[Netmod-ver-dt] YANG package updates

[Mostly] based on the discussions last Thursday, I have had another ago at updating the packages.  Files pushed to github (as per attached).  Tree output at the end of this email.

  1.  I've currently ditched the idea of using "<pkg-name>@<version>" as the identifier for a package and just gone back to separate name and version fields.  This makes the references slightly more verbose/ugly but has the benefit of consistency between the instance data file and the on the device data.
  2.  I've renamed the file ietf-yang-package.yang to ietf-yang-package-instance.yang
  3.  The structure between the YANG instance data package definition (ignoring the standard fields for all instance data documents) and the package list entry are the same, except that the package list entry also contains the location and checksum.  It doesn't make sense to put these into the instance data document because either they can't be known (checksum) or they are self-referential (location).

module: ietf-yang-package-instance
  structure package:
    +-- name                  pkg-name
    +-- version               pkg-version
     ... this is exactly the same as everything in the package list entry below ...

module: ietf-yl-packages
  augment /yanglib:yang-library:
    +--ro package* [name version]
       +--ro name                  pkg-name
       +--ro version               pkg-versionmodule: ietf-yl-packages
       |  ... matches above, plus the following two fields ...
       +--ro location*     inet:uri
       +--ro checksum?     pkg-types:sha-256-hash

  1.  I've removed the "supported-optional-feature" leaf-list from the YANG-library augmentation (to /yanglib:yang-library/yanglib:schema).  I think that it is more consistent to define a separate package for this use case, which can define the features used by the package, and also allows the schema to be available off the device.

I've had another bash at the schema-version-selection YANG module:

  1.  The "default-schema" is now also the schema that persistent configuration is restored from.  I.e. I'm thinking that generally the default schema is what the secondary schema are either selected subsets of or are converted into.
  2.  Custom-schema are now just a named union of selectable schema.  I.e. it no longer defines a package instance to sit alongside the custom schema, clients have to manage this themselves (which seems reasonable).
  3.  I've separated the naming of schema vs the naming of packages defining those schema.  If we follow this path we need to decide whether the names can contain "@" and whether they should match "<name>@<version>".
  4.  Schema's now no longer explicitly identify a package to represent the pan-datastore schema.  It still logically exists, but isn't explicitly reported (which keeps the definition closely to RFC8525).
  5.  Each schema defines whether it is selectable as a default schema, secondary schema, or as part of a custom schema.  The schema compatibility details are also split out depending on how it is being used.  I.e. to give implementations more control of what types of

Thoughts/comments welcome.

Tree output for the updates.

Version selection:

module: ietf-schema-selection
  +--rw schema-selection
     +--rw default-schema?     -> /schema-selection/schema/name {default-schema}?
     +--rw secondary-schema*   -> /schema-selection/schema/name {secondary-schema}?
     +--rw custom-schema* [name] {custom-schema}?
     |  +--rw name               string
     |  +--rw description?       string
     |  +--rw included-schema*   -> /schema-selection/schema/name
     +--ro schema* [name]
        +--ro name                           string
        +--ro datastores* [datastore]
        |  +--ro datastore    ds:datastore-ref
        |  +--ro package
        |     +--ro name?       -> /yanglib:yang-library/yl-pkg:package/name
        |     +--ro version?    -> /yanglib:yang-library/yl-pkg:package[yl-pkg:name = current()/../name]/version
        |     +--ro checksum?   -> /yanglib:yang-library/yl-pkg:package[yl-pkg:name = current()/../name][yl-pkg:version = current()/../version] /yl-pkg:checksum
        +--ro default-schema-selectable! {default-schema}?
        |  +--ro compatible-secondary-schema*   -> /schema-selection/schema/name
        +--ro secondary-schema-selectable! {secondary-schema}?
        |  +--ro compatible-default-schema*     -> /schema-selection/schema/name
        |  +--ro compatible-secondary-schema*   -> /schema-selection/schema/name
        +--ro custom-schema-selectable! {custom-schema}?
           +--ro combinable-schema*   -> /schema-selection/schema/name

