[Docs] [txt|pdf|xml|html] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: (draft-rtgyangdt-netmod-module-tags) 00 01 02

Network Working Group                                           C. Hopps
Internet-Draft                                          Deutsche Telekom
Updates: rfc6087bis (if approved)                              L. Berger
Intended status: Standards Track                 LabN Consulting, L.L.C.
Expires: January 1, 2019                                   D. Bogdanovic
                                                           June 30, 2018


                            YANG Module Tags
                    draft-ietf-netmod-module-tags-02

Abstract

   This document provides for the association of tags with YANG modules.
   The expectation is for such tags to be used to help classify and
   organize modules.  A method for defining, reading and writing a
   modules tags is provided.  Tags may be standardized and assigned
   during module definition; assigned by implementations; or dynamically
   defined and set by users.  This document provides guidance to future
   model writers and, as such, this document updates
   [I-D.ietf-netmod-rfc6087bis].

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on January 1, 2019.

Copyright Notice

   Copyright (c) 2018 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents



Hopps, et al.            Expires January 1, 2019                [Page 1]


Internet-Draft              YANG Module Tags                   June 2018


   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions Used in This Document . . . . . . . . . . . . . .   3
   3.  Tag Prefixes  . . . . . . . . . . . . . . . . . . . . . . . .   3
     3.1.  IETF Standard Tags  . . . . . . . . . . . . . . . . . . .   3
     3.2.  Vendor Tags . . . . . . . . . . . . . . . . . . . . . . .   3
     3.3.  Local Tags  . . . . . . . . . . . . . . . . . . . . . . .   3
     3.4.  Reserved Tags . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Tag Management  . . . . . . . . . . . . . . . . . . . . . . .   4
     4.1.  Module Definition Association . . . . . . . . . . . . . .   4
     4.2.  Implementation Association  . . . . . . . . . . . . . . .   4
     4.3.  Administrative Tagging  . . . . . . . . . . . . . . . . .   4
   5.  Tags Module Structure . . . . . . . . . . . . . . . . . . . .   4
     5.1.  Tags Module Tree  . . . . . . . . . . . . . . . . . . . .   4
     5.2.  Tags Module . . . . . . . . . . . . . . . . . . . . . . .   5
   6.  Other Classifications . . . . . . . . . . . . . . . . . . . .   6
   7.  Guidelines to Model Writers . . . . . . . . . . . . . . . . .   6
     7.1.  Define Standard Tags  . . . . . . . . . . . . . . . . . .   6
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
     8.1.  YANG Module Tag Prefix Registry . . . . . . . . . . . . .   7
     8.2.  YANG Module IETF Tag Registry . . . . . . . . . . . . . .   8
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   9
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .   9
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10

1.  Introduction

   The use of tags for classification and organization is fairly
   ubiquitous not only within IETF protocols, but in the internet itself
   (e.g., #hashtags).  Tags can be usefully standardized, but they can
   also serve as a non-standardized mechanism available for users to
   define themselves.  Our solution provides for both cases allowing for
   the most flexibility.  In particular, tags may be standardized as
   well as assigned during module definition; assigned by
   implementations; or dynamically defined and set by users.

   This document defines a module which provides a list of module
   entries to allow for adding or removing of tags as well as viewing
   the set of tags associated with a module.




Hopps, et al.            Expires January 1, 2019                [Page 2]


Internet-Draft              YANG Module Tags                   June 2018


   This document also defines an IANA registry for tag prefixes as well
   as a set of globally assigned tags.

   Section 7 provides guidelines for authors of YANG data models.  This
   section updates [I-D.ietf-netmod-rfc6087bis].

2.  Conventions Used in This Document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

   Note that lower case versions of these key words are used in section
   Section 7 where guidance is provided to future document authors.

3.  Tag Prefixes

   All tags have a prefix indicating who owns their definition.  An IANA
   registry is used to support standardizing tag prefixes.  Currently 3
   prefixes are defined with all others reserved.

3.1.  IETF Standard Tags

   An IETF standard tag is a tag that has the prefix "ietf:".  All IETF
   standard tags are registered with IANA in a registry defined later in
   this document.

3.2.  Vendor Tags

   A vendor tag is a tag that has the prefix "vendor:".  These tags are
   defined by the vendor that implements the module, and are not
   standardized; however, it is RECOMMENDED that the vendor include
   extra identification in the tag name to avoid collisions such as
   using the enterpise or organization name in the second field (e.g.,
   vendor:example.com:system-management:...).

3.3.  Local Tags

   A local tag is any tag that has the prefix "local:".  These tags are
   defined by the local user/administrator and will never be
   standardized.

3.4.  Reserved Tags

   Any tag not starting with the prefix "ietf:", "vendor:" or "local:"
   is reserved for future standardization.





Hopps, et al.            Expires January 1, 2019                [Page 3]


Internet-Draft              YANG Module Tags                   June 2018


4.  Tag Management

   Tags can become associated with a module in a number of ways.  Tags
   may be defined and associated at model design time, at implementation
   time, or via user administrative control.  As the main consumer of
   tags are users, users may also remove any tag, no matter how the tag
   became associated with a module.

