Re: [netmod] status-description

[Martin Björklund <[e-mail]>]

Hi,

Balázs Lengyel <[e-mail]> wrote:
> Hello,
> While status-description is not a critical part of this work, it is
> still useful, does not harm and is such a small addition, I do not
> understand why Martin objects.

Every additional statement adds to the overall complexity.  As Jason
explained, this particular statement doesn't really help much.


/martin


> 
> So why is status-description good:
> Sometimes additional information is needed about deprecation,
> obsolescence:
> - is the item still fully functional?
> - when will its functionality be removed?
> - when will the schema node itself be removed?
> - is there a replacement or workaround that could/should be used instead
> - of deprecated/obsolete item?
> The text can be used by tools. Using a separate statement to provide
> this
> information is a method to separate the main description from this
> status specific description.
> In most cases both in the CLI and on NMS GUIs only the description is
> displayed.
> However there is a possibility  to display the status information too.
> 
> In a way it is similar why we have separate description, contact,
> reference, organization statements under module.
> All these are just text, they could all be pushed under a single
> description statement. Tools can't act on these automatically, still
> it is good to separate them.
> 
> Regards Balazs
> 
> -----Original Message-----
> From: netmod <[e-mail]> On Behalf Of Sterne, Jason
> (Nokia - CA/Ottawa)
> Sent: 2020. április 29., szerda 23:38
> To: Reshad Rahman (rrahman) <rrahman=[e-mail]>;
> Martin Björklund <[e-mail]>; [e-mail]
> Subject: Re: [netmod] status-description (WAS Re: mbj review of
> draft-verdt-netmod-yang-module-versioning-01)
> 
> I think we could wait until YANG 2.0 to add a description to the
> status.
> 
> Without a status description, an intelligent "YANG diff" of the models
> would produce this:
> a) new status deprecated statement
> b) change to a description
> 
> With a status description we'd identify this:
> a) new status deprecated statement
> b) new status description
> 
> In both cases it is (a) that identifies the most clear information.
> 
> In both cases (b) provides no additional information that can be acted
> upon in an automated fashion. The tool could only flag that (b)
> occurred in both cases and a human would then have to go look at it.
> 
> If the only change between two versions of a module was a status
> description change, then again a human would have to take a look. If
> we add some sort of "nbc" tag to the leaf for tooling, then it also
> doesn't matter which description changed.
> 
> Jason
> 
> 
> > -----Original Message-----
> > From: netmod <[e-mail]> On Behalf Of Reshad Rahman
> > (rrahman)
> > Sent: Friday, March 27, 2020 5:43 PM
> > To: Martin Björklund <[e-mail]>; [e-mail]
> > Subject: [netmod] rev:status-description (WAS Re: mbj review of 
> > draft-verdt-
> > netmod-yang-module-versioning-01)
> > 
> > Hi,
> > 
> > https://github.com/netmod-wg/yang-ver-dt/issues/51
> > 
> >         o  3.4
> > 
> >              leaf imperial-temperature {
> >                type int64;
> >                units "degrees Fahrenheit";
> >                status deprecated {
> >                  rev:status-description
> >                    "Imperial measurements are being phased out in favor
> >                     of their metric equivalents.  Use metric-temperature
> >                     instead.";
> >                }
> >                description
> >                  "Temperature in degrees Fahrenheit.";
> >              }
> > 
> >           I don't think rev:status-description is necessary / worth it.  This
> >           can easily be written with the normal description statement
> >           instead:
> > 
> >              leaf imperial-temperature {
> >                type int64;
> >                units "degrees Fahrenheit";
> >                status deprecated;
> >                description
> >                    "Imperial measurements are being phased out in favor
> >                     of their metric equivalents.  Use metric-temperature
> >                     instead.
> > 
> >                     Temperature in degrees Fahrenheit.";
> >              }
> > 
> > While rev:status-description isn't strictly necessary, without it we'd
> > have to modify the node's description as you pointed out. That'd make 
> > tooling more
> > difficult: is the description change BC or NBC? Also, a user looking 
> > at a diff would need to go through the description change. Use of  
> > rev:status- description makes this easier to handle.
> > 
> > Regards,
> > Reshad.
> > 
> > 
> > 
> > On 2020-03-20, 5:08 PM, "netmod on behalf of Reshad Rahman (rrahman)"
> > <[e-mail] on behalf of
> > rrahman=[e-mail]> wrote:
> > 
> >     Hi Martin,
> > 
> >     We've opened issues to track your review comments (see below). 
> > Will kick off separate therads for each issue.
> > 
> >     https://github.com/netmod-wg/yang-ver-
> > dt/issues?q=is%3Aissue+is%3Aopen+label%3Aupdated-mod-rev-handling
> > 
> >     Regards,
> >     Reshad.
> > 
> >     On 2020-03-10, 3:31 PM, "netmod on behalf of Martin Björklund" 
> > <netmod- [e-mail] on behalf of [e-mail]> wrote:
> > 
> >         Hi,
> > 
> >         Here are my review comments of
> >         draft-verdt-netmod-yang-module-versioning-01.
> > 
> > 
> > 
> >         o  3.1.1
> > 
> >             o  In statements that have any data definition statements as
> >                substatements, those data definition substatements MAY be
