[Freeipa-devel] [PATCH 0373] Upgrade: Fix IPA version comparison

[Jan Cholasta]

On 11.12.2015 19:01, Tomas Babej wrote:
>
>
> On 12/11/2015 09:36 AM, Martin Kosek wrote:
>> On 12/10/2015 05:09 PM, Martin Basti wrote:
>>>
>>>
>>> On 10.12.2015 15:49, Tomas Babej wrote:
>>>>
>>>> On 12/10/2015 11:23 AM, Martin Basti wrote:
>>>>>
>>>>> On 10.12.2015 09:13, Lukas Slebodnik wrote:
>>>>>> On (09/12/15 19:22), Martin Basti wrote:
>>>>>>> https://fedorahosted.org/freeipa/ticket/5535
>>>>>>>
>>>>>>> Patch attached.
>>>>>> >From 8ef93485d61e8732166fb0c5b6c4559209740f3e Mon Sep 17 00:00:00
>>>>>> 2001
>>>>>>> From: Martin Basti <mbasti at redhat.com>
>>>>>>> Date: Wed, 9 Dec 2015 18:53:35 +0100
>>>>>>> Subject: [PATCH] Fix version comparison
>>>>>>>
>>>>>>> Use RPM library to compare vendor versions of IPA for redhat platform
>>>>>>>
>>>>>>> https://fedorahosted.org/freeipa/ticket/5535
>>>>>>> ---
>>>>>>> freeipa.spec.in             |  2 ++
>>>>>>> ipaplatform/redhat/tasks.py | 19 +++++++++++++++++++
>>>>>>> 2 files changed, 21 insertions(+)
>>>>>>>
>>>>>>> diff --git a/freeipa.spec.in b/freeipa.spec.in
>>>>>>> index
>>>>>>> 9f82b3695fb10c4db65cc31278364b3b34e26098..09feba7b8324f5e645da3e8010de86b6c3ee5ab9
>>>>>>>
>>>>>>>
>>>>>>> 100644
>>>>>>> --- a/freeipa.spec.in
>>>>>>> +++ b/freeipa.spec.in
>>>>>>> @@ -166,6 +166,8 @@ Requires: %{etc_systemd_dir}
>>>>>>> Requires: gzip
>>>>>>> Requires: python-gssapi >= 1.1.0
>>>>>>> Requires: custodia
>>>>>>> +Requires: rpm-python
>>>>>>> +Requires: rpmdevtools
>>>>>> Could you explain why do you need the 2nd package?
>>>>>> It does not contains any python modules
>>>>>> and I cannot see usage of any binary in this patch
>>>>>>
>>>>>> LS
>>>>> Thanks for this catch, it is actually located in yum package, I rather
>>>>> copy stringToVersion function from there to IPA, to avoid dependency
>>>>> hell
>>>>>
>>>>> Updated patch attached.
>>>>>
>>>>>
>>>> Looking good. The __cmp__ function, however, is not available in Python
>>>> 3. As we will eventually support python3 in RHEL as well, maybe we
>>>> should make sure even platform-dependent parts are python3 compatible?
>>>> For the future's sake.
>>>>
>>>> Tomas
>>>>
>>> Thanks,
>>>
>>> python 3 compatible patch attached.
>>
>> I wonder why we have to add so much code here and reimplement RPM
>> version checking if it is already provided by rpmdevtools:
>>
>> ~~~
>> $ /usr/bin/rpmdev-vercmp ipa-4.2.0-15.el7 4.2.0-15.el7_2.3; echo $?
>> WARNING: hyphen in release1: 4.2.0-15.el7
>>
>> rpmdev-vercmp <epoch1> <ver1> <release1> <epoch2> <ver2> <release2>
>> rpmdev-vercmp <EVR1> <EVR2>
>> rpmdev-vercmp # with no arguments, prompt
>>
>> Exit status is 0 if the EVR's are equal, 11 if EVR1 is newer, and 12 if
>> EVR2
>> is newer.  Other exit statuses indicate problems.
>>
>> ipa-4.2.0-15.el7 < 4.2.0-15.el7_2.3
>> 12
>> ~~~
>>
>> which could be directly called from __eq__ or __lt__, since we are in
>> platform specific code anyway already.
>>
>> Martin
>
> Imho we should generally prefer reaching out to a Python library rather
> launching a subprocess to compare the versions, it's unnecessary overhead.
>
> That said, the main argument for the usage of rpm-python over
> rpmdevtools I see is that rpm-python is very likely to be present on the
> system (i.e. it is yum's own dependency), while rpmdevtools will not be
> present by default.
>
>  From the standpoint of trying to minimize the size of freeipa
> installation (i.e recent wget -> curl migration), we should keep the
> spirit here and do not introduce a dependency for a collection of
> developer tools.
>
> /2 cents

+1, also a single function is hardly "much code".

-- 
Jan Cholasta