Eureka Client注册服务
Eureka Client注册服务
动过程： Eureka客户端在启动时也会装载很多配置类，我们通过spring-cloud-netflix-eureka-client-
xxxx.jar下的spring.factories⽂件可以看到加载的配置类
EurekaClientAutoConfiguration
//标志为配置类，可以被Spring扫描与管理
@Configuration
//启用配置属性
@EnableConfigurationProperties
@ConditionalOnClass(EurekaClientConfig.class)
@Import(DiscoveryClientOptionalArgsConfiguration.class)
@ConditionalOnBean(EurekaDiscoveryClientConfiguration.Marker.class)
@ConditionalOnProperty(value = "eureka.client.enabled", matchIfMissing = true)
@AutoConfigureBefore({ NoopDiscoveryClientAutoConfiguration.class,
CommonsClientAutoConfiguration.class, ServiceRegistryAutoConfiguration.class })
//必须先把配置类装配扣，再装配当前类
@AutoConfigureAfter(name = {"org.springframework.cloud.autoconfigure.RefreshAutoConfiguration",
"org.springframework.cloud.netflix.eureka.EurekaDiscoveryClientConfiguration",
"org.springframework.cloud.client.serviceregistry.AutoServiceRegistrationAutoConfiguration"})
public class EurekaClientAutoConfiguration {
如果不想作为客户端，可以设置eureka.client.enabled=false
EurekaDiscoveryClientConfiguration
@Configuration
@EnableConfigurationProperties
@ConditionalOnClass(EurekaClientConfig.class)
//默认为true
@ConditionalOnProperty(value = "eureka.client.enabled", matchIfMissing = true)
public class EurekaDiscoveryClientConfiguration {
class Marker {}
//自动注入一个Marker Bean
@Bean
public Marker eurekaDiscoverClientMarker() {
return new Marker();
}
启动过程中要作的事
1）读取配置⽂件
2）启动时从EurekaServer获取服务实例信息
3）注册⾃⼰到EurekaServer（addInstance）
4）开启⼀些定时任务（⼼跳续约，刷新本地服务缓存列表）
1.读取配置
@Bean
@ConditionalOnMissingBean(value = EurekaClientConfig.class, search = SearchStrategy.CURRENT)
public EurekaClientConfigBean eurekaClientConfigBean(ConfigurableEnvironment env) {
EurekaClientConfigBean client = new EurekaClientConfigBean();
if ("bootstrap".equals(this.env.getProperty("spring.config.name"))) {
// We don't register during bootstrap by default, but there will be another
// chance later.
client.setRegisterWithEureka(false);
}
return client;
}
@Bean
@ConditionalOnMissingBean(value = EurekaInstanceConfig.class, search = SearchStrategy.CURRENT)
public EurekaInstanceConfigBean eurekaInstanceConfigBean(InetUtils inetUtils,
ManagementMetadataProvider managementMetadataProvider) {
String hostname = getProperty("eureka.instance.hostname");
boolean preferIpAddress = Boolean.parseBoolean(getProperty("eureka.instance.prefer-ip-address"));
String ipAddress = getProperty("eureka.instance.ip-address");
boolean isSecurePortEnabled = Boolean.parseBoolean(getProperty("eureka.instance.secure-port-enabled"));
String serverContextPath = env.getProperty("server.context-path", "/");
int serverPort = Integer.valueOf(env.getProperty("server.port", env.getProperty("port", "8080")));
Integer managementPort = env.getProperty("management.server.port", Integer.class);// nullable. should be wrapped into optional
String managementContextPath = env.getProperty("management.server.servlet.context-path");// nullable. should be wrapped into optional
Integer jmxPort = env.getProperty("com.sun.management.jmxremote.port", Integer.class);//nullable
EurekaInstanceConfigBean instance = new EurekaInstanceConfigBean(inetUtils);
instance.setNonSecurePort(serverPort);
instance.setInstanceId(getDefaultInstanceId(env));
instance.setPreferIpAddress(preferIpAddress);
instance.setSecurePortEnabled(isSecurePortEnabled);
if (StringUtils.hasText(ipAddress)) {
instance.setIpAddress(ipAddress);
}
if(isSecurePortEnabled) {
instance.setSecurePort(serverPort);
}
if (StringUtils.hasText(hostname)) {
instance.setHostname(hostname);
}
String statusPageUrlPath = getProperty("eureka.instance.status-page-url-path");
String healthCheckUrlPath = getProperty("eureka.instance.health-check-url-path");
if (StringUtils.hasText(statusPageUrlPath)) {
instance.setStatusPageUrlPath(statusPageUrlPath);
}
if (StringUtils.hasText(healthCheckUrlPath)) {
instance.setHealthCheckUrlPath(healthCheckUrlPath);
}
ManagementMetadata metadata = managementMetadataProvider.get(instance, serverPort,
serverContextPath, managementContextPath, managementPort);
if(metadata != null) {
instance.setStatusPageUrl(metadata.getStatusPageUrl());
instance.setHealthCheckUrl(metadata.getHealthCheckUrl());
