七、Dockerfile-练习：构建Flask镜像

1. 准备flask文件

from flask import Flask
app = Flask(__name__)
@app.route('/')
def hello_world():
    return 'Hello World!'

2. 准备Dockerfile

FROM python:3.9.5-slim
COPY app.py /zhangtao/app.py
RUN pip3 install flask
WORKDIR /zhangtao
ENV FLASK_APP=app.py
CMD ["flask","run"]

3. 构建镜像

[root@localhost zhangtao]# docker image build -f Dockerfile -t flask-demo .
Sending build context to Docker daemon  3.698MB
Step 1/6 : FROM python:3.9.5-slim
3.9.5-slim: Pulling from library/python
b4d181a07f80: Downloading [========================>                          ]  13.04MB/27.15MB
a1111a8f2ec3: Download complete
445d04774519: Download complete
24f3f85d41f3: Download complete
d299f7fb612d: Download complete

4. 运行容器

[root@localhost zhangtao]# docker container run -d flask-demo
30324fee8eaaf5e9e4dc3d0f9d9cab33240ad0198e9c9c27e6c235e619202213
[root@localhost zhangtao]#
[root@localhost zhangtao]# docker container ls
CONTAINER ID   IMAGE        COMMAND                  CREATED         STATUS         PORTS                               NAMES
30324fee8eaa   flask-demo   "flask run"              7 seconds ago   Up 6 seconds                                       determined_galois
f82028e4f127   nginx        "/docker-entrypoint.…"   2 weeks ago     Up 2 weeks     0.0.0.0:80->80/tcp, :::80->80/tcp   condescending_brattain

5. 进行端口转发

• 修改Dockerfile

FROM python:3.9.5-slim
COPY app.py /zhangtao/app.py
RUN pip3 install flask
WORKDIR /zhangtao
ENV FLASK_APP=app.py
EXPOSE 5000
CMD ["flask", "run", "-h", "0.0.0.0"]

• 重新构建镜像
  docker build -t flask-demo .
• 重新运行容器

[root@localhost zhangtao]# docker container run -d -p 5000:5000 flask-demo
3533523e34335212bad30537494dba3bb4caa2563222f49081d73988a5d19660
[root@localhost zhangtao]#
[root@localhost zhangtao]# docker container ls
CONTAINER ID   IMAGE        COMMAND                  CREATED         STATUS         PORTS                                       NAMES
3533523e3433   flask-demo   "flask run -h 0.0.0.0"   6 seconds ago   Up 5 seconds   0.0.0.0:5000->5000/tcp, :::5000->5000/tcp   quizzical_herschel
f82028e4f127   nginx        "/docker-entrypoint.…"   2 weeks ago     Up 2 weeks     0.0.0.0:80->80/tcp, :::80->80/tcp           condescending_brattain

6. 访问5000端口