14. Docker Compose 编排微服务

淩亂°似流年 2023-07-05 13:22 3阅读 0赞

# Docker Compose 编排微服务 #

Compose 定义和运行多容器Docker应用程序的工具，前身是Fig。

构建CI工作流

本书用 1.10.0

curl -L https://get.daocloud.io/docker/compose/releases/download/1.22.0/docker-compose-`uname -s`-`uname -m` > /usr/local/bin/docker-compose
    
    chmod +x /usr/local/bin/docker-compose

curl -L https://raw.githubusercontent.com/docker/compose/$(docker-compose version --short)/contrib/completion/bash/docker-compose -o /etc/bash_completion.d/docker-compose
    
     docker-compose s
    scale  start  stop

### Dockerfile ###

FROM java:8
    VOLUME /tmp #本地文件夹挂载到当前容器
    # 复制文件到容器
    ADD microservice-discovery-eureka-0.0.1-SNAPSHOT.jar app.jar
    RUN bash -c 'touch /app.jar'
    EXPOSE 8761 # 声明需要暴露的端口
    ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"] # 配置容器启动后执行的命令，java -jar /app.jar

### docker-compose.yml ###

在docker-compose.yml定义组成应用程序的服务

version: '2'
    services:
      microservice-discovery-eureka:                                  # 指定服务名称
        image: itmuch/microservice-discovery-eureka:0.0.1-SNAPSHOT    # 指定服务所使用的镜像
        ports:                                                        # 暴露端口信息
          - "8761:8761"

> docker-compose up 自动构建并使用镜像启动容器
> 
> docker-compose up -d 后台运行

http://宿主机ip:8761/ 访问

# 工程，服务，容器 #

compose

vt. 构成；写作；使平静；排…的版

vi. 组成；作曲；排字

分为3层： project 工程，service 服务，container 容器

## docker-compose.yml 常用指令 ##

Version 2.x 已经 Version 3.x

*  build
    
     *  build: ./dir 一个路径
     *  或者一个对象
        
            build：
            	context：./dir
            	dockerfile: Dockerfile-alternate
            	args:
            		buildno: 1
 *  command
    
     *  command: bundle exec this -p 3000
     *  command: \[bundle,exec,this,-p,3000\]
 *  dns
    
     *  dns服务器
     *  dns: 8.8.8.8
        
            dns: 
             - 8.8.8.8
             - 8.8.8.8
 *  dns\_search dns的搜索域
    
     *  dns\_search : example.com 也可以像dns一样
        
            dns_search: 
             - dc1.example.com
             - dc2.example.com
 *  environment 环境变量设置
    
     可使用数字和字典
    
        environment:
        	RACK_ENV: development
        	SHOW: 'true'
        	SESSION_SECRET:
        environment:
         - RACK_ENV=development
         - SHOW='true'
         - SESSION_SECRET=
 *  env\_file
    
     *  从文件中获取环境变量
     *  docker-compose -f FILE指定了文件
        
            env_file: .env
            env_file:
             - ./common.env
             - ./apps/web.env
             - ./opt/secrets.env
 *  expose 端口暴露给链接的服务，而不是宿主机
    
        expose:
         - "3000"
         - "8000"
 *  external\_links
    
     *  连接到docker-compose.yml 外部的容器。公共服务器的容器
        
            external_LINKS:
             - redis_1
             - project_db_1:mysql
 *  image
    
     *  image : java
 *  links
    
     *  连接到服务器的的， 服务器别名（SERVICE：ALIAS）
        
            web：
             links:
              - db
              - db:database
              - redis
 *  networks
 *  networks\_mode 网络模式
    
        network_mode: "bridge"
        还有： host none service:[service name] container:[container name/id]
 *  ports
    
     *  端口暴露 HOSST:CONTAINER ,类似 docker run -p
     *  小于60将会得到错误端口，使用字符串
        
            ports:
             - "3000"
             - "3000-3005"
             - "8000:8000"
             - "3000-3005:3000-3005"
             - "49100:22"
             - "127.0.0.1:8001:8001"
             - "127.0.0.1:3000-3005:3000-3005"
 *  volumes
    
