Would that return the 202 w/ a link to the task because the publication hasn't been created yet? Then using the created_resources they can see what was created, and in the event of failure the task fails and there are no created_resources.
@dkliban is ^ the idea? On Tue, Oct 31, 2017 at 3:48 PM, Dennis Kliban <[email protected]> wrote: > > > On Tue, Oct 31, 2017 at 3:40 PM, Brian Bouterse <[email protected]> > wrote: > >> +1 to updating #3033 to have a created_resources attribute which would be >> a list of GenericForeignKeys. It also needs docs, but I'm not entirely sure >> where. >> >> If we're going to introduce the above attribute, I think having the >> controller endpoint as-is would be the most usable. @dkliban do you see >> value in changing the URL structure if the created_resources attribute is >> introduced? >> >> > This API call creates a publication resource. A POST to > publishers/<id>/publications/ seems most appropriate for creating new > publication resources. > > I can help review/groom these if that is helpful. >> >> -Brian >> >> >> On Tue, Oct 31, 2017 at 1:39 PM, David Davis <[email protected]> >> wrote: >> >>> Personally I am not opposed to the url endpoint you suggest. >>> >>> It also seems like there is some consensus around adding a ‘created >>> resources’ relationship to Task or at least prototyping that out to see >>> what it would look like. >>> >>> If no one disagrees, should I update issue #3033 with those two items? >>> >>> >>> David >>> >>> On Wed, Oct 25, 2017 at 1:23 PM, Dennis Kliban <[email protected]> >>> wrote: >>> >>>> On Wed, Oct 25, 2017 at 11:24 AM, David Davis <[email protected]> >>>> wrote: >>>> >>>>> I don’t know that the ambiguity around whether a task has a >>>>> publication or not is a big deal. If I call the publication endpoint, I’d >>>>> expect a publication task which either has 1 publication or 0 (if the >>>>> publication failed) attached to it. >>>>> >>>>> In terms of ambiguity, I see a worse problem around adding a task_id >>>>> field to publications. As a user, I don’t know if a publication failed or >>>>> not when I get back a publication object. Instead, I have to look up the >>>>> task to see if it is a real (or successful) publication. Moreover, since >>>>> we >>>>> allow users to remove/clean up tasks, that task may not even exist >>>>> anymore. >>>>> >>>>> >>>> I agree that the ephemeral nature of tasks makes the originally >>>> proposed solution non-deterministic. I am open to associating 'resources >>>> created' with a task instead. >>>> >>>> However, I still think there is value in changing the rest API endpoint >>>> for starting a publish task to POST /api/v3/repositories/<repo-id> >>>> /publishers/<type>/<name>/publications/. However, I will start a >>>> separate thread for that discussion. >>>> >>>> - Dennis >>>> >>>> >>>>> >>>>> David >>>>> >>>>> On Wed, Oct 25, 2017 at 11:03 AM, Brian Bouterse <[email protected]> >>>>> wrote: >>>>> >>>>>> >>>>>> >>>>>> On Tue, Oct 24, 2017 at 10:00 PM, Michael Hrivnak < >>>>>> [email protected]> wrote: >>>>>> >>>>>>> >>>>>>> >>>>>>> On Tue, Oct 24, 2017 at 2:11 PM, Brian Bouterse <[email protected] >>>>>>> > wrote: >>>>>>> >>>>>>>> Thanks everyone for all the discussion! I'll try to recap the >>>>>>>> problem and some of the solutions I've heard. I'll also share some of >>>>>>>> my >>>>>>>> perspective on them too. >>>>>>>> >>>>>>>> What problem are we solving? >>>>>>>> When a user calls "publish" (the action API endpoint) they get a >>>>>>>> 202 w/ a link to the task. That task will produce a publication. How >>>>>>>> can >>>>>>>> the user find the publication that was produced by the task? How can >>>>>>>> the >>>>>>>> user be sure the publication is fully complete? >>>>>>>> >>>>>>>> >>>>>>>> What are our options? >>>>>>>> 1) Start linking to created objects from task status. I believe its >>>>>>>> been clearly stated about why we can't do this. If it's not clear, or >>>>>>>> if >>>>>>>> there are other things we should consider, let's talk about it. >>>>>>>> Acknowledging or establishing agreement on this is crucial because a >>>>>>>> change >>>>>>>> like this would bring back a lot of the user pain from pulp2. I >>>>>>>> believe the >>>>>>>> HAL suggestion falls into this area. >>>>>>>> >>>>>>> >>>>>>> I may have missed something, but I do not think this is clear. I >>>>>>> know that Pulp 2's API included a lot of unstructured data, but that is >>>>>>> not >>>>>>> at all what I'm suggesting here. >>>>>>> >>>>>>> It is standard and recommended practice for REST API responses to >>>>>>> include links to resources along with information about what type of >>>>>>> resource each link references. We could include a reference to the >>>>>>> created >>>>>>> resource and an identifier for what type of resource it is, and that >>>>>>> would >>>>>>> be well within the bounds of good REST API design. HAL is just one of >>>>>>> several ways to accomplish that, and I'm not pitching any particular >>>>>>> solution there. In any case, I'm not sure what the problem would be with >>>>>>> this approach. >>>>>>> >>>>>> >>>>>> I agree it is a standard practice for a resource to include links to >>>>>> other resources, but the proposal is to include "generic" links is >>>>>> different and creates a different user experience. I believe referencing >>>>>> the task from the publication will be easier for users and clients. When >>>>>> a >>>>>> user looks up a publication, they will always know they'll get between 0 >>>>>> and 1 links to a task. You can use that to check the state of the >>>>>> publication. If we link to "generic" resources (like a publication) from >>>>>> a >>>>>> task, then if I ask a user "do you expect task >>>>>> ede3af3e-d5cf-4e18-8c57-69ac4d4e4de6 