Docker下的Spring Cloud三部曲之二(细说Spring Cloud开发)

卧疾丰暇豫,翰墨时间作。这篇文章主要讲述Docker下的Spring Cloud三部曲之二:细说Spring Cloud开发相关的知识,希望能为你提供帮助。
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本篇概览

  • 本文是《Docker下的Spring Cloud三部曲》系列的第二篇,详细讲解上一篇实例中用到的eureka、provider、consumer等三个应用的开发过程;
环境信息
  • 回顾一下实战环境,如下图:
Docker下的Spring Cloud三部曲之二(细说Spring Cloud开发)

文章图片

源码地址
  • 上图的eureka、provider、consumer是三个spring boot的web工程,源码可以在GitHub下载,地址和链接信息如下表所示:
名称 链接 备注
项目主页 https://github.com/zq2599/blog_demos 该项目在GitHub上的主页
git仓库地址(https) https://github.com/zq2599/blog_demos.git 该项目源码的仓库地址,https协议
git仓库地址(ssh) git@github.com:zq2599/blog_demos.git 该项目源码的仓库地址,ssh协议
  • 这个git项目中有多个工程,本次实战的工程是springcloudscaledemo,如下图红框所示:
Docker下的Spring Cloud三部曲之二(细说Spring Cloud开发)

文章图片

如何将spring boot工程构建成docker镜像
  • 如果您想了解如何将spring boot工程构建docker镜像,欢迎访问以下三篇实战文章:
    1. 《maven构建docker镜像三部曲之一:准备环境》;
    2. 《maven构建docker镜像三部曲之二:编码和构建镜像》;
    3. 《maven构建docker镜像三部曲之三:推送到远程仓库(内网和阿里云)》;
  • 本次实战用到的知识点主要集中在上面的第二部;
开发环境
  • 本次实战开发环境的具体信息如下:
    1. 操作系统:Ubuntu16;
    2. Docker版本:17.03.2-ce;
    3. JDK:1.8.0_151;
    4. maven:3.3.3;
  • 接下来我们依次开发eureka、provider、consumer等三个应用;
eureka-server应用的pom.xml
  • 新建一个名为 eureka-server的spring boot应用,pom.xml内容如下:
    < ?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.bolingcavalry< /groupId> < artifactId> eureka-server< /artifactId> < version> 0.0.1-SNAPSHOT< /version> < packaging> jar< /packaging> < name> eureka-server< /name> < description> Demo project for Spring Boot< /description> < parent> < groupId> org.springframework.boot< /groupId> < artifactId> spring-boot-starter-parent< /artifactId> < version> 1.5.9.RELEASE< /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> < spring-cloud.version> Edgware.SR1< /spring-cloud.version> < /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-test< /artifactId> < scope> test< /scope> < /dependency> < /dependencies> < dependencyManagement> < dependencies> < dependency> < groupId> org.springframework.cloud< /groupId> < artifactId> spring-cloud-dependencies< /artifactId> < version> $spring-cloud.version< /version> < type> pom< /type> < scope> import< /scope> < /dependency> < /dependencies> < /dependencyManagement> < build> < plugins> < plugin> < groupId> org.springframework.boot< /groupId> < artifactId> spring-boot-maven-plugin< /artifactId> < /plugin> < !--新增的docker maven插件--> < plugin> < groupId> com.spotify< /groupId> < artifactId> docker-maven-plugin< /artifactId> < version> 0.4.12< /version> < !--docker镜像相关的配置信息--> < configuration> < !--镜像名,这里用工程名--> < imageName> bolingcavalry/$project.artifactId< /imageName> < !--TAG,这里用工程版本号--> < imageTags> < imageTag> $project.version< /imageTag> < /imageTags> < !--镜像的FROM,使用java官方镜像--> < baseImage> java:8u111-jdk< /baseImage> < !--该镜像的容器启动后,直接运行spring boot工程--> < entryPoint> ["java", "-jar", "/$project.build.finalName.jar"]< /entryPoint> < !--构建镜像的配置信息--> < resources> < resource> < targetPath> /< /targetPath> < directory> $project.build.directory< /directory> < include> $project.build.finalName.jar< /include> < /resource> < /resources> < /configuration> < /plugin> < /plugins> < /build> < /project>

