Re: [netmod] All IETF YANG modules MUST include revision-label statements

[Andy Bierman <[e-mail]>]

On Mon, Mar 30, 2020 at 1:26 PM Reshad Rahman (rrahman) <[e-mail]>
wrote:

>
>
> *From: *'Andy Bierman' <[e-mail]>
> *Date: *Monday, March 30, 2020 at 2:51 PM
> *To: *Martin Björklund <[e-mail]>
> *Cc: *"Reshad Rahman (rrahman)" <[e-mail]>, NetMod WG <
> [e-mail]>
> *Subject: *Re: [netmod] All IETF YANG modules MUST include revision-label
> statements
>
>
>
>
>
>
>
> On Mon, Mar 30, 2020 at 11:20 AM Martin Björklund <[e-mail]>
> wrote:
>
> "Reshad Rahman (rrahman)" <[e-mail]> wrote:
> > On 2020-03-28, 4:41 AM, "Martin Björklund" <[e-mail]> wrote:
> >
> >     "Reshad Rahman (rrahman)" <[e-mail]> wrote:
> >     > Hi,
> >     >
> >     > https://github.com/netmod-wg/yang-ver-dt/issues/45
> >     >
> >     >         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.
> >     >
> >     > We believe some IETF models may not follow linear history, this was
> >     > brought up (I think) for IDR. Modified semver allows for non-linear
> >     > history and also doesn't preclude linear history. So even if we
> end up
> >     > having no IETF modules using branching, modified semver still
> works.
> >
> >     With the clarifiactions and updates in
> >     draft-verdt-netmod-yang-module-versioning, non-linear versioning
> >     works without modified semver.  So there is no technical reason to
> use
> >     modified semver in IETF modules.
> >
> > So are you proposing we use some other revision-label scheme (e.g.
> semver 2.0.0) for IETF modules?
> >
> > Or that IETF modules shouldn't use revision-labels?
>
> That IETF shouldn't use revision labels.
>
>
>
> I do not like modified semver because it will cause confusion with the
> real semver
>
> introduced by OpenConfig.
>
>
>
> Sometimes multiple release trains are needed, and the revision label (in
> addition to revision-date)
>
> can help distinguish revisions from each release train, so plain semver
> that is introduced over time
>
> would be OK.
>
>
>
> It is possible to introduce only BC changes on each release train.
>
> The BC vs. NBC issue has nothing to do with multiple release trains.
>
>
>
>
>
>
>
> I am all for using rev:nbc-changes or rev:editorial-changes (which I
> think should be added) in IETF modules.
>
>
>
> I agree that this is sufficient and modified semver provides no added
> value, only confusion.
>
> <RR> There are 2 questions here:
>
>    1. Is revision-label useful? We believe it is useful since it allows a
>    user to easily figure out whether 2 revisions are (N)BC
>    2. If it is useful, what’s the best scheme to use? Semver, modified
>    semver, …?
>
>
>
> You’re not keen on modified semver just because of the name, or are there
> other reasons?
>
>
>


IMO it is a bad idea to overload a well-understood pattern like
major.minor.patch with
extra semantics like backward-compatibility.  A tool or a person can read
the revision history
for details about revision changes.  Adding letters to the end just
confuses people who
thought they were looking at openconfig-version or a familiar linux library
version string.


I don't agree that the IETF should be working to normalize NBC changes in
the first place.


Regards,
>
> Reshad.
>
>
>
> Regards,
>
> Reshad.
>
>
>

Andy


>
>
>
> /martin
>
>
>
>
>
> Andy
>
>
>
>
> >
> > Or do you have something else in mind?
> >
> > Regards,
> > Reshad.
> >
> >     I can reluctantly accept that modified smever is published as
> >     Experimental.  But that doesn't mean that IETF modules should use it.
> >
> >
> >     /martin
> >
> >
> >     >
> >     > 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"
> >     >     <[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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> >     >         https://www.ietf.org/mailman/listinfo/netmod
> >     >
> >     >
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> >     >
> >     >
> >
> >
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