[Yum] yum via socks 4/5 proxy

[Zdenek Pavlas]

> Can yum be configured to download packages via socks proxy directly?
> Can yum.conf handle this?

No, it can't, ATM.  yum/config.py:

: proxy = UrlOption(default=False, schemes=('http', 'ftp', 'https'), allow_none=True)

Only these proxy schemes are supported.

Yum runs on top of urlgrabber, pycurl, and libcurl.  Since curl 7.21.7
socks{4,4a,5,5h}:// proxy protocol prefixes are supported, so adding
support in urlgrabber and yum should be quite easy, but there's some
glue code involved.  Does the following work?

$ curl http://some-url --proxy socks4://your-proxy