[Freeipa-devel] Build system refactoring - design document

[Jan Cholasta]

On 11.10.2016 09:36, Petr Spacek wrote:
> On 11.10.2016 09:00, Jan Cholasta wrote:
>> Hi,
>>
>> On 7.10.2016 11:56, Petr Spacek wrote:
>>> Dear FreeIPA developers and packagers,
>>>
>>> you can find first version of the Build system refactoring design document on:
>>> http://www.freeipa.org/page/V4/Build_system_refactoring
>>>
>>> If you do not care about implementation details, please be so kind and quickly
>>> scan through chapter
>>> http://www.freeipa.org/page/V4/Build_system_refactoring#Feature_Management
>>>
>>> I'm not an FreeIPA packager so I might miss some important thing which needs
>>> to be configurable.
>>
>> 1) There should be a --with-python switch to select the version of Python to
>> use in our command line tools and/or during build. The default would be
>> "python", i.e. the default Python interpreter found in the path.
>
> Okay. Can we pick some descriptive name?
>
> --with-default-python
> or
> --with-<something-else>-python?
>
> I think that it would be confusing if we had just
> --with-python
> --with-python2
> --with-python3

If the default values are "python", "python2", "python3" respectively, I 
don't think it would be confusing, since most of the time you only need 
to specify --with-python, if anything.

Do we even need --with-python2 and --with-python3? I think they would 
only make sense if you had multiple Python minor versions installed and 
wanted to make packages for all of them.

>
>
> Besides that, I would make --with-default-python to accept either "2" or "3"
> (and thus use path specified by --with-python? option).
>
>
>
>> 2) There is --with-pylint, --with-jslint, but no --with-po-validate.
>
> Let me clarify: I plan to use --with for things which have paths or other
> parameters, --enable for booleans.

I see, that was not clear to me, I confused the two.

>
> Where po-validate belongs? AFAIK target validate-po in install/po/Makefile is
> calling script ../../ipatests/i18n.py which is in IPA source tree anyway.
>
> Do you want to have a --enable/--disable switch for these PO checks?

Not really.

>
>
>> 3) I would prefer that if pylint (or jslint or python-polib) is not installed
>> the build would fail instead of silently skipping the lint. Let it be a wilful
>> decision of the packager whether to run the lint or not.
>
> Yes, that is my intent. It will not skip anything automatically.

Right.

>
>
>
>> 4) It is explicitly stated that I can turn off features using
>> --without-feature. But how do I disable building server components?
>
> I've added explicit mention of --disable-feature:
> http://www.freeipa.org/index.php?title=V4%2FBuild_system_refactoring&type=revision&diff=14311&oldid=14310

Thanks.

>
>
>>> Also, I would appreciate ideas how to handle build versioning:
>>> http://www.freeipa.org/page/V4/Build_system_refactoring#Versioning
>>>
>>> My main questions are:
>>> * What is triggering IPA upgrade?
>>> * Would it be sufficient to bump release in RPM? (I mean - theoretically.
>>> Could the code be modified to detect this?)
>>>
>>> Here I'm trying to avoid unnecessary rebuilds caused by changes to
>>> IPA_VENDOR_VERSION during each build.
>>
>> How exactly is IPA_VENDOR_VERSION causing unnecessary rebuilds? I can see it
>> is written only to ipapython/version.py:
>>
>> $ git grep -E '\bIPA_VENDOR_VERSION\b'
>> Makefile:IPA_VENDOR_VERSION=$(IPA_VERSION)$(IPA_VENDOR_VERSION_SUFFIX)
>> Makefile:       sed -i -e "s:__VENDOR_VERSION__:$(IPA_VENDOR_VERSION):"
>> ipapython/version.py
>
> My bad, I should write 'IPA*VERSION*'.
>
> Especially unconditional write to version.m4 is problematic but unconditional
> writes to other files slows things as well, just not that much.

Could this be worked around by writing into a temporary file, comparing 
it with the real file and mv'ing the temporary file over the real file 
only if the differ?

-- 
Jan Cholasta