4.1.  Module Definition Association

   A module definition SHOULD indicate a set of tags to be automatically
   added by the module implementer.  If the module definition will be
   standard the tags MUST also be standard tags (Section 3.1).  Thus,
   new modules can drive the addition of new standard tags to the IANA
   registry, and the IANA registry can serve as a check against
   duplication.

4.2.  Implementation Association

   An implementation MAY include additional tags associated with a
   module.  These tags may be standard or vendor specific tags.

4.3.  Administrative Tagging

   Tags of any kind can be assigned and removed with normal
   configuration mechanisms.

   Implementations MUST ensure that a modules tag list is consistent
   across any location from which the list is accessible.  So if a user
   adds a tag through configuration that tag should also be seen when
   using any augmentation that exposes the modules tag list.

5.  Tags Module Structure

5.1.  Tags Module Tree

   The tree associated with the tags module is:

   module: ietf-module-tags
       +--rw module-tags* [name]
          +--rw name          yang:yang-identifier
          +--rw tag*          string
          +--rw masked-tag*   string








Hopps, et al.            Expires January 1, 2019                [Page 4]


Internet-Draft              YANG Module Tags                   June 2018


5.2.  Tags Module

<CODE BEGINS> file "ietf-module-tags@2018-03-06.yang"
module ietf-module-tags {
  yang-version "1";
  namespace "urn:ietf:params:xml:ns:yang:ietf-module-tags";
  prefix "mtags";

  import ietf-yang-types {
    prefix yang;
  }

  organization "IETF NetMod Working Group (NetMod)";

  contact
    "NetMod Working Group - <netmod@ietf.org>";

  description
    "This module describes a tagging mechanism for yang module.
     Tags may be IANA assigned or privately defined types.";

  revision "2018-03-06" {
    description
      "Initial revision.";
    reference "TBD";
  }

  list module-tags {
    key "name";

    description
      "A list of modules and their associated tags";

    leaf name {
        type yang:yang-identifier;
        mandatory true;
        description
            "The YANG module or submodule name.";
    }

    leaf-list tag {
        type string;

        description
            "A tag associated with the module. See the IANA 'YANG Module
             Tag Prefix' registry for reserved prefixes and the IANA
             'YANG Module IETF Tag' registry for IETF standard tags.




Hopps, et al.            Expires January 1, 2019                [Page 5]


Internet-Draft              YANG Module Tags                   June 2018


             The operational view of this list will contain all
             user-configured tags as well as any predefined tags that
             have not been masked by the user using the masked-tag leaf
             list below.";
    }

    leaf-list masked-tag {
        type string;

        description
            "The list of tags that should not be associated with this
             module. This user can remove (mask) predefined tags by
             adding them to this list. It is not an error to add tags to
             this list that are not predefined for the module.";
    }
  }
}
<CODE ENDS>

6.  Other Classifications

   It's worth noting that a different yang module classification
   document exists [RFC8199].  That document is classifying modules in
   only a logical manner and does not define tagging or any other
   mechanisms.  It divides yang modules into 2 categories (service or
   element) and then into one of 3 origins: standard, vendor or user.
   It does provide a good way to discuss and identify modules in
   general.  This document defines standard tags to support [RFC8199]
   style classification.

7.  Guidelines to Model Writers

   This section updates [I-D.ietf-netmod-rfc6087bis].

7.1.  Define Standard Tags

   A module SHOULD indicate, in the description statement of the module,
   a set of tags that are to be associated with it.  This description
   should also include the appropriate conformance statement or
   statements, using [RFC2119] language for each tag.











Hopps, et al.            Expires January 1, 2019                [Page 6]


Internet-Draft              YANG Module Tags                   June 2018


         module example-module {
           ...
           description
             "[Text describing the module...]

             RFC<this document> TAGS:
             The following tags MUST be included by an implementation:
                  - ietf:some-required-tag:foo
                  - ...
             The following tags SHOULD be included by an implementation:
                  - ietf:some-recommended-tag:bar
                  - ...
             The following tags MAY be included by an implementation:
                  - ietf:some-optional-tag:baz
                  - ...
               ";
           ...
         }


   One SHOULD only include conformance text if there will be tags listed
   (i.e., there's no need to indicate an empty set).

   The module writer may use existing standard tags, or use new tags
   defined in the model definition, as appropriate.  New tags should be
   assigned in the IANA registry defined below, see Section 8.2 below.

8.  IANA Considerations

8.1.  YANG Module Tag Prefix Registry

   This registry allocates tag prefixes.  All YANG module tags SHOULD
   begin with one of the prefixes in this registry.

   The allocation policy for this registry is Specification Required
   [RFC5226].

   The initial values for this registry are as follows.

    prefix    description
    --------  ---------------------------------------------------
    ietf:     IETF Standard Tag allocated in the IANA YANG Module
              IETF Tag Registry.
    vendor:   Non-standardized tags allocated by the module implementer.
    local:    Non-standardized tags allocated by and for the user.

   Other SDOs (standard organizations) wishing to standardize their own
   set of tags could allocate a top level prefix from this registry.



