Step 1 Build the base Eureka-client project

1. Build a project that acts as a Eureka-client

<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.example</groupId>
  <artifactId>eureka-provider</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>
    
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <java.version>1.8</java.version>
    </properties>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
    
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Finchley.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
</project>

2. Create the main-entry for the app

Content of src\main\java\app\EurekaClientApp.java

package app;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

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

3. Prepare application.yml to configure the client

Content of application.yml

spring:
  application:
    name: eureka-client
    
server:
  port: 8766

eureka:
  client:
    register-with-eureka: true
    serviceUrl:
      defaultZone: http://aaa.bbb.ccc.ddd:8761/eureka/
  instance:
    ip-address: 127.0.0.1
    prefer-ip-address: true

Step 2 Add dependency to access MySQL through JPA

1. Add the dependency in the pom.xml

        <!-- JPA Data  -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <!-- Use MySQL Connector-J -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

2. Update the application.yml file, to define the parameters to MySQL

Content of application.yml

spring:
  application:
    name: eureka-client
  jpa:
    database: MYSQL
    show-sql: true
    hibernate:
      ddl-auto: none
  datasource:
    url: jdbc:mysql://127.0.0.1:3306/xiaoyouhui
    username: root
    password: password123
    driver-class-name: com.mysql.jdbc.Driver

server:
  port: 8766

eureka:
  client:
    register-with-eureka: true
    serviceUrl:
      defaultZone: http://aaa.bbb.ccc.ddd:8761/eureka/
  instance:
    ip-address: 127.0.0.1
    prefer-ip-address: true

3. Create the model-class

package app.domain;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Table;

@Entity
@Table(name = "member")
public class Member{
  //fields
  //getters & setters
}

4. Create the repository

package app.repository;

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

import domain.Member;

@Repository
public interface MemberRepository extends JpaRepository<Member, String>{

}

Step 3 Add a controller to handle request

The controller-class should under the package of the main-entry. Since Spring-boot will scan from the root-package.

Content of src\main\java\app\controller\MainController.java

package app.controller;

import java.util.List;
import java.util.Optional;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;

import domain.Member;
import repository.MemberRepository;

@RestController
public class MainController {
    @Autowired
    private MemberRepository memberRepository;
    

    @RequestMapping("/greeting")
    public Optional<Member> greeting(@RequestParam(value="id", defaultValue="na") String id) {
        return memberRepository.findById(id);
    }

    @RequestMapping("/greetings")
    public List<Member> greetings() {
        List<Member> list = memberRepository.findAll();
        System.out.println(list.size());
        return list;
    }

    
    @GetMapping(path="/user/{id}")
    public String findById(@PathVariable Long id) {
        return "hello";
    }

    @RequestMapping("/test")
    public @ResponseBody String testm() {
        return "test";
    }
}

Step 4 Configure to open some Actuator end-point

management:
  endpoints:
    web:
      exposure:
        include: "*"
  endpoint:
    shutdown:
      enabled: false

References

• Spring document to access MySQL
• Spring document to build a restful service
• Blog post to configure Actuator