Django, Docker, Python - Unable to install Pillow on python-alpine

14
votes

I have a dockerized django app that I want to put in production. But ever since I added an Imagefield Pillow is required and I struggle to install Pillow in the Docker container.

As far as I understand it, adding the dependencies jpeg-dev ibjpeg & zlib-dev should be enough for django (?). With the configuration below I receive the error:

Error on runserver:

product.Product.image: (fields.E210) Cannot use ImageField because Pillow is not installed.
    HINT: Get Pillow at https://pypi.org/project/Pillow/ or run command "pip install Pillow".
product.Product.thumbnail: (fields.E210) Cannot use ImageField because Pillow is not installed.
    HINT: Get Pillow at https://pypi.org/project/Pillow/ or run command "pip install Pillow".

If I add Pillow to requirements.txt (or putting pip install Pillow in the Dockerfile) I get an even longer error message while trying to build the container.

Without putting pip install Pillow in Dockerfile or requirements.txt - this is my configuration.

Dockerfile:

# pull official base image
FROM python:3.7-alpine

# set environment varibles
ENV PYTHONDONTWRITEBYTECODE 1
ENV PYTHONUNBUFFERED 1

# set work directory
WORKDIR /usr/src/kitschoen-dj

RUN pip install --upgrade pip

# install psycopg2
RUN apk update \
    && apk add --virtual build-deps gcc python3-dev musl-dev \
    && apk add postgresql \
    && apk add postgresql-dev \
    && pip install psycopg2 \
    && apk del build-deps
    && apk add jpeg-dev \
    && apk add libjpeg \
    && apk add zlib-dev

# install dependencies
RUN pip install --upgrade pip
COPY ./requirements.txt /usr/src/kitschoen-dj/requirements.txt
RUN pip install -r requirements.txt

# copy entrypoint.sh
COPY ./entrypoint.sh /usr/src/kitschoen-dj/entrypoint.sh

# copy project
COPY . /usr/src/kitschoen-dj/

# run entrypoint.sh
ENTRYPOINT ["/usr/src/kitschoen-dj/entrypoint.sh"]

Requirements.txt

astroid==2.1.0
certifi==2018.11.29
chardet==3.0.4
Django==2.1.7
django-cors-headers==2.4.0
django-filter==2.1.0
djangorestframework==3.9.1
djangorestframework-simplejwt==3.3
gunicorn==19.9.0
httpie==1.0.2
httpie-jwt-auth==0.3.0
idna==2.8
isort==4.3.4
lazy-object-proxy==1.3.1
Markdown==3.0.1
mccabe==0.6.1
PyJWT==1.7.1
requests==2.21.0
six==1.12.0
urllib3==1.24.1
wrapt==1.11.1

I have been stuck with this for a while. Can someone help?

4
pythondjangodockerpython-imaging-library

4 Answers

43
votes

For anyone who is interested in what worked for me.

My problem had many aspects - one was that I am simply not that good when it comes do docker and Ubuntu.

But here is comes some insight: installing Pillow will require several dependencies. As far as I can tell, you need: gcc python3-dev jpeg-dev zlib-dev

To prevent these dependencies from ending up in the final image (keeping image-size small) you can install some (not all!) them in a virtual package, and delete them after Pillow is installed (these dependencies are called build dependencies - only needed during build).

So this is the code that worked for me:

RUN apk update \
    && apk add --virtual build-deps gcc python3-dev musl-dev \
    && apk add postgresql \
    && apk add postgresql-dev \
    && pip install psycopg2 \
    && apk add jpeg-dev zlib-dev libjpeg \
    && pip install Pillow \
    && apk del build-deps

(Some of the stuff is not required for Pillow, e. g. postgressql, postgresql-dev) - As you can see I installed my build dependencies in a virtual package called build-deps. Afterwards, I am installing Pillow and at the end I am removing the build dependencies.

I think, it is also the solution that @LinPy proposed I just wanted explain this very verbose to eventually help others.

What is .build-deps for apk add --virtual command?

20
votes

add this to your Dockerfile:

RUN apk add --no-cache jpeg-dev zlib-dev
RUN apk add --no-cache --virtual .build-deps build-base linux-headers \
    && pip install Pillow

source: Github

5
votes

I just added these lines to my Dockerfile and it worked

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

My Dockerfile (using python:3.8-alpine):

COPY ./requirements.txt /requirements.txt
RUN apk add --update --no-cache --virtual .tmp gcc libc-dev linux-headers
RUN apk add --no-cache jpeg-dev zlib-dev
RUN pip install -r /requirements.txt
RUN apk del .tmp
0
votes

Add this to your Docker file

RUN apk add postgresql-dev gcc python3-dev musl-dev jpeg-dev zlib-dev