【SpringCloud】（五）：服务注册到Eureka Server

  上篇文章我们创建了Eureka Server实例。本篇文章我们把用户服务和电影服务注册到Eureka Server上。（服务消费者和服务提供者）

  首先我们以注册用户服务为整个讲述核心

  注册文档，SpringCloud官网，我们定位到How to Include Eureka Client，跟着文档一步一步来。

一.基本注册

1.How to Include Eureka Client

  在用户服务的POM.xml 中加入依赖

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

2.Registering with Eureka

package com.dynamic.cloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@SpringBootApplication
@EnableEurekaClient
public class MicroserviceSimpleProviderUserApplication {

	public static void main(String[] args) {
		SpringApplication.run(MicroserviceSimpleProviderUserApplication.class, args);
	}
}

3.在application.yml中加入Eureka的地址

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/

  至此基本的服务注册就已经完成了，我们的服务已经成功的注册在了Erueka上面。我们启动Eureka，并启动用户服务，可以观察到，注册在Eureka上面的服务实例。

  但是上面Application和Status有些问题。应用名称是未知，状态是电脑的名字。我们可以通过配置，进行定制，设置应用名称和将状态修改为主机+ 端口。

二.配置Application和Status

  在用户服务的application.yml配置文件中那个进行配置。

1.配置Application的名称

2.配置Status

重启服务，查看。

三.为Eureka Server进行认证；

1.配置Eureka服务的application.yml

2.在Eureka服务的POM.xml中添加依赖

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

3.Eureka增加了认证，那么服务在注册的使用，也就需要访问认证的Eureka。所以需要修改用户的请求方式，修改用户服务的Application.yml文件。

四. 监控和管理生产环境

在用户服务的POM.xml中加入依赖

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

五. Eureka’s Health Checks （健康检查）

在Eureka项目的application.yml中添加配置；

六. Using the EurekaClient

在用户微服务的Controller中加入：

ServiceId = Spring.application.name

我们不但将用户服务注册到了Eureka Server中，并进行了Application配置，同时对Eureka进行了认证和使用。

同样的方式把电影微服务注册到Eureka中

1.修改application.yml配置文件

2.在启动类上加入注解@EnableEurekaClient

3.加入相关依赖。

启动Eureka，用户服务和电影服务。

代码展示：

Eureka

application.yml配置文件

server:
  port: 8761 #Eurake
eureka:
  client:
    healthcheck: 
      enabled: true
    register-with-eureka: false
    fetch-registry: false
    service-url:
      defaultZone: http://user:[e-mail]:8761/eureka #把Eureka註冊到那個Eureka
      
security:
  basic:
    enabled: true
  user: 
    name: user #login username
    password: pass123
    
    

POM.xml

<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-discovery-eureka</artifactId>
  <packaging>jar</packaging>

	<parent>
			<groupId>com.dynamic.cloud</groupId>
			<artifactId>microservice-spring-cloud</artifactId>
			<version>0.0.1-SNAPSHOT</version>
			<relativePath/> 
	</parent>
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>


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

</dependencies>


</project>

用户微服务：

application.yml

server:
  port: 7900
spring:
  jpa:
    generate-ddl: false
    show-sql: true
    hibernate:
      ddl-auto: none
  datasource:
    platform: h2
    schema: classpath:schema.sql  #建表语句
    data: classpath:data.sql #数据
    
  application: 
    name: microservice-provider-user #使用小写
    
logging:
  level:
    root: INFO
    org.hibernate: INFO
    org.hibernate.type.descriptor.sql.BasicBinder: TRACE
    org.hibernate.type.descriptor.sql.BasicExtractor: TRACE
    com.dynamic: DEBUG
eureka:
  client:
    serviceUrl:
      defaultZone: http://user:[e-mail]:8761/eureka
  instance:
    prefer-ip-address: true
    instance-id: ${spring.application.name}:${spring.application.instance_id:${server.port}}
   

启动类

package com.dynamic.cloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@SpringBootApplication
@EnableEurekaClient
public class MicroserviceSimpleProviderUserApplication {

	public static void main(String[] args) {
		SpringApplication.run(MicroserviceSimpleProviderUserApplication.class, args);
	}
}

Controller

package com.dynamic.cloud.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import com.dynamic.cloud.entity.User;
import com.dynamic.cloud.repository.UserRepository;
import com.netflix.appinfo.InstanceInfo;
import com.netflix.discovery.EurekaClient;
import org.springframework.cloud.client.discovery.DiscoveryClient;

@RestController
public class UserController
{

	@Autowired
	private UserRepository userRepository;


	
	@GetMapping("/simple/{id}")
	public User findById(@PathVariable Long id)
	{
		return this.userRepository.findById(id);
	}
	
	@Autowired
	private EurekaClient eurekaClient;
	
	@GetMapping("/eureka-instance")
	public String serviceUrl() {
	    InstanceInfo instance = eurekaClient.getNextServerFromEureka("MICROSERVICE-PROVIDER-USER", false);
	    return instance.getHomePageUrl();
	}
	
	@Autowired
	private DiscoveryClient discoveryClient;
	@GetMapping("/instance-info")
	public ServiceInstance showInfo()
	{
		ServiceInstance localServiceInstance = this.discoveryClient.getLocalServiceInstance();
				return localServiceInstance;
	}
	
}

电影微服务类比用户微服务，进行修改。

application.yml

server:
  port: 7901

user: 
 userServicePath: http://localhost:7900/simple/
 
spring:
  application:
    name: microservice-comsumer-movie
  
eureka:
  client:
    serviceUrl:
      defaultZone: http://user:[e-mail]:8761/eureka
  instance: 
    prefer-ip-address: true
    instance-id: ${spring.application.name}:${spring.application.instance_id:${server.port}}

POM.xml

<?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.dynamic.cloud</groupId>
			<artifactId>microservice-spring-cloud</artifactId>
			<version>0.0.1-SNAPSHOT</version>
			<relativePath/> <!-- lookup parent from repository -->
	</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>
		
				<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-eureka</artifactId>
		</dependency>
		
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-actuator</artifactId>
		</dependency>
	</dependencies>
</project>

启动类加上注解：@EnableEurekaClient