注册中心 Eureka 源码解析 —— Eureka-Client 初始化（一）之 EurekaInstanceConfig

public abstract class AbstractInstanceConfig implements EurekaInstanceConfig {

    /**
     * 契约过期时间，单位：秒
     */
    private static final int LEASE_EXPIRATION_DURATION_SECONDS = 90;
    /**
     * 租约续约频率，单位：秒。
     */
    private static final int LEASE_RENEWAL_INTERVAL_SECONDS = 30;
    /**
     * 应用 https 端口关闭
     */
    private static final boolean SECURE_PORT_ENABLED = false;
    /**
     * 应用 http 端口开启
     */
    private static final boolean NON_SECURE_PORT_ENABLED = true;
    /**
     * 应用 http 端口
     */
    private static final int NON_SECURE_PORT = 80;
    /**
     * 应用 https 端口
     */
    private static final int SECURE_PORT = 443;
    /**
     * 应用初始化后开启
     */
    private static final boolean INSTANCE_ENABLED_ON_INIT = false;
    /**
     * 主机信息
     * key：主机 IP 地址
     * value：主机名
     */
    private static final Pair<String, String> hostInfo = getHostInfo();
    /**
     * 数据中心信息
     */
    private DataCenterInfo info = new DataCenterInfo() {
        @Override
        public Name getName() {
            return Name.MyOwn;
        }
    };

    private static Pair<String, String> getHostInfo() {
        Pair<String, String> pair;
        try {
            InetAddress localHost = InetAddress.getLocalHost();
            pair = new Pair<String, String>(localHost.getHostAddress(), localHost.getHostName());
        } catch (UnknownHostException e) {
            logger.error("Cannot get host info", e);
            pair = new Pair<String, String>("", "");
        }
        return pair;
    }

    // .... 省略 setting / getting 方法
}

public abstract class PropertiesInstanceConfig extends AbstractInstanceConfig implements EurekaInstanceConfig {

    /**
     * 命名空间
     */
    protected final String namespace;
    /**
     * 配置文件对象
     */
    protected final DynamicPropertyFactory configInstance;
    /**
     * 应用分组
     * 从 环境变量 获取
     */
    private String appGrpNameFromEnv;

    public PropertiesInstanceConfig() {
        this(CommonConstants.DEFAULT_CONFIG_NAMESPACE);
    }

    public PropertiesInstanceConfig(String namespace) {
        this(namespace, new DataCenterInfo() {
            @Override
            public Name getName() {
                return Name.MyOwn;
            }
        });
    }

    public PropertiesInstanceConfig(String namespace, DataCenterInfo info) {
        super(info);
        // 设置 namespace，为 "." 结尾
        this.namespace = namespace.endsWith(".")
                ? namespace
                : namespace + ".";
        // 从 环境变量 获取 应用分组
        appGrpNameFromEnv = ConfigurationManager.getConfigInstance()
                .getString(FALLBACK_APP_GROUP_KEY, Values.UNKNOWN_APPLICATION);
        // 初始化 配置文件对象
        this.configInstance = Archaius1Utils.initConfig(CommonConstants.CONFIG_FILE_NAME);
    }

    @Override
    public String getAppGroupName() {
        return configInstance.getStringProperty(namespace + APP_GROUP_KEY, appGrpNameFromEnv).get().trim();
    }
}

public class MyDataCenterInstanceConfig extends PropertiesInstanceConfig implements EurekaInstanceConfig {

    public MyDataCenterInstanceConfig() {
    }

    public MyDataCenterInstanceConfig(String namespace) {
        super(namespace);
    }

    public MyDataCenterInstanceConfig(String namespace, DataCenterInfo dataCenterInfo) {
        super(namespace, dataCenterInfo);
    }

