On 29/03/16 20:36 +0300, Nir Soffer wrote:
On Tue, Mar 29, 2016 at 7:44 PM, Martin Polednik <mpolednik@redhat.com> wrote:
On 29/03/16 11:12 -0400, Francesco Romani wrote:
Hi,
in the last Vdsm developer call we agreed to promote a few modules in the common repository. The common repository provides the additional guarantees over regular modules in lib/vdsm/
- stable API - (thus) safe to use across verticals
the planned moves are:
lib/vdsm/schedule.py -> lib/vdsm/common/schedule.py lib/vdsm/periodic.py -> lib/vdsm/common/periodic.py lib/vdsm/virt/api.py -> lib/vdsm/common/api.py
Question is if those modules should go under common/ or under another subdirectory, maybe infra?
Hi.
I agree that some modules should be kept (and advertised) as stable.
The name 'common' is more suited for such package as 'infra' is very ovirt specific and could hurt readability and navigation of the project. It does make sense to structure the project as follows:
lib/vdsm/common lib/vdsm/virt/common lib/vdsm/storage/common lib/vdsm/network/common
This creates a dependency between the packages. The goal is to have packages that do not depend on each other except the common package, which is library code used by other parts.
True, forgot about that. We fortunately still have possibility of further sharding 'common' if that need arises.
Taking extra care taken to avoid 'common junkyard' situation and making sure that the scope of common corresponds to it's package.
List of modules that I consider public (mostly author/main contributor of these lately):
lib/vdsm/cpuarch.py lib/vdsm/cpuinfo.py lib/vdsm/hostdev.py lib/vdsm/machinetype.py lib/vdsm/numa.py lib/vdsm/osinfo.py lib/vdsm/udevadm.py
+1
Lastly, i have a proposal about better handling of those modules.
First, the mere fact a module is placed under lib/vdsm/common provides the extra guarantees I mentioned. But should we added more annotations?
for example something like
__API__ = {}
near the top of the module
if this attribute exist, then the module is safe to use across verticals, has stable API and so forth (this is _in addition_ to the common/ package, not as replacement).
Like:
__API__ = { "introduced-in": "4.14.0", "deprecated-from": "4.18.0", "removed-at": "4.20.0", "contact": "fromani@redhat.com" }
We could refine further this concept if we like it. The idea is to be lightweight as possible while carrying all the information we need.
I agree about keeping global metadata in that way, except ideally using docstrings for better readability (e.g. interactive help()). To better reflect the needs for granular deprecation and based on our private discussion on this subject, I'd like to see at least @deprecated(target_removal_version) decorator. On top of that, we need properly documented public API and deprecation process.
Using standard way such as __author__ is better than docstrings, see for example the output of help(module)
Partially agreed. Having proper docstrings wouldn't hurt either. I frequently use repl w/ vdsm now that it is in lib, this would help myself - am I the only one? I would still like to see some kind of proper deprecation in private APIs. It might as well serve as a testing ground for deprecation in public API.
Nir _______________________________________________ Devel mailing list Devel@ovirt.org http://lists.ovirt.org/mailman/listinfo/devel