单机容器编排工具之Docker Compose

Docker Compse介绍

当在宿主机启动较多的容器时候，如果每一个都要手动操作来启动的话会非常麻烦而且容易出错，
并且不同的容器互相配合使用的时候有一定的依赖关系，需要按一定的次序来启动才行。

每次启动容器前还得想一想先启动哪一个，这就更加麻烦了。而docker-compose正是用来解决这一问题的工具。

Docker Compose是docker容器的一种单机编排服务，docker-compose 是一个管理多个容器的工具，它有点类似于ansible-playbook命令，可以自动的批量执行容器操作，从而实现自动化的容器管理，使用提前写好的docker-compose.yml文件，按一定的次序来启动，删除，操作容器。

Docker Compose项目是Docker官方的开源项目，负责实现对Docker容器集群的快速编排，
docker-compose将所管理的容器分为三层，分别是工程（project），服务（service）以及容器（container）。Docker Compose运行目录下的所有文件（docker-compose.yml）组成一个工程,一个工程包含多个服务，每个服务中又定义了容器运行的镜像、参数、依赖，一个服务还可以包括多个容器实例。
Docker Compse官方地址

安装方法

• 方法1：pip安装

  • Ubuntu:

  [root@ubuntu2004:~]#apt update
  [root@ubuntu2004:~]#apt install -y python3-pip
  [root@ubuntu2004:~]#pip3 install docker-compose
  [root@ubuntu2004:~]# docker-compose --version
  docker-compose version 1.27.4, build unknown
  

  • Centos:

  # 需要提前配好epel源
  [root@centos8 ~]#dnf install -y python3-pip
  [root@centos8 ~]#pip3 install docker-compose
  

• 方法2：从github直接下载

  github下载链接

  比较推荐这种方法，可以自行选择版本。就是可能下载速度有点慢。

  [root@ubuntu2004:~]# curl -L https://github.com/docker/compose/releases/download/1.27.4/docker-compose-`uname -s`-`uname -m` -o /usr/local/bin/docker-compose
    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                   Dload  Upload   Total   Spent    Left  Speed
  100   651  100   651    0     0    179      0  0:00:03  0:00:03 --:--:--   179
  100 11.6M  100 11.6M    0     0   483k      0  0:00:24  0:00:24 --:--:--  171k
  [root@ubuntu2004:~]# chmod +x /usr/local/bin/docker-compose
  [root@ubuntu2004:~]# docker-compose --version
  docker-compose version 1.27.4, build 40524192
  

• 方法3：直接从包仓库下载

  仓库自带的版本比较旧，不是很推荐使用此种方法

  • Ubuntu:

  [root@ubuntu2004:~]#apt list docker-compose
  Listing... Done
  docker-compose/focal 1.25.0-1 all
  [root@ubuntu2004:~]#apt -y install docker-compose
  [root@ubuntu2004 ~]#docker-compose --version
  docker-compose version 1.25.0-1, build unknown
  

  • Centos:

  # 需要提前配好epel源
  #CentOS7安装，依赖EPEL源
  [root@centos7 ~]#yum -y install docker-compose
  [root@centos7 ~]#docker-compose --version
  docker-compose version 1.18.0, buil 8dd22a9
  
  #Centos8的epel仓库中目前还没有docker-compose包
  

docker-compose命令的使用

[root@ubuntu2004:~]# docker-compose --help
Define and run multi-container applications with Docker.

Usage:
  docker-compose [-f <arg>...] [options] [--] [COMMAND] [ARGS...]
  docker-compose -h|--help

Options:
  -f, --file FILE	      指定Compose文件，默认为当前目录下的docker-compose.yml
  -p, --project-name NAME     指定项目名称，默认将使用当前目录名称作为项目名
  -c, --context NAME          Specify a context name
  --verbose                   Show more output
  --log-level LEVEL           设置日志级别(DEBUG, INFO, WARNING, ERROR, CRITICAL)
  --no-ansi                   Do not print ANSI control characters
  -v, --version               Print version and exit
  -H, --host HOST             Daemon socket to connect to
...省略...

