Eureka源码阅读解析Server服务端启动流程实例

<dependencyManagement>
    <!--引入springcloud依赖的-->
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>2020.0.2E</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

<dependencies>
    <!--web依赖-->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-commons</artifactId>
    </dependency>
    <!--unit test-->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
    </dependency>
    <!--spring cloud eureka server 依赖-->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    </dependency>
</dependencies>

eureka:
  instance:
    hostname: localhost
  client:
    service-url:   #  eureka server 的地址， 咱们单实例模式就写自己好了
      defaultZone:  http://localhost:7000/eureka
    register-with-eureka: false  # 不向eureka server 注册自己
    fetch-registry: false  # 不向eureka server 获取服务列表

@SpringBootApplication
@EnableEurekaServer
public class EurekaServer {
    public static void main(String[] args) {
        SpringApplication.run(EurekaServer.class, args);
    }
}

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Import(EurekaServerMarkerConfiguration.class)
public @interface EnableEurekaServer {
}

@Configuration
public class EurekaServerMarkerConfiguration {
	@Bean
	public Marker eurekaServerMarkerBean() {
		return new Marker();
	}
	class Marker {
	}
}

@Configuration
@Import(EurekaServerInitializerConfiguration.class)
@ConditionalOnBean(EurekaServerMarkerConfiguration.Marker.class)
@EnableConfigurationProperties({ EurekaDashboardProperties.class,
		InstanceRegistryProperties.class })
@PropertySource("classpath:/eureka/server.properties")
public class EurekaServerAutoConfiguration extends WebMvcConfigurerAdapter{}

@Autowired
private ApplicationInfoManager applicationInfoManager;
@Autowired
private EurekaServerConfig eurekaServerConfig;
@Autowired
private EurekaClientConfig eurekaClientConfig;
@Autowired
private EurekaClient eurekaClient;
@Autowired
private InstanceRegistryProperties instanceRegistryProperties;

@Bean
@ConditionalOnProperty(prefix = "eureka.dashboard", name = "enabled", matchIfMissing = true)
public EurekaController eurekaController() {
return new EurekaController(this.applicationInfoManager);
}

@Bean
public PeerAwareInstanceRegistry peerAwareInstanceRegistry(
                ServerCodecs serverCodecs) {
        this.eurekaClient.getApplications(); // force initialization
        return new InstanceRegistry(this.eurekaServerConfig, this.eurekaClientConfig,
                        serverCodecs, this.eurekaClient,
                        this.instanceRegistryProperties.getExpectedNumberOfClientsSendingRenews(),
                        this.instanceRegistryProperties.getDefaultOpenForTrafficCount());
}

@Bean
@ConditionalOnMissingBean
public PeerEurekaNodes peerEurekaNodes(PeerAwareInstanceRegistry registry,
                ServerCodecs serverCodecs) {
        return new RefreshablePeerEurekaNodes(registry, this.eurekaServerConfig,
                        this.eurekaClientConfig, serverCodecs, this.applicationInfoManager);
}

@Bean
public EurekaServerContext eurekaServerContext(ServerCodecs serverCodecs,
                PeerAwareInstanceRegistry registry, PeerEurekaNodes peerEurekaNodes) {
        return new DefaultEurekaServerContext(this.eurekaServerConfig, serverCodecs,
                        registry, peerEurekaNodes, this.applicationInfoManager);
}

@Bean
public EurekaServerBootstrap eurekaServerBootstrap(PeerAwareInstanceRegistry registry,
                EurekaServerContext serverContext) {
        return new EurekaServerBootstrap(this.applicationInfoManager,
                        this.eurekaClientConfig, this.eurekaServerConfig, registry,
                        serverContext);
}

@Configuration
public class EurekaServerInitializerConfiguration
		implements ServletContextAware, SmartLifecycle, Ordered {
}

@Override
public void start() {
	new Thread(new Runnable() {
		@Override
		public void run() {
			try {
				//TODO: is this class even needed now?
				eurekaServerBootstrap.contextInitialized(EurekaServerInitializerConfiguration.this.servletContext);
				log.info("Started Eureka Server");
				publish(new EurekaRegistryAvailableEvent(getEurekaServerConfig()));
				EurekaServerInitializerConfiguration.this.running = true;
				publish(new EurekaServerStartedEvent(getEurekaServerConfig()));
			}
			catch (Exception ex) {
				// Help!
				log.error("Could not initialize Eureka servlet context", ex);
			}
		}
	}).start();
}

public void contextInitialized(ServletContext context) {
	initEurekaEnvironment();
	initEurekaServerContext();
	context.setAttribute(EurekaServerContext.class.getName(), this.serverContext);
}

if (isAws(this.applicationInfoManager.getInfo())) {
	this.awsBinder = new AwsBinderDelegate(this.eurekaServerConfig,
			this.eurekaClientConfig, this.registry, this.applicationInfoManager);
	this.awsBinder.start();
}
EurekaServerContextHolder.initialize(this.serverContext);
log.info("Initialized server context");
// Copy registry from neighboring eureka node
int registryCount = this.registry.syncUp();
this.registry.openForTraffic(this.applicationInfoManager, registryCount);
// Register all monitoring statistics.
EurekaMonitors.registerAllStats();

int registryCount = this.registry.syncUp();
this.registry.openForTraffic(this.applicationInfoManager, registryCount);

@PostConstruct
public void initialize() {
    this.peerEurekaNodes.start();
    this.registry.init(this.peerEurekaNodes);
}

public void start() {
     updatePeerEurekaNodes(resolvePeerUrls());
     Runnable peersUpdateTask = new Runnable() {
         @Override
         public void run() {
             updatePeerEurekaNodes(resolvePeerUrls());
         }
     };
     taskExecutor.scheduleWithFixedDelay(
             peersUpdateTask,
             serverConfig.getPeerEurekaNodesUpdateIntervalMs(),
             serverConfig.getPeerEurekaNodesUpdateIntervalMs(),
             TimeUnit.MILLISECONDS
     );
}

@Override
public void init(PeerEurekaNodes peerEurekaNodes) throws Exception {
    this.numberOfReplicationsLastMin.start();
    this.peerEurekaNodes = peerEurekaNodes;
    initializedResponseCache();
    scheduleRenewalThresholdUpdateTask();
    initRemoteRegionRegistry();
}