聊聊EurekaRibbonClientConfiguration-白红宇

聊聊EurekaRibbonClientConfiguration

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发布时间：2019-06-21

本文共 9804 字，大约阅读时间需要 32 分钟。

序

本文主要研究一下EurekaRibbonClientConfiguration

EurekaRibbonClientConfiguration

spring-cloud-netflix-eureka-client-2.0.0.RELEASE-sources.jar!/org/springframework/cloud/netflix/ribbon/eureka/EurekaRibbonClientConfiguration.java

/** * Preprocessor that configures defaults for eureka-discovered ribbon clients. Such as: * @zone, NIWSServerListClassName, DeploymentContextBasedVipAddresses, * NFLoadBalancerRuleClassName, NIWSServerListFilterClassName and more * * @author Spencer Gibb * @author Dave Syer * @author Ryan Baxter */@Configurationpublic class EurekaRibbonClientConfiguration {    private static final Log log = LogFactory.getLog(EurekaRibbonClientConfiguration.class);    @Value("${ribbon.eureka.approximateZoneFromHostname:false}")    private boolean approximateZoneFromHostname = false;    @RibbonClientName    private String serviceId = "client";    @Autowired(required = false)    private EurekaClientConfig clientConfig;    @Autowired(required = false)    private EurekaInstanceConfig eurekaConfig;    @Autowired    private PropertiesFactory propertiesFactory;    public EurekaRibbonClientConfiguration() {    }    public EurekaRibbonClientConfiguration(EurekaClientConfig clientConfig,            String serviceId, EurekaInstanceConfig eurekaConfig,            boolean approximateZoneFromHostname) {        this.clientConfig = clientConfig;        this.serviceId = serviceId;        this.eurekaConfig = eurekaConfig;        this.approximateZoneFromHostname = approximateZoneFromHostname;    }    @Bean    @ConditionalOnMissingBean    public IPing ribbonPing(IClientConfig config) {        if (this.propertiesFactory.isSet(IPing.class, serviceId)) {            return this.propertiesFactory.get(IPing.class, config, serviceId);        }        NIWSDiscoveryPing ping = new NIWSDiscoveryPing();        ping.initWithNiwsConfig(config);        return ping;    }    @Bean    @ConditionalOnMissingBean    public ServerList
     ribbonServerList(IClientConfig config, Provider
    
      eurekaClientProvider) {        if (this.propertiesFactory.isSet(ServerList.class, serviceId)) {            return this.propertiesFactory.get(ServerList.class, config, serviceId);        }        DiscoveryEnabledNIWSServerList discoveryServerList = new DiscoveryEnabledNIWSServerList(                config, eurekaClientProvider);        DomainExtractingServerList serverList = new DomainExtractingServerList(                discoveryServerList, config, this.approximateZoneFromHostname);        return serverList;    }    @Bean    public ServerIntrospector serverIntrospector() {        return new EurekaServerIntrospector();    }    @PostConstruct    public void preprocess() {        String zone = ConfigurationManager.getDeploymentContext()                .getValue(ContextKey.zone);        if (this.clientConfig != null && StringUtils.isEmpty(zone)) {            if (this.approximateZoneFromHostname && this.eurekaConfig != null) {                String approxZone = ZoneUtils                        .extractApproximateZone(this.eurekaConfig.getHostName(false));                log.debug("Setting Zone To " + approxZone);                ConfigurationManager.getDeploymentContext().setValue(ContextKey.zone,                        approxZone);            }            else {                String availabilityZone = this.eurekaConfig == null ? null                        : this.eurekaConfig.getMetadataMap().get("zone");                if (availabilityZone == null) {                    String[] zones = this.clientConfig                            .getAvailabilityZones(this.clientConfig.getRegion());                    // Pick the first one from the regions we want to connect to                    availabilityZone = zones != null && zones.length > 0 ? zones[0]                            : null;                }                if (availabilityZone != null) {                    // You can set this with archaius.deployment.* (maybe requires                    // custom deployment context)?                    ConfigurationManager.getDeploymentContext().setValue(ContextKey.zone,                            availabilityZone);                }            }        }        RibbonUtils.initializeRibbonDefaults(serviceId);    }}

创建了NIWSDiscoveryPing、DomainExtractingServerList、EurekaServerIntrospector

初始化之后调用RibbonUtils.initializeRibbonDefaults(serviceId)

NIWSDiscoveryPing

ribbon-eureka-2.2.5-sources.jar!/com/netflix/niws/loadbalancer/NIWSDiscoveryPing.java

