seems missing _ffi.abi3.so when pip installing in docker

[CACppuccino]

Hi,

We encountered a weird error when installing the argon2 in Alpine Linux Docker.
When using the argon2 as part of hasher in Django, it triggers an error saying Couldn't load 'Argon2PasswordHasher' algorithm library: No module named 'argon2._ffi'

After we looked into the docker's site-package, we found that the argon2 directory is missing the _ffi.abi3.so file which generates this error. We rebuilt the docker several times and the error still exists, it can be reproduced every time.

Python: 3.6.10
Docker base image: python3.6-alpine3.10
Django: 2.2.4
Argon2: 19.1.0

So is there any better solutions than copying so file directly into docker? and I was wondering what makes this happen?

[hynek]

Could it be that the build of the C extension fails? When use alpine, you can't use wheels and have to compile all your C extensions yourself.

[CACppuccino]

Could it be that the build of the C extension fails? When use alpine, you can't use wheels and have to compile all your C extensions yourself.

This could be the reason, but from the records of building docker, I didn't see any errors generated from there.

Collecting argon2-cffi==19.1.0
  Downloading argon2_cffi-19.1.0.tar.gz (1.8 MB)
  Installing build dependencies: started
  Installing build dependencies: finished with status 'done'
  Getting requirements to build wheel: started
  Getting requirements to build wheel: finished with status 'done'
    Preparing wheel metadata: started
    Preparing wheel metadata: finished with status 'done'

...

Building wheel for argon2-cffi (setup.py): started
  Building wheel for argon2-cffi (setup.py): finished with status 'done'
  Created wheel for argon2-cffi: filename=argon2_cffi-16.0.0-cp36-cp36m-linux_x86_64.whl size=37754 sha256=e41e66f9f81a7e75bdf69c7c8c8a7ea90a7d95419c22450fec6793591102cc63
  Stored in directory: /tmp/pip-ephem-wheel-cache-bw4l_lpc/wheels/3b/31/e5/816e76bc4496b810ac0eb9452fc96858c08155a06d5c877583

[hynek]

There is something going very wrong. It says

Collecting argon2-cffi==19.1.0

But then it says

Created wheel for argon2-cffi: filename=argon2_cffi-16.0.0-cp36-cp36m-linux_x86_64.whl

!?

This looks like an old-fashioned packaging FUBAR to me TBH.

[CACppuccino]

oh its a mistake of pasting, sry on that part. I did try downgrade the version but still failed on installation

Collecting argon2-cffi==16.0.0
  Downloading argon2_cffi-16.0.0.tar.gz (822 kB)

Building wheel for argon2-cffi (setup.py): started
  Building wheel for argon2-cffi (setup.py): finished with status 'done'
  Created wheel for argon2-cffi: filename=argon2_cffi-16.0.0-cp36-cp36m-linux_x86_64.whl size=37754 sha256=e41e66f9f81a7e75bdf69c7c8c8a7ea90a7d95419c22450fec6793591102cc63
  Stored in directory: /tmp/pip-ephem-wheel-cache-bw4l_lpc/wheels/3b/31/e5/816e76bc4496b810ac0eb9452fc96858c08155a06d5c877583

[CACppuccino]

# Python build stage
FROM python:3.6-alpine3.10

ENV PYTHONUNBUFFERED 1

RUN apk update \
  # psycopg2 dependencies
  && apk add --virtual build-deps gcc python3-dev musl-dev \
  # Pillow dependencies
  && apk add jpeg-dev zlib-dev freetype-dev lcms2-dev openjpeg-dev tiff-dev tk-dev tcl-dev \
  # for grpcio
  && apk add linux-headers build-base \ 
  # CFFI dependencies
  && apk add libffi-dev py-cffi

RUN pip install --no-cache-dir argon2-cffi==19.1.0

USER root

WORKDIR /app

ENTRYPOINT ["/bin/sh"]

Thats the simplified version, after goes into shell, when trying to import argon2, there comes

/app # python
Python 3.6.10 (default, May 21 2020, 06:00:59) 
[GCC 8.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import argon2
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.6/site-packages/argon2/__init__.py", line 5, in <module>
    from . import exceptions, low_level
  File "/usr/local/lib/python3.6/site-packages/argon2/low_level.py", line 17, in <module>
    from ._ffi import ffi, lib
ModuleNotFoundError: No module named 'argon2._ffi'

[hynek]

If I change it to argon2-cffi==20.1.0 it works for me – same for you?

[CACppuccino]

If I change it to argon2-cffi==20.1.0 it works for me – same for you?

Yes, this resolved my problem, thanks!