8.使用Docker Compose管理多个容器

一个使用Docker容器的应用，通常由多个容器组成。使用Docker Compose，不再需要使用shell脚本来启动容器。在配置文件中，所有的容器通过 services 来定义，然后使用 docker-compose 脚本来启动，停止和重启应用，和应用中的服务以及所有依赖服务的容器。完整的命令列表如下：

8.1. 安装Docker Compose

curl -L https://github.com/docker/compose/releases/download/1.4.2/docker-compose-`uname -s`-`uname -m` > /usr/local/bin/docker-compose
 chmod  x /usr/local/bin/docker-compose

8.2. 配置文件

1.Compose的配置文件是 docker-compose.yml 。让我们看看下面这个文件：

mysqldb:
 image: [classroom.example.com:5000/]mysql
 environment:
 MYSQL_DATABASE: sample
 MYSQL_USER: mysql
 MYSQL_PASSWORD: mysql
 MYSQL_ROOT_PASSWORD: supersecret
 mywildfly:
 image: [classroom.example.com:5000|arungupta]/wildfly-mysql-javaee7
 links:
 - mysqldb:db
 ports:
 - 8080

这个文件在 https://raw.githubusercontent. ... dees/ ，它表明：

b. 使用 image 定义每个服务的镜像名

d. MySQL容器使用 links 和WildFly容器链接

e. 使用 ports 实现端口转发

8.3. 启动服务

1. 如果你从互联网运行，将 docker-compose-internet.yml 保存为 docker-compose.yml 。

1. 如果你使用教师给的镜像，将 docker-compose-instructor.yml 保存为 docker-compose.yml 。
2. 使用下面的命令，所有的服务将使用后台模式被启动
   

   docker-compose up -d
   

   显示的输出如下：
   Creating attendees_mysqldb_1...
Creating attendees_mywildfly_1...
   使用 -f 指定代替的compose文件。
   使用 -p 指定代替compose文件所在的目录。
3. 验证启动的服务
   

   docker-compose ps
    Name                       Command               State                Ports
    attendees_mysqldb_1     /entrypoint.sh mysqld            Up      3306/tcp
    attendees_mywildfly_1   /opt/jboss/wildfly/customi ...   Up      0.0.0.0:32773->8080/tcp
   

   这里提供了一个整合的列表显示所有启动的服务和容器。

同时，通常使用 docker ps 命令来验证应用的容器，和在Docker主机上运行的其他容器。

docker ps
 CONTAINER ID        IMAGE                                    COMMAND                CREATED             STATUS              PORTS                              NAMES
 3598e545bd2f        arungupta/wildfly-mysql-javaee7:latest   "/opt/jboss/wildfly/   59 seconds ago      Up 58 seconds       0.0.0.0:32773->8080/tcp         attendees_mywildfly_1
 b8cf6a3d518b        mysql:latest                             "/entrypoint.sh mysq   2 minutes ago       Up 2 minutes        3306/tcp                        attendees_mysqldb_1

1. 查询服务日志

   {{{

   taching to attendees_mywildfly_1, attendees_mysqldb_1

   mywildfly_1 | => Starting WildFly server

   mywildfly_1 | => Waiting for the server to boot

   mywildfly_1 | =========================================================================

   mywildfly_1 |

   mywildfly_1 | JBoss Bootstrap Environment

   mywildfly_1 |

   mywildfly_1 | JBOSS_HOME: /opt/jboss/wildfly

   mywildfly_1 |

   mywildfly_1 | JAVA: /usr/lib/jvm/java/bin/java

   mywildfly_1 |

   mywildfly_1 | JAVA_OPTS: -server -Xms64m -Xmx512m -XX:MaxPermSize=256m -Djava.net.preferIPv4Stack=true -Djboss.modules.system.pkgs=org.jboss.byteman -Djava.awt.headless=true

   mywildfly_1 |

. . .

