[CentOS-devel] URLs in centos-release-<sig> packages: /altarch vs. /centos/

[Murilo Opsfelder Araujo]

On 03/06/2018 11:34 AM, Fabian Arrotin wrote:
> On 06/03/18 13:21, Murilo Opsfelder Araujo wrote:
>> On 03/06/2018 03:11 AM, Brian Stinson wrote:
>>> Hi Folks,
>>>
>>> Now that we have SIG Content in the /altarch directories for CentOS 7 on the
>>> mirrors, we need to come with some requirements and recommendations for dealing
>>> with the different locations. 
>>>
>>> tl;dr The current thinking is to add the following snippet in the %post of
>>> centos-release and release to all of the arches. This will set a yum var to the
>>> correct content location when a new system gets installed: 
>>>
>>>     `uname -m | grep -q 'x86_64'  && echo 'centos' >/etc/yum/vars/contentdir || echo 'altarch' >/etc/yum/vars/contentdir`
>>>
>>> Here's the start of a proposal from the SIG perspective
>>>
>>> ## Requirements:
>>>
>>> - The same noarch binary RPM *must* be distributable to the Extras
>>>   repo for each architecture
>>>
>>> - The centos-release-<SIG> packages *must* require centos-release
>>>
>>>
>>> ## New Recommendations for creating a centos-release file:
>>>
>>> - A yum variable called 'contentdir' will be populated with the toplevel
>>>   directory for SIGs to use
>>>
>>> 1.) Modify baseurls in the SIG repo files to look like the following (using
>>> openstack-queens as an example):
>>>
>>>
>>>  [centos-openstack-queens]
>>>  name=CentOS-7 - OpenStack queens
>>>  baseurl=https://mirror.centos.org/$contentdir/cloud/$basearch/openstack-queens/
>>>  gpgcheck=1
>>>  enabled=1
>>>  gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-SIG-Cloud
>>>  exclude=sip,PyQt4
>>>
>>>
>>> ## Discussion
>>>
>>> I'd like to hear thoughts, additions, and subtractions here before we update
>>> the SIGGuide and rework centos-release. 
>>>
>>> Cheers!
>>>
>>>
>>
>> Hi, Brian.
>>
>> I don't have the whole background of why non-x86_64 architectures are
>> placed at /altarch. Perhaps you or someone else from CentOS can provide
>> some of the details.
>>
>> Wouldn't it be simpler if a non-x86_64 architecture was just another
>> directory on, for example, /centos/7/<content>/<arch> hierarchy?
>>
>> This also simplifies packaging.
>>
>> Cheers
>> Murilo
> 
> The approach given by Brian isn't rocket science and would permit to
> cover that /altarch/ vs /centos/ difference for baseurl=  , that's also
> more or less what we use for armhfp , to redirect the kernel repo to
> correct one, so it's just a one liner snippet in the .spec for the
> -release noarch pkg :-)
> 
> WRT difference in the URI, it was a decision taken by KB and Jim when
> the first altarch (aarch64) landed on mirror.centos.org, and then we
> continued with it , as it also added more content/storage, and some
> external mirrors weren't keen on adding all those arches.
> That's the reason why they can then do an "opt-in" for those if they want :
>  - https://www.centos.org/download/mirrors/
>  - https://www.centos.org/download/altarch-mirrors/
> 
> Does that answer your question ?

Hi, Fabian.

Thanks for the background information.

Cheers
Murilo