Python flask dockerfile

app.py

import time

from flask import Flask
import redis

app = Flask(__name__)
cache = redis.Redis(host='redis', port=6379)

def get_hit_count():
    retries = 5
    while True:
        try:
            return cache.incr('hits')
        except redis.exceptions.ConnectionError as exc:
            if retries == 0:
                raise exc
            retries -= 1
            time.sleep(0.5)

@app.route('/')
def hello():
    count = get_hit_count()
    return 'Hello World! I have been seen {} times.\n'.format(count)

if __name__ == "__main__":
    app.run(debug=True, host='0.0.0.0')

docker-compose.yml

version: "3.9"
services:
  web:
    build: .
    ports:
      - "8000:5000"
    environment:
      FLASK_DEBUG: development
  redis:
    image: "redis:alpine"

Dockerfile

# syntax=docker/dockerfile:1

FROM python:3.7-alpine

WORKDIR /code

RUN apk add --no-cache gcc musl-dev linux-headers

COPY ./requirements.txt requirements.txt

COPY ./app.py /code/app.py

RUN pip install -r requirements.txt

EXPOSE 5000

CMD [ "python3", "-m" , "flask", "run", "--host=0.0.0.0"]

requirements.txt

flask
redis