Open Stack

On Tue, Mar 14, 2017 at 9:27 PM, Clint Byrum <clint at fewbar.com> wrote:
> Excerpts from Doug Hellmann's message of 2017-03-14 20:05:54 -0400:
>> Excerpts from Doug Hellmann's message of 2017-03-14 19:20:08 -0400:
>> > Excerpts from Clint Byrum's message of 2017-03-13 13:49:22 -0700:
>> > > Excerpts from Doug Hellmann's message of 2017-03-13 15:12:42 -0400:
>> > > > Excerpts from Farr, Kaitlin M.'s message of 2017-03-13 18:55:18 +0000:
>> > > > > Proposed library name: Rename Castellan to oslo.keymanager
>> > > > >
>> > > > > Proposed library mission/motivation: Castellan's goal is to provide a
>> > > > > generic key manager interface that projects can use for their key
>> > > > > manager needs, e.g., storing certificates or generating keys for
>> > > > > encrypting data.  The interface passes the commands and Keystone
>> > > > > credentials on to the configured back end. Castellan is not a service
>> > > > > and does not maintain state. The library can grow to have multiple
>> > > > > back ends, as long as the back end can authenticate Keystone
>> > > > > credentials.  The only two back end options now in Castellan are
>> > > > > Barbican and a limited mock key manager useful only for unit tests.
>> > > > > If someone wrote a Keystone auth plugin for Vault, we could also have a
>> > > > > Vault back end for Castellan.
>> > > > >
>> > > > > The benefit of using Castellan versus using Barbican directly
>> > > > > is Castellan allows the option of swapping out for other key managers,
>> > > > > mainly for testing.  If projects want their own custom back end for
>> > > > > Castellan, they can write a back end that implements the Castellan
>> > > > > interface but lives in their own code base, i.e., ConfKeyManager in
>> > > > > Nova and Cinder. Additionally, Castellan already has oslo.config
>> > > > > options defined which are helpful for configuring the project to talk
>> > > > > to Barbican.
>> > > > >
>> > > > > When the Barbican team first created the Castellan library, we had
>> > > > > reached out to oslo to see if we could name it oslo.keymanager, but the
>> > > > > idea was not accepted because the library didn't have enough traction.
>> > > > > Now, Castellan is used in many projects, and we thought we would
>> > > > > suggest renaming again.  At the PTG, the Barbican team met with the AWG
>> > > > > to discuss how we could get Barbican integrated with more projects, and
>> > > > > the rename was also suggested at that meeting.  Other projects are
>> > > > > interested in creating encryption features, and a rename will help
>> > > > > clarify the difference between Barbican and Castellan.
>> > > >
>> > > > Can you expand on why you think that is so? I'm not disagreeing with the
>> > > > statement, but it's not obviously true to me, either. I vaguely remember
>> > > > having it explained at the PTG, but I don't remember the details.
>> > > >
>> > >
>> > > To me, Oslo is a bunch of libraries that encompass "the way OpenStack
>> > > does XXXX". When XXXX is key management, projects are, AFAICT, universally
>> > > using Castellan at the moment. So I think it fits in Oslo conceptually.
>> > >
>> > > As far as what benefit there is to renaming it, the biggest one is
>> > > divesting Castellan of the controversy around Barbican. There's no
>> > > disagreement that explicitly handling key management is necessary. There
>> > > is, however, still hesitance to fully adopt Barbican in that role. In
>> > > fact I heard about some alternatives to Barbican, namely "Vault"[1] and
>> > > "Tang"[2], that may be useful for subsets of the community, or could
>> > > even grow into de facto standards for key management.
>> > >
>> > > So, given that there may be other backends, and the developers would
>> > > like to embrace that, I see value in renaming. It would help, I think,
>> > > Castellan's developers to be able to focus on key management and not
>> > > have to explain to every potential user "no we're not Barbican's cousin,
>> > > we're just an abstraction..".
>> > >
>> > > > > Existing similar libraries (if any) and why they aren't being used: N/A
>> > > > >
>> > > > > Reviewer activity: Barbican team
>> > > >
>> > > > If the review team is going to be largely the same, I'm not sure I
>> > > > see the benefit of changing the ownership of the library. We certainly
>> > > > have other examples of Oslo libraries being managed mainly by
>> > > > sub-teams made up of folks who primarily focus on other projects.
>> > > > oslo.policy and oslo.versionedobjects come to mind, but in both of
>> > > > those cases the code was incubated in Oslo or brought into Oslo
>> > > > before the tools for managing shared libraries were widely used
>> > > > outside of the Oslo team. We now have quite a few examples of project
>> > > > teams managing shared libraries (other than their clients).
>> > > >
>> > >
>> > > While this makes sense, I'm not so sure any of those are actually
>> > > specifically in the same category as Castellan. Perhaps you can expand
>> > > on which libraries have done this, and how they're similar to Castellan?
>> >
>> > oslo.versionedobjects was extracted from nova, and came with a small
>> > set of contributors who have made up a subteam of Oslo. As far as
>> > I know, they rarely contribute outside of that library (I haven't
>> > checked lately, so apologies if my info is out of date). I forget
>> > where the oslo.policy code came from, but it is largely managed by
>> > contributors from the keystone team. Those seem quite similar to this
>> > case.
>> >
>> > Maybe I'm misunderstanding, though. Are there Oslo team members
>> > ready to sign up to help manage this new library, or is the expectation
>> > that it will be handled by exactly the same group of people under
>> > a different name?
>>
>> I feel that I need to clarify my position.
>>
>> Although I am not 100% convinced a rename and ownership change is
>> needed, if the Oslo and Barbican teams agree that it makes sense
>> and the contributors want to work under the Oslo banner, I am not
>> fundamentally opposed to the move.
>>
>> If the primary thing we seek to gain is the neutrality from having
>> the Oslo team own the library, then I am more in favor of simply
>> changing the ownership and not renaming the library, because the
>> rename comes with extra roll-out and maintenance burden (we have
>> to maintain the old library until we have no stable releases of
>> server projects using it).
>>
>
> +1 for just pulling it under the oslo umbrella but not renaming it. As
> much as I like the uniformity oslo.keymanager would bring, I think it's
> already adopted well enough we just want to make it clear that it is
> blessed and ok to adopt.

The precedent here is "tooz" that we use for DLM is under oslo umbrella.

-- Dims

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-- 
Davanum Srinivas :: https://twitter.com/dims