Commands:
  build              Build or rebuild services
  config             检查当前.yml文件配置，如果文件格式有错误则报错，没有错误则打印.yml信息
  create             Create services
  down               Stop and remove containers, networks, images, and volumes
  events             Receive real time events from containers
  exec               Execute a command in a running container
  help               Get help on a command
  images             List images
  kill               Kill containers
  logs               View output from containers
  pause              Pause services
  port               Print the public port for a port binding
  ps                 List containers
  pull               Pull service images
  push               Push service images
  restart            Restart services
  rm                 删除已停止的容器
  run                Run a one-off command
  scale              Set number of containers for a service
  start              启动容器服务
  stop               停止容器服务
  top                Display the running processes
  unpause            Unpause services
  up                 创建并启动容器
  version            Show version information and quit
  
  
# 还可以docker-compose 子命令 --help 查看更详细的帮助信息
[root@ubuntu2004:~]# docker-compose config --help
Validate and view the Compose file.

Usage: config [options]

Options:
    --resolve-image-digests  Pin image tags to digests.
    --no-interpolate         Don't interpolate environment variables.
    -q, --quiet              Only validate the configuration, don't print
                             anything.
    --services               Print the service names, one per line.
    --volumes                Print the volume names, one per line.
    --hash="*"               Print the service config hash, one per line.
                             Set "service1,service2" for a list of specified services
                             or use the wildcard symbol to display all services.

docker-compse.yml文件格式

官方文档

docker-compose文件的格式很多不同版本，版本不同，语法和格式有所不同。详见官方文档。

下面给出几个范例，演示版本为最新的3.9版本。

范例一：nginx

[root@ubuntu2004:/data/docker-compose]# cat docker-compose.yml
version: "3.9"
services:
    nginx1:
        image: nginx:alpine
        restart: always
        expose:
            - 80
        ports:
            - "8080:80"

# 检查.yml文件有没有错误 
[root@ubuntu2004:/data/docker-compose]# docker-compose config
services:
  nginx1:
    expose:
    - 80
    image: nginx:alpine
    ports:
    - published: 8080
      target: 80
    restart: always
version: '3.9'

# up是前台启动，一般会加上-d后台启动
[root@ubuntu2004:/data/docker-compose]# docker-compose up
Recreating docker-compose_nginx_1 ... done
Attaching to docker-compose_nginx_1
nginx1_1  | /docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration
nginx1_1  | /docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/
nginx1_1  | /docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh
nginx1_1  | 10-listen-on-ipv6-by-default.sh: Getting the checksum of /etc/nginx/conf.d/default.conf
nginx1_1  | 10-listen-on-ipv6-by-default.sh: Enabled listen on IPv6 in /etc/nginx/conf.d/default.conf
nginx1_1  | /docker-entrypoint.sh: Launching /docker-entrypoint.d/20-envsubst-on-templates.sh
nginx1_1  | /docker-entrypoint.sh: Configuration complete; ready for start up
^CGracefully stopping... (press Ctrl+C again to force)
Stopping docker-compose_nginx1_1 ... done

[root@ubuntu2004:/data/docker-compose]# docker-compose up -d
Starting docker-compose_nginx_1 ... done

# 查看容器已经启动了，并且可以访问
[root@ubuntu2004:/data/docker-compose]# docker-compose ps
         Name                       Command               State          Ports        
--------------------------------------------------------------------------------------
docker-compose_nginx1_1   /docker-entrypoint.sh ngin ...   Up      0.0.0.0:8080->80/tcp

[root@ubuntu2004:/data/docker-compose]# curl 10.0.0.202:8080
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
         35em;
        margin: 0 auto;
        font-family: Tahoma, Verdana, Arial, sans-serif;
    }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>

# 进入容器，类似于docker exec -it nginx sh
[root@ubuntu2004:/data/docker-compose]# docker-compose exec nginx1 sh
/ # ls
bin                   home                  proc                  sys
dev                   lib                   root                  tmp
docker-entrypoint.d   media                 run                   usr
docker-entrypoint.sh  mnt                   sbin                  var
etc                   opt                   srv

# docker-compose exec nginx1 sh这里使用的nginx1是.yml中的服务名称nginx1

# docker-compose停止所有容器
[root@ubuntu2004:/data/docker-compose]# docker-compose stop
Stopping docker-compose_nginx1_1 ... done

