0402-服务注册与发现-Eureka Server使用、将服务注册到Eureka server上

一、Eureka Server使用

官方文档地址：http://cloud.spring.io/spring-cloud-static/Edgware.SR3/single/spring-cloud.html#_spring_cloud_netflix

1.1、原项目改造【方便后续开发增加父pom】

　　1》复制改名

　　　　

　　2》编写一个父pom

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.lhx.cloud</groupId>
    <artifactId>microservice-spring-cloud</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>pom</packaging>

    <name>microservice-spring-cloud</name>
    <description>Demo project for Spring Boot</description>

    <modules>
        <module>microservice-comsumer-movie</module>
        <module>microservice-provider-user</module>
    </modules>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
    </parent>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Edgware.SR3</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

　　3》修改上两个pom使其名称内外一致

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <artifactId>microservice-provider-user</artifactId>
    <packaging>jar</packaging>
    <parent>
        <groupId>com.lhx.cloud</groupId>
        <artifactId>microservice-spring-cloud</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </dependency>
    </dependencies>
</project>

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <artifactId>microservice-comsumer-movie</artifactId>
    <packaging>jar</packaging>

    <parent>
        <groupId>com.lhx.cloud</groupId>
        <artifactId>microservice-spring-cloud</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    </dependencies>



</project>

　　4》导入项目，更新maven即可。

1.2、eureka server使用

　　新建maven module项目，microservice-discovery-eureka，单机使用

　　pom依赖

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

　　配置文件　　

#server.port: 指明了应用启动的端口号
#eureka.client.registerWithEureka: 值为false意味着自身仅作为服务器，不作为客户端
#eureka.client.fetchRegistry: 值为false意味着无需注册自身
#eureka.client.serviceUrl.defaultZone: 指明了应用的URL

server:
  port: 8761
eureka:
  client:
    register-with-eureka: false
    fetch-registry: false
    service-url:
      defaultZone: http://localhost:8761/eureka

　　项目启动类

@SpringBootApplication
@EnableEurekaServer
public class EurekaApplication {
    public static void main(String[] args) {
        SpringApplication.run(EurekaApplication.class, args);
    }
}

　　现在可以访问http://localhost:8761，基本都是字面含义

　　git地址：https://github.com/bjlhx15/spring-cloud

　　使用tag：初始化eureka-server

二、将服务注册到Eureka server上

按照官方文档：http://cloud.spring.io/spring-cloud-static/Edgware.SR3/single/spring-cloud.html#_service_discovery_eureka_clients

修改microservice-provider-user服务

1、pom引用

        <dependency>
            <groupId>org.springframework.cloud</groupId>
                        <!--原引用方式，可用-->
            <!-- <artifactId>spring-cloud-starter-eureka</artifactId> -->
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>

2、注册Eureka

旧版本需要增加@EnableEurekaClient、@EnableDiscoveryClient

新版本按照文档不需要增加，必须是spring-boot项目 

3、配置文件配置application.yml

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
  instance:
    prefer-ip-address: true
    instance-id: ${spring.application.name}:${spring.application.instance_id:${server.port}}

尽量补全应用程序名

spring:
  application:
    name: mircoservice-provider-user # 建议小写

此时启动项目即可。

三、Eureka Server增加授权认证

官方文档：http://cloud.spring.io/spring-cloud-static/Edgware.SR3/single/spring-cloud.html#_service_discovery_eureka_clients

修改microservice-discovery-eureka项目

1、配置属性

eureka.client.serviceUrl.defaultZone=http://user:password@localhost:8761/eureka即可

实践证明不可行。需要增加security配置

2、security配置pom.xml

　　添加 spring-boot-starter-security,该依赖为Eureka Server 提供用户认证能力。 

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>

3、增加配置文件

security:
  basic:
    enabled: true #开启验证
  user:
    name: user #用户名
    password: a123 #密码

注意如果此处增加了认证，在注册服务的时候也需要修改注册服务的链接，即第二部分的3设置为

eureka:
  client:
    serviceUrl:
      defaultZone: http://user:a123@localhost:8761/eureka/

四、应用服务增加监控和管理

在user 的pom增加

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

参看地址：http://www.cnblogs.com/bjlhx/p/8719625.html

修改eureka路径

eureka:
  instance:
    statusPageUrlPath: ${management.context-path}/info
    healthCheckUrlPath: ${management.context-path}/health

五、其他

5.1、注册安全应用程序

也就是https配置：http://cloud.spring.io/spring-cloud-static/Edgware.SR3/single/spring-cloud.html#_registering_a_secure_application

5.2、eureka的健康检查

在spring-cloud-netfix-eureka 1.1 之后使用eureka.client.healthcheck.enabled=true配置，此配置也是基础acturator的

　　查看：http://localhost:8761/health

5.3、实例Id

　　eureka.instance.instanceId=${spring.application.name}:${spring.application.instance_id:${server.port}}

5.4、eurekaClient与discoveryClient

import

import org.springframework.cloud.client.discovery.DiscoveryClient;
import com.netflix.discovery.EurekaClient;

代码

    @GetMapping("/eureka-instance")
    public String serviceUrl() {
        InstanceInfo instance = eurekaClient.getNextServerFromEureka("MIRCOSERVICE-PROVIDER-USER", false);
        return instance.getHomePageUrl();
    }
    @GetMapping("/eureka-info")
    public ServiceInstance showInfo() {
        ServiceInstance serviceInstance = discoveryClient.getLocalServiceInstance();
        return serviceInstance;
    }
    @GetMapping("/eureka-url")
    public Object serviceUrl2() {
        List<ServiceInstance> list = discoveryClient.getInstances("MIRCOSERVICE-PROVIDER-USER");
        if (list != null && list.size() > 0 ) {
            return list.get(0).getUri();
        }
        return null;
    }

5.5、http 使用

　　默认情况下，EurekaClient使用Jersey进行HTTP通信。如果您希望避免来自Jersey的依赖关系，则可以将它从依赖关系中排除。 Spring Cloud将自动配置基于Spring RestTemplate的传输客户端。

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-eureka</artifactId>
    <exclusions>
        <exclusion>
            <groupId>com.sun.jersey</groupId>
            <artifactId>jersey-client</artifactId>
        </exclusion>
        <exclusion>
            <groupId>com.sun.jersey</groupId>
            <artifactId>jersey-core</artifactId>
        </exclusion>
        <exclusion>
            <groupId>com.sun.jersey.contribs</groupId>
            <artifactId>jersey-apache-client4</artifactId>
        </exclusion>
    </exclusions>
</dependency>

以上类似的配置可以配置到microservice-comsumer-movie上即可

代码地址：https://github.com/bjlhx15/spring-cloud

以上项目启动 先启动发现服务，启动后在分别启动user和movie