adding .dockerignore

Dockerfile

@@ -1,7 +1,10 @@
-FROM python:3-alpine
-COPY ./requirements.txt ./
+FROM debian
+RUN apt-get update && apt-get install \
+  -y --no-install-recommends python3 python3-virtualenv
+RUN python3 -m virtualenv --python=/usr/bin/python3 /opt/venv
+COPY ./requirements.txt /usr/src/app/
 WORKDIR /usr/src/app/
-RUN pip install --no-cache-dir -r requirements.txt
+RUN . /opt/venv/bin/activate && pip install -r requirements.txt
 COPY . .
 EXPOSE 8000
 CMD ["python", "./manage.py", "runserver"]