Deploying a django project from docker?

Question

Django

I'm deploying a finished project from docker, and I don't quite understand how dependencies are installed from requirements.txt. Everything unfolds without errors, in the console I see that requirements.txt is also installed. But it is not clear where it is all installed and how to run it. manage.py runserverdoes not see the installed dependencies and, of course, issues

File "manage.py", line 8, in <module>
    from django.core.management import execute_from_command_line
ModuleNotFoundError: No module named 'django'

If you create a virtualenv as standard and run install requirements.txt, then everything is ok. But I feel that it's not right to do the installation twice.
Please explain how this should work properly. Dockerfile _

FROM python:3.6
ENV PYTHONUNBUFFERED 1
RUN mkdir /lifeline
WORKDIR /lifeline
ADD requirements.txt /lifeline/
RUN pip install --default-timeout=100 -r requirements.txt
ADD . /lifeline/
RUN chmod +x /lifeline/docker/start.sh

CMD ["/lifeline/docker/start.sh"]

Answer 1

I did this based on python:3.6-alpine (the config is a bit truncated):

version: "3.5"
services:
  db:
    build:
      context: ./db
      dockerfile: postgresql.Dockerfile
    env_file:
      - .env
    restart: always
    volumes:
      - postgres:/var/lib/postgresql/data
    ports:
      - "127.0.0.1:5432:5432"
  web:
    build: .
    restart: always
    env_file:
      - .env
      - secret.env
    command: gunicorn --bind 0.0.0.0:8080 --user nginx you_proj.wsgi
    volumes:
      - django-static:/data
    ports:
      - "127.0.0.1:8080:8080"

volumes:
  django-static:
  postgres:

Dockerfile

FROM python:3.6-alpine

RUN apk add build-base python-dev py-pip jpeg-dev zlib-dev
ENV LIBRARY_PATH=/lib:/usr/lib

WORKDIR /code

ADD requirements.txt /code/
RUN apk update
RUN apk upgrade
RUN apk --no-cache add \
    python3 \
    python3-dev \
    postgresql-client \
    postgresql-dev \
    build-base \
    gettext
RUN pip3 install --upgrade pip
RUN pip3 install -r requirements.txt

RUN set -x ; \
  addgroup -g 101 -S nginx ; \
  adduser -u 101 -D -S -G nginx nginx && exit 0 ; exit 1

RUN mkdir -p /data/static/ && mkdir -p /data/media/

ADD . /code/
RUN /code/maxmind.sh

ENV PYTHONUNBUFFERED 1