if(instance.isSecurePortEnabled()) {
instance.setSecureHealthCheckUrl(metadata.getSecureHealthCheckUrl());
}
Map<String, String> metadataMap = instance.getMetadataMap();
if (metadataMap.get("management.port") == null) {
metadataMap.put("management.port", String.valueOf(metadata.getManagementPort()));
}
} else {
//without the metadata the status and health check URLs will not be set
//and the status page and health check url paths will not include the
//context path so set them here
if(StringUtils.hasText(managementContextPath)) {
instance.setHealthCheckUrlPath(managementContextPath + instance.getHealthCheckUrlPath());
instance.setStatusPageUrlPath(managementContextPath + instance.getStatusPageUrlPath());
}
}
setupJmxPort(instance, jmxPort);
return instance;
}
private void setupJmxPort(EurekaInstanceConfigBean instance, Integer jmxPort) {
Map<String, String> metadataMap = instance.getMetadataMap();
if (metadataMap.get("jmx.port") == null && jmxPort != null) {
metadataMap.put("jmx.port", String.valueOf(jmxPort));
}
}
2.启动时从EurekaServer获取服务实例信息
@Bean(destroyMethod = "shutdown")
@ConditionalOnMissingBean(value = EurekaClient.class, search = SearchStrategy.CURRENT)
public EurekaClient eurekaClient(ApplicationInfoManager manager, EurekaClientConfig config) {
//实例化CloudEurekaClient -返回CloudEurekaClient对象
return new CloudEurekaClient(manager, config, this.optionalArgs,
this.context);
}
构造方法
public CloudEurekaClient(ApplicationInfoManager applicationInfoManager,
EurekaClientConfig config,
AbstractDiscoveryClientOptionalArgs<?> args,
ApplicationEventPublisher publisher) {
//调用父类的
super(applicationInfoManager, config, args);
this.applicationInfoManager = applicationInfoManager;
this.publisher = publisher;
this.eurekaTransportField = ReflectionUtils.findField(DiscoveryClient.class, "eurekaTransport");
ReflectionUtils.makeAccessible(this.eurekaTransportField);
}
com.netflix.discovery.DiscoveryClient
public DiscoveryClient(ApplicationInfoManager applicationInfoManager, final EurekaClientConfig config, AbstractDiscoveryClientOptionalArgs args) {
//这里调用了另外一个构造方法
this(applicationInfoManager, config, args, new Provider<BackupRegistry>() {
private volatile BackupRegistry backupRegistryInstance;
@Override
public synchronized BackupRegistry get() {
下面的构造
@Inject
DiscoveryClient(ApplicationInfoManager applicationInfoManager, EurekaClientConfig config, AbstractDiscoveryClientOptionalArgs args,
Provider<BackupRegistry> backupRegistryProvider) {
//从注册中心获取列表
if (clientConfig.shouldFetchRegistry() && !fetchRegistry(false)) {
fetchRegistryFromBackup();
}
...
fetchRegistry
private boolean fetchRegistry(boolean forceFullRegistryFetch) {
//从注册中心获取列表
Stopwatch tracer = FETCH_REGISTRY_TIMER.start();
try {
// If the delta is disabled or if it is the first time, get all
// applications
//从本地缓存中获取
Applications applications = getApplications();
if (clientConfig.shouldDisableDelta()
|| (!Strings.isNullOrEmpty(clientConfig.getRegistryRefreshSingleVipAddress()))
|| forceFullRegistryFetch
|| (applications == null)
|| (applications.getRegisteredApplications().size() == 0)
|| (applications.getVersion() == -1)) //Client application does not have latest library supporting delta
{
logger.info("Disable delta property : {}", clientConfig.shouldDisableDelta());
logger.info("Single vip registry refresh property : {}", clientConfig.getRegistryRefreshSingleVipAddress());
logger.info("Force full registry fetch : {}", forceFullRegistryFetch);
logger.info("Application is null : {}", (applications == null));
logger.info("Registered Applications size is zero : {}",
(applications.getRegisteredApplications().size() == 0));
logger.info("Application version is -1: {}", (applications.getVersion() == -1));
//全量接口
getAndStoreFullRegistry();
} else {
//增量获取
getAndUpdateDelta(applications);
}
applications.setAppsHashCode(applications.getReconcileHashCode());
logTotalInstances();
} catch (Throwable e) {
logger.error(PREFIX + "{} - was unable to refresh its cache! status = {}", appPathIdentifier, e.getMessage(), e);
return false;
} finally {
if (tracer != null) {
tracer.stop();
}
}
// Notify about cache refresh before updating the instance remote status
onCacheRefreshed();
