[PATCHES] Port pytalloc to Python 3

[Alexander Bokovoy]

On Mon, Dec 8, 2014 at 5:44 PM, Jelmer Vernooij <jelmer at samba.org> wrote:
> On Mon, Dec 08, 2014 at 10:12:08AM -0500, Simo wrote:
>> On Mon, 2014-12-08 at 14:22 +0100, Petr Viktorin wrote:
>> > On 12/05/2014 02:50 PM, Alexander Bokovoy wrote:
>> > > On Fri, Dec 5, 2014 at 2:27 PM, Petr Viktorin <pviktori at redhat.com> wrote:
>> > >>>>> For talloc, tdb and ldb it makes sense to support both python2 and
>> > >>>>> python3. For Samba itself, the burden of maintaining support for both
>> > >>>>> is much higher, and the benefits smaller.
>> > >>>>
>> > >>>> Yes. However, talloc/tdb/ldb support for both Python2 and Python3
>> > >>>> means there is need to improve our build system to support both Python
>> > >>>> versions so this task is relevant.
>> > >>
>> > >>
>> > >> Just to clarify: Are you just saying it needs to be possible to build Samba
>> > >> with Python 3?
>> > >> Or are you proposing that the modules for both Python 2 and 3 be built in
>> > >> the same configure/make run? It seems (to me, currently) that this would
>> > >> require rather big changes in Waf, while a configure-time switch for the
>> > >> Python version is practically free.
>> > > The latter because how otherwise would you be able to package both
>> > > python2 and python3 modules when packaging Samba?
>> > > We are not going to have two more samba packages differing in their
>> > > python bindings.
>> >
>> > Right.
>> > Since that the stand-alone libraries will need to support both versions
>> > for a longer time, it does make sense to invest in adding this to the
>> > build system. I'll put some effort into that.
>> >
>>
>> I do not think it is reasonable to drop Python 2 support in the short
>> term. We have a ton of people still recompiling and installing on older
>> OSs that do not have Python 3, and I am not talking only about
>> RHEL/CentOS 6 or older Ubuntu LTS but also other Unix flavors.
> Python3 was released in 2008. All supported Ubuntu LTS releases (lucid and
> later) ship Python3. Does RHEL 6 not?
No, it does not, and RHEL7 does not ship Python3 in the base either.
We (Red Hat) are willing to work on Python 3 support to eventually get
everything off the Python2 but reality is much different. Python2
support was extended to 2020 "thanks" to realization that people are
using this language actively and many of those use cases have no
incentives to move over to a slightly different language named
Python3.

So killing Python2 support in Samba would be short-sighted. However,
Petr's team (Developer Experience) is looking forward to ease Python
bindings maintenance burden so that both Python2 and Python3 bindings
can co-exist in Samba.

>> Forcing people to recompile Python 3 on those systems just to get Samba
>> to run on them seem a little bit excessive. (And please do not propose
>> to embed a version of python3 in our sources or my head will explode! :)
> I agree shipping Python3 sources is a terrible idea. :-)
>
> This would only affect those people that want a new *major* version of Samba
> and run an OS that ships Python2 but not Python3, in a year from now. Is
> that really going to affect more than a handful of people?
>
> If these users are really an issue, then let's just wait some more time until
> we attempt a migration from Python2 to Python3.
Maybe. Let's see how large will be the effort to make Python2 and
Python3 bindings buildable in waf that Petr is looking at now.
This is something that will be required anyway for libraries and can
be used as a canary to see how far can we go.

-- 
/ Alexander Bokovoy