YANG instance data definition:

module: ietf-yang-package-instance

  structure package:
    +-- name                  pkg-name
    +-- version               pkg-version
    +-- timestamp?            yang:date-and-time
    +-- organization?         string
    +-- contact?              string
    +-- description?          string
    +-- reference?            string
    +-- complete?             boolean
    +-- local?                boolean
    +-- previous-version?     pkg-version
    +-- nbc-changes?          boolean
    +-- tag*                  tags:tag
    +-- mandatory-feature*    scoped-feature
    +-- included-package* [name version]
    |  +-- name                pkg-name
    |  +-- version             pkg-version
    |  +-- replaces-version*   pkg-version
    |  +-- nbc-modified?       boolean
    |  +-- location*           inet:uri
    |  +-- checksum?           pkg-types:sha-256-hash
    +-- module* [name]
    |  +-- name                 yang:yang-identifier
    |  +-- revision?            rev:revision-date-or-label
    |  +-- replaces-revision*   rev:revision-date-or-label
    |  +-- namespace?           inet:uri
    |  +-- location*            inet:uri
    |  +-- checksum?            pkg-types:sha-256-hash
   |  +-- submodule* [name]
    |     +-- name        yang:yang-identifier
    |     +-- revision    yang:revision-identifier
    |     +-- location*   inet:uri
    |     +-- checksum?   pkg-types:sha-256-hash
    +-- import-only-module* [name revision]
       +-- name                 yang:yang-identifier
       +-- revision             rev:revision-date-or-label
       +-- replaces-revision*   rev:revision-date-or-label
       +-- namespace?           inet:uri
       +-- location*            inet:uri
       +-- checksum?            pkg-types:sha-256-hash
       +-- submodule* [name]
          +-- name        yang:yang-identifier
          +-- revision    yang:revision-identifier
          +-- location*   inet:uri
          +-- checksum?   pkg-types:sha-256-hash

YANG library augmentations:

module: ietf-yl-packages
  augment /yanglib:yang-library:
    +--ro package* [name version]
       +--ro name                  pkg-name
       +--ro version               pkg-version
       +--ro timestamp?            yang:date-and-time
       +--ro organization?         string
       +--ro contact?              string
       +--ro description?          string
       +--ro reference?            string
       +--ro complete?             boolean
       +--ro local?                boolean
       +--ro previous-version?     pkg-version
       +--ro nbc-changes?          boolean
       +--ro tag*                  tags:tag
       +--ro mandatory-feature*    scoped-feature
       +--ro included-package* [name version]
       |  +--ro name                pkg-name
       |  +--ro version             pkg-version
       |  +--ro replaces-version*   pkg-version
       |  +--ro nbc-modified?       boolean
       |  +--ro location*           inet:uri
       |  +--ro checksum?           pkg-types:sha-256-hash
       +--ro module* [name]
       |  +--ro name                 yang:yang-identifier
       |  +--ro revision?            rev:revision-date-or-label
       |  +--ro replaces-revision*   rev:revision-date-or-label
       |  +--ro namespace?           inet:uri
       |  +--ro location*            inet:uri
       |  +--ro checksum?            pkg-types:sha-256-hash
       |  +--ro submodule* [name]
       |     +--ro name        yang:yang-identifier
       |     +--ro revision    yang:revision-identifier
       |     +--ro location*   inet:uri
       |     +--ro checksum?   pkg-types:sha-256-hash
       +--ro import-only-module* [name revision]
       |  +--ro name                 yang:yang-identifier
       |  +--ro revision             rev:revision-date-or-label
       |  +--ro replaces-revision*   rev:revision-date-or-label
       |  +--ro namespace?           inet:uri
       |  +--ro location*            inet:uri
       |  +--ro checksum?            pkg-types:sha-256-hash
       |  +--ro submodule* [name]
       |     +--ro name        yang:yang-identifier
       |     +--ro revision    yang:revision-identifier
       |     +--ro location*   inet:uri
       |     +--ro checksum?   pkg-types:sha-256-hash
       +--ro location*             inet:uri
       +--ro checksum?             pkg-types:sha-256-hash
  augment /yanglib:yang-library/yanglib:schema:
    +--ro package
       +--ro name?       -> /yanglib:yang-library/package/name
       +--ro version?    -> /yanglib:yang-library/package[name = current()/../name]/version
       +--ro checksum?   -> /yanglib:yang-library/package[name = current()/../name][version = current()/../version]/checksum

Thanks,
Rob