[openstack-dev] [requirements] History lesson please

Thomas Goirand zigo at debian.org
Wed Aug 10 08:27:07 UTC 2016

On 08/09/2016 08:33 PM, Ian Cordasco wrote:
> -----Original Message-----
> From: John Dickinson <me at not.mn>
> Reply: OpenStack Development Mailing List (not for usage questions) <openstack-dev at lists.openstack.org>
> Date: August 9, 2016 at 13:17:08
> To: OpenStack Development Mailing List <openstack-dev at lists.openstack.org>
> Subject:  Re: [openstack-dev] [requirements] History lesson please
>> I'd like to advocate for *not* raising minimum versions very often. Every time some OpenStack  
>> project raises minimum versions, this change is propagated to all projects, and that  
>> puts extra burden on anyone who is maintaining packages and dependencies in their own  
>> deployment. If one project needs a new feature introduced in version 32, but another  
>> project claims compatibility with >=28, that's ok. There's no need for the second project  
>> to raise the minimum version when there isn't a conflict. (This is the position I advocated  
>> for at the Austin summit.)
>> Yes, I know that currently we don't test every possible version permutation. Yes, I know  
>> that doing that is hard. I'm not ignoring that.
> Right. So with the current set-up, where these requirements are propogated to every project, how do projects express their own minimum version requirement?
> Let's assume someone is maintaining their own packages and dependencies.
> If (for example) Glance requires a minimum version of Routes and Nova has
> a minimum requirement newer than Glance's, they're not coinstallable
> (which was the original goal of the requirements team).

Not necessarily. Take for example Swift. It has lower requirements than
other projects in OpenStack. Yet, Swift is fully co-installable with all
other OpenStack projects. They just support lower versions than others.

> If OpenStack drops the illusion of coinstallability that ends up being
> fine. I don't think anyone wants to drop that though.

Lucky, that's currently no illusion. It's a fact that currently,
everything is co-installable. :)


Thomas Goirand (zigo)

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