/** * "Ping" Discovery Client * i.e. we dont do a real "ping". We just assume that the server is up if Discovery Client says so * @author stonse * */public class NIWSDiscoveryPing extends AbstractLoadBalancerPing {                    BaseLoadBalancer lb = null;                 public NIWSDiscoveryPing() {        }                public BaseLoadBalancer getLb() {            return lb;        }        /**         * Non IPing interface method - only set this if you care about the "newServers Feature"         * @param lb         */        public void setLb(BaseLoadBalancer lb) {            this.lb = lb;        }        public boolean isAlive(Server server) {            boolean isAlive = true;            if (server!=null && server instanceof DiscoveryEnabledServer){                DiscoveryEnabledServer dServer = (DiscoveryEnabledServer)server;                                InstanceInfo instanceInfo = dServer.getInstanceInfo();                if (instanceInfo!=null){                                        InstanceStatus status = instanceInfo.getStatus();                    if (status!=null){                        isAlive = status.equals(InstanceStatus.UP);                    }                }            }            return isAlive;        }        @Override        public void initWithNiwsConfig(                IClientConfig clientConfig) {        }        }

NIWSDiscoveryPing通过获取实例的eureka状态来判断是否健康

DomainExtractingServerList

spring-cloud-netflix-eureka-client-2.0.0.RELEASE-sources.jar!/org/springframework/cloud/netflix/ribbon/eureka/DomainExtractingServerList.java

public class DomainExtractingServerList implements ServerList
    
      {    private ServerList
     
       list;    private final RibbonProperties ribbon;    private boolean approximateZoneFromHostname;    public DomainExtractingServerList(ServerList
      
        list,            IClientConfig clientConfig, boolean approximateZoneFromHostname) {        this.list = list;        this.ribbon = RibbonProperties.from(clientConfig);        this.approximateZoneFromHostname = approximateZoneFromHostname;    }    @Override    public List
       
         getInitialListOfServers() {        List
        
          servers = setZones(this.list                .getInitialListOfServers());        return servers;    }    @Override    public List
         
           getUpdatedListOfServers() { List
          
            servers = setZones(this.list .getUpdatedListOfServers()); return servers; } private List
           
             setZones(List
            
              servers) { List
             
               result = new ArrayList<>(); boolean isSecure = this.ribbon.isSecure(true); boolean shouldUseIpAddr = this.ribbon.isUseIPAddrForServer(); for (DiscoveryEnabledServer server : servers) { result.add(new DomainExtractingServer(server, isSecure, shouldUseIpAddr, this.approximateZoneFromHostname)); } return result; }}class DomainExtractingServer extends DiscoveryEnabledServer { private String id; @Override public String getId() { return id; } @Override public void setId(String id) { this.id = id; } public DomainExtractingServer(DiscoveryEnabledServer server, boolean useSecurePort, boolean useIpAddr, boolean approximateZoneFromHostname) { // host and port are set in super() super(server.getInstanceInfo(), useSecurePort, useIpAddr); if (server.getInstanceInfo().getMetadata().containsKey("zone")) { setZone(server.getInstanceInfo().getMetadata().get("zone")); } else if (approximateZoneFromHostname) { setZone(ZoneUtils.extractApproximateZone(server.getHost())); } else { setZone(server.getZone()); } setId(extractId(server)); setAlive(server.isAlive()); setReadyToServe(server.isReadyToServe()); } private String extractId(Server server) { if (server instanceof DiscoveryEnabledServer) { DiscoveryEnabledServer enabled = (DiscoveryEnabledServer) server; InstanceInfo instance = enabled.getInstanceInfo(); if (instance.getMetadata().containsKey("instanceId")) { return instance.getHostName()+":"+instance.getMetadata().get("instanceId"); } } return super.getId(); }}

getInitialListOfServers及getUpdatedListOfServers都调用了setZones从eureka的metadata读取zone

EurekaServerIntrospector

spring-cloud-netflix-eureka-client-2.0.0.RELEASE-sources.jar!/org/springframework/cloud/netflix/ribbon/eureka/EurekaServerIntrospector.java

public class EurekaServerIntrospector extends DefaultServerIntrospector {    @Override    public boolean isSecure(Server server) {        if (server instanceof DiscoveryEnabledServer) {            DiscoveryEnabledServer discoveryServer = (DiscoveryEnabledServer) server;            return discoveryServer.getInstanceInfo().isPortEnabled(InstanceInfo.PortType.SECURE);        }        return super.isSecure(server);    }    @Override    public Map
    
      getMetadata(Server server) {        if (server instanceof DiscoveryEnabledServer) {            DiscoveryEnabledServer discoveryServer = (DiscoveryEnabledServer) server;            return discoveryServer.getInstanceInfo().getMetadata();        }        return super.getMetadata(server);    }}