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On Mon, Feb 1, 2021 at 5:07 AM Gorka Eguileor <geguileo at redhat.com> wrote:
>
> On 29/01, Ghanshyam Mann wrote:
> >  ---- On Fri, 29 Jan 2021 11:23:47 -0600 Gorka Eguileor <geguileo at redhat.com> wrote ----
> >  > On 28/01, Lance Bragstad wrote:
> >  > > Hey folks,
> >  > >
> >  > > As I'm sure some of the cinder folks are aware, I'm updating cinder
> >  > > policies to include support for some default personas keystone ships with.
> >  > > Some of those personas use system-scope (e.g., system-reader and
> >  > > system-admin) and I've already proposed a series of patches that describe
> >  > > what those changes look like from a policy perspective [0].
> >  > >
> >  > > The question now is how we test those changes. To help guide that decision,
> >  > > I worked on three different testing approaches. The first was to continue
> >  > > testing policy using unit tests in cinder with mocked context objects. The
> >  > > second was to use DDT with keystonemiddleware mocked to remove a dependency
> >  > > on keystone. The third also used DDT, but included changes to update
> >  > > NoAuthMiddleware so that it wasn't as opinionated about authentication or
> >  > > authorization. I brought each approach in the cinder meeting this week
> >  > > where we discussed a fourth approach, doing everything in tempest. I
> >  > > summarized all of this in an etherpad [1]
> >  > >
> >  > > Up to yesterday morning, the only approach I hadn't tinkered with manually
> >  > > was tempest. I spent some time today figuring that out, resulting in a
> >  > > patch to cinderlib [2] to enable a protection test job, and
> >  > > cinder_tempest_plugin [3] that adds the plumbing and some example tests.
> >  > >
> >  > > In the process of implementing support for tempest testing, I noticed that
> >  > > service catalogs for system-scoped tokens don't contain cinder endpoints
> >  > > [4]. This is because the cinder endpoint contains endpoint templating in
> >  > > the URL [5], which keystone will substitute with the project ID of the
> >  > > token, if and only if the catalog is built for a project-scoped token.
> >  > > System and domain-scoped tokens do not have a reasonable project ID to use
> >  > > in this case, so the templating is skipped, resulting in a cinder service
> >  > > in the catalog without endpoints [6].
> >  > >
> >  > > This cascades in the client, specifically tempest's volume client, because
> >  > > it can't find a suitable endpoint for request to the volume service [7].
> >  > >
> >  > > Initially, my testing approaches were to provide examples for cinder
> >  > > developers to assess the viability of each approach before committing to a
> >  > > protection testing strategy. But, the tempest approach highlighted a larger
> >  > > issue for how we integrate system-scope support into cinder because of the
> >  > > assumption there will always be a project ID in the path (for the majority
> >  > > of the cinder API). I can think of two ways to approach the problem, but
> >  > > I'm hoping others have more.
> >  > >
> >  >
> >  > Hi Lance,
> >  >
> >  > Sorry to hear that the Cinder is giving you such trouble.
> >  >
> >  > > First, we remove project IDs from cinder's API path.
> >  > >
> >  > > This would be similar to how nova (and I assume other services) moved away
> >  > > from project-specific URLs (e.g., /v3/%{project_id}s/volumes would become
> >  > > /v3/volumes). This would obviously require refactoring to remove any
> >  > > assumptions cinder has about project IDs being supplied on the request
> >  > > path. But, this would force all authorization information to come from the
> >  > > context object. Once a deployer removes the endpoint URL templating, the
> >  > > endpoints will populate in the cinder entry of the service catalog. Brian's
> >  > > been helping me understand this and we're unsure if this is something we
> >  > > could even do with a microversion. I think nova did it moving from /v2/ to
> >  > > /v2.0/, which was technically classified as a major bump? This feels like a
> >  > > moon shot.
> >  > >
> >  >
> >  > In my opinion such a change should not be treated as a microversion and
> >  > would require us to go into v4, which is not something that is feasible
> >  > in the short term.
> >
> > We can do it by supporting both URL with and without project_id. Nova did the same way
>
> Hi,
>
> I was not doubting that this was technically possible, I was arguing
> that a change that affects every single API endpoint in Cinder would not
> be described as "micro" and doing so could be considered a bit of abuse
> to the microversion infrastructure.
>
> This is just my opinion, not the Cinder official position.
>
>
> > in Mitaka cycle and also bumped the microversion but just for
> > notification. It was done in 2.18 microversion[1].
> >
> > That way you can request compute API with or without project_id and later is recommended.
> > I think the same approach Cinder can consider.
> >
>
> Thanks for this information.  It will definitely come in handy knowing
> where we have code references if we decide to go with the microversion
> route.
>
> Cheers,
> Gorka.
>
>
> > [1] https://docs.openstack.org/nova/latest/reference/api-microversion-history.html#id16
> >
> > -gmann
> >
> >  >
> >  >
> >  > > Second, we update cinder's clients, including tempest, to put the project
> >  > > ID on the URL.
> >  > >
> >  > > After we update the clients to append the project ID for cinder endpoints,
> >  > > we should be able to remove the URL templating in keystone, allowing cinder
> >  > > endpoints to appear in system-scoped service catalogs (just like the first
> >  > > approach). Clients can use the base URL from the catalog and append the
> >  >
> >  > I'm not familiar with keystone catalog entries, so maybe I'm saying
> >  > something stupid, but couldn't we have multiple entries?  A
> >  > project-specific URL and another one for the project and system scoped
> >  > requests?
> >  >
> >  > I know it sounds kind of hackish, but if we add them in the right order,
> >  > first the project one and then the new one, it would probably be
> >  > backward compatible, as older clients would get the first endpoint and
> >  > new clients would be able to select the right one.
> >  >
> >  > > admin project ID before putting the request on the wire. Even though the
> >  > > request has a project ID in the path, cinder would ignore it for
> >  > > system-specific APIs. This is already true for users with an admin role on
> >  > > a project because cinder will allow you to get volumes in one project if
> >  > > you have a token scoped to another with the admin role [8]. One potential
> >  > > side-effect is that cinder clients would need *a* project ID to build a
> >  > > request, potentially requiring another roundtrip to keystone.
> >  >
> >  > What would happen in this additional roundtrip? Would we be converting
> >  > provided project's name into its UUID?
> >  >
> >  > If that's the case then it wouldn't happen when UUIDs are being
> >  > provided, so for cases where this extra request means a performance
> >  > problem they could just provide the UUID.
> >  >
> >  > >
> >  > > Thoughts?
> >  >
> >  > Truth is that I would love to see the Cinder API move into URLs without
> >  > the project id as well as move out everything from contrib, but that
> >  > doesn't seem like a realistic piece of work we can bite right now.

