Re: [netmod] IETF 108: Summary of insignificant whitespace changes and versioning

Jan Lindblad <janl@tail-f.com> Thu, 13 August 2020 10:53 UTC

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From: Jan Lindblad <janl@tail-f.com>
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Date: Thu, 13 Aug 2020 12:52:58 +0200
Cc: Ladislav Lhotka <ladislav.lhotka@nic.cz>, "netmod@ietf.org" <netmod@ietf.org>
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To: Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de>
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Subject: Re: [netmod] IETF 108: Summary of insignificant whitespace changes and versioning
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+1
/jan

> On 13 Aug 2020, at 12:23, Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de> wrote:
> 
> On Thu, Aug 13, 2020 at 11:37:18AM +0200, Ladislav Lhotka wrote:
>> 
>> 
>> $ pyang -f yin ietf-inet-types.yang | xmllint --c14n - | sha256sum
>> 8d1ca8f30566ce8cbeffa095e20642f8f6e9f3a724286be4ead863b4467dc40b  -
>> 
>> might be a very good start. It is certainly much more robust than
>> relying on a simple checksum of the YANG module text.
> 
> This work started with the need for _semantic_ version numbers and now
> we are down to hashes of modules? Do we still have a clear idea which
> problem we are solving?
> 
> - Sane development environments use version control systems, we should
>  in my view not attempt to go there. We should assume that people
>  developing YANG modules use version control systems to track
>  changes.
> 
> - There apparently is a need for a packaging system that can express
>  which combinations of YANG module version are known to work
>  together.
> 
> The YANG versioning work was driven (I think) by the desire to
> support non-backwards compatible changes (section 4 of
> draft-ietf-netmod-yang-versioning-reqs-03). Why do we end up
> discussing how to calculate hashes or the impact of whitespace
> changes? Whitespace and layout changes are backwards compatible,
> even today's YANG versioning rules handle them well.
> 
> /js
> 
> -- 
> Juergen Schoenwaelder           Jacobs University Bremen gGmbH
> Phone: +49 421 200 3587         Campus Ring 1 | 28759 Bremen | Germany
> Fax:   +49 421 200 3103         <https://www.jacobs-university.de/>
> 
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