NETCONF Model for NMDA
draft-ietf-netconf-nmda-netconf-01

Network Working Group                                       M. Bjorklund
Internet-Draft                                            Tail-f Systems
Updates: 7950 (if approved)                             J. Schoenwaelder
Intended status: Standards Track                       Jacobs University
Expires: May 3, 2018                                           P. Shafer
                                                               K. Watsen
                                                        Juniper Networks
                                                               R. Wilton
                                                           Cisco Systems
                                                        October 30, 2017

                         NETCONF Model for NMDA
                   draft-ietf-netconf-nmda-netconf-01

Abstract

   The "Network Management Datastore Architecture" (NMDA) improves on
   NETCONF by adding new features to give more accurate handling of
   configuration and operational data.  These include ability to inspect
   the current operational values of configuration data, allowing
   clients to use identical paths for retrieving the configured values
   and the operational values.  These new features require additional
   operations in network management applications such as NETCONF.  This
   document details those new operations.

Status of This Memo

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   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on May 3, 2018.

Copyright Notice

   Copyright (c) 2017 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
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   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
     1.1.  Keywords  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  The NMDA Model for NETCONF  . . . . . . . . . . . . . . . . .   3
     2.1.  Operations  . . . . . . . . . . . . . . . . . . . . . . .   3
       2.1.1.  The <get-data> Operation  . . . . . . . . . . . . . .   3
       2.1.2.  The <edit-data> Operation . . . . . . . . . . . . . .   4
     2.2.  Augmentations to the Base NETCONF Model . . . . . . . . .   5
     2.3.  RPCs and Actions  . . . . . . . . . . . . . . . . . . . .   5
     2.4.  YANG Library Capability . . . . . . . . . . . . . . . . .   5
   3.  YANG Model  . . . . . . . . . . . . . . . . . . . . . . . . .   6
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   6.  Informative References  . . . . . . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  12

1.  Introduction

   This document provides a YANG model that adds NETCONF ([RFC6241])
   support for the "Network Management Datastore Architecture" (NMDA)
   [I-D.ietf-netmod-revised-datastores].  NMDA defines a framework for
   datastores, a fundamental concept binding network management data
   models to network management protocols, enabling data models to be
   written in a network management protocol agnostic way.  NETCONF
   operations currently refer to the datastores defined in the original
   model, so new operations are required to allow references to the new
   datastores.

   Operations like <copy-config>, <lock> and <unlock> are augmented to
   allow them to target additional datastores.

   In addition the original <get> operation is deprecated, since the
   information it returns is no longer needed.  <get>'s deficiencies
   were a major motivation for the NMDA.

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1.1.  Keywords

   The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14, [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here..

1.2.  Terminology

   This document uses the terminology defined by the NMDA
   [I-D.ietf-netmod-revised-datastores].

2.  The NMDA Model for NETCONF

   This section describes the changes needed for NMDA support.  These
   changes are contained in a new YANG ([RFC7950]) model
   "ietf-netconf-datastores".

   These changes include the use of source and target parameters based
   on the "datastore" identity defined in the "ietf-datastores" from
   [I-D.ietf-netmod-revised-datastores].  The use of identities allows
   future expansion in a way that the choice-based strategy from the
   original operations (e.g., <get-config>, <edit-config>) do not.

2.1.  Operations

   Support for the NMDA includes two new operations defined in this
   document.

2.1.1.  The <get-data> Operation

   The <get-data> operation retrieves data from a specific NMDA
   datastore.  This operation is similar to NETCONF's <get-config>
   operation, but adds flexibility in naming the source datastore.

   The "source" parameter indicates the datastore which is the source of
   the data to be retrieved.  This is a datastore identity.

   The <get-data> operation accepts a content filter parameter, similar
   to the "filter" parameter of "get-config", but using explicit nodes
   for subtree filtering and XPath filtering.

   Additional filters are defined to retrieve only "config true" nodes
   or nodes matching a given "origin" value.

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   The <get-data> operation also supports the "with-defaults" parameter
   as defined in [RFC6243].  The supported values follow the constraints
   given by the "with-defaults" capability.

2.1.1.1.  Origin Metadata Attribute

   The <get-data> operation adds a new parameter named "with-origin",
   which if present, requests that the server includes "origin" metadata
   anotations in its response, as detailed in the NMDA.  This parameter
   is only valid for <operational> and any datastores with identities
   derived from the "operational" identity.  Otherwise, if an invalid
   datastore is specified then an <rpc-error> element is returned with
   an <error-tag> value of "invalid-value".  "origin" metadata
   annotations are not included unless a client explicitly requesteds
   them.

   Data from <operational> can come from multiple sources.  The server
   should return the most accurate value for the "origin" metadata
   annotation as possible, indicating the source of the operational
   value, as specified in section 5.3.4 of the NMDA.

