5. Docker Compose 安装使用

概况

Compose is a tool for defining and running multi-container Docker applications. With Compose, you use a Compose file to configure your application’s services. Then, using a single command, you create and start all the services from your configuration.

Using Compose is basically a three-step process.

1. Define your app’s environment with a Dockerfile so it can be reproduced anywhere.
2. Define the services that make up your app in docker-compose.yml so they can be run together in an isolated environment.
3. Lastly, run docker-compose up and Compose will start and run your entire app.

Docker Compose 是定义和运行多容器 Docker 应用的工具。何谓多容器？Gogs 应用需要gogs 和 mysql这两个容器。如果没有Compose 工具，就必须分别安装好Mysql镜像和Gogs镜像，再分别启动。Compose 工具提供了一种能力，一个命令就可以创建和启动Gogs 应用

参考网页： Docker Compose Overview

Docker Compose 的安装

前置条件

• 桌面操作系统： Win 10 64位家庭中文版
• 虚拟机软件 ： Oracle VirtualBox 5.1.6
• 虚拟机操作系统 ： CentOS Linux release 7.2.1511 (Core)
• Linux 内核 ： 3.10.0-327.36.2.el7.x86_64
• docker 安装版本：docker 1.12.2

安装过程
参考页面： Compose Install

1. 下载 docker-compose 并安装

[root@localhost ~]# curl -L https://github.com/docker/compose/releases/download/1.8.1/docker-compose-`uname -s`-`uname -m` > /usr/local/bin/docker-compose
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   600    0   600    0     0    363      0 --:--:--  0:00:01 --:--:--   363
  0 7798k    0 69186    0     0    304      0  7:17:50  0:03:47  7:14:03     0
[root@localhost ~]# chmod +x /usr/local/bin/docker-compose
[root@localhost ~]# ll /usr/local/bin/docker-compose
-rwxr-xr-x. 1 root root 7986086 10月 19 13:04 /usr/local/bin/docker-compose
[root@localhost ~]# docker-compose --version
docker-compose version 1.8.1, build 878cff1

2. 编写Docker Compose 服务配置文件 yml

[root@localhost ~]# mkdir compose
[root@localhost ~]# cd compose
[root@localhost compose]# vi docker-compose.yml
# mysql service
mydb:
    image: mysql:latest
    ports:
      - "13307:3306"
    environment:
      MYSQL_ROOT_PASSWORD: 123456
    volumes:
      - /opt/mydata2/:/var/lib/mysql
# gogs service
mygogs:
    image: gogs/gogs:latest
    ports:
      - "10033:22"
      - "10090:3000"
    volumes:
      - /var/gogs2/:/data
    links:
      - mydb
[root@localhost compose]# docker-compose up

3. 使用Compose 启动应用

[root@localhost compose]# docker-compose up
[root@localhost compose]# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                                            NAMES
07a5e03d6353        gogs/gogs:latest    "docker/start.sh /bin"   4 minutes ago       Up 4 minutes        0.0.0.0:10033->22/tcp, 0.0.0.0:10090->3000/tcp   compose_mygogs_1
fd10f315ad68        mysql:latest        "docker-entrypoint.sh"   4 minutes ago       Up 4 minutes        0.0.0.0:13307->3306/tcp                          compose_mydb_1

说明：

• 默认情况，docker-compose 会找当前目录下的 docker-compose.yml 文件，工程名使用目录名
• 所以 docker ps 看到的容器名称是[工程名]_[服务名]_1

4. docker-compose 命令参数

[root@localhost compose]# mv docker-compose.yml gogs_app.yml
[root@localhost compose]# ls
gogs_app.yml
[root@localhost compose]# docker-compose -f gogs_app.yml -p GogsApp up -d
Creating gogsapp_mydb_1
Creating gogsapp_mygogs_1
[root@localhost compose]# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED              STATUS              PORTS                                            NAMES
a5c85165cb29        gogs/gogs:latest    "docker/start.sh /bin"   About a minute ago   Up About a minute   0.0.0.0:10033->22/tcp, 0.0.0.0:10090->3000/tcp   gogsapp_mygogs_1
43e0a6d11c5a        mysql:latest        "docker-entrypoint.sh"   About a minute ago   Up About a minute   0.0.0.0:13307->3306/tcp                          gogsapp_mydb_1

命令 docker-compose -f gogs_app.yml -p GogsApp up -d 说明如下：

• -f gogs_app.yml 指定读取的 yml 文件
• -p GogsApp 指定工程名
• -d 指定是docker-compose 以后台进程的方式启动

5. Compose 配置文件格式有两个版本，推荐使用Version 2.0

here are two versions of the Compose file format:

• Version 1, the legacy format. This is specified by omitting a version key at the root of the YAML.
• Version 2, the recommended format. This is specified with a version: '2' entry at the root of the YAML.

我们把上述例子修改成版本2.0，然后演示了启动应用、列出容器、停止容器、启动容器、卸载应用

[root@localhost compose]# vi gogs_app.yml
# compose demo
version: '2'

services:
    # mysql service
    mydb:
        image: mysql:latest
        ports:
            - "13307:3306"
        environment:
            MYSQL_ROOT_PASSWORD: 123456
        volumes:
            - /opt/mydata2/:/var/lib/mysql
    # gogs service
    mygogs:
        image: gogs/gogs:latest
        ports:
            - "10033:22"
            - "10090:3000"
        volumes:
            - /var/gogs2/:/data
        links:
            - mydb
[root@localhost compose]# docker-compose -f gogs_app.yml -p gapp up -d
Creating network "gapp_default" with the default driver
Creating gapp_mydb_1
Creating gapp_mygogs_1
[root@localhost compose]# docker-compose -f gogs_app.yml -p gapp ps
    Name                   Command               State                       Ports
-------------------------------------------------------------------------------------------------------
gapp_mydb_1     docker-entrypoint.sh mysqld      Up      0.0.0.0:13307->3306/tcp
gapp_mygogs_1   docker/start.sh /bin/s6-sv ...   Up      0.0.0.0:10033->22/tcp, 0.0.0.0:10090->3000/tcp
[root@localhost compose]# docker-compose -f gogs_app.yml -p gapp stop
Stopping gapp_mygogs_1 ... done
Stopping gapp_mydb_1 ... done
[root@localhost compose]# docker-compose -f gogs_app.yml -p gapp start
Starting mydb ... done
Starting mygogs ... done
[root@localhost compose]# docker-compose -f gogs_app.yml -p gapp down
Stopping gapp_mygogs_1 ... done
Stopping gapp_mydb_1 ... done
Removing gapp_mygogs_1 ... done
Removing gapp_mydb_1 ... done
Removing network gapp_default

参考

Docker Compose 配置文件说明
Docker Compose Get Started
YAML 模板文件