flask를 통해 구축한 웹을 컨테이너로 배포해보자

1.디렉터리 생성

root@hostos1:~/DockerLabs# mkdir flask
root@hostos1:~/DockerLabs# cd flask

2.도커파일 작성

root@hostos1:~/DockerLabs/flask# vi Dockerfile

FROM python:3.8-alpine

RUN apk update && \
        apk add --no-cache \
        bash

RUN apk add --update build-base python3-dev py-pip
ENV LIBRARY_PATH=/lib:/usr/lib
EXPOSE 9000
WORKDIR /py_app
COPY . /py_app
RUN pip install -r ./app/requirements.txt

ENTRYPOINT ["python"]
CMD ["./add/py_app.py"]

3. py_app.py 작성

from flask import Flask
py_app =Flask(__name__)
@py_app.route('/')
def python_flask():
    return """
    <h1 style="text-algin:center; color:deepskyblue;">
      Docker container application: Python & Flask!</h1>
      <p style="text-algin:center; color:deepskyblue;">
        This is micro web framework for running Flask
        inside Docker.</p>
    """

if __name__ == '__main__':
    py_app.run(host='0.0.0.0', port=9000, debug=True)

4.파일 정리

root@hostos1:~/DockerLabs/flask# mkdir app
root@hostos1:~/DockerLabs/flask# mv py_app.py  app/
root@hostos1:~/DockerLabs/flask# mv requirements.txt app/

.dockerignore
빌드시 여기에 적혀있는 파일들은 컨테이너에 포함되지 않는다

root@hostos1:~/DockerLabs/flask# vi .dockerignore
Dockerfile

5.빌드

root@hostos1:~/DockerLabs/flask# docker build -t py_flask:1.0 .

6.빌드된 이미지 확인

root@hostos1:~/DockerLabs/flask# docker images | grep py_flask
py_flask                            1.0          9421d7a3995b   2 minutes ago   358MB

root@hostos1:~/DockerLabs/flask# docker image history py_flask:1.0
IMAGE          CREATED         CREATED BY                                      SIZE      COMMENT
9421d7a3995b   2 minutes ago   /bin/sh -c #(nop)  CMD ["./app/py_app.py"]      0B
69e969404687   2 minutes ago   /bin/sh -c #(nop)  ENTRYPOINT ["python"]        0B
a8f83f64b2a9   2 minutes ago   /bin/sh -c pip install -r ./app/requirements…   11.7MB
483c930f5110   2 minutes ago   /bin/sh -c #(nop) COPY dir:7e4164a91bf7cf098…   466B
4f0280fb6cd4   2 minutes ago   /bin/sh -c #(nop) WORKDIR /py_app               0B
b97629209e51   2 minutes ago   /bin/sh -c #(nop)  EXPOSE 9000                  0B
89e317819c2a   2 minutes ago   /bin/sh -c #(nop)  ENV LIBRARY_PATH=/lib:/us…   0B
0eea2d150d39   2 minutes ago   /bin/sh -c apk add --update build-base pytho…   300MB
1a3d68bb49b4   3 minutes ago   /bin/sh -c apk update &&         apk add --n…   3.44MB

7.컨테이너 실행

root@hostos1:~/DockerLabs/flask# docker run -it -p 9000:9000 py_flask:1.0
 * Serving Flask app "py_app" (lazy loading)
 * Environment: production
   WARNING: This is a development server. Do not use it in a production deployment.
   Use a production WSGI server instead.
 * Debug mode: on
 * Running on all addresses.
   WARNING: This is a development server. Do not use it in a production deployment.
 * Running on http://172.17.0.8:9000/ (Press CTRL+C to quit)
 * Restarting with stat
 * Debugger is active!
 * Debugger PIN: 550-471-881
192.168.56.104 - - [13/Aug/2021 05:23:59] "GET / HTTP/1.1" 200 -

8. warning 문제 해결

ENV FLASK_APP=py_app
ENV FLASK_APP=development
개발 환경을 development로 명시해줘야 warning이 뜨지 않는다
사실 이것도 임시방편
제대로 개발을 하려면 gunicorn과 같은 웹소켓을 사용해야한다!

FROM python:3.8-alpine

RUN apk update && \
        apk add --no-cache \
        bash

RUN apk add --update build-base python3-dev py-pip
ENV LIBRARY_PATH=/lib:/usr/lib
EXPOSE 9000
WORKDIR /py_app
COPY . /py_app
RUN pip install -r ./app/requirements.txt

ENV FLASK_APP=py_app
ENV FLASK_APP=development


ENTRYPOINT ["python"]
CMD ["./app/py_app.py"]

10.warning 제거 확인

root@hostos1:~/DockerLabs/flask# docker run -it -p 9004:9000 yk1700/py_flask:1.0
 * Serving Flask app "py_app" (lazy loading)
 * Environment: development
 * Debug mode: on
 * Running on all addresses.
   WARNING: This is a development server. Do not use it in a production deployment.
 * Running on http://172.17.0.8:9000/ (Press CTRL+C to quit)
 * Restarting with stat
 * Debugger is active!
 * Debugger PIN: 908-847-921

warning이 성공적으로 제거되었다!

9.재빌드

root@hostos1:~/DockerLabs/flask# docker build -t py_flask:2.0 .

10.태그 변경

root@hostos1:~/DockerLabs/flask# docker image tag py_flask:2.0 yk1700/py_flask:1.0

11.도커허브 push

root@hostos1:~/DockerLabs/flask# docker push yk1700/py_flask:1.0

성공적으로 업로드되었다!

12.hostos2에서 테스트

root@hostos2:~# docker pull yk1700/py_flask:1.0

13.실행

root@hostos2:~# docker run -it -p 10000:100001 yk1700/py_flask:1.0
 * Serving Flask app "py_app" (lazy loading)
 * Environment: production
 * Debug mode: on
 * Running on all addresses.
 * Running on http://172.17.0.3:9000/ (Press CTRL+C to quit)
 * Restarting with stat
 * Debugger is active!
 * Debugger PIN: 129-806-730

도커파일 없이 빌드된 것을 확인할 수 있다!!

root@hostos2:~# docker exec -it 83887ba48dd5 bash
bash-5.1# ls
app
bash-5.1# cd app/
bash-5.1# ls
py_app.py         requirements.txt

flask 컨테이너가 정상적으로 작동하고 있다!