Docker Compose

Compose的使用步骤

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. Run docker compose up and the Docker compose command starts and runs your entire app. You can alternatively run docker-compose up using the docker-compose binary.

version: "3.9"  # optional since v1.27.0
services:
  web:
    build: .
    ports:
      - "5000:5000"
    volumes:
      - .:/code
      - logvolume01:/var/log
    links:
      - redis
  redis:
    image: redis
volumes:
  logvolume01: {}

安装

# 1.下载
# 官网提供 （没有下载成功）
curl -L "https://github.com/docker/compose/releases/download/1.26.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
 
# 国内地址
curl -L https://get.daocloud.io/docker/compose/releases/download/1.25.5/docker-compose-`uname -s`-`uname -m` > /usr/local/bin/docker-compose

# 2.授权
chmod +x /usr/local/bin/docker-compose

# 3.查看版本
[root@iz8vbd1ko98b0el6771a37z bin]# docker-compose version
docker-compose version 1.25.5, build 8a1c60f6
docker-py version: 4.1.0
CPython version: 3.7.5
OpenSSL version: OpenSSL 1.1.0l  10 Sep 2019

体验

1. 创建项目目录

[root@iz8vbd1ko98b0el6771a37z ~]# mkdir composetest
[root@iz8vbd1ko98b0el6771a37z ~]#  cd composetest

2. 创建应用文件app.py

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. 创建requirements.txt

flask
redis

4. 编写Dockerfile,将app.py应用打包为精细

# syntax=docker/dockerfile:1
FROM python:3.7-alpine
WORKDIR /code
ENV FLASK_APP=app.py
ENV FLASK_RUN_HOST=0.0.0.0
RUN apk add --no-cache gcc musl-dev linux-headers
COPY requirements.txt requirements.txt
RUN pip install -r requirements.txt
EXPOSE 5000
COPY . .
CMD ["flask", "run"]

5. 编写docker-compose.yml文件，定义整个服务，需要的环境。web、redis

version: "3.3"
services:
  web:
    build: .
    ports:
      - "5000:5000"
  redis:
    image: "redis:alpine"

6. 启动compose项目

[root@iz8vbd1ko98b0el6771a37z ~]#  docker-compose up

流程

1. 创建网络
   Creating network "composetest_default" with the default driver
2. 执行Docker-compose.yml
3. 启动服务

Creating composetest_redis_1 ... done
Creating composetest_web_1   ... done

yaml规则

version: "2.4" # 版本
services:        # 服务
  服务1：web
  images
  build
  network
  ......
  服务2：redis
  images
  build
  network
  ......
# 其他配置
volumes:
netowrks:
configs: