Installing numpy on Docker Alpine

I've been having a bit of trouble with this myself and, long story short, I would encourage you to ask if it's really worth the hassle. Numpy is enormous when you start adding things to the stack like pandas, gpus, and scipy so the benefit of building it on alpine is limited, the savings over using Debian, Arch, or even Ubuntu are relatively modest when 500MB of your space is on this library anyway.

That having been said, I threw together an image that does it. I needed as build-time dependencies musl-dev, linux-headers, and g++. I also wound up needing to add openblas from edge for something later in the stack so it's possible that some dependencies from that are required too. But I believe just adding the three former libraries with

apk --no-cache add musl-dev linux-headers g++

should be sufficient to prevent the gcc error you are getting. You can view the image at https://hub.docker.com/r/o76923/alpine-numpy-stack/

If you don't necessary need to install numpy from pypi, you could install it from alpine repositories. Package is named py-numpy and is in testing repository, see here. Minimal Dockerfile example that works for me

FROM alpine:3.2ADD repositories /etc/apk/repositoriesRUN apk add --update python python-dev gfortran py-pip build-base py-numpy@community

Content of repositories file

http://dl-cdn.alpinelinux.org/alpine/v3.2/main@community http://dl-cdn.alpinelinux.org/alpine/edge/community

A package is now available in the Alpine repository: py3-numpy. But you won't be able to use it straightaway.

py3-numpy installs libraries into /usr/lib/python3.8/site-packages directory but the default Python module path does not use it:

$ docker run -it python:3.8-alpine sh/ # apk add --update --no-cache py3-numpy/ # python>>> import numpyTraceback (most recent call last):  File "<stdin>", line 1, in <module>ModuleNotFoundError: No module named 'numpy'>>> import sys>>> sys.path['', '/usr/local/lib/python38.zip', '/usr/local/lib/python3.8', '/usr/local/lib/python3.8/lib-dynload', '/usr/local/lib/python3.8/site-packages']

This can be fixed by setting the $PYTHONPATH environment variable to the path of the site-packages in /usr/lib:

FROM python:3.8-alpineRUN apk add --update --no-cache py3-numpyENV PYTHONPATH=/usr/lib/python3.8/site-packages