apache.zookeeper.ClientCnxn : Session establishment complete on server localhost/127.0.0.1:2181, sessionid = 0x1000b5e22f50002, negotiated timeout = 5000
2021-01-20 17:35:59.126 INFO 64583 --- [ain-EventThread] org.I0Itec.zkclient.ZkClient : zookeeper state changed (SyncConnected)4、查看 zookeeper 上的 soul 网关同步的注册信息 
三、Soul 网关 Zookeeper 数据同步原理解析
在 soul-admin 启动后在控制台中看到了 org.I0Itec.zkclient.ZkClient，以此为入口进行跟踪调试。
1、ZookeeperConfiguration 作用：注册 zkClient 到 Spring 容器。
// EnableConfigurationProperties 作用：使用 @ConfigurationProperties 注解的类生效。如果一个配置类只配置@ConfigurationProperties注解，而没有使用@Component，那么在IOC容器中是获取不到properties 配置文件转化的bean。@EnableConfigurationProperties 相当于把使用@ConfigurationProperties 的类进行了一次注入。
// @ConditionalOnMissingBean 容器中没有指定的类，就进行注入，@ConditionalOnBean与之相反
/**
* ZookeeperConfiguration .
* @author xiaoyu(Myth)
*/
@EnableConfigurationProperties(ZookeeperProperties.class)
public class ZookeeperConfiguration {
/**
* register zkClient in spring ioc.
*
* @param zookeeperProp the zookeeper configuration
* @return ZkClient {@linkplain ZkClient}
*/
@Bean
@ConditionalOnMissingBean(ZkClient.class)
public ZkClient zkClient(final ZookeeperProperties zookeeperProp) {
return new ZkClient(zookeeperProp.getUrl(), zookeeperProp.getSessionTimeout(), zookeeperProp.getConnectionTimeout());
}
}soul-admin 启动后，会实读取 zookeeper 配置信息，向容器中注入 zkClient 和 zookeeper 建立连接。 
2、实例化 ZkClient 的调用栈中会调用 DataChangedEventDispatcher 的 afterPropertiesSet 方法。
org.dromara.soul.admin.listener.DataChangedEventDispatcher 作用：事件转发器，将更改的事件转发到每个 ConfigEventListener。
此类 实现了 InitializingBean，在 DataChangedEventDispatcher 初始化过程中，会执行 afterPropertiesSet 方法。
afterPropertiesSet 方法会在容器中查找类型是 DataChangedListener.class 的 bean。
@Component
public class DataChangedEventDispatcher implements ApplicationListener<DataChangedEvent>, InitializingBean {
private ApplicationContext applicationContext;
private List<DataChangedListener> listeners;
public DataChangedEventDispatcher(final ApplicationContext applicationContext) {
this.applicationContext = applicationContext;
}
@Override
@SuppressWarnings("unchecked")
public void onApplicationEvent(final DataChangedEvent event) {
for (DataChangedListener listener : listeners) {
switch (event.getGroupKey()) {
case APP_AUTH:
listener.onAppAuthChanged((List<AppAuthData>) event.getSource(), event.getEventType());
break;
.......
default:
throw new IllegalStateException("Unexpected value: " + event.getGroupKey());
}
}
......
@Override
public void afterPropertiesSet() {
Collection<DataChangedListener> listenerBeans = applicationContext.getBeansOfType(DataChangedListener.class).values();
this.listeners = Collections.unmodifiableList(new ArrayList<>(listenerBeans));
}
}3、afterPropertiesSet 方法的执行会查找 DataChangedListener.class 相关类的实例化。
org.dromara.soul.admin.config.DataSyncConfiguration 作用：数据同步配置类。
ZookeeperDataChangedListener 数据变化监听器，作用：应该是监听元数据变化，然后同步到 zookeeper。
ZookeeperDataInit zookeeper 数据初始化，作用：向 zookeeper 同步初始化数据。
/**
* The type Zookeeper listener.
*/
@Configuration
@ConditionalOnProperty(prefix = "soul.sync.zookeeper", name = "url")
@Import(ZookeeperConfiguration.class)
static class ZookeeperListener {
/**
* Config event listener data changed listener.
