openstack team mailing list archive

[Jorge Williams <jorge.williams@xxxxxxxxxxxxx>]

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On Nov 15, 2011, at 3:36 AM, Doude wrote:

> Thanks a lot for your answers.
> 
> But why do you want to move the Zone code into the extension part ?
> It's a core part of OpenStack, why it doesn't stay in the core code ?

If something is in core then it's guaranteed to be available always.  A client should be able to count on the functionality in core for a particular version of an API.  Zone's offer admin level functionality that may not be available to all users.  I don't think that Rackspace will expose Zones to it's customers right away, for example. By having Zones as an extension a client can detect whether zone support is available or not.

> 
> Another question about extensions. I had understand that an extension
> will be integrated to the core OSAPI when it will be mature, is that
> true ? The extension mechanism is like an incubator for OSAPI
> functionalities ?

Yes, the extension mechanism can be used as an incubator for functionality.   But, not all extensions are destine to make it to the core.  Some extension for example will cover niche functionality that may be useful for a small set of users. Other extension may cover functionality that would set the bar high for folks deploying OS clouds. Other extension may expose functionality that's applicable to a specific hypervisor etc.

That said, at the end of the day, the PTL decides which of these extensions make it to core and which stay as extensions.

I've got a draft of a write up to explain extensions in some detail here:

https://github.com/RackerWilliams/OpenStack-Extensions/blob/master/apix-intro.pdf

Nothing there is set entirely in stone, but it drafts the concept as we're currently thinking of  it.  I'm in the process of setting up an extension registry and documenting a number of extensions. These certainly inform the doc above -- so expect some changes.  As soon as things stabilize I'll publish the doc in our doc site.

-jOrGe W.