Docker 使用docker-compose部署项目

原文地址：https://github.com/eacdy/spring-cloud-book/blob/master/3%20%E4%BD%BF%E7%94%A8Docker%E6%9E%84%E5%BB%BA%E5%BE%AE%E6%9C%8D%E5%8A%A1/3.8.5%20%E4%BD%BF%E7%94%A8Docker%20Compose%E9%83%A8%E7%BD%B2%E9%A1%B9%E7%9B%AE.md

经过前文对Docker Compose的讲解，我们以Spring Cloud章节的几个示例项目为例，讲解如何使用Docker Compose部署项目：

准备工作

使用到的示例项目有：

项目名称	作用
microservice-api-gateway	API Gateway
microservice-consumer-movie-ribbon-with-hystrix	服务消费者
microservice-discovery-eureka	服务发现
microservice-hystrix-dashboard	监控
microservice-hystrix-turbine	Turbine
microservice-provider-user	服务提供者

要想使用Docker Compose部署项目，我们首先得将项目打包成Docker镜像。本文使用Docker的Maven插件将项目打包成Docker镜像，当然也可以使用Dockerfile或者其他方式打包。

• 为了管理方便，我们首先在父pom中添加插件管理：

    <pluginManagement>
      <plugins>
        <plugin>
          <groupId>com.spotify</groupId>
          <artifactId>docker-maven-plugin</artifactId>
          <version>0.4.12</version>
        </plugin>
      </plugins>
    </pluginManagement>

• 然后依次在上文提到的6个项目添加以下内容：

 <build>
    <plugins>
      <plugin>
        <groupId>com.spotify</groupId>
        <artifactId>docker-maven-plugin</artifactId>
        <executions>
          <execution>
            <id>build-image</id>
            <phase>package</phase>
            <goals>
              <goal>build</goal>
            </goals>
          </execution>
        </executions>
        <configuration>
          <imageName>${docker.image.prefix}/${project.artifactId}</imageName>
          <baseImage>java</baseImage>
          <entryPoint>["java", "-jar", "/${project.build.finalName}.jar"]</entryPoint>
          <resources>
            <resource>
              <targetPath>/</targetPath>
              <directory>${project.build.directory}</directory>
              <include>${project.build.finalName}.jar</include>
            </resource>
          </resources>
        </configuration>
      </plugin>
    </plugins>
  </build>

• 在父项目所在路径下，执行命令：

mvn clean package

这样，项目就会为各个项目打包成jar包，并且自动制作成Docker镜像。

运行docker images 查看本地镜像：

reg.itmuch.com/microservice-api-gateway                          latest              98c2997cb8c6        3 days ago          678.4 MB
reg.itmuch.com/microservice-hystrix-turbine                      latest              c482e8da54dc        3 days ago          677.6 MB
reg.itmuch.com/microservice-hystrix-dashboard                    latest              1daa15df3508        3 days ago          666.7 MB
reg.itmuch.com/microservice-consumer-movie-ribbon-with-hystrix   latest              694634d340b1        3 days ago          677.2 MB
reg.itmuch.com/microservice-provider-user                        latest              2049cfe6794c        3 days ago          689.3 MB
reg.itmuch.com/microservice-discovery-eureka                     latest              73e2e80bf567        3 days ago          679.4 MB

我们发现Docker镜像已经制作成功了。

编写docker-compose.yml文件

在任意路径，新建一个docker-compose.yml文件，并添加如下内容：

microservice-discovery-eureka:
  image: reg.itmuch.com/microservice-discovery-eureka
  ports:
  - :
  hostname: discovery
microservice-provider-user:
  image: reg.itmuch.com/microservice-provider-user
  ports:
  - :
  links:
  - microservice-discovery-eureka
microservice-consumer-movie-ribbon-with-hystrix:
  image: reg.itmuch.com/microservice-consumer-movie-ribbon-with-hystrix
  ports:
  - :
  links:
  - microservice-discovery-eureka
microservice-hystrix-dashboard:
  image: reg.itmuch.com/microservice-hystrix-dashboard
  ports:
  - :
  links:
  - microservice-discovery-eureka
  - microservice-hystrix-turbine
microservice-hystrix-turbine:
  image: reg.itmuch.com/microservice-hystrix-turbine
  ports:
  - :
  links:
  - microservice-discovery-eureka
microservice-api-gateway:
  image: reg.itmuch.com/microservice-api-gateway
  ports:
  - :
  links:
  - microservice-discovery-eureka

相信经过前文多docker-compose.yml的讲解，大家已经能够看懂这个yaml文件了，简单讲解一下：

第一个段落：

microservice-discovery-eureka:                                    # 指定一个名词
  image: reg.itmuch.com/microservice-discovery-eureka            # 指定所使用的镜像
  ports:                                                        # 指定端口映射
  - :
  hostname: discovery                                            # 指定主机名

第二个段落：

microservice-hystrix-dashboard:
  image: reg.itmuch.com/microservice-hystrix-dashboard
  ports:
  - :
  links:
  - microservice-discovery-eureka                            # 表示连接到某个服务
  - microservice-hystrix-turbine

我们看到microservice-discovery-eureka 这个服务配置了hostname。为什么呢？

假设不配置，下文links 配置了microservice-discovery-eureka ，默认将会使用该名称访问。而在我们各个配置文件中配置了eureka.client.serviceUrl.defaultZone ，是http://discovery:8761/eureka/ ，所以要保持一致，为microservice-discovery-eureka 这个服务配置一下hostname。

启动测试与故障排查

我们在docker-compose.yml所在路径执行：

docker-compose up

即可启动容器，容器启动时，应用的大量报错暂且不管，后文会有详细的讲解。

我们发现容器启动后，我们按照如下表格，依次访问进行测试：

应用	地址	测试结果
microservice-discovery-eureka	http://192.168.11.143:8761/	正常
microservice-provider-user	http://192.168.11.143:8000/1	正常
microservice-consumer-movie-ribbon-with-hystrix	http://192.168.11.143:8011/ribbon/1	不正常	走了fallback
microservice-hystrix-turbine	http://192.168.11.143:8031/turbine.stream	不正常	一直ping
microservice-api-gateway	http://192.168.11.143:8050/movie/ribbon/1	不正常	500错误
microservice-hystrix-dashboard	http://192.168.11.143:8030/hystrix.stream	正常

发现测试到microservice-hystrix-turbine 开始发生异常，那么为什么会出现异常呢？

访问：[http://192.168.11.143:8011/ribbon/1](http://192.168.11.143:8011/ribbon/1) ，会看到日志：

microservice-hystrix-turbine_1                     | 2016-09-26 11:17:44.849  INFO 1 --- [        Timer-0] c.n.t.monitor.instance.InstanceMonitor   : Url for host: http://ribbon:8011/hystrix.stream default
microservice-hystrix-turbine_1                     | 2016-09-26 11:17:44.995  WARN 1 --- [InstanceMonitor] c.n.t.monitor.instance.InstanceMonitor   : Stopping InstanceMonitor for: ribbon default

好像知道了点什么……我们查看Eureka（ http://192.168.11.143:8761/）界面，发现microservice-consumer-movie-ribbon-with-hystrix 这个服务在注册中心登记的地址是http://ribbon:8011/info 。而此时microservice-consumer-movie-ribbon-with-hystrix 而这个应用并没有绑定主机名，试问要如何访问到呢？再回溯到启动的日志，我们发现其实这个应用连启动都没启动成功。

我们将docker-compose.yml修改一下，变为：

microservice-discovery-eureka:
  image: reg.itmuch.com/microservice-discovery-eureka
  ports:
  - :
  hostname: discovery
microservice-provider-user:
  image: reg.itmuch.com/microservice-provider-user
  ports:
  - :
  links:
  - microservice-discovery-eureka
microservice-consumer-movie-ribbon-with-hystrix:
  image: reg.itmuch.com/microservice-consumer-movie-ribbon-with-hystrix
  ports:
  - :
  links:
  - microservice-discovery-eureka
  hostname: ribbon
microservice-hystrix-dashboard:
  image: reg.itmuch.com/microservice-hystrix-dashboard
  ports:
  - :
  links:
  - microservice-discovery-eureka
  - microservice-hystrix-turbine
microservice-hystrix-turbine:
  image: reg.itmuch.com/microservice-hystrix-turbine
  ports:
  - :
  links:
  - microservice-discovery-eureka
  - microservice-consumer-movie-ribbon-with-hystrix
microservice-api-gateway:
  image: reg.itmuch.com/microservice-api-gateway
  ports:
  - :
  links:
  - microservice-discovery-eureka
  - microservice-consumer-movie-ribbon-with-hystrix

重新启动测试，发现一切正常了。