  • pom.xml中的几个关键点如下:
    1. spring cloud的版本是Edgware.SR1;
    2. 添加spring-cloud-starter-eureka-server的依赖;
    3. 添加spring-cloud-dependencies的依赖(pom的形式);
    4. 添加插件docker-maven-plugin,用于将当前工程制作成本地docker镜像;
eureka-server应用的源码
  • eureka-server应用只有一个java文件,内容如下:
    package com.bolingcavalry.eurekaserver;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
@SpringBootApplication@EnableEurekaServer
br/>@EnableEurekaServer
public static void main(String[] args) SpringApplication.run(EurekaServerApplication.class, args);


- 注意要添加**@EnableEurekaServer**注解;### eureka-server的配置信息 - 配置信息application.properties的内容如下: ```properties server.port=8080eureka.instance.hostname=localhost eureka.client.register-with-eureka=false eureka.client.fetch-registry=false eureka.client.serviceUrl.defaultZone=http://$eureka.instance.hostname:$server.port/eureka/

构建eureka-server应用的docker镜像
  • 在pom.xml文件所在目录下,执行如下命令可以构建docker镜像:
    mvn clean package -U -DskipTests docker:build

  • 构建成功后,执行命令docker images可见新构建的镜像,如下:
    ubuntu@VM-129-56-ubuntu:~$ sudo docker images REPOSITORYTAGIMAGE IDCREATEDSIZE bolingcavalry/eureka-server0.0.1-SNAPSHOT80663220a5f535 hours ago683 MB bolingcavalry/eureka-serverlatest80663220a5f535 hours ago683 MB

  • eureka-server的镜像OK后,我们接下来构建provide的镜像;
provider应用的pom.xml
  • 新建一个名为service-provider的spring boot应用,pom.xml内容如下:
    < ?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.bolingcavalry< /groupId> < artifactId> service-provider< /artifactId> < version> 0.0.1-SNAPSHOT< /version> < packaging> jar< /packaging> < name> service-provider< /name> < description> Demo project for Spring Boot< /description> < parent> < groupId> org.springframework.boot< /groupId> < artifactId> spring-boot-starter-parent< /artifactId> < version> 1.5.9.RELEASE< /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> < spring-cloud.version> Edgware.SR1< /spring-cloud.version> < /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-web< /artifactId> < /dependency> < dependency> < groupId> org.springframework.boot< /groupId> < artifactId> spring-boot-starter-test< /artifactId> < scope> test< /scope> < /dependency> < /dependencies> < dependencyManagement> < dependencies> < dependency> < groupId> org.springframework.cloud< /groupId> < artifactId> spring-cloud-dependencies< /artifactId> < version> $spring-cloud.version< /version> < type> pom< /type> < scope> import< /scope> < /dependency> < /dependencies> < /dependencyManagement> < build> < plugins> < plugin> < groupId> org.springframework.boot< /groupId> < artifactId> spring-boot-maven-plugin< /artifactId> < /plugin> < !--新增的docker maven插件--> < plugin> < groupId> com.spotify< /groupId> < artifactId> docker-maven-plugin< /artifactId> < version> 0.4.12< /version> < !--docker镜像相关的配置信息--> < configuration> < !--镜像名,这里用工程名--> < imageName> bolingcavalry/$project.artifactId< /imageName> < !--TAG,这里用工程版本号--> < imageTags> < imageTag> $project.version< /imageTag> < /imageTags> < !--镜像的FROM,使用java官方镜像--> < baseImage> java:8u111-jdk< /baseImage> < !--该镜像的容器启动后,直接运行spring boot工程--> < entryPoint> ["java", "-jar", "/$project.build.finalName.jar"]< /entryPoint> < !--构建镜像的配置信息--> < resources> < resource> < targetPath> /< /targetPath> < directory> $project.build.directory< /directory> < include> $project.build.finalName.jar< /include> < /resource> < /resources> < /configuration> < /plugin> < /plugins> < /build> < /project>

provider应用的源码
  • 入口类ServiceProviderApplication的源码如下:
    package com.bolingcavalry.serviceprovider;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
@EnableDiscoveryClient@SpringBootApplication
br/>@SpringBootApplication
public static void main(String[] args)
SpringApplication.run(ServiceProviderApplication.class, args);


