pip抱怨包问题

Question

我正在尝试安装cffi包，因为bcrypt依赖于它，但我一直收到这个错误，这对我来说没有任何意义。它说找不到cffi的相关版本，但在需求文件中，我列出了最新版本。

为什么我会得到这个错误？

我正在使用Docker构建镜像，使用：

FROM python:3.6.5-alpine

WORKDIR /app
ADD . /app
RUN pip3 install -r requirements.txt
EXPOSE 5000
CMD ["python", "main.py"]   # I've got set alias on Python == Python 3.6

requirements.txt：

alembic==1.0.9
cffi==1.12.3
bcrypt==3.1.6
blinker==1.4
Click==7.0
Faker==1.0.5
Flask==1.0.2
Flask-Bcrypt==0.7.1
Flask-Login==0.4.1
Flask-Mail==0.9.1
Flask-Migrate==2.4.0
Flask-Moment==0.7.0
Flask-Script==2.0.6
Flask-SQLAlchemy==2.3.2
Flask-Testing==0.7.1
Flask-WTF==0.14.2
itsdangerous==1.1.0
Jinja2==2.10.1
MarkupSafe==1.1.1
PyMySQL==0.9.3
SQLAlchemy==1.3.3
text-unidecode==1.2
Werkzeug==0.15.2
WTForms==2.2.1

但是，在构建时：

Step 1/6 : FROM python:3.6.5-alpine
---> 5be6d36f77ee
Step 2/6 : WORKDIR /app
---> Using cache
---> f9e7cc24d767
Step 3/6 : ADD . /app
---> 7d9d5bdcf5d6
Step 4/6 : RUN pip3 install -r requirements.txt
---> Running in b455df1a48e2
Collecting alembic==1.0.9 (from -r requirements.txt (line 1))
Downloading https://files.pythonhosted.org/packages/fc/42/8729e2491fa9b8eae160d1cbb429f61712bfc2d779816488c25cfdabf7b8/alembic-1.0.9.tar.gz (1.0MB)
Collecting bcrypt==3.1.6 (from -r requirements.txt (line 2))
Downloading https://files.pythonhosted.org/packages/ce/3a/3d540b9f5ee8d92ce757eebacf167b9deedb8e30aedec69a2a072b2399bb/bcrypt-3.1.6.tar.gz (42kB)
Could not find a version that satisfies the requirement cffi>=1.1 (from versions: )
No matching distribution found for cffi>=1.1
You are using pip version 10.0.1, however version 19.1.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
The command '/bin/sh -c pip3 install -r requirements.txt' returned a non-zero code: 1

Answer 1

安装cffi需要gcc，而alpine映像中不包含该文件。

如果运行

docker run -it python:3.6.5-alpine sh

然后在容器中运行

pip install cffi==1.12.3

将得到：

    unable to execute 'gcc': No such file or directory
    error: command 'gcc' failed with exit status 1

    ----------------------------------------
Command "/usr/local/bin/python -u -c "import setuptools, tokenize;__file__='/tmp/pip-install-juslf1fb/cffi/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-record-md66dk3u/install-record.txt --single-version-externally-managed --compile" failed with error code 1 in /tmp/pip-install-juslf1fb/cffi/

要解决此问题，您可以使用python镜像的stretch版本，如：

FROM python:3.6.5-stretch