// Update remote status based on refreshed data held in the cache
updateInstanceRemoteStatus();
// registry was fetched successfully, so return true
return true;
}
注册自己到Eureka中心
private void getAndStoreFullRegistry() throws Throwable {
long currentUpdateGeneration = fetchRegistryGeneration.get();
logger.info("Getting all instance registry info from the eureka server");
Applications apps = null;
EurekaHttpResponse<Applications> httpResponse = clientConfig.getRegistryRefreshSingleVipAddress() == null
//获取
? eurekaTransport.queryClient.getApplications(remoteRegionsRef.get())
: eurekaTransport.queryClient.getVip(clientConfig.getRegistryRefreshSingleVipAddress(), remoteRegionsRef.get());
if (httpResponse.getStatusCode() == Status.OK.getStatusCode()) {
apps = httpResponse.getEntity();
}
logger.info("The response status is {}", httpResponse.getStatusCode());
if (apps == null) {
logger.error("The application is null for some reason. Not storing this information");
} else if (fetchRegistryGeneration.compareAndSet(currentUpdateGeneration, currentUpdateGeneration + 1)) {
localRegionApps.set(this.filterAndShuffle(apps));
logger.debug("Got full registry with apps hashcode {}", apps.getAppsHashCode());
} else {
logger.warn("Not updating applications as another thread is updating it already");
}
}
getApplications
@Override
public EurekaHttpResponse<Applications> getApplications(String... regions) {
return getApplicationsInternal("apps/", regions);
}
- 另一个方法
private EurekaHttpResponse<Applications> getApplicationsInternal(String urlPath, String[] regions) {
ClientResponse response = null;
String regionsParamValue = null;
try {
//通过jerseyClient获取资源
WebResource webResource = jerseyClient.resource(serviceUrl).path(urlPath);
if (regions != null && regions.length > 0) {
regionsParamValue = StringUtil.join(regions);
webResource = webResource.queryParam("regions", regionsParamValue);
}
Builder requestBuilder = webResource.getRequestBuilder();
addExtraHeaders(requestBuilder);
response = requestBuilder.accept(MediaType.APPLICATION_JSON_TYPE).get(ClientResponse.class);
Applications applications = null;
if (response.getStatus() == Status.OK.getStatusCode() && response.hasEntity()) {
applications = response.getEntity(Applications.class);
}
return anEurekaHttpResponse(response.getStatus(), Applications.class)
.headers(headersOf(response))
.entity(applications)
.build();
} finally {
if (logger.isDebugEnabled()) {
logger.debug("Jersey HTTP GET {}/{}?{}; statusCode={}",
serviceUrl, urlPath,
regionsParamValue == null ? "" : "regions=" + regionsParamValue,
response == null ? "N/A" : response.getStatus()
);
}
if (response != null) {
response.close();
}
}
}
注册自己 com.netflix.discovery.DiscoveryClient
boolean register() throws Throwable {
logger.info(PREFIX + "{}: registering service...", appPathIdentifier);
EurekaHttpResponse<Void> httpResponse;
try {
httpResponse = eurekaTransport.registrationClient.register(instanceInfo);
} catch (Exception e) {
logger.warn(PREFIX + "{} - registration failed {}", appPathIdentifier, e.getMessage(), e);
throw e;
}
if (logger.isInfoEnabled()) {
logger.info(PREFIX + "{} - registration status: {}", appPathIdentifier, httpResponse.getStatusCode());
}
return httpResponse.getStatusCode() == Status.NO_CONTENT.getStatusCode();
}
调用 com.netflix.discovery.shared.transport.jersey.AbstractJerseyEurekaHttpClient发起rest请求注册自己,使用jerseyClient
public EurekaHttpResponse<Void> register(InstanceInfo info) {
String urlPath = "apps/" + info.getAppName();
ClientResponse response = null;
try {
Builder resourceBuilder = jerseyClient.resource(serviceUrl).path(urlPath).getRequestBuilder();
addExtraHeaders(resourceBuilder);
response = resourceBuilder
.header("Accept-Encoding", "gzip")
.type(MediaType.APPLICATION_JSON_TYPE)
.accept(MediaType.APPLICATION_JSON)
.post(ClientResponse.class, info);
return anEurekaHttpResponse(response.getStatus()).headers(headersOf(response)).build();
} finally {
if (logger.isDebugEnabled()) {
logger.debug("Jersey HTTP POST {}/{} with instance {}; statusCode={}", serviceUrl, urlPath, info.getId(),
response == null ? "N/A" : response.getStatus());
}
if (response != null) {
response.close();
}
}
}