在 Docker 中设置 cassandra 驱动程序（python）

Question

几个月前我使用了一个 docker 文件，它 (1) 使用基本 ubuntu 映像，(2) 安装 miniconda python 发行版，(3) 使用 miniconda 安装一些 python 库，(4) 运行以下命令来设置 cassandra-driver对于python。

RUN pip install --upgrade pip
RUN pip install cassandra-driver

这在六个月前运行良好。但现在我得到了这个例外。

Step 13 : RUN pip install cassandra-driver
 ---> Running in ba9955650d7c
Collecting cassandra-driver
  Downloading cassandra-driver-3.0.0.tar.gz (186kB)
    Complete output from command python setup.py egg_info:
    warning: no files found matching '*.pyx' under directory 'Cython/Debugger/Tests'
    warning: no files found matching '*.pxd' under directory 'Cython/Debugger/Tests'
    warning: no files found matching '*.h' under directory 'Cython/Debugger/Tests'
    warning: no files found matching '*.pxd' under directory 'Cython/Utility'
    unable to execute 'gcc': No such file or directory
    Unable to find pgen, not compiling formal grammar.
    Traceback (most recent call last):
      File "<string>", line 20, in <module>
      File "/tmp/pip-build-0XzsPv/cassandra-driver/setup.py", line 375, in <module>
        run_setup(None)
      File "/tmp/pip-build-0XzsPv/cassandra-driver/setup.py", line 373, in run_setup
        **kw)
      File "/miniconda/lib/python2.7/distutils/core.py", line 111, in setup
        _setup_distribution = dist = klass(attrs)
      File "/miniconda/lib/python2.7/site-packages/setuptools-19.1.1-py2.7.egg/setuptools/dist.py", line 268, in __init__
      File "/miniconda/lib/python2.7/site-packages/setuptools-19.1.1-py2.7.egg/setuptools/dist.py", line 312, in fetch_build_eggs
      File "/miniconda/lib/python2.7/site-packages/setuptools-19.1.1-py2.7.egg/pkg_resources/__init__.py", line 846, in resolve
      File "/miniconda/lib/python2.7/site-packages/setuptools-19.1.1-py2.7.egg/pkg_resources/__init__.py", line 1091, in best_match
      File "/miniconda/lib/python2.7/site-packages/setuptools-19.1.1-py2.7.egg/pkg_resources/__init__.py", line 1103, in obtain
      File "/miniconda/lib/python2.7/site-packages/setuptools-19.1.1-py2.7.egg/setuptools/dist.py", line 379, in fetch_build_egg
      File "/miniconda/lib/python2.7/site-packages/setuptools-19.1.1-py2.7.egg/setuptools/command/easy_install.py", line 639, in easy_install
      File "/miniconda/lib/python2.7/site-packages/setuptools-19.1.1-py2.7.egg/setuptools/command/easy_install.py", line 669, in install_item
      File "/miniconda/lib/python2.7/site-packages/setuptools-19.1.1-py2.7.egg/setuptools/command/easy_install.py", line 852, in install_eggs
      File "/miniconda/lib/python2.7/site-packages/setuptools-19.1.1-py2.7.egg/setuptools/command/easy_install.py", line 1080, in build_and_install
      File "/miniconda/lib/python2.7/site-packages/setuptools-19.1.1-py2.7.egg/setuptools/command/easy_install.py", line 1068, in run_setup
    distutils.errors.DistutilsError: Setup script exited with error: command 'gcc' failed with exit status 1

    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-0XzsPv/cassandra-driver
The command '/bin/sh -c pip install cassandra-driver' returned a non-zero code: 1

可能出了什么问题？是安装包坏了还是我做的不对？

Answer 1

为了安装cassandra-driver，您需要编译一些C 源文件，但是您的容器中没有gcc：

unable to execute 'gcc': No such file or directory

在安装cassandra-driver之前尝试安装gcc和python-dev包：

RUN apt-get update \
  && apt-get install -y --no-install-recommends \
    python-dev \
    gcc \
  && rm -rf /var/lib/apt/lists/*

Answer 2

python cassandra-driver 现在默认使用 Cython 扩展 since version 2.7.0，但是对于那些无法轻松访问 cython 发行版或不需要它的人来说，这可能是一个不错的选择你也是。 cython 扩展确实提供了性能提升，但它可能不适合很多情况（尤其是在您没有进行高吞吐量的情况下）。

来自install documentation：

默认情况下，此包使用 Cython 优化核心模块并构建自定义扩展。这不是硬性要求，但默认情况下用于构建扩展，提供比纯 Python 实现更好的性能。

可以使用构建开关或环境变量来避免此构建阶段：

python setup.py install --no-cython
-or-
pip install --install-option="--no-cython" <spec-or-path>

或者，无论上下文如何，都可以使用环境变量来切换此选项：

CASS_DRIVER_NO_CYTHON=1 <your script here>