centos安装python及导入cv2出现的问题及踩坑记录

想在容器中使用python，但python的官方镜像太过于精简，里面不管是yum还是vi 还是vim都没有安装，使用起来比较不方便，于是决定在centos基础镜像中安装python环境，具体步骤和遇到的问题如下：

下载centos官方镜像

[root@lingg ~]# docker pull centos

运行centos镜像

[root@lingg ~]# docker run -it 镜像ID /bin/bash

安装python环境

yum -y install python3

查看python版本

[root@3e3dc19e8e08 /]# python3
Python 3.6.8 (default, Mar 19 2021, 05:13:41) 
[GCC 8.4.1 20200928 (Red Hat 8.4.1-1)] on linux
Type "help", "copyright", "credits" or "license" for more information.

导入包cv2失败

[root@3e3dc19e8e08 /]# python3
Python 3.6.8 (default, Mar 19 2021, 05:13:41) 
[GCC 8.4.1 20200928 (Red Hat 8.4.1-1)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import cv2
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ModuleNotFoundError: No module named 'cv2'

安装opencv-python

[root@3e3dc19e8e08 /]# pip3 install opencv-python   
WARNING: Running pip install with root privileges is generally not a good idea. Try `pip3 install --user` instead.
Collecting opencv-python
  Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ConnectTimeoutError(<pip._vendor.urllib3.connection.VerifiedHTTPSConnection object at 0x7fcaf7138f28>, 'Connection to pypi.python.org timed out. (connect timeout=15)')': /simple/opencv-python/

解决：

• 临时性解决

可以在使用pip的时候在后面加上-i参数，指定pip源 
eg: pip install opencv-python -i https://pypi.tuna.tsinghua.edu.cn/simple

• 永久性解决：

mkdir ~/.pip
vim ~/.pip/pip.conf

提示vim :command not found的话换成vi ~/.pip/pip.conf

然后在pip.conf中输入

[global]
index-url = https://pypi.tuna.tsinghua.edu.cn/simple

报错：

Collecting opencv-python
  Downloading http://pypi.doubanio.com/packages/01/9b/be08992293fb21faf35ab98e06924d7407fcfca89d89c5de65442631556a/opencv-python-4.5.3.56.tar.gz (89.2MB)
    100% |████████████████████████████████| 89.2MB 13.9MB/s 
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-build-s_bpkw_2/opencv-python/setup.py", line 10, in <module>
        import skbuild
    ModuleNotFoundError: No module named 'skbuild'

解决：

pip3 install scikit-build

报错：

Building wheels for collected packages: opencv-python
  Running setup.py bdist_wheel for opencv-python ... error
  Complete output from command /usr/bin/python3.6 -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-nnxlnrca/opencv-python/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" bdist_wheel -d /tmp/tmp2i6xp72gpip-wheel- --python-tag cp36:
  Traceback (most recent call last):
    File "/usr/local/lib/python3.6/site-packages/skbuild/setuptools_wrap.py", line 564, in setup
      cmkr = cmaker.CMaker(cmake_executable)
    File "/usr/local/lib/python3.6/site-packages/skbuild/cmaker.py", line 95, in __init__
      self.cmake_version = get_cmake_version(self.cmake_executable)
    File "/usr/local/lib/python3.6/site-packages/skbuild/cmaker.py", line 82, in get_cmake_version
      "Problem with the CMake installation, aborting build. CMake executable is %s" % cmake_executable)
  
  Problem with the CMake installation, aborting build. CMake executable is cmake
  
  ----------------------------------------
  Failed building wheel for opencv-python
  Running setup.py clean for opencv-python
Failed to build opencv-python
Installing collected packages: numpy, opencv-python
  Running setup.py install for opencv-python ... error
    Complete output from command /usr/bin/python3.6 -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-nnxlnrca/opencv-python/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /tmp/pip-tuz2u8xk-record/install-record.txt --single-version-externally-managed --compile:
    Traceback (most recent call last):
      File "/usr/local/lib/python3.6/site-packages/skbuild/setuptools_wrap.py", line 564, in setup
        cmkr = cmaker.CMaker(cmake_executable)
      File "/usr/local/lib/python3.6/site-packages/skbuild/cmaker.py", line 95, in __init__
        self.cmake_version = get_cmake_version(self.cmake_executable)
      File "/usr/local/lib/python3.6/site-packages/skbuild/cmaker.py", line 82, in get_cmake_version
        "Problem with the CMake installation, aborting build. CMake executable is %s" % cmake_executable)
    
    Problem with the CMake installation, aborting build. CMake executable is cmake
    
    ----------------------------------------
Command "/usr/bin/python3.6 -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-nnxlnrca/opencv-python/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /tmp/pip-tuz2u8xk-record/install-record.txt --single-version-externally-managed --compile" failed with error code 1 in /tmp/pip-build-nnxlnrca/opencv-python/

解决：升级pip

pip3 install --upgrade pip

报错：

[root@3e3dc19e8e08 /]# python3
Python 3.6.8 (default, Mar 19 2021, 05:13:41) 
[GCC 8.4.1 20200928 (Red Hat 8.4.1-1)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import cv2
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib64/python3.6/site-packages/cv2/__init__.py", line 5, in <module>
    from .cv2 import *
ImportError: libGL.so.1: cannot open shared object file: No such file or directory

解决：

pip3 uninstall opencv-python 
pip3 install opencv-python-headless

同时按住Ctrl+p+q退出容器，保证容器不关闭。

然后执行docker ps命令查看当前运行中的容器

CONTAINER ID        IMAGE                  COMMAND                  CREATED             STATUS              PORTS                     NAMES
3e3dc19e8e08        5d0da3dc9764           "/bin/bash"              29 minutes ago      Up 29 minutes                           

将配置好环境的docker commit成一个新的镜像

docker commit 3e3dc19e8e08 lingg/centos:3.6.8

执行docker images命令查看刚刚commit的镜像

REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
lingg/centos        3.6.8               898e55b46a3d        27 seconds ago      639MB

向/root/centos-py/目录下拷贝两张照片

[root@lingg ~]# cp images/275cd4eb-8825-49ad-b2fa-44d9aa67c0c6.png images/67f7b6b4-5324-4e2d-935f-7d04b6d8a85a.png ./centos-py/

启动新镜像 将/root/centos-py/目录挂载到镜像里面的/usr/lcoal/src目录下

[root@lingg ~]#  docker run -it -v /root/centos-py/:/usr/local/src --name python  -p 10000:8080 898e55b46a /bin/bash

查看照片shape属性

[root@c3dadddc745e src]# python3     
Python 3.6.8 (default, Mar 19 2021, 05:13:41) 
[GCC 8.4.1 20200928 (Red Hat 8.4.1-1)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import cv2
>>> image = cv2.imread("/usr/local/src/275cd4eb-8825-49ad-b2fa-44d9aa67c0c6.png")
>>> print(image.shape)
(80, 320, 3)

成功