Re: [netmod] Text in import to indicate whether a module is needed as import-only or as implemented

As a draft author who was asked to add text about the imports IMHO

*	it would be easy for me to remove the description from the import. Actually I really just want to know what is acceptable to the group, so I can proceed
*	I also think that adding this text is in most cases easy and it does not need updates later.
*	The rules in some cases might not be trivial.

*	Imported YAMs need to be implemented if

*	Imported parts are included in Xpath (augment, when, must, require-instance)

*	Imported YAMs do not need to be implemented if only the following are used

*	Types
*	Features
*	extensions

*	Ambiguous if

*	groupings are used
*	if the dependency is not formally defined by YANG, but functionally needed. (E.g. notification-capabilities does not formally need YANG-Push to be implemented, however there is no sense in defining capabilities if YANG-Push is itself not implemented.)
*	deviation ?
*	other cases ?

Regards Balazs

From: netmod <netmod-bounces@ietf.org> On Behalf Of Andy Bierman
Sent: 2019. december 19., csütörtök 17:23
To: Ladislav Lhotka <lhotka@nic.cz>
Cc: NetMod WG <netmod@ietf.org>
Subject: Re: [netmod] Text in import to indicate whether a module is needed as import-only or as implemented

On Thu, Dec 19, 2019 at 8:00 AM Ladislav Lhotka <lhotka@nic.cz <mailto:lhotka@nic.cz> > wrote:

On Thu, 2019-12-19 at 07:52 +0000, Schönwälder, Jürgen wrote:
> On Thu, Dec 19, 2019 at 08:23:27AM +0100, Ladislav Lhotka wrote:
> > I don't see how YANG syntax defines this. If a module imports ietf-netconf-
> > acm, it could be because
> > 
> > - it just uses a typedef, such as "node-instance-identifier", and then
> >   ietf-netconf-acm needn't be implemented (but can be),
> > 
> > or
> > 
> > - it augments ietf-netconf-acm, which makes sense only if the latter
> >   module is implemented.
> > 
> > It it the YANG library that specifies whether a module is implemented or
> > not, but the "import" statement itself doesn't tell you anything.
> > 
> 
> Can we not assume that an implementor will figure out the difference?

An implementor should be able to figure it out, but other potential module users
may not. For example, if somebody is evaluating whether to use a module for
their device or not, it is important to know that NACM has to be implemented (or
not).

You seem to be talking about a new conformance documentation procedure

that attempts to solve the problem "to use modules A, B, and C together

to achieve some functionality X, all these conditions need to be met".

(Sounds more like a problem for YANG Packages to solve)

IMO this is a much harder problem than something that can be solved

with extra description-stmt text. The writer is likely to get it wrong or not

keep it up to date, so a tool to analyze the file seems like a better solution.

Lada

Andy

> Or someone writes a pyang plugin to determine from the schema tree the
> kind of imports there are (for a given set of features).
> 
> /js
> 
-- 
Ladislav Lhotka
Head, CZ.NIC Labs
PGP Key ID: 0xB8F92B08A9F76C67

_______________________________________________
netmod mailing list
netmod@ietf.org <mailto:netmod@ietf.org> 
https://www.ietf.org/mailman/listinfo/netmod

Re: [netmod] Text in import to indicate whether a module is needed as import-only or as implemented

Attachment: smime.p7s