}

  1: @Singleton
  2: public class EurekaConfigBasedInstanceInfoProvider implements Provider<InstanceInfo> {
  3:     private static final Logger LOG = LoggerFactory.getLogger(EurekaConfigBasedInstanceInfoProvider.class);
  4: 
  5:     private final EurekaInstanceConfig config;
  6: 
  7:     private InstanceInfo instanceInfo;
  8: 
  9:     @Inject(optional = true)
 10:     private VipAddressResolver vipAddressResolver = null;
 11: 
 12:     @Inject
 13:     public EurekaConfigBasedInstanceInfoProvider(EurekaInstanceConfig config) {
 14:         this.config = config;
 15:     }
 16: 
 17:     @Override
 18:     public synchronized InstanceInfo get() {
 19:         if (instanceInfo == null) {
 20:             // Build the lease information to be passed to the server based on config
 21:             // 创建 租约信息构建器，并设置属性
 22:             LeaseInfo.Builder leaseInfoBuilder = LeaseInfo.Builder.newBuilder()
 23:                     .setRenewalIntervalInSecs(config.getLeaseRenewalIntervalInSeconds())
 24:                     .setDurationInSecs(config.getLeaseExpirationDurationInSeconds());
 25: 
 26:             // 创建 VIP地址解析器
 27:             if (vipAddressResolver == null) {
 28:                 vipAddressResolver = new Archaius1VipAddressResolver();
 29:             }
 30: 
 31:             // Builder the instance information to be registered with eureka server
 32:             // 创建 应用实例信息构建器
 33:             InstanceInfo.Builder builder = InstanceInfo.Builder.newBuilder(vipAddressResolver);
 34: 
 35:             // 应用实例编号
 36:             // set the appropriate id for the InstanceInfo, falling back to datacenter Id if applicable, else hostname
 37:             String instanceId = config.getInstanceId();
 38:             DataCenterInfo dataCenterInfo = config.getDataCenterInfo();
 39:             if (instanceId == null || instanceId.isEmpty()) {
 40:                 if (dataCenterInfo instanceof UniqueIdentifier) {
 41:                     instanceId = ((UniqueIdentifier) dataCenterInfo).getId();
 42:                 } else {
 43:                     instanceId = config.getHostName(false);
 44:                 }
 45:             }
 46: 
 47:             // 获得 主机名
 48:             String defaultAddress;
 49:             if (config instanceof RefreshableInstanceConfig) {
 50:                 // Refresh AWS data center info, and return up to date address
 51:                 defaultAddress = ((RefreshableInstanceConfig) config).resolveDefaultAddress(false);
 52:             } else {
 53:                 defaultAddress = config.getHostName(false);
 54:             }
 55:             // fail safe
 56:             if (defaultAddress == null || defaultAddress.isEmpty()) {
 57:                 defaultAddress = config.getIpAddress();
 58:             }
 59: 
 60:             // 设置 应用实例信息构建器 的 属性
 61:             builder.setNamespace(config.getNamespace())
 62:                     .setInstanceId(instanceId)
 63:                     .setAppName(config.getAppname())
 64:                     .setAppGroupName(config.getAppGroupName())
 65:                     .setDataCenterInfo(config.getDataCenterInfo())
 66:                     .setIPAddr(config.getIpAddress())
 67:                     .setHostName(defaultAddress) // 主机名
 68:                     .setPort(config.getNonSecurePort())
 69:                     .enablePort(PortType.UNSECURE, config.isNonSecurePortEnabled())
 70:                     .setSecurePort(config.getSecurePort())
 71:                     .enablePort(PortType.SECURE, config.getSecurePortEnabled())
 72:                     .setVIPAddress(config.getVirtualHostName()) // VIP 地址
 73:                     .setSecureVIPAddress(config.getSecureVirtualHostName())
 74:                     .setHomePageUrl(config.getHomePageUrlPath(), config.getHomePageUrl())
 75:                     .setStatusPageUrl(config.getStatusPageUrlPath(), config.getStatusPageUrl())
 76:                     .setASGName(config.getASGName())
 77:                     .setHealthCheckUrls(config.getHealthCheckUrlPath(),
 78:                             config.getHealthCheckUrl(), config.getSecureHealthCheckUrl());
 79: 
 80:             // 应用初始化后是否开启
 81:             // Start off with the STARTING state to avoid traffic
 82:             if (!config.isInstanceEnabledOnit()) {
 83:                 InstanceStatus initialStatus = InstanceStatus.STARTING;
 84:                 LOG.info("Setting initial instance status as: " + initialStatus);
 85:                 builder.setStatus(initialStatus);
 86:             } else {
 87:                 LOG.info("Setting initial instance status as: {}. This may be too early for the instance to advertise "
 88:                          + "itself as available. You would instead want to control this via a healthcheck handler.",
 89:                          InstanceStatus.UP);
 90:             }
 91: 
 92:             // 设置 应用实例信息构建器 的 元数据( Metadata )集合
 93:             // Add any user-specific metadata information
 94:             for (Map.Entry<String, String> mapEntry : config.getMetadataMap().entrySet()) {
 95:                 String key = mapEntry.getKey();
 96:                 String value = mapEntry.getValue();
 97:                 builder.add(key, value);
 98:             }
 99: 
100:             // 创建 应用实例信息
101:             instanceInfo = builder.build();
102: 
103:             // 设置 应用实例信息 的 租约信息
104:             instanceInfo.setLeaseInfo(leaseInfoBuilder.build());
105:         }
106:         return instanceInfo;
107:     }
108: 
109: }

public class ApplicationInfoManager {

    /**
     * 单例
     */
    private static ApplicationInfoManager instance = new ApplicationInfoManager(null, null, null);

    /**
     * 状态变更监听器
     */
    protected final Map<String, StatusChangeListener> listeners;
    /**
     * 应用实例状态匹配
     */
    private final InstanceStatusMapper instanceStatusMapper;
    /**
     * 应用实例信息
     */
    private InstanceInfo instanceInfo;
    /**
     * 应用实例配置
     */
    private EurekaInstanceConfig config;

    // ... 省略其它构造方法

    public ApplicationInfoManager(EurekaInstanceConfig config, InstanceInfo instanceInfo, OptionalArgs optionalArgs) {
        this.config = config;
        this.instanceInfo = instanceInfo;
        this.listeners = new ConcurrentHashMap<String, StatusChangeListener>();
        if (optionalArgs != null) {
            this.instanceStatusMapper = optionalArgs.getInstanceStatusMapper();
        } else {
            this.instanceStatusMapper = NO_OP_MAPPER;
        }

        // Hack to allow for getInstance() to use the DI'd ApplicationInfoManager
        instance = this;
    }

    // ... 省略其它方法
}