范例二：mysql

[root@ubuntu2004:/data/docker-compose]# cat docker-compose.yml 
version: "3.9"
services:
    db:
        image: mysql:5.7.32
        container_name: mysql1
        network_mode: "bridge"
        expose:
            - 3306
        ports:
            - "3306:3306"
        volumes:
            - /data/mysql:/var/lib/mysql
        #environment:
            #- MYSQL_ROOT_PASSWORD=744123
        env_file: env_mysql.list
        restart: always

# env文件的相对路径为.yml所在目录
[root@ubuntu2004:/data/docker-compose]# cat env_mysql.list 
MYSQL_ROOT_PASSWORD=744123

[root@ubuntu2004:/data/docker-compose]# docker-compose config
services:
  db:
    container_name: mysql1
    environment:
      MYSQL_ROOT_PASSWORD: '744123'
    expose:
    - 3306
    image: mysql:5.7.32
    network_mode: bridge
    ports:
    - published: 3306
      target: 3306
    restart: always
    volumes:
    - /data/mysql:/var/lib/mysql:rw
version: '3.9'

# 这里我们把docker-compose.yml改名为mysql.yml，并切换目录然后试着使用docker-compose -f命令来启动容器
[root@ubuntu2004:/data/docker-compose]# ls
docker-compose.yml  env_mysql.list
[root@ubuntu2004:/data/docker-compose]# cp docker-compose.yml mysql.yml
[root@ubuntu2004:/data/docker-compose]# ls
docker-compose.yml  env_mysql.list  mysql.yml
[root@ubuntu2004:/data/docker-compose]# cd
[root@ubuntu2004:~]# 
[root@ubuntu2004:~]# docker-compose -f /data/docker-compose/mysql.yml up -d
Creating mysql1 ... done

# 使用docker ps命令查看，没问题，启动成功了并且端口和名称都和我们指定的一样
[root@ubuntu2004:~]# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                               NAMES
800990401cc8        mysql:5.7.32        "docker-entrypoint.s…"   2 minutes ago       Up 2 minutes        0.0.0.0:3306->3306/tcp, 33060/tcp   mysql1

# 但是使用docker-compose ps好像失败了
[root@ubuntu2004:~]# docker-compose ps
ERROR: 
        Can't find a suitable configuration file in this directory or any
        parent. Are you in the right directory?

        Supported filenames: docker-compose.yml, docker-compose.yaml
        
# 我们切回到.yml目录再次执行下docker-compose ps命令
[root@ubuntu2004:~]# cd /data/docker-compose/
[root@ubuntu2004:/data/docker-compose]# docker-compose ps
 Name              Command             State                 Ports              
--------------------------------------------------------------------------------
mysql1   docker-entrypoint.sh mysqld   Up      0.0.0.0:3306->3306/tcp, 33060/tcp

# 居然没问题了，是不是很神奇，所以最好一般还是不要修改默认的docker-compose.yml文件名，也不要切出去目录执行docker-compose命令，否则可能会有很多莫名其妙的问题

范例三：Wordpress + Mysql 快速搭建博客网站

# mysql配置文件
[root@ubuntu2004:/data/docker-compose]# cat /data/mysql_conf/mysql_test.cnf 
[mysqld]
server-id=201
log-bin=mysql-bin

# mysql环境变量，创建一个数据库和用户
[root@ubuntu2004:/data/docker-compose]# cat /data/docker-compose/env_mysql.list 
MYSQL_ROOT_PASSWORD=744123
MYSQL_DATABASE=wordpress
MYSQL_USER=wpuser
MYSQL_PASSWORD=123456

# wordpress环境变量，指定数据库相关信息
[root@ubuntu2004:/data/docker-compose]# cat /data/docker-compose/env_wordpress.list 
WORDPRESS_DB_HOST=mysql:3306			<<== 这里使用容器名称来代替IP
WORDPRESS_DB_NAME=wordpress
WORDPRESS_DB_USER=wpuser
WORDPRESS_DB_PASSWORD=123456
WORDPRESS_TABLE_PREFIX=wp_

