SpringCloud-笔记2-Eureka Client项目创建

Posted 2023-03-24

参考技术A File/New/Module

有时spring网站无法访问时，我们可以把https->改为http

一路next到finsh

选择pom.xml文件/

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问题2

Failed to read artifact descriptor for org.springframework.cloud:spring-cloud-starter-netflix-eureka-client:jar:2.1.2.RELEASE

到moven仓库查看版本 https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-starter-netflix-eureka-client

日志打印可看到是注册上去了

可在eureka后台看不到Client的注册实例信息

可以看到成功注册上来了

工程的pom.xml文件加入

工程的运行类添加注解

在application.yml添加注册配置

运行wechatTask-guns项目

访问

springcloud笔记三注册中心eurekazookeeperconsul

一、eureka

1.服务端

pom文件

添加eureka-server

		<!--eureka-server-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </dependency>

yaml文件

# eureka集群互相注册
server:
  port: 7002
#eureka:
#  instance:
#    hostname: eureka7002.com
#  client:
#    register-with-eureka: false
#    fetch-registry: false
#    com.fox.springcloud.service-url:
#      defaultzone: http://eureka7001.com:7001/eureka/
eureka:
  instance:
    hostname: eureka7002.com
  client:
    register-with-eureka: false
    fetch-registry: false
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka/
  server:
    enable-self-preservation: false
    eviction-interval-timer-in-ms: 20000

启动类

添加@EnableEurekaServer注解

2.客户端(服务注册+restTemplate)

pom文件

添加eureka-client maven坐标

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>

yaml文件

eureka:
  client:
    register-with-eureka: true
    service-url:
#      defaultZone: http://localhost:7001/eureka
      defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/
    fetch-registry: true
  instance:
    instance-id: payment8001
    prefer-ip-address: true
    lease-renewal-interval-in-seconds: 10
    lease-expiration-duration-in-seconds: 30

启动类

添加@EnableEurekaClient、@EnableDiscoveryClient注解

备注：@EnableEurekaClient只适用于使用Eureka作为注册中心的场景，@EnableDiscoveryClient可以适用于其他注册中心的场景比如nacos等。

调用远程服务

使用服务名代替服务提供者的ip端口调用

获取注册中心的服务

@Resource
private DiscoveryClient discoveryClient;

可以通过discoveryClient获取注册中心的服务和对应的instances

3.客户端(openfeign)

pom文件

添加eureka-client和openfeign

		<dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>

yaml文件

eureka:
  client:
    register-with-eureka: false
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/
feign:
  client:
    config:
      default:
        ReadTimeout: 5000
        ConnectTimeout: 5000

启动类

添加@EnableFeignClients注解

调用远程服务

PaymentFeignService中的服务名和接口路径要和服务提供者一致，项目中注入PaymentFeignService即可调用

@Component
@FeignClient("PAYMENT-SERVICE")
public interface PaymentFeignService {
    @GetMapping("/payment/lb")
    public String getPaymentLB();

    @GetMapping("/payment/timeout")
    public String getTimeout();
}

二、zookeeper

1.zookeeper服务端安装

下载zookeeper

wget https://mirrors.tuna.tsinghua.edu.cn/apache/zookeeper/zookeeper-3.5.9/apache-zookeeper-3.5.9-bin.tar.gz

zookeeper安装后要注意检查防火墙是否关闭

查看防火墙状态
systemctl status firewalld.service
关闭防火墙
systemctl stop firewalld.service

java项目连接zookeeper时要注意和服务器版本一致。

进入bin目录下，启动zookeeper

./zkServer.sh start
连接zookeeper
./zkCli.sh

2.客户端(服务注册调用)

pom文件

		<!--SpringBoot整合Zookeeper客户端-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-zookeeper-discovery</artifactId>
            <exclusions>
                <!--先排除自带的zookeeper3.5.3-->
                <exclusion>
                    <groupId>org.apache.zookeeper</groupId>
                    <artifactId>zookeeper</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <!--添加zookeeper3.5.9版本-->
        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
            <version>3.5.9</version>
        </dependency>

yaml文件

spring:
  application:
    # 服务别名---注册zookeeper到注册中心的名称
    name: cloud-provider-payment
  cloud:
    zookeeper:
      # 默认localhost:2181
      connect-string: 192.168.137.200:2181

启动类

添加@EnableDiscoveryClient注解

调用远程服务

通过服务名代替ip端口

zookeeper节点类型

1、PERSISTENT--持久化目录节点
客户端与zookeeper断开连接后，该节点依旧存在
2、PERSISTENT_SEQUENTIAL-持久化顺序编号目录节点
客户端与zookeeper断开连接后，该节点依旧存在，只是Zookeeper给该节点名称进行顺序编号
3、EPHEMERAL-临时目录节点
客户端与zookeeper断开连接后，该节点被删除
4、EPHEMERAL_SEQUENTIAL-临时顺序编号目录节点
客户端与zookeeper断开连接后，该节点被删除，只是Zookeeper给该节点名称进行顺序编号

三、consul

1.consul服务端安装

consul下载安装官网写的非常详细https://www.consul.io/downloads

sudo yum install -y yum-utils
sudo yum-config-manager --add-repo https://rpm.releases.hashicorp.com/RHEL/hashicorp.repo
sudo yum -y install consul

查看是否安装成功

consul -version

启动consul

window启动
consul agent dev
centos启动(0.0.0.0允许远程访问)
consul agent -dev -client 0.0.0.0 -ui &
查看进程是否启动成功
netstat -anp|grep 8500
查看Consul集群的成员
consul members

2.客户端(服务注册调用)

pom文件

添加consul-discovery

		<!--SpringCloud consul-server-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-consul-discovery</artifactId>
        </dependency>

yaml文件

spring:
  application:
    # 服务别名---注册consul到注册中心的名称
    name: cloud-provider-payment
  cloud:
    consul:
      host: 192.168.137.200
      port: 8500
      discovery:
        service-name: ${spring.application.name}

启动类

添加@EnableDiscoveryClient注解

调用远程服务

通过服务名代替ip端口

3.使用过程中遇到的问题

问题一、注册服务提供者连接不上consul

使用telnet ip端口报错

telnet: connect to address 192.168.137.200: No route to host

查看防火墙状态

firewall-cmd --state

发现防火墙是running状态，关闭防火墙，再telnet成功

service firewalld stop

问题二、consul中服务健康状态为unhealth

页面显示叉

点进去

通过output信息判断可能是使用了服务运行时的主机名，查看主机名确实是DESKTOP-JOKG37G

127.0.0.1 DESKTOP-JOKG37G

原因是springcloud服务注册到consul的是主机名，consul所在的服务器不能识别该主机名导致

解决方法：

一、在consul服务器/etc/hosts文件中配置主机名映射到Springcloud服务ip

二、指定注册到consul的ip地址spring.cloud.consul.discovery.hostname

spring:
  application:
    name: cloud-consumer-order
  cloud:
    consul:
      host: 192.168.137.200
      port: 8500
      discovery:
        hostname: 192.168.137.166
        service-name: ${spring.application.name}