Hopps, et al.            Expires January 1, 2019                [Page 7]


Internet-Draft              YANG Module Tags                   June 2018


8.2.  YANG Module IETF Tag Registry

   This registry allocates prefixes that have the standard prefix
   "ietf:".  New values should be well considered and not achievable
   through a combination of already existing standard tags.

   The allocation policy for this registry is IETF Review [RFC5226].

   The initial values for this registry are as follows.

   [Editor's note: many of these tags may move to
   [I-D.ietf-rtgwg-device-model] if/when that document is refactored to
   use tags.]

   +------------------------+------------------------------+-----------+
   |          Tag           |         Description          | Reference |
   +------------------------+------------------------------+-----------+
   |  ietf:rfc8199:element  |    A module for a network    | [RFC8199] |
   |                        |           element.           |           |
   |                        |                              |           |
   |  ietf:rfc8199:service  |    A module for a network    | [RFC8199] |
   |                        |           service.           |           |
   |                        |                              |           |
   | ietf:rfc8199:standard  |    A module defined by a     | [RFC8199] |
   |                        |   standards organization.    |           |
   |                        |                              |           |
   |  ietf:rfc8199:vendor   |    A module defined by a     | [RFC8199] |
   |                        |           vendor.            |           |
   |                        |                              |           |
   |   ietf:rfc8199:user    |   A module defined by the    | [RFC8199] |
   |                        |            user.             |           |
   |                        |                              |           |
   |  ietf:device:hardware  | A module relating to device  |   [This   |
   |                        | hardware (e.g., inventory).  | document] |
   |                        |                              |           |
   |  ietf:device:software  | A module relating to device  |   [This   |
   |                        |  software (e.g., installed   | document] |
   |                        |             OS).             |           |
   |                        |                              |           |
   |    ietf:device:qos     |    A module for managing     |   [This   |
   |                        |     quality of service.      | document] |
   |                        |                              |           |
   |     ietf:protocol      |   A module representing a    |   [This   |
   |                        |          protocol.           | document] |
   |                        |                              |           |
   | ietf:system-management | A module relating to system  |   [This   |
   |                        |  management (e.g., a system  | document] |
   |                        |    management protocol).     |           |



Hopps, et al.            Expires January 1, 2019                [Page 8]


Internet-Draft              YANG Module Tags                   June 2018


   |                        |                              |           |
   |  ietf:network-service  | A module relating to network |   [This   |
   |                        |   service (e.g., a network   | document] |
   |                        |      service protocol).      |           |
   |                        |                              |           |
   |        ietf:oam        |    A module representing     |   [This   |
   |                        | Operations, Administration,  | document] |
   |                        |       and Maintenance.       |           |
   |                        |                              |           |
   |      ietf:routing      | A module related to routing. |   [This   |
   |                        |                              | document] |
   |                        |                              |           |
   |    ietf:routing:rib    | A module related to routing  |   [This   |
   |                        |      information bases.      | document] |
   |                        |                              |           |
   |    ietf:routing:igp    | An interior gateway protocol |   [This   |
   |                        |           module.            | document] |
   |                        |                              |           |
   |    ietf:routing:egp    | An exterior gateway protocol |   [This   |
   |                        |           module.            | document] |
   |                        |                              |           |
   |     ietf:signaling     |    A module representing     |   [This   |
   |                        |   control plane signaling.   | document] |
   |                        |                              |           |
   |        ietf:lmp        | A module representing a link |   [This   |
   |                        |     management protocol.     | document] |
   +------------------------+------------------------------+-----------+

                     Table 1: IETF Module Tag Registry

9.  References

9.1.  Normative References

   [I-D.ietf-netmod-rfc6087bis]
              Bierman, A., "Guidelines for Authors and Reviewers of YANG
              Data Model Documents", draft-ietf-netmod-rfc6087bis-20
              (work in progress), March 2018.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
              IANA Considerations Section in RFCs", RFC 5226,
              DOI 10.17487/RFC5226, May 2008,
              <https://www.rfc-editor.org/info/rfc5226>.



Hopps, et al.            Expires January 1, 2019                [Page 9]


Internet-Draft              YANG Module Tags                   June 2018


   [RFC8199]  Bogdanovic, D., Claise, B., and C. Moberg, "YANG Module
              Classification", RFC 8199, DOI 10.17487/RFC8199, July
              2017, <https://www.rfc-editor.org/info/rfc8199>.

9.2.  Informative References

   [I-D.ietf-rtgwg-device-model]
              Lindem, A., Berger, L., Bogdanovic, D., and C. Hopps,
              "Network Device YANG Logical Organization", draft-ietf-
              rtgwg-device-model-02 (work in progress), March 2017.

Authors' Addresses

   Christan Hopps
   Deutsche Telekom

   Email: chopps@chopps.org


   Lou Berger
   LabN Consulting, L.L.C.

   Email: lberger@labn.net


   Dean Bogdanovic

   Email: ivandean@gmail.com























Hopps, et al.            Expires January 1, 2019               [Page 10]


Html markup produced by rfcmarkup 1.127, available from https://tools.ietf.org/tools/rfcmarkup/