docker-单机多容器的编排-compose
docker-compose是定义和运行多容器Docker应用程序的工具。我们可以把特定的几个容器组合起来构建成一个应用向下图一样。看上去有点像我们以前用过的saltstack的使用方式一样，同样compose使用yaml语法，通过这种方式我们可以把就像单机版本(docker版)saltstack.compose也可以yml文件为管理单位进行项目管理。现在大家是不是很感兴趣啊。[*]composer安装
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yum-config-manager
--add-repohttps://docs.docker.com/engine/installation/linux/repo_files/centos/docker.repo
yum -y install
docker-engine
centos7下面直接用pip install docker-compose
第一步创建一个自己的Dockerfile
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$ mkdir composetest
$ cd composetest
$ cat app.py
from flask import
Flask
from redis import
Redis
app =
Flask(__name__)
redis =
Redis(host='redis', port=6379)
@app.route('/')
def hello():
count = redis.incr('hits')
return 'Hello World! I have been seen {}
times.\n'.format(count)
if __name__ ==
"__main__":
app.run(host="0.0.0.0",
debug=True)
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[iyunv@salt-node1
composetest]# cat requirements.txt
flask
redis
创建一个dockerfile依赖于 python3.4添加本地文件到容器，工作目录当前目录下的code，安装flask和redis'插件，启动flask的一个小app
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[iyunv@salt-node1
composetest]# cat Dockerfile
FROM
python:3.4-alpine
ADD . /code
WORKDIR /code
RUN pip install -r
requirements.txt
CMD
["python", "app.py"]
第二部写一个docker-compose.yml配置文件，注意名字不要写错。本services总需要两个镜像分别是当前Dockerfile编译出的镜像和远程redis镜像，web当前目录下构建出的镜像web自动映射端口月5000，挂载当前目录到镜像内的code目录redis：直接拉取远程镜像并启动注意：因为docker非默认网络可以自动解析容器名到对应容器，所以直接使用“redis”就可以访问到启动的redis容器。
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version: '2'
services:
web:
build: .
ports:
- "5000:5000"
volumes:
- .:/code
redis:
image:
"registry.cn-hangzhou.aliyuncs.com/forker/redis:latest"
第三部启动compose整个启动过程包括镜像构建，拉取，启动。
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[iyunv@salt-node1
composetest]# docker-compose up
Creating network
"composetest_default" with the default driver
Building web
Step 1/5 : FROM
python:3.4-alpine
---> 765c483d587c
。。。。。
redis_1| 1:M 26 Jan 14:25:40.111 * The server is now
ready to accept connections on port 6379
web_1 |*
Running on http://0.0.0.0:5000/ (Press
CTRL+C to quit)
web_1 |*
Restarting with stat
web_1 |*
Debugger is active!
web_1 |*
Debugger pin code: 301-431-697
现在可以测试访问一下，因为上面flask的脚本每次访问都会写入redis一次
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#
curl http://0.0.0.0:5000/
Hello World! I have
been seen 1 times.
#
curl http://0.0.0.0:5000/
Hello World! I have
been seen 2 times.
#
curl http://0.0.0.0:5000/
Hello World! I have
been seen 3 times.
#
curl http://0.0.0.0:5000/
Hello World! I have
been seen 4 times.
现在修改下代码在app.py里面修改返回“return 'Hello from Docker! I have been seen {}times.\n'.format(count)”
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[iyunv@salt-node1
composetest]# vim app.py
[iyunv@salt-node1
composetest]# curl http://0.0.0.0:5000/
Hello from Docker! I
have been seen 5 times.
[iyunv@salt-node1
composetest]# curl http://0.0.0.0:5000/
Hello from Docker! I
have been seen 6 times.
[iyunv@salt-node1
composetest]# curl http://0.0.0.0:5000/
Hello from Docker! I
have been seen 7 times.
后台启动
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[iyunv@salt-node1
composetest]# docker-compose up -d
Recreating
composetest_web_1
Starting
composetest_redis_1
[iyunv@salt-node1
composetest]# docker-compose ps
Name Command State Ports
-------------------------------------------------------------------------------------
composetest_redis_1 /bin/sh -c /usr/local/redi ... Up
6379/tcp
composetest_web_1 python app.py Up 0.0.0.0:5000->5000/tcp
查看指定容器的环境变量
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[iyunv@salt-node1
composetest]# docker-compose run web env
PATH=/usr/local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
HOSTNAME=230491939a67
TERM=xterm
LANG=C.UTF-8
GPG_KEY=97FC712E4C024BBEA48A61ED3A5CA953F73C700D
PYTHON_VERSION=3.4.6
PYTHON_PIP_VERSION=9.0.1
HOME=/root
停止服务
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[iyunv@salt-node1
composetest]# docker-compose stop
Stopping
composetest_web_1 ... done
Stopping
composetest_redis_1 ... done
删除容器，逻辑卷和网络
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[iyunv@salt-node1
composetest]# docker-compose down --volumes
Removing
composetest_web_run_1 ... done
Removing
composetest_web_1 ... done
Removing
composetest_redis_1 ... done
Removing network
composetest_defau
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