[Pulp-dev] Repo version validation

Wed Oct 9 15:52:39 UTC 2019

On Wed, Oct 9, 2019 at 5:23 AM Tatiana Tereshchenko <ttereshc at redhat.com>
wrote:

> I think the main confusion I have is that we call it validation.
> Semantically, I'd expect the validation operation to complain if something
> is invalid and to pass if everything is fine.
>

Yes let's have validation perform, just validation. Thank you for bringing
us back to this. +1

> The solution [0] also implies that I think:
>         Raises:
>             django.core.exceptions.ValidationError: if the repository is
> invalid
>
> As I mentioned below I think a plugin needs to have an ability to change
> the content of a repo version, it sounds more than just validation to me.
> Let me know if I misunderstand something or misuse any terms.
>
I agree. What about if we add add_content, remove_content classmethod for
plugin writers to override on their Content subclass, and these were called
by RepositoryVersion.add_content and RepositoryVersion.remove_content?
These would be hooks similar to the validation hook, only these are
designed to "handle" changes. The queryset would be type-filtered in the
RepositoryVersion.add_content and RepositoryVersion.remove_content, so each
Content model's implementation only needs to handle it's own type and it
can rely on that. I'm open to other pattern suggestions with a similar
outcome.

This would handle the Advisory-merge use case for pulp_rpm for example. The
Advisory object would define these two hook implementations, and when
adding it would provide the merge-with-existing-content feature.

We may need to take care that references to content could be invalidated
anytime a call to RepositoryVersion.add_content or
RepositoryVersion.remove_content occurs. That sounds do-able but it becomes
a somewhat subtle requirement.

I don't think this would fully handle the dependency use case though. This
type of pattern only can account for the content that is already in the
repsitory_version being created. So it lacks a reference to for example
where content is being copied from, and what source content set it should
look into to even provide dependency resolution. Also at sync-time it
couldn't know if the packages it's "going to bring in extra" are just
coming in a later part of the pipeline. So while I think we should
implement these hooks, it doesn't solve the dependency solving use case.
I'm ok w/ that, but what do you think?

> I keep thinking these use cases are for copy not sync, because only in the
>> copy case is the plugin writer's code not already involved.
>
> I think any use case that modifies repo version in some way is important
> here - sync, copy, upload, removal of content.
> It's just happened that for sync we already have a mechanism for plugins
> to influence the result, however it can likely be simplified and reuse what
> will be implemented for the story [0] under discussion.
>
> Tanya
>
> [0] https://pulp.plan.io/issues/3541#note-3
>
> On Tue, Oct 8, 2019 at 11:01 PM Brian Bouterse <bmbouter at redhat.com>
> wrote:
>
>>
>>
>> On Tue, Oct 8, 2019 at 2:55 PM David Davis <daviddavis at redhat.com> wrote:
>>
>>> I think @bmbouter's solution could handle the first example of checking
>>> RPMs against a specific key.
>>>
>>> The second example is trickier though because the validation would have
>>> to know which module is being removed in order to know which packages to
>>> remove from the repo. This is because the packages could exist in the repo
>>> independently of the module. I think it'd have to have the list of
>>> additions/removals in order to handle that use case.
>>>
>>
>> It would have reference to the repo_version being created, so I think it
>> would have the RepositoryVersion.removed queryset to inspect.  I think this
>> is mainly useful for copy operations at which point the copy endpoint may
>> be a better tool for features like plugin-provided dependency resolution
>> versus the generic copy operations in core.
>>
>> I keep thinking these use cases are for copy not sync, because only in
>> the copy case is the plugin writer's code not already involved.
>>
>>
>>> David
>>>
>>>
>>> On Tue, Oct 8, 2019 at 12:55 PM Tatiana Tereshchenko <
>>> ttereshc at redhat.com> wrote:
>>>
>>>> The solution proposed in #3541 looks good for validation purposes.
>>>> My understanding of the problem is that a plugin needs to apply some
>>>> logic and decide which content to keep and which content to remove at repo
>>>> version creation time and perform these changes.
>>>> Examples:
>>>>  - add to a repo version only RPMs signed with a specific key
>>>>  - removal of the moduled content should automagically remove related
>>>> RPMs from a repo version.
>>>>
>>>> In theory, for the examples above, if we have validation only, user can
>>>> be forced to prepare perfect add/remove requests, however I think it won't
>>>> be a good user experience.
>>>>
>>>> Can it be done in the same way as the suggestion for validation? Just
>>>> if it makes sense for plugin to "fix" repo version itself, they will do it,
>>>> otherwise validation error can be raised. What do you think?
>>>>
>>>> Tanya
>>>>
>>>>
>>>> On Tue, Oct 8, 2019 at 4:46 PM Dennis Kliban <dkliban at redhat.com>
>>>> wrote:
>>>>
>>>>> The plan outlined in 3541 solves the problem in a way that gives
>>>>> plugin writers a lot of control. +1 to implementing it.
>>>>>
>>>>> On Thu, Oct 3, 2019 at 12:23 PM David Davis <daviddavis at redhat.com>
>>>>> wrote:
>>>>>
>>>>>> We have a blocker for Pulp 3.0 GA[0] that we need to address soon in
>>>>>> order to let plugins leverage it in their upcoming GA releases. It involves
>>>>>> allowing plugin writers to validate content in a repo version. It's
>>>>>> somewhat related to validating uniqueness in a repo version[1] except there
>>>>>> are cases other than uniqueness that plugins might want to handle. One
>>>>>> example might be a case where we want to prevent a user from adding a
>>>>>> docker tag that points to a manifest outside a repo from getting added to
>>>>>> the repo. I'm not sure if this is an actual example but it gives you an
>>>>>> idea that there might be other non-unique validation plugin writers might
>>>>>> want to add.
>>>>>>
>>>>>> Brian proposed a solution on 3541 that I think solves the problem[2].
>>>>>> I was hoping to maybe get some feedback on it so we could proceed by
>>>>>> October 9.
>>>>>>
>>>>>> [0] https://pulp.plan.io/issues/3541
>>>>>> [1] https://pulp.plan.io/issues/5008
>>>>>> [2] https://pulp.plan.io/issues/3541
>>>>>>
>>>>>> David
>>>>>> _______________________________________________
>>>>>> Pulp-dev mailing list
>>>>>> Pulp-dev at redhat.com
>>>>>> https://www.redhat.com/mailman/listinfo/pulp-dev
>>>>>>
>>>>> _______________________________________________
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>>
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