to contain a link to a >>>>>> publication or not?" you can't know until you query it. I think that >>>>>> ambiguity was a pain point in Pulp2. I don't totally reject this >>>>>> solution, >>>>>> but this is an undesirable property (I think). >>>>>> >>>>>> >>>>>>> >>>>>>>> >>>>>>>> 2) Have the user find the publication via query that sorts on time >>>>>>>> and filters only for a specific publisher. This could be fragile >>>>>>>> because >>>>>>>> with a multi-user system and no hard references between publications >>>>>>>> and >>>>>>>> tasks, answering the question "which is the publication for me" is hard >>>>>>>> because another user could have submitted a publish too. While not >>>>>>>> totally >>>>>>>> perfect, this could work. >>>>>>>> >>>>>>> >>>>>>> In theory if a user queried for a publication from a specific >>>>>>> publisher that was created between the start and end times of the task, >>>>>>> that should unambiguously identify the correct publication. But >>>>>>> depending >>>>>>> on timestamps is not a particularly robust nor confidence-inspiring way >>>>>>> to >>>>>>> reference a resource. >>>>>>> >>>>>> Agreed and Agreed >>>>>> >>>>>> >>>>>>> >>>>>>>> >>>>>>>> 3) Have the user create a publication directly like any other REST >>>>>>>> resource, and help the user understand the state of that resource over >>>>>>>> time. I believe the proposal at the start of this thread is >>>>>>>> recommending >>>>>>>> this solution. I'm also +1 on this solution. >>>>>>>> >>>>>>> >>>>>>> I think the problem with this is that a user cannot create a >>>>>>> publication. A user can only ask a plugin to create a publication. Until >>>>>>> the plugin creates the publication, there is no publication. >>>>>>> >>>>>> >>>>>> Note a publication is an object, but really we mean a publication and >>>>>> it's related PublishedArtifact, PublishedMetadat, etc objects. It would >>>>>> be >>>>>> straightforward for a user to create a publication using the viewset and >>>>>> have the task associated with it call the publisher to build out the >>>>>> associated PublishedArtifact, PublishedContent, PublishedMetadata, etc. >>>>>> We >>>>>> should explore if this is good or not, but it is possible. >>>>>> >>>>>> As an aside, this is related to a problem everyone should be aware >>>>>> of: the existence of a publication does not guarantee that publication is >>>>>> finished publishing. Even with option 1, where the task creates the >>>>>> publisher and links to it in the task status, while the publisher is >>>>>> running it must save the Publication so that the PublishedArtifact, etc >>>>>> can >>>>>> link to it. So for any given publication, in order to know if it's "fully >>>>>> finished and consistent" you must be able to check the status of the >>>>>> associated task that produced it. >>>>>> >>>>>> >>>>>>> >>>>>>>> As an aside, I don't think considering versioned repos as a >>>>>>>> possible solution is helping us with this problem. The scope of the >>>>>>>> current >>>>>>>> problem is relatively small and the scope of planning for versioned >>>>>>>> repos >>>>>>>> is large. >>>>>>>> >>>>>>>> >>>>>>> Versioned repos is a potential solution. In that scenario, a user >>>>>>> would request publication of a specific repo version (perhaps >>>>>>> defaulting to >>>>>>> the latest), the publication would be linked to that version, and that >>>>>>> is >>>>>>> an easy mechanism for the user to find the publication they want. >>>>>>> Ultimately the user is interested in working with a specific content set >>>>>>> anyway. They get a repo to a state where it has the content they want, >>>>>>> and >>>>>>> then they publish that content set. No matter what we do with >>>>>>> publications, >>>>>>> users will think of them in terms of related content sets. A repo >>>>>>> version >>>>>>> is that immutable content set they can work with confidently. >>>>>>> >>>>>> >>>>>> It's neat to me that that versions are snapshots of content and >>>>>> publications are snapshots of content. Publications already create much >>>>>> of >>>>>> the value propostion of versioned repos with publications. They allow you >>>>>> to work with specific content sets like you describe. Also they allow for >>>>>> rollback. So that is all great for our users. For this thread, I want to >>>>>> bring the conversation back to where it started, solving a small problem >>>>>> about linking two resources that already exist. >>>>>> >>>>>> >>>>>>> It helps the rollback scenario a lot as well. Versioning repos >>>>>>> allows a user to see what the differences are between two content sets, >>>>>>> and >>>>>>> thus two different publications, which informs them about when and how >>>>>>> far >>>>>>> back they should roll back a distribution. >>>>>>> >>>>>> >>>>>>> - user discovers a horrible flaw in a piece of content >>>>>>> - user queries for which version of the repo introduced that piece >>>>>>> of content >>>>>>> - user updates the distribution to serve the publication that came >>>>>>> before the one which introduced the piece of content, optionally >>>>>>> re-publishing that version in case its publication was deleted or had >>>>>>> never >>>>>>> been made in the first place. >>>>>>> >>>>>>> -- >>>>>>> >>>>>>> Michael Hrivnak >>>>>>> >>>>>>> Principal Software Engineer, RHCE >>>>>>> >>>>>>> Red Hat >>>>>>> >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> Pulp-dev mailing list >>>>>> [email protected] >>>>>> https://www.redhat.com/mailman/listinfo/pulp-dev >>>>>> >>>>>> >>>>> >>>>> _______________________________________________ >>>>> Pulp-dev mailing list >>>>> [email protected] >>>>> https://www.redhat.com/mailman/listinfo/pulp-dev >>>>> >>>>> >>>> >>> >> >
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