Docker应用中，为了达到高可用，可以做很多的web服务，保持服务的稳定性，在web的出口处是haproxy等负载应用。

命令：

在和yml文件的同文件下，执行任何的docker-pose的命令，否则是提示找不到文件的。

docker up -d 后台启动某个程序

他会根据.yml文件中的yml自动下载和构建，文中的dicker images是获取的dockerhub上线的资源，尝试过阿里云和dockercn，可能和环境问题，python2.7运行pip安装时报错。

docker-compose up --scale wordpress=20 -d

wordpress是你在yml中写的web程序，上面的含义是：

通过scale的方式创建wordpress 20台机器

docker-compose ps 查看是否创建成功

docker-compose stop 通知容器，但是保留数据

docker-compose start 启动容器

下面是示例：

示例一：

docker-compose+mysql+wordpress+dockercloud/haproxy

version: '3'services:wordpress:image: wordpressenvironment:WORDPRESS_DB_HOST: mysqlWORDPRESS_DB_PASSWORD: rootnetworks:- my-bridgemysql:image: mysqlenvironment:MYSQL_ROOT_PASSWORD: rootMYSQL_DATABASE: wordpressvolumes:- /home/mysql-data:/var/lib/mysqlnetworks:- my-bridgelb:image: dockercloud/haproxylinks:- wordpressports:- 8080:80volumes:- /var/run/docker.sock:/var/run/docker.sock networks:- my-bridge
volumes:mysql-data:networks:my-bridge:driver: bridge

实例二：

flask-redis

app.py

from flask import Flask
from redis import Redis
import os
import socketapp = Flask(__name__)
redis = Redis(host=os.environ.get('REDIS_HOST', '127.0.0.1'), port=6379)@app.route('/')
def hello():redis.incr('hits')return 'Hello Container World! I have been seen %s times and my hostname is %s.\n' % (redis.get('hits'),socket.gethostname())if __name__ == "__main__":app.run(host="0.0.0.0", port=5000, debug=True)

yml文件

version: "3"services:redis:image: redisweb:build:context: .dockerfile: Dockerfileports:- 8080:5000environment:REDIS_HOST: redis

Dockerfile

FROM python:2.7
LABEL maintaner="Peng Xiao xiaoquwl@gmail.com"
COPY . /app
WORKDIR /app
RUN pip install flask redis
EXPOSE 5000
CMD [ "python", "app.py" ]

示例三：

app.py

from flask import Flask
from redis import Redis
import os
import socketapp = Flask(__name__)
redis = Redis(host=os.environ.get('REDIS_HOST', '127.0.0.1'), port=6379)@app.route('/')
def hello():redis.incr('hits')return 'Hello Container World! I have been seen %s times and my hostname is %s.\n' % (redis.get('hits'),socket.gethostname())if __name__ == "__main__":app.run(host="0.0.0.0", port=80, debug=True)

Dockerfile

[root@docker-host lb-scale]# cat Dockerfile 
FROM python:2.7
LABEL maintaner="Peng Xiao xiaoquwl@gmail.com"
COPY . /app
WORKDIR /app
RUN pip install flask redis
EXPOSE 80
CMD [ "python", "app.py" ]

Dockerfile

version: "3"services:redis:image: redisweb:build:context: .dockerfile: Dockerfileenvironment:REDIS_HOST: redislb:image: dockercloud/haproxylinks:- webports:- 8080:80volumes:- /var/run/docker.sock:/var/run/docker.sock