- 注意要添加**@EnableDiscoveryClient**注解;- 只有一个controller类UserController ,对外提供http服务: ```java @RestController public class UserController @RequestMapping(value = "https://www.songbingjia.com/getuserinfo/id", method = RequestMethod.GET) public String getUserInfo(@PathVariable String id) return String.format("user[%s]", id); @RequestMapping(value = "https://www.songbingjia.com/getuserinfo", method = RequestMethod.GET) public String getUserInfoWithRequestParam(@RequestParam("id") String id, @RequestParam("name") String name) return String.format("user [%s], id [%s], from server [%s]", name, id, getIPAddr()); /** * 获取本机IP地址 * @return */ private static String getIPAddr() String hostAddress = null; try InetAddress address = InetAddress.getLocalHost(); hostAddress = address.getHostAddress(); catch (UnknownHostException e) e.printStackTrace(); return hostAddress;

  • 上面的controller提供两个http服务,getUserInfoWithRequestParam服务会返回应用所在机器的IP地址;
provider的配置信息
  • provider的配置信息存放在application.yml文件中,内容如下:
    server: port: 8080 spring: application: name: microservice-provider-user eureka: client: serviceUrl: defaultZone: http://eurekahost:8080/eureka/ instance: prefer-ip-address: true

  • 注意上面配置的注册中心地址为http://eurekahost:8080/eureka/,eurekahost在docker-compose中会作为link参数对应eureka server;
构建provider应用的docker镜像
  • 在pom.xml文件所在目录下,执行如下命令可以构建docker镜像:
    mvn clean package -U -DskipTests docker:build

  • 构建成功后,执行命令docker images可见新构建的镜像,如下:
    ubuntu@VM-129-56-ubuntu:~$ sudo docker images REPOSITORYTAGIMAGE IDCREATEDSIZE bolingcavalry/eureka-server0.0.1-SNAPSHOT80663220a5f535 hours ago683 MB bolingcavalry/eureka-serverlatest80663220a5f535 hours ago683 MB bolingcavalry/service-provider0.0.1-SNAPSHOTa02f307bc1a922 hours ago683 MB bolingcavalry/service-providerlatesta02f307bc1a922 hours ago683 MB

  • provider已经OK,接下来是consumer工程;
consumer应用的pom.xml
  • 新建一个名为service-consumer的spring boot应用,pom.xml内容如下:
    < ?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.bolingcavalry< /groupId> < artifactId> service-consumer< /artifactId> < version> 0.0.1-SNAPSHOT< /version> < packaging> jar< /packaging> < name> service-consumer< /name> < description> Demo project for Spring Boot< /description> < parent> < groupId> org.springframework.boot< /groupId> < artifactId> spring-boot-starter-parent< /artifactId> < version> 1.5.9.RELEASE< /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> < spring-cloud.version> Edgware.SR1< /spring-cloud.version> < /properties> < dependencies> < dependency> < groupId> org.springframework.cloud< /groupId> < artifactId> spring-cloud-starter-eureka-server< /artifactId> < /dependency> < dependency> < groupId> org.springframework.cloud< /groupId> < artifactId> spring-cloud-starter-feign< /artifactId> < /dependency> < dependency> < groupId> org.springframework.boot< /groupId> < artifactId> spring-boot-starter-test< /artifactId> < scope> test< /scope> < /dependency> < /dependencies> < dependencyManagement> < dependencies> < dependency> < groupId> org.springframework.cloud< /groupId> < artifactId> spring-cloud-dependencies< /artifactId> < version> $spring-cloud.version< /version> < type> pom< /type> < scope> import< /scope> < /dependency> < /dependencies> < /dependencyManagement> < build> < plugins> < plugin> < groupId> org.springframework.boot< /groupId> < artifactId> spring-boot-maven-plugin< /artifactId> < /plugin> < !--新增的docker maven插件--> < plugin> < groupId> com.spotify< /groupId> < artifactId> docker-maven-plugin< /artifactId> < version> 0.4.12< /version> < !--docker镜像相关的配置信息--> < configuration> < !--镜像名,这里用工程名--> < imageName> bolingcavalry/$project.artifactId< /imageName> < !--TAG,这里用工程版本号--> < imageTags> < imageTag> $project.version< /imageTag> < /imageTags> < !--镜像的FROM,使用java官方镜像--> < baseImage> java:8u111-jdk< /baseImage> < !--该镜像的容器启动后,直接运行spring boot工程--> < entryPoint> ["java", "-jar", "/$project.build.finalName.jar"]< /entryPoint> < !--构建镜像的配置信息--> < resources> < resource> < targetPath> /< /targetPath> < directory> $project.build.directory< /directory> < include> $project.build.finalName.jar< /include> < /resource> < /resources> < /configuration> < /plugin> < /plugins> < /build> < /project>

