Netflix Eureka 入门示例

目录

• 说明
• 前置需求
• 源码下载
• 源码修改
  • 修改eureka-server配置
• 构建项目
• 部署Eureka-Server
• 服务注册和发现测试

说明

• 脱离SpringCloud独立部署实践Eureka
• 包含部署一个Eureka Server，一个服务提供者，一个服务消费者
• 不包含代码讲解，用于体验原生的Eureka使用流程
• 对于打算阅读Eureka源码有前置帮助

前置需求

• 安装gradle，我的是6.6.1
• 安装tomcat，我的是8

源码下载

• git clone https://github.com/Netflix/eureka.git
  

源码修改

修改eureka-server配置

• 修改路径eureka-server/src/main/resources/eureka-client.properties
• 新增配置：eureka.shouldFetchRegistry=false
  • 不拉取注册信息
• 新增配置：eureka.registration.enabled=false
  • 不注册到eureka

构建项目

• cd eureka
  gradle -x test clean build
  

部署Eureka-Server

• cp ./eureka-server/build/libs/eureka-server-XXX-SNAPSHOT.war $TOMCAT_HOME/webapps/eureka.war
  

• $TOMCAT_HOME替换为自己的tomcat安装目录
• 注意：一定要重命名为eureka.war！
• 启动tomcat，等待一会儿
• 访问WebUI，就能看到丑丑的页面了： http://localhost:8080/eureka
  

服务注册和发现测试

• 启动服务提供者 gradle :eureka-examples:runExampleService

  • 实际运行的是：ExampleEurekaService.java

  • 服务启动后会挂起，等待服务消费者连接，看到以下日志表示启动成功：Service started and ready to process requests..

  • Service started and ready to process requests..
    [DiscoveryClient-InstanceInfoReplicator-0] INFO com.netflix.discovery.DiscoveryClient - DiscoveryClient_SAMPLEREGISTERINGSERVICE/xxxMacBook-Pro.local - registration status: 204
    <===========--> 90% EXECUTING [27s]
    > :eureka-examples:runExampleService
    
    

  • 此时查看WebUI就能看到注册的服务提供者了
    

• 启动服务消费者 gradle :eureka-examples:runExampleClient

  • 实际运行的是：ExampleEurekaClient.java

  • 以下为消费成功日志

  • Found an instance of example service to talk to from eureka: sampleservice.mydomain.net:8001
    healthCheckUrl: http://xxxMacBook-Pro.local:8001/healthcheck
    override: UNKNOWN
    Connected to server. Sending a sample request: FOO Tue Feb 23 16:50:41 CST 2021
    Waiting for server response..
    Received response from server: BAR Tue Feb 23 16:50:41 CST 2021
    Exiting the client. Demo over..
    [main] INFO com.netflix.discovery.DiscoveryClient - Shutting down DiscoveryClient ...
    [main] INFO com.netflix.discovery.DiscoveryClient - Completed shut down of DiscoveryClient
    
    Deprecated Gradle features were used in this build, making it incompatible with Gradle 7.0.
    Use '--warning-mode all' to show the individual deprecation warnings.
    See https://docs.gradle.org/6.6.1/userguide/command_line_interface.html#sec:command_line_warnings
    
    BUILD SUCCESSFUL in 14s
    6 actionable tasks: 3 executed, 3 up-to-date
    

• 同时提供者会打印后续日志

  • Client got connected... processing request from the client
    Received a request from the example client: FOO Tue Feb 23 16:56:58 CST 2021
    Sending the response to the client: BAR Tue Feb 23 16:56:58 CST 2021
    Simulating service doing work by sleeping for 5 seconds...
    Shutting down server. Demo over.
    

  • 消费完成后，提供者会在5s后退出