使用Docker Compose编排Spring Cloud微服务
微服务项目名称 | 项目微服务中的角色 |
---|---|
microservice-discovery-eureka | 服务发现组件 |
microservice-provider-user | 服务提供者 |
microservice-consumer-movie-ribbon-hystrix | 服务消费者 |
microservice-gateway-zuul | API Gateway |
microservice-hystrix-turbine | Hystrix聚合监控工具 |
microservice-hystrix-dashboard | Hystrix监控界面 |
微服务构建实例
1:使用Maven插件构建镜像,在各个项目的pom.xml中添加以下内容。
<!-- 添加docker-maven插件 -->
<plugin>
<groupId>com.sptify</groupId>
<artifactId>docker-maven-plugin</artifactId>
<version>0.4.13</version>
<configuration>
<imageName>itmuch/${project.artifactId}:${project.version}</imageName>
<forceTages>true</forceTages>
<baseImage>java</baseImage>
<entryPoint>["java","-jar","/${project.build.finalName}.jar"]</entryPoint>
<resoureces>
<resourece>
<targetPath>/</targetPath>
<directory>${project.build.directory}</directory>
<include>${project.build.finalName}.jar</include>
</resource>
</resources>
</configuration>
</plugin>
由配置可知,构建出来的镜像名称是itmuch/各个微服务的artifactId:各个微服务的版本,例如:microservice-discovery-eureka:0.0.1-SNAPSHOT。
2:为Eureka Server所在容器配置一个主机名(如discover),并让各个微服务使用主机名访问Eureka Server。
将所有微服务eureka.client.serviceUrl.defaultZone修改为如下内容:
eureka:
client:
serviceUrl:
defaultZone:http://discovery:8761/eureka/
3:在每个项目的根目录执行以下命令,构建Docker镜像。
mvn clean package docker:build
4:编写docker-compose.yml
version: '3'
#Version 2 file format的固定写法,为project定义服务
services:
#指定服务名称
microservice-discovery-eureka:
#指定服务所使用的镜像
image: itmuch/microservice-discovery-eureka:0.0.1-SNAPSHOT
#暴露端口信息
ports:
- "8761:8761"
microservice-provider-user:
image: itmuch/microservice-provider-user:0.0.1-SNAPSHOT
#连接到microservice-discovery-eureka,这边使用的是SERVICE:ALIAS的形式
links:
- microservice-disvoery-eureka:discovery
-
microservice-consumer-movie-ribbon-hystrix:
image: itmuch/microservice-consumer-movie-ribbon-hystrix:0.0.1-SNAPSHOT
links:
- microservice-disvoery-eureka:discovery
microservice-gateway-zuul:
image: itmuch/microservice-gateway-zuul:0.0.1-SNAPSHOT
links:
- microservice-disvoery-eureka:discovery
microservice-hystrix-dashboard:
image: itmuch/microservice-hystrix-dashboard:0.0.1-SNAPSHOT
links:
- microservice-disvoery-eureka:discovery
microservice-hystrix-turbine:
image: itmuch/microservice-hystrix-turbine:0.0.1-SNAPSHOT
links:
- microservice-disvoery-eureka:discovery
测试,执行docker-compose up启动项目,即可看到Eureka Server上的微服务列表服务发布成功。
简化Compose的编写
同一个Compose工程中的所有服务共享一个隔离网络,可使用服务名称作为主机名来发现其他服务。
因此,将docker-compose.yml简化:
version: '2'
services:
discovery:
image: itmuch/discovery-eureka:0.0.1-SNAPSHOT
ports:
- "8761:8761"
microservice-provider-user:
image: itmuch/microservice-provider-user:0.0.1-SNAPSHOT
microservice-consumer-movie-ribbon-hystrix:
image: itmuch/microservice-consumer-movie-ribbon-hystrix:0.0.1-SNAPSHOT
microservice-gateway-zuul:
image: itmuch/microservice-gateway-zuul:0.0.1-SNAPSHOT
microservice-hystrix-dashboard:
image: itmuch/microservice-hystrix-dashboard:0.0.1-SNAPSHOT
microservice-hystrix-turbine:
image: itmuch/microservice-hystrix-turbine:0.0.1-SNAPSHOT
编排高可用的Eureka Server
使用Compose编排Eureka Server集群。
1.执行以下命令构建Dokcer镜像。
mvn clean package docker:build
2.编写docker-compose.yml
version: '3'
services:
microservice-discovery-eureka-ha1:
hostname: peer1 #指定hostname
image: itmuch/discovery=eureka-ha:0.0.1:SNAPSHOT
links:
- discovery-eureka-ha2
ports:
- "8761:8761"
environment:
- spring.profiles.active=peer1
microservice-discovery-eureka-ha2:
hostname: peer2 #指定hostname
image: itmuch/discovery=eureka-ha:0.0.1:SNAPSHOT
links:
- discovery-eureka-ha1
ports:
- "8762:8762"
environment:
- spring.profiles.active=peer2
3.执行以下命令启动项目。
docker-compose up
但是,这样并不会成功,终端会输出异常。
因为存在循环依赖,links无法实现双向连接。
如何解决呢? 例如使用 ambassador pattern,使用外部DNS容器等。
编排高可用Spring Cloud微服务集群及动态伸缩
微服务项目名称 | 项目微服务中的角色 |
---|---|
microservice-discovery-eureka-ha | 服务发现组件 |
microservice-provider-user | 服务提供者 |
microservice-consumer-movie-ribbon-hystrix | 服务消费者 |
microservice-gateway-zuul | API Gateway |
microservice-hystrix-turbine | Hystrix聚合监控工具 |
microservice-hystrix-dashboard | Hystrix监控界面 |
1.由于使用了microservice-discovery-eureka-ha,需要将所有的微服务eureka.client.serviceUrl.defaultZone属性修改为如下内容:
eureka:
client:
service-url:
defaultZone: http://peer1:8761/eureka/,http://peer2:8762/eureka/
2.在每个项目的根目录,执行以下命令创建Docker镜像。
mvn clean package docker:build
3.编写docker-compose.yml
version: "2"
services:
peer1:
image: itemuch/microservice-discovery-eureka-ha:0.0.1-SNAPSHOT
ports:
- "8761:8761"
enviroment:
- spring.profiles.active=peer1
peer2:
image: itemuch/microservice-discovery-eureka-ha:0.0.1-SNAPSHOT
hostname: peer2
ports:
- "8761:8761"
enviroment:
- spring.profiles.active=peer2
microservice-provider-user:
image: itmuch/microservice-provider-user:0.0.1-SNAPSHOT
microservice-consumer-movie-ribbon-hystrix:
image: itmuch/microservice-consumer-movie-ribbon-hystrix:0.0.1-SNAPSHOT
microservice-gateway-zuul:
image: itmuch/microservice-gateway-zuul:0.0.1-SNAPSHOT
microservice-hystrix-dashboard:
image: itmuch/microservice-hystrix-dashboard:0.0.1-SNAPSHOT
microservice-hystrix-turbine:
image: itmuch/microservice-hystrix-turbine:0.0.1-SNAPSHOT
测试,执行docker-compose up启动项目。
然后可以在Eureka Server看到微服务列表。
执行以下命令,为各个微服务动态扩容,让除Eureka Server以外的所有微服务都启动3个实例。
docker-compose scale microservice-provider-user=3 microservice-consumer-movie-ribbon-hystrix=3 microservice-gateway-zuul=3
microservice-hystrix-turbine=3