  • 和前面两个应用相比,这里要引入spring-cloud-starter-feign;
consumer的源码
  • 入口类ServiceConsumerApplication 源码如下:
    package com.bolingcavalry.serviceconsumer;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.netflix.feign.EnableFeignClients;
@EnableDiscoveryClient@SpringBootApplication
br/>@SpringBootApplication
public class ServiceConsumerApplication
public static void main(String[] args) SpringApplication.run(ServiceConsumerApplication.class, args);


- 注意要增加**@EnableDiscoveryClient**和**@SpringBootApplication**这两个注解;- 增加一个带注解**@FeignClient**的接口,用于在spring cloud环境中声明远程调用信息: ```java @FeignClient(name = "microservice-provider-user") public interface UserFeignClient @RequestMapping(value = "https://www.songbingjia.com/getuserinfo", method = RequestMethod.GET) String getUserInfoWithRequestParam(@RequestParam("id") String id, @RequestParam("name") String name);

  • 增加一个controller类UserFacadeController,为浏览器访问提供http服务,并且在响应请求的时候会通过UserFeignClient接口的实现远程调用provider应用的服务:
    @RestController public class UserFacadeController @Autowired private UserFeignClient userFeignClient; @GetMapping("/user/id/name") public String getUserInfo(@PathVariable("id") final String id, @PathVariable("name") final String name) return "1. ---" + userFeignClient.getUserInfoWithRequestParam(id, name);

consumer的配置信息
  • provider的配置信息存放在application.yml文件中,内容如下:
    server: port: 8080 spring: application: name: service-consumer eureka: client: serviceUrl: defaultZone: http://eurekahost:8080/eureka/ instance: prefer-ip-address: true

  • 注意上面配置的注册中心地址为http://eurekahost:8080/eureka/,eurekahost在docker-compose中会作为link参数对应eureka server;
构建provider应用的docker镜像
  • 在pom.xml文件所在目录下,执行如下命令可以构建docker镜像:
    mvn clean package -U -DskipTests docker:build

  • 【Docker下的Spring Cloud三部曲之二(细说Spring Cloud开发)】构建成功后,执行命令docker images可见新构建的镜像,如下:
    ubuntu@VM-129-56-ubuntu:~$docker images REPOSITORYTAGIMAGE IDCREATEDSIZE bolingcavalry/service-provider0.0.1-SNAPSHOTa02f307bc1a947 hours ago683 MB bolingcavalry/service-providerlatesta02f307bc1a947 hours ago683 MB bolingcavalry/service-consumer0.0.1-SNAPSHOTae6b37b997542 days ago683 MB bolingcavalry/service-consumerlatestae6b37b997542 days ago683 MB bolingcavalry/eureka-server0.0.1-SNAPSHOT80663220a5f52 days ago683 MB bolingcavalry/eureka-serverlatest80663220a5f52 days ago683 MB

  • 至此,本次实战所需的所有镜像都制作完毕,相关的demo工程的开发过程我们也一起过了一遍,上一章中的实战您已经可以独立做出来了,接下来的实战中,我们一起来尝试服务横向扩容;
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