> >                reordered, as long as they do not change the ordering or any
> >                "rpc"
> >                "input" substatements.
> > 
> >           I think this needs to capture that no descendant statements to
> >           "input" can be reordered.  Same for "output" (note, "input" and
> >           "output" in both "rpc" and "action").
> > 
> > 
> >         o  3.3
> > 
> >             All revision labels that match the pattern for the "version"
> >             typedef in the ietf-yang-semver YANG module MUST be interpreted
> >             as
> >             YANG semantic version numbers.
> > 
> >           I don't think this is a good idea.  Seems like a layer violation.
> >           What if my project use another dialect of semver, that wouldn't be
> >           possible with this rule.  I think this needs to be removed.
> > 
> > 
> >         o  3.3
> > 
> >             Submodules MUST NOT use revision label schemes that could 
> > be confused
> >             with the including module's revision label scheme.
> > 
> >           Hmm, how do I ensure that this MUST NOT is handled correctly?  What
> >           exactly does "could be confused with" mean?
> > 
> > 
> >         o  3.3
> > 
> >               In the filename of a YANG module, where it takes the form:
> >               module-
> >               or-submodule-name ['@' revision-label] ( '.yang' / 
> > '.yin' )
> > 
> >           Should this section update 5.2 of RFC 7950?  I know that 5.2 just
> >           says "SHOULD".  But existing tools implement this SHOULD, and they
> >           need to be updated to handle this new convention.
> > 
> >           But I wonder if this a good idea.  It means that a tool that looks
> >           for a module with a certain revision date cannot simply check the
> >           filenames, but need to parse all available modules (wijust 
> > to find the
> > 
> > 
> > 
> >         o  3.4
> > 
> >              leaf imperial-temperature {
> >                type int64;
> >                units "degrees Fahrenheit";
> >                status deprecated {
> >                  rev:status-description
> >                    "Imperial measurements are being phased out in favor
> >                     of their metric equivalents.  Use metric-temperature
> >                     instead.";
> >                }
> >                description
> >                  "Temperature in degrees Fahrenheit.";
> >              }
> > 
> >           I don't think rev:status-description is necessary / worth it.  This
> >           can easily be written with the normal description statement
> >           instead:
> > 
> >              leaf imperial-temperature {
> >                type int64;
> >                units "degrees Fahrenheit";
> >                status deprecated;
> >                description
> >                    "Imperial measurements are being phased out in favor
> >                     of their metric equivalents.  Use metric-temperature
> >                     instead.
> > 
> >                     Temperature in degrees Fahrenheit.";
> >              }
> > 
> > 
> >         o  3.5
> > 
> >           The example modules should be legal YANG modules.  Use e.g.
> >           "urn:example:module" as namespace.
> > 
> >           Also, the modules are missing the last "}", which confuses the
> >           "rfcstrip" tool.
> > 
> > 
> >         o 4.1.1
> > 
> >             Alternatively, the first example could have used the revision
> >             label
> >             "1.0.0" instead, which selects the same set of
> >             revisions/versions.
> > 
> >             import example-module {
> >               rev:revision-or-derived 1.0.0;
> >             }
> > 
> >           Shouldn't this be s/1.0.0/2.0.0/g ?
> > 
> > 
> >         o  5
> > 
> >           I think the module name "ietf-yl-revisions" should be changed to
> >           "ietf-yang-library-revisions".   "yl" is not a well-known acronym.
> > 
> > 
> >         o  5.2.2
> > 
> >           Wouldn't it be better if the leaf "deprecated-nodes-implemented"
> >           and
> >           "obsolete-nodes-absent" were of type "boolean" rather than type
> >           "empty"?
> > 
> > 
> >         o  7.1
> > 
> >           The text says:
> > 
> >             All IETF YANG modules MUST include revision-label statements for
> >             all
> >             newly published YANG modules, and all newly published revisions
> >             of
> >             existing YANG modules.  The revision-label MUST take the form of
> >             a
> >             YANG semantic version number [I-D.verdt-netmod-yang-semver].
> > 
> >           I strongly disagree with this new rule.  IETF modules use a linear
> >           history, so there are no reasons to use "modified semver".
> > 
> >           It is ok to use rev:nbc-changes if needed, though.
> > 
> > 
> >         o 7.1.1
> > 
> >           There is a missing " in:
> > 
> >            4.  For status "obsolete", it is RECOMMENDED to keep the "status-
> >                description" information, from when the node had status
> >                "deprecated, which is still relevant.
> >          HERE  -----------^
> > 
> > 
> >         o  8
> > 
> >           s/CODE ENDS>/<CODE ENDS>/
> > 
> > 
> >         o Both YANG modules
> > 
> >           All extensions should specify the grammar; i.e., in which
> >           statements
> >           they can be present and which substatements they can have.
> > 
> > 
> > 
> >         /martin
> > 
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> > 
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