Or-tools: Add support for Alpine

[torepettersen]

It does not seems like it is possible to install the ortools on Alpine.
Is it possible to add support for that?

FROM python:3-alpine

RUN pip install ortools

Step 2/2 : RUN pip install ortools
 ---> Running in 2cf3452ad8a8
Collecting ortools
  Could not find a version that satisfies the requirement ortools (from versions: )
No matching distribution found for ortools
The command '/bin/sh -c pip install ortools' returned a non-zero code: 1

[Mizux]

I'll try to do it on my free time once I finish my docker rework !
Should be easy to add alpine docker image.

Alpine is good but never use it, except to create a port for assimp

[marzetas]

Is it possible, though? I'm trying to get or-tools running on an alpine distro, and it seems like ortools is trying to call to dlvsym, causing an error:

Traceback (most recent call last):
  File "/root/.local/lib/python3.6/site-packages/ortools-6.8.5510-py3.6-linux-x86_64.egg/ortools/linear_solver/pywraplp.py", line 14, in swig_import_helper
    return importlib.import_module(mname)
  File "/usr/lib/python3.6/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 994, in _gcd_import
  File "<frozen importlib._bootstrap>", line 971, in _find_and_load
  File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 658, in _load_unlocked
  File "<frozen importlib._bootstrap>", line 571, in module_from_spec
  File "<frozen importlib._bootstrap_external>", line 922, in create_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
ImportError: Error relocating /root/.local/lib/python3.6/site-packages/ortools-6.8.5510-py3.6-linux-x86_64.egg/ortools/linear_solver/../../ortools/.libs/libortools.so: dlvsym: symbol not found

dlvsym is a glibc specific extension, which unfortunately is not implemented in musl libc, the C standard library used by alpine. From dlvsym man page

Glibc extensions: dladdr() and dlvsym()
Glibc adds two functions not described by POSIX, with prototypes

I've been trying a number of workarounds, but I've been unable to get it to work, so any ideas are welcome.

[Mizux]

ortools is a python native library, and like you figure out alpine is based on libmusl not glibc that's why they are binary incompatible

[Mizux]

You may be interested on https://github.com/pypa/manylinux/issues/37
TLDR: python native package for alpine is not supported by Pypi.org :cry:

[lperron]

Sorry won't fix on our side.
We welcome PR though.

[kasaiee]

Maybe this is the reason of there is no whl for or-tools https://pythonspeed.com/articles/alpine-docker-python/
in this article, we find out alpine is not the best choice to dockerize python based projects

[Mizux]

we do have alpine docker to test python and all other languages, we simply don't upload the wheel package to pypi yet...