Docker Django installation error of Pillow Package - django

Question

I am dockerising my django apps, you know all if you use django image field, you need to use Pillow package but currently my docker installing all the package and show error when it try install pillow
my Dockerfile
# pull official base image
FROM python:3.7-alpine
# set work directory
WORKDIR /app
# set environment variables
ENV PYTHONDONTWRITEBYTECODE 1
ENV PYTHONUNBUFFERED 1
ENV DEBUG 0
# install psycopg2
RUN apk update \
&& apk add --virtual build-deps gcc python3-dev musl-dev \
&& apk add postgresql-dev \
&& pip install psycopg2 \
&& apk del build-deps
# install dependencies
COPY ./requirements.txt .
RUN pip install -r requirements.txt
# copy project
COPY . .
# collect static files
RUN python manage.py collectstatic --noinput
# add and run as non-root user
RUN adduser -D myuser
USER myuser
# run gunicorn
CMD gunicorn projectile.wsgi:application --bind 0.0.0.0:$PORT
and this is requirements.txt file
Django==2.2.2
Pillow==5.0.0
dj-database-url==0.5.0
gunicorn==19.9.0
whitenoise==4.1.2
psycopg2==2.8.4
I am not getting whats wrong with it, why pilow not installing, it throws an error, this is below:
The headers or library files could not be found for zlib,
remote: a required dependency when compiling Pillow from source.
remote:
remote: Please see the install instructions at:
remote: https://pillow.readthedocs.io/en/latest/installation.html
remote:
remote:
remote: ----------------------------------------
remote: ERROR: Command errored out with exit status 1: /usr/local/bin/python -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-k4_gcdwn/Pillow/setup.py'"'"'; __file__='"'"'/tmp/pip-install-k4_gcdwn/Pillow/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /tmp/pip-record-qgvai9fm/install-record.txt --single-version-externally-managed --compile Check the logs for full command output.
Can anyone help me to fix this error?
Thanks

Answer 1

You can add zlib-dev in your apk add section and install pillow there. For example(explanations are in comment section):
RUN apk update \
&& apk add --virtual build-deps gcc python3-dev musl-dev zlib-dev postgresql-dev jpeg-dev \ # will be removed after dependent python packages are installed
&& apk add postgresql zlib jpeg \ # these packages won't be deleted from docker image
&& pip install psycopg2 Pillow==5.0.0 \ # Here I am installing these python packages which have dependencies on the libraries installed in build-deps, because later build-deps will be deleted
&& apk del build-deps # for reducing the size of the Docker Image, we are removing the build-deps folder
# install dependencies
COPY ./requirements.txt .
RUN pip install -r requirements.txt
# Rest of the code