mywildfly_1 | 15:40:20,866 INFO [org.jboss.resteasy.spi.ResteasyDeployment] (MSC service thread 1-2) Deploying javax.ws.rs.core.Application: class org.javaee7.samples.employees.MyApplication

mywildfly_1 | 15:40:20,914 INFO [org.wildfly.extension.undertow] (MSC service thread 1-2) JBAS017534: Registered web context: /employees

mywildfly_1 | 15:40:21,032 INFO [org.jboss.as.server] (ServerService Thread Pool -- 28) JBAS018559: Deployed "employees.war" (runtime-name : "employees.war")

mywildfly_1 | 15:40:21,077 INFO [org.jboss.as] (Controller Boot Thread) JBAS015961: Http management interface listening on http://127.0.0.1:9990/management

mywildfly_1 | 15:40:21,077 INFO [org.jboss.as] (Controller Boot Thread) JBAS015951: Admin console listening on http://127.0.0.1:9990

mywildfly_1 | 15:40:21,077 INFO [org.jboss.as] (Controller Boot Thread) JBAS015874: WildFly 8.2.0.Final "Tweek" started in 9572ms - Started 280 of 334 services (92 services are lazy, passive or on-demand)

mysqldb_1 | Running mysql_install_db

mysqldb_1 | 2015-06-05 15:38:31 0 [Note] /usr/sbin/mysqld (mysqld 5.6.25) starting as process 27 ...

mysqldb_1 | 2015-06-05 15:38:31 27 [Note] InnoDB: Using atomics to ref count buffer pool pages

. . .

mysqldb_1 | 2015-06-05 15:38:40 1 [Note] Event Scheduler: Loaded 0 events

mysqldb_1 | 2015-06-05 15:38:40 1 [Note] mysqld: ready for connections.

mysqldb_1 | Version: '5.6.25' socket: '/var/run/mysqld/mysqld.sock' port: 3306 MySQL Community Server (GPL)

mysqldb_1 | 2015-06-05 15:40:18 1 [Warning] IP address '172.17.0.24' could not be resolved: Name or service not known

}}}

8.4. 验证应用

1. 通过 http://dockerhost:32773/employ ... yees/ 访问应用。在浏览器里显示如下：

   > 使用 docker-compose ps 命令显示端口

   

8.5. 扩展服务

你能像这样扩展服务:

docker-compose scale mywildfly=4
 Creating and starting 2... done
 Creating and starting 3... done
 Creating and starting 4... done

检查日志：

docker-compose logs

检查运行的实例：

docker-compose ps

Name Command State Ports

rafael_mysqldb_1 /entrypoint.sh mysqld Up 3306/tcp

rafael_mywildfly_1 /opt/jboss/wildfly/customi ... Up 0.0.0.0:32773->8080/tcp

rafael_mywildfly_2 /opt/jboss/wildfly/customi ... Up 0.0.0.0:32777->8080/tcp

rafael_mywildfly_3 /opt/jboss/wildfly/customi ... Up 0.0.0.0:32780->8080/tcp

rafael_mywildfly_4 /opt/jboss/wildfly/customi ... Up 0.0.0.0:32781->8080/tcp

你也能减少运行的实例数目：

docker-compose scale mywildfly=2
 Stopping rafael_mywildfly_3... done
 Stopping rafael_mywildfly_4... done
 Removing rafael_mywildfly_3... done
 Removing rafael_mywildfly_4... done

8.6. 停止服务

停止服务：

docker-compose stop
 Stopping attendees_mywildfly_1...
 Stopping attendees_mywildfly_2...
 Stopping attendees_mysqldb_1...

wildfly_1 |
   wildfly_1 | 09:11:07,802 ERROR [org.jboss.as.controller.management-operation] (management-handler-thread - 4) JBAS014613: Operation ("add") failed - address: ([
   wildfly_1 |     ("subsystem" => "datasources"),
   wildfly_1 |     ("jdbc-driver" => "mysql")
   wildfly_1 | ]) - failure description: "JBAS014803: Duplicate resource [
   wildfly_1 |     (/"subsystem/" => /"datasources/"),
   wildfly_1 |     (/"jdbc-driver/" => /"mysql/")
   wildfly_1 | ]"

原文链接： Multiple Containers Using Docker Compose