Hi,

As I've discussed in private with you folks, manila has the exact same
issue as cinder in this domain. As has been mentioned in this thread,
having the project_id in the API routes was something that most
projects forked out of nova had, since the beginning. The manila team
weighed the options we had and we concluded that the nova approach [1]
of advertising routes without project_id and raising the API
microversion is a good step for the API consumers.

This is a grey area for micro versioning, I agree - however, we're
maintaining backwards compatibility by not breaking any consumer that
would like to use project_ids in the v2 URLs. It would be a more
painful pill to swallow if we wanted to make this change at another
major API microversion given all the client automation, sdks and CLIs
written against the micro-versioned API. You could also, in theory,
make an argument that the "project_id" resolution/substitution is
owned by Keystone and the service catalog mechanism - it is controlled
by the cloud administrator who creates these endpoints/services, and
the catalog endpoints can be updated at any time. These sort of
changes are outside of the service API's control. For example, the
catalog entry for manila today can be:

     https://192.168.10.1/share/v2/{project_id}

and the administrator may decide to rename it to:

    https://shared-file-systems.fancycloud.org/v2/{project_id}

We shouldn't expect this to break anyone if the application always
used the service catalog as the source of truth, and hence, after
upgrading to Wallaby, if administrators can change the catalog
endpoint to remove the project_id, it shouldn't affect applications
negatively - and no matter our choice of major or minor versioning of
the API here, endpoint URL changes are really outside of our control.

manila's changes to remove the "project_id" requirement from URLs are
here: https://review.opendev.org/q/topic:%22bp/remove-project-id-from-urls%22

[1] https://review.opendev.org/233076


> >  >
> >  > So I think your second proposal is the way to go.
> >  >
> >  > Thanks for all the work you are putting into this.
> >  >
> >  > Cheers,
> >  > Gorka.
> >  >
> >  >
> >  > >
> >  > > [0] https://review.opendev.org/q/project:openstack/cinder+topic:secure-rbac
> >  > > [1] https://etherpad.opendev.org/p/cinder-secure-rbac-protection-testing
> >  > > [2] https://review.opendev.org/c/openstack/cinderlib/+/772770
> >  > > [3] https://review.opendev.org/c/openstack/cinder-tempest-plugin/+/772915
> >  > > [4] http://paste.openstack.org/show/802117/
> >  > > [5] http://paste.openstack.org/show/802097/
> >  > > [6]
> >  > > https://opendev.org/openstack/keystone/src/commit/c239cc66615b41a0c09e031b3e268c82678bac12/keystone/catalog/backends/sql.py
> >  > > [7] http://paste.openstack.org/show/802092/
> >  > > [8] http://paste.openstack.org/show/802118/
> >  >
> >  >
> >  >
> >
>
>