docker进阶使用

Docker Compose

Docker Compose 进行批量容器编排，无需单独启动多个容器

安装

官网的安装

#官方下载
sudo curl -L "https://github.com/docker/compose/releases/download/1.26.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
#授权
chmod +x /usr/local/bin/docker-compose
# 加速下载
curl -L https://get.daocloud.io/docker/compose/releases/download/1.26.2/docker-compose-`uname -s`-`uname -m` > /usr/local/bin/docker-compose
#授权
chmod +x /usr/local/bin/docker-compose

Compose配置变写规则

官方文档

• docker-compose.yaml核心(三层)

#1、版本号
version: "3.9"
#2、服务名
services:
#可以通过dockerfile构建镜像
  web:
    build: .
    ports:
      - "5000:5000"
#可以通过官方镜像引用
  redis:
    image: "redis:alpine"
#3、其他配置 网络/卷、全局规则
volumes:
networks:
...

使用例子

• 官方文档的快速开始

  1、创建对应文件夹并进入

   mkdir composetest
   cd composetest
  

  2、编写app.py

  import time
  
  import redis
  from flask import Flask
  
  app = Flask(__name__)
  cache = redis.Redis(host='redis', port=6379)
  
  def get_hit_count():
      retries = 5
      while True:
          try:
              return cache.incr('hits')
          except redis.exceptions.ConnectionError as exc:
              if retries == 0:
                  raise exc
              retries -= 1
              time.sleep(0.5)
  
  @app.route('/')
  def hello():
      count = get_hit_count()
      return 'Hello World! I have been seen {} times.\n'.format(count)
  

  3、编写python需导入的包名的requirements.txt

  flask
  redis
  

  4、配置Dockerfile文件将app.py打包成镜像

  # syntax=docker/dockerfile:1
  FROM python:3.7-alpine
  #配置国内pip镜像源
  RUN echo -e http://mirrors.ustc.edu.cn/alpine/v3.7/main/ > /etc/apk/repositories
  WORKDIR /code
  ENV FLASK_APP=app.py
  ENV FLASK_RUN_HOST=0.0.0.0
  COPY requirements.txt requirements.txt
  RUN pip install -r requirements.txt
  EXPOSE 5000
  COPY . .
  CMD ["flask", "run"]
  

  5、编写docker-compose.yaml进行容器编排

  version: "3.9"
  services:
    web:
      build: .
      ports:
        - "5000:5000"
    redis:
      image: "redis:alpine"
  

  6、docker-compose up启动，docker-compose up -d 后台启动

• 使用docker-compose部署wp博客

  官方文档

  具体步骤同官方快速开始例子

  [root@localhost home]# mkdir my_wordpress
  [root@localhost home]# cd my_wordpress/
  [root@localhost my_wordpress]# vi docker-compose.yml
  [root@localhost my_wordpress]# vi docker-compose.yml
  

  version: '3.3'
  
  services:
     db:
       image: mysql:5.7
       volumes:
         - db_data:/var/lib/mysql
       restart: always
       environment:
         MYSQL_ROOT_PASSWORD: somewordpress
         MYSQL_DATABASE: wordpress
         MYSQL_USER: wordpress
         MYSQL_PASSWORD: wordpress
  
     wordpress:
       depends_on:
         - db
       image: wordpress:latest
       ports:
         - "8000:80"
       restart: always
       environment:
         WORDPRESS_DB_HOST: db:3306
         WORDPRESS_DB_USER: wordpress
         WORDPRESS_DB_PASSWORD: wordpress
         WORDPRESS_DB_NAME: wordpress
  volumes:
      db_data: {}
  

  docker-compose up