[openstack-dev] [Neutron] Core API vs extension: the subnet pool feature
amotoki at gmail.com
Mon Mar 30 20:59:35 UTC 2015
I am now reading the detail from Salvatore, but would like to response
I don't want to kill this useful feature too and move the thing forward.
I am fine with the empty/shim extension approach.
The subnet pool is regarded as a part of Core API, so I think this
extension can be
always enabled even if no plugin declares to use it.
Sorry for interrupting the work at the last stage, and thank for understanding.
2015-03-31 5:28 GMT+09:00 Carl Baldwin <carl at ecbaldwin.net>:
> If we go with the empty extension you proposed in the patch will that be
> We've got to stop killing new functionality on the very last day like this .
> It just kills progress. This proposal isn't new.
> On Mar 30, 2015 11:37 AM, "Akihiro Motoki" <amotoki at gmail.com> wrote:
>> Hi Neutron folks
>> (API folks may be interested on this)
>> We have another discussion on Core vs extension in the subnet pool
>> feature reivew
>> We did the similar discussion on VLAN transparency and MTU for a
>> network model last week.
>> I would like to share my concerns on changing the core API directly.
>> I hope this help us make the discussion productive.
>> Note that I don't want to discuss the micro-versioning because it
>> mainly focues on Kilo FFE BP.
>> I would like to discuss this topic in today's neutron meeting,
>> but I am not so confident I can get up in time, I would like to send this
>> The extension mechanism in Neutron provides two points for extensibility:
>> - (a) visibility of features in API (users can know which features are
>> available through the API)
>> - (b) opt-in mechanism in plugins (plugin maintainers can decide to
>> support some feature after checking the detail)
>> My concerns mainly comes from the first point (a).
>> If we have no way to detect it, users (including Horizon) need to do a
>> dirty work around
>> to determine whether some feature is available. I believe this is one
>> important point in API.
>> On the second point, my only concern (not so important) is that we are
>> making the core
>> API change at this moment of the release. Some plugins do not consume
>> db_base_plugin and
>> such plugins need to investigate the impact from now on.
>> On the other hand, if we use the extension mechanism all plugins need to
>> their extension list in the last moment :-(
>> My vote at this moment is still to use an extension, but an extension
>> layer can be a shim.
>> The idea is to that all implementation can be as-is and we just add an
>> extension module
>> so that the new feature is visible thru the extension list.
>> It is not perfect but I think it is a good compromise regarding the first
>> I know there was a suggestion to change this into the core API in the
>> spec review
>> and I didn't notice it at that time, but I would like to raise this
>> before releasing it.
>> For longer term (and Liberty cycle), we need to define more clear
>> on "Core vs extension vs micro-versioning" in spec reviews.
>> OpenStack Development Mailing List (not for usage questions)
>> Unsubscribe: OpenStack-dev-request at lists.openstack.org?subject:unsubscribe
> OpenStack Development Mailing List (not for usage questions)
> Unsubscribe: OpenStack-dev-request at lists.openstack.org?subject:unsubscribe
Akihiro Motoki <amotoki at gmail.com>
More information about the OpenStack-dev