# compose文件
[root@ubuntu2004:/data/docker-compose]# cat docker-compose.yml 
version: "3.9"
services:
    db:
        image: mysql:5.7.32
        container_name: mysql
        expose:
            - 3306
        ports:
            - "3306:3306"
        volumes:
            - /data/mysql/:/var/lib/mysql/
            - /data/mysql_conf/:/etc/mysql/conf.d/
        env_file: env_mysql.list
        restart: always

    wordpress:
        image: wordpress
        container_name: wordpress
        ports:
            - 80:80
        volumes:
            - /data/wp_html/:/var/www/html/
        env_file: env_wordpress.list
        links:
            - "db:mysql"
        restart: always
        
[root@ubuntu2004:/data/docker-compose]# docker-compose config
services:
  db:
    container_name: mysql
    environment:
      MYSQL_DATABASE: wordpress
      MYSQL_PASSWORD: '123456'
      MYSQL_ROOT_PASSWORD: '744123'
      MYSQL_USER: wpuser
    expose:
    - 3306
    image: mysql:5.7.32
    ports:
    - published: 3306
      target: 3306
    restart: always
    volumes:
    - /data/mysql:/var/lib/mysql:rw
    - /data/mysql_conf:/etc/mysql/conf.d:rw
  wordpress:
    container_name: wordpress
    environment:
      WORDPRESS_DB_HOST: mysql:3306
      WORDPRESS_DB_NAME: wordpress
      WORDPRESS_DB_PASSWORD: '123456'
      WORDPRESS_DB_USRE: wpuser
      WORDPRESS_TABLE_PREFIX: wp_
    image: wordpress
    links:
    - db:mysql
    ports:
    - published: 80
      target: 80
    restart: always
    volumes:
    - /data/wp_html:/var/www/html:rw
version: '3.9'
       
# 使用docker-compose启动服务
[root@ubuntu2004:/data/docker-compose]# docker-compose up -d
Creating network "docker-compose_default" with the default driver
Pulling wordpress (wordpress:)...
latest: Pulling from library/wordpress
852e50cd189d: Already exists
0266fc315b01: Pull complete
4c8a5fa787a1: Pull complete
46fc127c1884: Pull complete
f768b7fadf16: Pull complete
345b578c1a78: Pull complete
90aafe41e78d: Pull complete
af01fae4e5fc: Pull complete
9e463236c8bc: Pull complete
cd12b0a220f2: Pull complete
d9f76220cef4: Pull complete
c09cf9a96ea9: Pull complete
6dda8bec068c: Pull complete
fd36a10c28fe: Pull complete
e11e483ab28e: Pull complete
ab40cb22800e: Pull complete
b08636db59dd: Pull complete
d2c7678bc02b: Pull complete
f903e014412a: Pull complete
114ff1eb7cb0: Pull complete
Digest: sha256:92e97d9b3147038e3cc541a224cc951bef597061827e23a208a24c36bff1c1fe
Status: Downloaded newer image for wordpress:latest
Creating mysql     ... done
Creating wordpress ... done

# 查看端口，发现80端口已经打开了
[root@ubuntu2004:/data/docker-compose]# ss -nlt
State     Recv-Q    Send-Q       Local Address:Port       Peer Address:Port   Process    
LISTEN    0         4096         127.0.0.53%lo:53              0.0.0.0:*                 
LISTEN    0         128                0.0.0.0:22              0.0.0.0:*                 
LISTEN    0         128              127.0.0.1:6010            0.0.0.0:*                 
LISTEN    0         128              127.0.0.1:6011            0.0.0.0:*                 
LISTEN    0         4096               0.0.0.0:111             0.0.0.0:*                 
LISTEN    0         128                   [::]:22                 [::]:*                 
LISTEN    0         128                  [::1]:6010               [::]:*                 
LISTEN    0         128                  [::1]:6011               [::]:*                 
LISTEN    0         4096                     *:3306                  *:*                 
LISTEN    0         4096                  [::]:111                [::]:*                 
LISTEN    0         4096                     *:80                    *:*         

web端测试访问一下，哎，成功了。

稍加设置，一个wordpress博客就这样简单的搭好了！是不是很轻松愉快啊@_@ ~