     *  卷挂在路径设置
     *  宿主机路径 HOST：CONTAINER ,指定访问模式 （HOST:CONTAINER:ro)
    
        volumes:
        	- /var/lib/mysql
        	- /opt/data:/var/lib/mysql
        	- ./cache:/tmp/cache
        	- ~/configs:/etc/configs:ro
        	- datavolume:/var/lib/mysql
 *  volumes\_from 另一个服务或容器挂在卷
    
     *  只读 ro，读写 rw ,默认为读写
        
            volumes_from:
             - service_name
             - service_name:ro
             - container:container_name:rw

# docker-compose常用命令 #

*  build
 *  help
    
     *  docker-compose help COMMAND
 *  kill
    
     *  docker-compose kill eureka
     *  docker-compose kill -s SIGINT
 *  logs
 *  port
    
     *  docker-compose port eureka 8761 打印eureka 服务8761端口的公共端口
 *  ps
    
     *  docker-compose ps
     *  docker-compose ps eureka
 *  pull
 *  rm
    
     *  docker-compose rm eureka
 *  run
    
     *  docker-compose run web bash
 *  scale
    
     *  设置指定运行服务器的个数 service=num
     *  docker-compose scale user=3 movice=3
 *  start
    
     *  docker-compose start eureka
 *  stop 停止后，可再次启动
 *  up
    
     *  docker-compose up 聚合所有容器的输出，当命令退出，所有容器都会停止
     *  docker-compose up -d 后台

# Docker Compose 网络设置 #

version: '2'
    service:
    	web:
    		build: .
    		ports:
    			-"8000:8000"
    	db:
    		image:postgres

一个应用程序在myapp的目录中，docker-compose.yml如上

创建 myapp\_default网络

使用web配置的，以 web名字加入这个网络。 db配置用，db名字加入

可使用web或db作为hostname访问

web可以用： postgres://db:5432 访问db

## 更新容器 ##

用docker-compose up 更新

version: '2'
    service:
    	web:
    		build: .
    		links:
    			- "db:database"
    	db:
    		image:postgres

这样web就可使用db或者database访问 db服务了

## 自定义网络 ##

如配置各个网络隔离，中间一个网络可以和其他都进行通信

version: "2"
    service:
    	proxy:
    		build: ./proxy
    		networks:
    			- front
    	app:
    		build: ./app
    		networks:
    			- front
                - back
     	db:
    		build: ./db
    		networks:
                - back
    networks:
    	front:
    		driver:custom-driver-1
    	back:
    		driver:custom-driver-2	
    		driver_opts:
    			foo:"1"
    			bar:"2"

proxy 和 db不通。 app都通

### 默认网络 ###

version: '2'
    service:
    	web:
    		build: .
    		port：
    			- "8000:8000"
    	db:
    		image:postgres
    networks:
    	default:
    		driver:custome-driver-1

### 指定已经存在的网络 ###

networks:
    	default:
    		external:
    			name: my-pre-existing-network

# 综合实战 #

抽取maven父类：添加

<modules>
        <module>microservice-consumer-movie-ribbon-hystrix</module>
    	<module>microservice-discovery-eureka</module>
    	<module>microservice-gateway-zuul</module>
    	<module>microservice-hystrix-dashboard</module>
    	<module>microservice-hystrix-turbine</module>
    	<module>microservice-provider-user</module>
      </modules>

<plugins>
          
          <plugin>
            <groupId>com.spotify</groupId>
            <artifactId>docker-maven-plugin</artifactId>
            <version>0.4.13</version>
            <configuration>
              <imageName>itmuch/${project.artifactId}:${project.version}</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>

docker 默认的网络模式为 bridge，各个容器的ip都不相同

配置eureka的主机名

eureka:
      client:
        serviceUrl:
          defaultZone: http://discovery:8761/eureka/
      instance:
        prefer-ip-address: true

执行：

> mvn clean package docker:build

编写： docker-compose.yml

同一个compose工程的所有服务共享一个隔离网络，可使用服务名字发现其他网络。

version: '3'
    services:
      discovery:
        image: itmuch/microservice-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
    
