[Yum] mirrorlist server selection

[James Antill]

Adrian Reber <adrian at lisas.de> writes:

> On Thu, Mar 18, 2010 at 01:54:41PM +0100, Adrian Reber wrote:
>> >  Now, in theory, it'd be possible to change _getMetalink() to have a
>> > list of URLs and try each in turn until we get "something that
>> > parses". But it's not super easy, and it'd need a lot of testing
>> > (... patches accepted :).
>> 
>> I am not sure I formulated my problem correctly, so I have written a
>> patch that does what I want. Maybe this helps to describe my problem
>> better. To test it I have created a DNS entry (mirrors.lisas.de) which
>> points to four IPs:
>
> So... Any chance to get something like the patch I posted into yum?

 I don't think we'd want it in yum, for a couple of reasons:

. yum doesn't call getaddrinfo() or gethostby*() currently, and I'm
not dying to change that.

. Doing it there means it'll only affect mirrorlists, not
metalink/repomd/etc. ... which is fine for you, but I'd rather not
have more complicated code in _just_ the mirrorlist path.

. A better change comes to mind to have "mirrorlist" be a UrlList
config. and not just a Url config. option. So you can have:

[blah]
mirrorlist = http://mirror1.example.com/blah
             http://mirror2.example.com/blah

...dito. metalink. This is a bit more complicated, but the code should
be shared ... and seems "better".

. For the mirrorlist esp. we could just make failure much nicer
(eg. just use the current mirrorlist on failure).

. Someone is bound to complain that yum is doing the wrong thing
because the mirrorlist they've pointed to happens to hit 16 IPs and
the network is down somewhere.

. It just seems wrong to do it at this layer, and I worry about SSL
cert. validation etc.

 Optionally doing it in urlgrabber seems less "icky", but still has
some of the above problems.

-- 
James Antill -- james at fedoraproject.org
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