[Python知识库]镜像的制作

第一步：编辑Dockerfile

[root@mxy-docker ~]# mkdir /mydocker
[root@mxy-docker ~]# cd /mydocker
[root@mxy-docker mydocker]# 
[root@mxy-docker mydocker]# vim Dockerfile
FROM python:2.7-slim
WORKDIR /app
ADD . /app
RUN pip install --trusted-host  pypi.python.org -r requirements.txt
EXPOSE 80
ENV NAME World
ENV AUTHOR cali
CMD ["python","app.py"]

第二步：：编辑requirements.txt文件

[root@mxy-docker mydocker]# vim requirements.txt
Flask
Redis

第三步：：编辑app.py文件，即程序文件

[root@mxy-docker mydocker]# vim app.py
from flask import Flask
from redis import Redis, RedisError
import os
import socket

# Connect to Redis
redis = Redis(host="redis", db=0, socket_connect_timeout=2, socket_timeout=2)

app = Flask(__name__)

@app.route("/")
def hello():
    try:
        visits = redis.incr("counter")
    except RedisError:
        visits = "<i>cannot connect to Redis, counter disabled</i>"

    html = "<h3>Hello {name}!</h3>" \
           "<b>Hostname:</b> {hostname}<br/>" \
           "<b>Visits:</b> {visits}"
    return html.format(name=os.getenv("NAME", "world"), hostname=socket.gethostname(), visits=visits)

if __name__ == "__main__":
    app.run(host='0.0.0.0', port=80)

第四步：生成镜像文件

[root@mxy-docker mydocker]# docker build -t sc_friendlyhello_1 .
Sending build context to Docker daemon  4.608kB
Step 1/9 : FROM python:2.7-slim
 ---> eeb27ee6b893
Step 2/9 : WORKDIR /app
 ---> Using cache
 ---> ed3a5d79cc04
Step 3/9 : ADD . /app
 ---> Using cache
 ---> 4f36b79e3431
Step 4/9 : VOLUME ["/data_flask"]
 ---> Using cache
 ---> c3dcb8190ab3
Step 5/9 : RUN pip install --trusted-host pypi.python.org -r requirements.txt
 ---> Running in 928613862e21
DEPRECATION: Python 2.7 reached the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 is no longer maintained. A future version of pip will drop support for Python 2.7. More details about Python 2 support in pip, can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support
Collecting Flask
  Downloading Flask-1.1.4-py2.py3-none-any.whl (94 kB)
Collecting Redis
  Downloading redis-3.5.3-py2.py3-none-any.whl (72 kB)
Collecting click<8.0,>=5.1
  Downloading click-7.1.2-py2.py3-none-any.whl (82 kB)
Collecting Werkzeug<2.0,>=0.15
  Downloading Werkzeug-1.0.1-py2.py3-none-any.whl (298 kB)
Collecting Jinja2<3.0,>=2.10.1
  Downloading Jinja2-2.11.3-py2.py3-none-any.whl (125 kB)
Collecting itsdangerous<2.0,>=0.24
  Downloading itsdangerous-1.1.0-py2.py3-none-any.whl (16 kB)
Collecting MarkupSafe>=0.23
  Downloading MarkupSafe-1.1.1-cp27-cp27mu-manylinux1_x86_64.whl (24 kB)
Installing collected packages: click, Werkzeug, MarkupSafe, Jinja2, itsdangerous, Flask, Redis
Successfully installed Flask-1.1.4 Jinja2-2.11.3 MarkupSafe-1.1.1 Redis-3.5.3 Werkzeug-1.0.1 click-7.1.2 itsdangerous-1.1.0
WARNING: You are using pip version 20.0.2; however, version 20.3.4 is available.
You should consider upgrading via the '/usr/local/bin/python -m pip install --upgrade pip' command.
Removing intermediate container 928613862e21
 ---> ff8adc66922e
Step 6/9 : EXPOSE 80
 ---> Running in b98dc3e45560
Removing intermediate container b98dc3e45560
 ---> 9f02633087c8
Step 7/9 : ENV NAME World
 ---> Running in 432fdd440b70
Removing intermediate container 432fdd440b70
 ---> da5a8e496578
Step 8/9 : ENV AUTHOR mxy
 ---> Running in c67016331ae3
Removing intermediate container c67016331ae3
 ---> 47452cbb6e66
Step 9/9 : CMD ["python","app.py"]
 ---> Running in 87440506cd07
Removing intermediate container 87440506cd07
 ---> a24400c200c3
Successfully built a24400c200c3
Successfully tagged sc_friendlyhello_1:latest
[root@mxy-docker mydocker]# 

此处可能会出现如下错误，原因是容器不能上网，可以使用service docker restart重启容器来解决

查看一下完成的镜像

[root@mxy-docker mydocker]# docker images
REPOSITORY                 TAG        IMAGE ID       CREATED         SIZE
sc_friendlyhello_1         latest     a24400c200c3   5 hours ago     159MB

第五步：使用镜像，启动容器

[root@mxy-docker mydocker]# docker run -d -p 5080:80 --name sc-hello-1 sc_friendlyhello_1

第六步：访问容器的web服务
? ? ? ? ? ? ? 使用curl或者chrome浏览器访问
? ? ? ? ? ? ? 宿主机ip:5080

?因为redis数据库容器没有启动，flask web服务不能连接到redis数据库

第7步： 启动redis容器

[root@mxy-docker mydocker]# docker run -d -p 6379:6379 --name sc-redis-1 redis

第八步： 再次启动一个自己制作镜像的容器，链接到redis容器

[root@mxy-docker mydocker]# docker run -d --name sc-hello-2 -p 5081:80 --link sc-redis-1:redis sc_friendlyhello_1

第九步：再次访问容器的web服务
? ? ? ? ? ? ? curl或者chrome浏览器访问
? ? ? ? ? ? ? 宿主机ip:5081

?这样我们就完成了一个镜像的制作！