Dockerfile

###########
# BUILDER #
###########

# pull official base image
FROM python:3.8.10-alpine as builder

# set work directory
WORKDIR /usr/src/app

# set environment variables
ENV PYTHONDONTWRITEBYTECODE 1
ENV PYTHONUNBUFFERED 1

# install psycopg2 dependencies
RUN apk update \
    && apk add postgresql-dev gcc python3-dev musl-dev libffi-dev

# lint
RUN pip install --upgrade pip

RUN apk add --update --no-cache --virtual .tmp gcc libc-dev linux-headers
RUN apk add --no-cache jpeg-dev zlib-dev
RUN apk del .tmp

# install dependencies
COPY ./requirements.txt .
RUN pip wheel --no-cache-dir --no-deps --wheel-dir /usr/src/app/wheels -r requirements.txt


#########
# FINAL #
#########

# pull official base image
FROM python:3.8.10-alpine

# create directory for the app user
RUN mkdir -p /home/app

# create the app user
RUN addgroup -S app && adduser -S app -G app

# create the appropriate directories
ENV HOME=/home/app
ENV APP_HOME=/home/app/web
RUN mkdir $APP_HOME
WORKDIR $APP_HOME

# install dependencies

RUN apk update && apk add libpq libffi-dev
COPY --from=builder /usr/src/app/wheels /wheels
COPY --from=builder /usr/src/app/requirements.txt .
RUN pip install --upgrade pip && pip install --no-cache /wheels/*


# chown all the files to the app user
RUN chown -R app:app $APP_HOME

# change to the app user
USER app