Re: [yang-doctors] [IANA #1289473] Revision statements in IANA-maintained YANG modules

Dne 22. 11. 23 v 11:24 Martin Björklund napsal(a):
> Hi,
> 
> Ladislav Lhotka <ladislav.lhotka=40nic.cz@dmarc.ietf.org> wrote:
>> Hi Amanda,
>>
>> "Amanda Baber via RT" <iana-issues@iana.org> writes:
>>
>>> Hi,
>>>
>>> We came across an issue when attempting to validate RFC 9403's
>>> ietf-rib-extension@2023-11-20.yang module before posting.
>>>
>>> That module refers to iana-routing-types@2022-08-19.yang, and pyang is
>>> refusing to validate it on the grounds that
>>> iana-routing-types@2022-08-19.yang doesn't have references for its
>>> revision statements. (Which it indeed does not.)
>>>
>>> However, if we try to validate iana-routing-types@2022-08-19.yang
>>> directly, we don't get any errors.
>>>
>>> Which pyang reaction is correct?
> 
> When I validate this module directly with pyang, I get the errors:
> 
>    $ pyang --ietf iana-routing-types@2022-08-19.yang
>    iana-routing-types@2022-08-19.yang:35: error: RFC 8407: 4.8: statement "revision" must have a "reference" substatement
>    ...
> 
> 
>>
>> RFC 8407 states in sec. 4.8:
>>
>>    The "revision" statement MUST have a "reference" substatement.
>>
>> The module description refers to RFC 8294 though, and I am not sure
>> how this particular module is updated and whether there is always a
>> relevant reference available for a given revision.
>>
>>>
>>> One larger issue is that we weren't aware that we needed to add
>>> references for revision statements in the IANA-maintained modules. We
>>> have no expertise in YANG and have been relying entirely on validation
>>> tools (and on IANA Considerations sections for registry maintenance
>>> instructions in general).
>>>
>>> Should we go back and add references to revision statements for all
>>> the IANA-maintained modules?
>>
>> This could lead to problems with versioning of modules.
>>
>>>
>>> Do we need to do so only going forward?
>>
>> I'd suggest to add reference statements to future (substantial)
>> revisions of modules, perhaps even retroactively, but only where it
>> makes sense.
>>
>>>
>>> Either way, we have two questions:
>>>
>>> 1) Many of the registries mirrored by the IANA-maintained modules have
>>> First Come First Served or Expert Review ranges that don't require
>>> that the applicant provide a specification. For those registrations,
>>> we list the name of a contact person in the registry's "Reference"
>>> field. In the module, would we continue to omit the reference field?
>>
>> If there is no suitable document to refer to, it makes no sense to me
>> to add any stub references. RFC 8407 is IMO unnecesarily strict here,
>> and a SHOULD might suffice.
> 
> The full text in RFC 8407 is:
> 
>     A "revision" statement MUST be present for each published version of
>     the module.  The "revision" statement MUST have a "reference"
>     substatement.  It MUST identify the published document that contains
>     the module.
> 
> In this case, there really isn't any "published document" - the module
> is published directly on the web.  One option could be to add the URL
> to the module in "reference".  The motivation for the rule is:

Right, but this link to the authoritative registry page belongs to the 
"reference" statement that is a direct substatement of "module" (see 
e.g. [1]). The problem here is that RFC 8407 requires *every* "revision" 
statement to contain "reference".

Lada

[1] 
https://www.iana.org/assignments/iana-dns-class-rr-type/iana-dns-class-rr-type.xhtml

> 
>     Modules are often extracted from their original
>     documents, and it is useful for developers and operators to know how
>     to find the original source document in a consistent manner.
> 
> So the URL would help for this.
> 
> 
> Side note.  In the description of the module it says:
> 
>       This version of this YANG module is part of RFC 8294; see
>       the RFC itself for full legal notices.";
> 
> This isn't true... Should IANA change the description of the module
> when it updates the module?  Perhaps to:
> 
>       This original version of this YANG module is part of RFC 8294; see
>       the RFC itself for full legal notices.";
> 
> 
> /martin
> 
> 
> 
> 
>>
>>>
>>> 2) When we need to correct an IANA-maintained module, in the absence
>>> of a document to refer to, what can we do to make the revision
>>> statement valid?
>>
>> I'd say yes.
>>
>> Best regards, Lada
>>
>>>
>>> Best regards,
>>>
>>> Amanda Baber
>>> IANA Operations Manager
>>>
>>> _______________________________________________
>>> yang-doctors mailing list
>>> yang-doctors@ietf.org
>>> https://www.ietf.org/mailman/listinfo/yang-doctors
>>
>> -- 
>> Ladislav Lhotka, CZ.NIC
>> PGP Key ID: 0xB8F92B08A9F76C67
>>
>> _______________________________________________
>> yang-doctors mailing list
>> yang-doctors@ietf.org
>> https://www.ietf.org/mailman/listinfo/yang-doctors

-- 
Ladislav Lhotka, CZ.NIC
PGP Key ID: 0xB8F92B08A9F76C67