* @param zkClient the zk client
* @return the data changed listener
*/
@Bean
@ConditionalOnMissingBean(ZookeeperDataChangedListener.class)
public DataChangedListener zookeeperDataChangedListener(final ZkClient zkClient) {
return new ZookeeperDataChangedListener(zkClient);
}
/**
* Zookeeper data init zookeeper data init
* @param zkClient the zk client
* @param syncDataService the sync data service
* @return the zookeeper data init
*/
@Bean
@ConditionalOnMissingBean(ZookeeperDataInit.class)
public ZookeeperDataInit zookeeperDataInit(final ZkClient zkClient, final SyncDataService syncDataService) {
return new ZookeeperDataInit(zkClient, syncDataService);
}
}4、org.dromara.soul.admin.listener.zookeeper.ZookeeperDataInit 作用：负责向 zookeeper 同步初始化数据。此类实现了 CommandLineRunner。
CommandLineRunner：作用：SpringBoot 在项目启动后会遍历所有实现 CommandLineRunner 的实体类并执行 run 方法，如果需要按照一定的顺序去执行，那么就需要在实体类上使用一个@Order 注解（或者实现 Order 接口）来表明顺序。
run 方法会调用 syncDataService.syncAll 方法。
public class ZookeeperDataInit implements CommandLineRunner {
private final ZkClient zkClient;
private final SyncDataService syncDataService;
/**
* Instantiates a new Zookeeper data init.
* @param zkClient the zk client
* @param syncDataService the sync data service
*/
public ZookeeperDataInit(final ZkClient zkClient, final SyncDataService syncDataService) {
this.zkClient = zkClient;
this.syncDataService = syncDataService;
}
@Override
public void run(final String... args) {
String pluginPath = ZkPathConstants.PLUGIN_PARENT;
String authPath = ZkPathConstants.APP_AUTH_PARENT;
String metaDataPath = ZkPathConstants.META_DATA;
if (!zkClient.exists(pluginPath) && !zkClient.exists(authPath) && !zkClient.exists(metaDataPath)) {
syncDataService.syncAll(DataEventTypeEnum.REFRESH);
}
}
}5、org.dromara.soul.admin.service.sync.SyncDataServiceImpl
syncAll 方法会调用事件发布器进行事件发布，事件类型是 DataEventTypeEnum.REFRESH。
/**
* The type sync data service.
* @author xiaoyu(Myth)
*/
@Service("syncDataService")
public class SyncDataServiceImpl implements SyncDataService {
// 发布事件，也就是把某个事件告诉的所有与这个事件相关的监听器
private final ApplicationEventPublisher eventPublisher;
......
@Override
public boolean syncAll(final DataEventTypeEnum type) {
appAuthService.syncData();
List<PluginData> pluginDataList = pluginService.listAll();
eventPublisher.publishEvent(new DataChangedEvent(ConfigGroupEnum.PLUGIN, type, pluginDataList));
List<SelectorData> selectorDataList = selectorService.listAll();
eventPublisher.publishEvent(new DataChangedEvent(ConfigGroupEnum.SELECTOR, type, selectorDataList));
List<RuleData> ruleDataList = ruleService.listAll();
eventPublisher.publishEvent(new DataChangedEvent(ConfigGroupEnum.RULE, type, ruleDataList));
metaDataService.syncData();
return true;
}
......
}
6、事件发布后 org.dromara.soul.admin.listener.DataChangedEventDispatcher 类的 onApplicationEvent 方法会监听事件变化，遍历所有的监听者进行数据同步处理，这里的监听者实现类是 ZookeeperDataChangedListener，根据对应的事件类型通过 zkClient 向 zookeeper 同步数据。
7、soul-admin 初始化到数据到 zookeeper 思维导图
四、总结
soul-admin 启动就会同步网关数据 rule、metaData、selector、plugin 等到 zookeeper。数据变化会发布 DataChangedEvent 事件，监听事件将数据同步至 zookeeper。