小编典典
我的猜测是,-alpine由于opencv软件包是二进制发行版(不仅是Python代码),而且版本不是在Alpine上构建的,因此您会看到该版本的失败。Alpine使用的C库与其他所有库都不相同(Alpine使用MUSL
libc,而其他几乎所有的库都使用Glibc);opencv代码库甚至可能无法为MUSL构建。也许仅仅是没有人去构建二进制包。无论哪种情况,最好使用以下选项之一:
如果我使用普通的python:3.5图像(而不是Alpine图像),则可以正常工作:
$ docker run -it --rm python:3.5 bash
root@95c81040aeaf:/# pip install opencv-contrib-python-headless
Collecting opencv-contrib-python-headless
Downloading https://files.pythonhosted.org/packages/c2/50/2427b286652cf64ea3618d08bfba38c04b6571f6f2c054e950367a2f309f/opencv_contrib_python_headless-3.4.3.18-cp35-cp35m-manylinux1_x86_64.whl (24.0MB)
100% |████████████████████████████████| 24.1MB 2.4MB/s
Collecting numpy>=1.11.1 (from opencv-contrib-python-headless)
Downloading https://files.pythonhosted.org/packages/86/04/bd774106ae0ae1ada68c67efe89f1a16b2aa373cc2db15d974002a9f136d/numpy-1.15.4-cp35-cp35m-manylinux1_x86_64.whl (13.8MB)
100% |████████████████████████████████| 13.8MB 4.7MB/s
Installing collected packages: numpy, opencv-contrib-python-headless
Successfully installed numpy-1.15.4 opencv-contrib-python-headless-3.4.3.18
root@95c81040aeaf:/# python
Python 3.5.6 (default, Nov 16 2018, 22:45:03)
[GCC 6.3.0 20170516] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import cv2
>>>
如果使用3.5-slim标记,则会看到与您报告的错误相同的错误:
root@63dca11a527f:/# python
Python 3.5.5 (default, May 5 2018, 03:17:29)
[GCC 4.9.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import cv2
Traceback (most recent call last):
File "", line 1, in
File "/usr/local/lib/python3.5/site-packages/cv2/__init__.py", line 3, in
from .cv2 import *
ImportError: libgthread-2.0.so.0: cannot open shared object file: No such file or directory
>>>
从包查询中可以看到,该库归libglib2.0包所有,-slim在Python映像版本中默认未安装该库。我们可以解决此问题:
# apt-get update
# apt-get -y install libglib2.0
现在,它按预期运行:
root@63dca11a527f:/# python
Python 3.5.5 (default, May 5 2018, 03:17:29)
[GCC 4.9.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import cv2
>>>
您可以使用以下方法结合此修复程序来构建自己的图像 Dockerfile:
FROM python:3.5-slim
RUN apt-get update && apt-get -y install libglib2.0; apt-get clean
RUN pip install opencv-contrib-python-headless
更新资料
关于您的评论:如果您希望软件包可用于在容器中运行的代码,那么,是的,您必须安装它。它还会从哪里来?
如果opencv-contrib-python-headless您的中包含 requirements.txt,则评论中发布的内容应该可以正常工作:
FROM python:3.5
COPY . /app
WORKDIR /app
RUN pip3 install -r requirements.txt
ENTRYPOINT ["python3"]
CMD ["app.py"]
如果requirements.txt不包括(为什么不包括),则需要显式安装:
FROM python:3.5
RUN pip install opencv-contrib-python-headless
COPY . /app
WORKDIR /app
RUN pip3 install -r requirements.txt
ENTRYPOINT ["python3"]
CMD ["app.py"]
2020-06-17