Re: [netmod] Definitions of YANG schema and Packages (in packages draft) - Issue #74

["Sterne, Jason (Nokia - CA/Ottawa)" <[e-mail]>]

After some discussions on the weekly calls, we are going to avoid defining "YANG schema".  We'll roll the following terms into the next version of the draft:

Abstract:

   This document defines YANG packages; a versioned organizational
   structure used to manage schema and conformance of YANG modules as a
   cohesive set instead of individually.

Terminology:

   o  YANG package: a versioned organizational structure used to manage
      a set of YANG modules that collectively define a package schema.
      YANG packages are defined in Section 5.

   o  package schema: The combined set of schema nodes defined by a YANG
      package.  Package schema can be used to define datastore schema.

Rgds,
Jason

From: Sterne, Jason (Nokia - CA/Ottawa)
Sent: Friday, January 7, 2022 5:37 PM
To: Juergen Schoenwaelder <[e-mail]>
Cc: [e-mail]
Subject: RE: [netmod] Definitions of YANG schema and Packages (in packages draft) - Issue #74


Thanks Jürgen.



That might be a good idea to be more specific (i.e. "package schema").  It would result in statements like this in the Packages draft:



YANG package: A versioned organizational structure holding a set of related YANG modules that collectively define a YANG package schema.



package schema: The combined set of schema nodes defined by a YANG package. A datastore schema can be a composition of one or more package schema.



   *  To allow YANG datastore schema to be specified in a concise way rather than…



   1.  A YANG package MAY represent a complete YANG datastore schema or only part of a YANG datastore schema with some module import dependencies missing, as described in Section 5.4.



Jason



> -----Original Message-----

> From: Jürgen Schönwälder <[e-mail]<mailto:[e-mail]>>

> Sent: Thursday, January 6, 2022 5:09 PM

> To: Sterne, Jason (Nokia - CA/Ottawa) <[e-mail]<mailto:[e-mail]>>

> Cc: [e-mail]<mailto:[e-mail]>

> Subject: Re: [netmod] Definitions of YANG schema and Packages (in packages

> draft) - Issue #74

>

> Perhaps it is best to avoid defining the term 'YANG schema', in

> particular if it is the same as the schema implied by a YANG package,

> which I would call a "package schema". I assume that a datastore can

> support multiple packages (not sure, but there is text about "the

> union of a set of compatible packages" in the YANG packages I-D) and

> hence a 'datastore schema' is a composition of one or more "package

> schema".

>

> Perhaps the term "YANG schema" should be left as an opaque name for

> any kind of schema, i.e., any of "datastore schema", "package schema",

> "TBD schema". I think we carefully avoided using "YANG schema" during

> the NMDA and YANG library update work. It might be good if the

> packages work also avoids allocating that term - and using "package

> schema" and 'datastore schema' may actually help to avoid confusion.

>

> /js

>

> On Thu, Jan 06, 2022 at 09:41:43PM +0000, Sterne, Jason (Nokia - CA/Ottawa)

> wrote:

> > Hi all,

> >

> > This email is related to the items (a) and (c) in Issue #74 of the YANG

> versioning work:

> > https://github.com/netmod-wg/yang-ver-dt/issues/74

> >

> > ========================================================

> > First some background:

> >

> > "YANG schema" is not defined in RFC7950 or 8342 (NMDA).

> >

> > 8342 defines the following:

> >

> >    o  schema node: A node in the schema tree.  The formal definition is

> >       provided in RFC 7950.

> >

> >    o  datastore schema: The combined set of schema nodes for all modules

> >       supported by a particular datastore, taking into consideration any

> >       deviations and enabled features for that datastore.

> >

> > 7950 defines the following:

> >

> >    o  schema node: A node in the schema tree.  One of action, container,

> >       leaf, leaf-list, list, choice, case, rpc, input, output,

> >       notification, anydata, and anyxml.

> >

> >    o  schema tree: The definition hierarchy specified within a module.

> >

> > ========================================================

> > Some current definitions in YANG Packages 02

> https://datatracker.ietf.org/doc/draft-ietf-netmod-yang-packages/

> >

> > Abstract

> >

> >    This document defines YANG packages, a versioned organizational

> >    structure holding a set of related YANG modules that collectively

> >    define a YANG schema.

> >

> > Section 1:

> >

> >    *  YANG schema:  A datastore schema, not bound to any particular

> datastore.

> >

> >    *  YANG package: An organizational structure containing a collection

> >       of YANG modules, normally defined in a YANG instance data file.  A

> >       YANG package defines a YANG schema by specifying a set of YANG

> >       modules and their revisions, other packages and their revisions,

> >       mandatory features, and deviations.  YANG packages are defined in

> >       Section 5.

> >

> > Section 2:

> >

> >    A YANG package is an organizational structure that groups a set of

> >    YANG modules together into a consistent versioned definition.

> >

> > Section 5:

> >

> >    A YANG package is a versioned organizational structure defining a set

> >    of related YANG modules, packages, features, and deviations.  A YANG

> >    package collectively defines a YANG schema.

> >

> > ========================================================

> > Proposed updates to the packages draft (changes highlighted in red)

> > - unify the short description of a package in the 4 places (don't try to include

> all details of a package in this short description)

> > - but do we need more than this short description in the abstract and

> sections 1 and 2 ?

> > - do we even need a term called "YANG Schema" ?

> >

> > Abstract

> >

> >    This document defines YANG packages: a versioned organizational

> >    structure defining a set of YANG modules, features, and deviations.

> >

> > Section 1:

> >

> >    This document also makes of the following terminology introduced in

> >    the YANG 1.1 Data Modeling Language [RFC7950]:

> >

> >    *  data node

> >

> >    *  schema node

> >

> >    In addition, this document defines the following terminology:

> >

> >   * YANG schema: The combined set of schema nodes for a set of modules,

> taking into consideration any deviations and enabled features.

> >

> >    * YANG package: A versioned organizational structure defining a set of

> YANG modules, features, and deviations.  A YANG package collectively defines

> a YANG schema.

> > - leave out "normally defined in a YANG instance data file"

> > - leave out "other packages and their revisions"

> > - leave out "submodules"

> > - leave out anything about mount points

> > - "set" vs "collection" vs "groups" vs "holding" of YANG modules:   use "set"

> of YANG modules

> >

> > Section 2:

> >

> >    A YANG package is a versioned organizational structure defining a set of

> YANG modules, features, and deviations.  For

> >    example, a YANG package could define the set of YANG modules required

> >    to implement an L2VPN service on a network device.  YANG packages can

> >    themselves refer to, and reuse, other package definitions.

> > [or add mentions of included packages and mount points here in section 2 ?

> section 1? abstract ?]

> >

> > Section 5:

> >

> >    A YANG package is a versioned organizational structure defining a set

> >    of related YANG modules, packages, features, and deviations.  A YANG

> >    package collectively defines a YANG schema.

> >

> > Jason

> >

> >

> >

>

> > _______________________________________________

> > netmod mailing list

> > [e-mail]<mailto:[e-mail]>

> > https://www.ietf.org/mailman/listinfo/netmod

>

>

> --

> Jürgen Schönwälder              Jacobs University Bremen gGmbH

> Phone: [phone]         Campus Ring 1 | 28759 Bremen | Germany

> Fax:   [phone]         <https://www.jacobs-university.de/>