    # 最简单的配置方式，等价于docker-compose.yml。

复杂的写法： 后面代码，作者使用3了

version: '3'        # 表示该docker-compose.yml文件使用的是Version 2 file format
    services:           # Version 2 file format的固定写法，为project定义服务。
      microservice-discovery-eureka:                                  # 指定服务名称
        image: itmuch/microservice-discovery-eureka:0.0.1-SNAPSHOT    # 指定服务所使用的镜像
        ports:                                                        # 暴露端口信息
          - "8761:8761"
      microservice-provider-user:
        image: itmuch/microservice-provider-user:0.0.1-SNAPSHOT
        links:          # 链接到microservice-discovery-eureka，这边使用的是SERVICE:ALIAS的形式
          - microservice-discovery-eureka:discovery
      microservice-consumer-movie-ribbon-hystrix:
        image: itmuch/microservice-consumer-movie-ribbon-hystrix:0.0.1-SNAPSHOT
        links: 
          - microservice-discovery-eureka:discovery
      microservice-gateway-zuul:
        image: itmuch/microservice-gateway-zuul:0.0.1-SNAPSHOT
        links: 
          - microservice-discovery-eureka:discovery
      microservice-hystrix-dashboard:
        image: itmuch/microservice-hystrix-dashboard:0.0.1-SNAPSHOT
        links: 
          - microservice-discovery-eureka:discovery
      microservice-hystrix-turbine:
        image: itmuch/microservice-hystrix-turbine:0.0.1-SNAPSHOT
        links: 
          - microservice-discovery-eureka:discovery

# 高可用的 eureka #

> mvn clean package docker:build

version: "3"            # 表示使用docker-compose.yml的Version 3 file format编写
    services:
      microservice-discovery-eureka-ha1:
        hostname: peer1             # 指定hostname
        image: itmuch/microservice-discovery-eureka-ha:0.0.1-SNAPSHOT
        links:
          - microservice-discovery-eureka-ha2
        ports:
          - "8761:8761"
        environment:
          - spring.profiles.active=peer1
      microservice-discovery-eureka-ha2:
        hostname: peer2
        image: itmuch/microservice-discovery-eureka-ha:0.0.1-SNAPSHOT
        links:
          - microservice-discovery-eureka-ha1
        ports:
          - "8762:8762"
        environment:
          - spring.profiles.active=peer2
          
    ## 该文件是最自然的写法，但无法正常使用。运行docker-compose up时，会报循环依赖的异常。

解决循环依赖

version: "3"
    services:
      peer1:      # 默认情况下，其他服务可使用服务名称连接到该服务。对于peer2节点，它需连接http://peer1:8761/eureka/，因此，我们可配置该服务的名称为peer1。
        image: itmuch/microservice-discovery-eureka-ha:0.0.1-SNAPSHOT
        ports:
          - "8761:8761"
        environment:
          - spring.profiles.active=peer1
      peer2:
        image: itmuch/microservice-discovery-eureka-ha:0.0.1-SNAPSHOT
        hostname: peer2
        ports:
          - "8762:8762"
        environment:
          - spring.profiles.active=peer2
    
    ## 使用Compose编排高可用的Eureka Server。

> docker-compose up

## 编排高可用 cloud微服务，集群 和动态伸缩 ##

eureka:
      client:
        serviceUrl:
          defaultZone: http://peer1:8761/eureka/,http://peer2:8762/eureka/
      instance:
        prefer-ip-address: true

> mvn clean package docker:build

version: "3"
    services:
      peer1:
        image: itmuch/microservice-discovery-eureka-ha:0.0.1-SNAPSHOT
        ports:
          - "8761:8761"
        environment:
          - spring.profiles.active=peer1
      peer2:
        image: itmuch/microservice-discovery-eureka-ha:0.0.1-SNAPSHOT
        hostname: peer2
        ports:
          - "8762:8762"
        environment:
          - 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-turbine:
        image: itmuch/microservice-hystrix-turbine:0.0.1-SNAPSHOT

> docker-compose up

为微服务扩容,出了eureka server以外的

> docker-compose scale microservice-provider-user=3 microservice-consumer-movie-ribbon-hystrix=3
> 
> …