   When encoding the origin metadata annotation for a hierarchy of
   returned nodes, the annotation may be omitted for a child node when
   the value matches that of the parent node (as described in ietf-
   origin@2017-08-17).  [RFC Editor, please check published revision
   date.]

   The "with-origin" parameter is optional to support.  It is identified
   with the URI:

     urn:ietf:params:netconf:capability:with-origin:1.0

2.1.2.  The <edit-data> Operation

   The <edit-data> operation changes the contents of a specific
   datastore, similar to the <edit-config> operation, but with
   additional flexibility in naming the target datastore.

   The "datastore" parameter is a datastore identity that indicates the
   desired target datastore where changes should be made.

   The "edit-content" parameter from "edit-config" it is modified to
   allow use "type anydata" for configuration content, rather than the
   "edit-config"'s use of "type anyxml".

   The "default-operation" parameter mirrors the parameter of the
   <edit-config> operation.

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2.2.  Augmentations to the Base NETCONF Model

   Several of the operations defined in the base NETCONF data model
   (ietf-netconf@2011-06-01.yang) will continue to be used under the
   NMDA.  The <lock>, <unlock>, and <validate> operations are augmented
   with a new "datastore" leaf can indicate a desired NMDA datastore.

   Only writable datastores can be locked.

2.3.  RPCs and Actions

   RPC operations and actions can be defined in YANG modules.  The
   evaluation context for constraints and references in RPC operations
   and actions is <operational>, as specified in the NMDA.

2.4.  YANG Library Capability

   RFC Ed.: Update 201X-XX-XX below with correct date.

   Support for NMDA requires the server to implement at least revision
   201X-XX-XX of the "ietf-yang-library" module defined in
   [I-D.nmdsdt-netconf-rfc7895bis].  The server MUST advertise the
   following capability in the <hello> message (line breaks and
   whitespaces are used for formatting reasons only):

     urn:ietf:params:netconf:capability:yang-library:1.1?
       revision=<date>&checksum=<checksum-value>

   The parameter "revision" has the same value as the revision date of
   the "ietf-yang-library" module implemented by the server.  This
   parameter MUST be present.

   The parameter "checksum" has the same value as the leaf
   "/yang-library/checksum" from "ietf-yang-library".  This parameter
   MUST be present.

   With this mechanism, a client can cache the supported modules for a
   server and only update the cache if the "checksum" value in the
   <hello> message changes.

   This document updates [RFC7950], section 5.6.4, to allow servers to
   advertise the capability :yang-library:1.1 instead of :yang-
   library:1.0, and to implement the subtree "/yang-library"
   [I-D.nmdsdt-netconf-rfc7895bis] instead of "/modules-state".

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3.  YANG Model

   <CODE BEGINS> file "ietf-netconf-datastores@2017-08-24.yang"

   module ietf-netconf-datastores {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-netconf-datastores";
     prefix ncds;

     import ietf-yang-types {
       prefix yang;
     }
     import ietf-inet-types {
       prefix inet;
     }
     import ietf-datastores {
       prefix ds;
     }
     import ietf-origin {
       prefix or;
     }
     import ietf-netconf {
       prefix nc;
     }
     import ietf-netconf-with-defaults {
       prefix ncwd;
     }

     organization
       "IETF NETCONF Working Group";
     contact
       "WG Web:   <https://datatracker.ietf.org/wg/netconf/>

        WG List:  <mailto:netconf@ietf.org>

        Author:   Martin Bjorklund
              <mailto:mbj@tail-f.com>

        Author:   Juergen Schoenwaelder
              <mailto:j.schoenwaelder@jacobs-university.de>

        Author:   Phil Shafer
              <mailto:phil@juniper.net>

        Author:   Kent Watsen
              <mailto:kwatsen@juniper.net>

        Author:   Rob Wilton

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              <rwilton@cisco.com>";
     description
       "This YANG module defines a set of NETCONF operations for the
        Network Management Datastore Architecture (NMDA).

        Copyright (c) 2017 IETF Trust and the persons identified as
        authors of the code.  All rights reserved.

        Redistribution and use in source and binary forms, with or
        without modification, is permitted pursuant to, and subject to
        the license terms contained in, the Simplified BSD License set
        forth in Section 4.c of the IETF Trust's Legal Provisions
        Relating to IETF Documents
        (http://trustee.ietf.org/license-info).

        This version of this YANG module is part of RFC XXXX
        (http://www.rfc-editor.org/info/rfcxxxx); see the RFC itself
        for full legal notices.";

     revision 2017-08-24 {
       description
         "Initial revision.";
       reference "RFC XXXX: NETCONF Support for NMDA";
     }

     feature origin {
       description
         "Indicates that the server supports the 'origin' annotation.";
       reference "RFC XXXX: Network Management Datastore Architecture";
     }

     typedef datastore {
       type identityref {
         base ds:datastore;
       }
       description
         "An NMDA datastore.";
       reference "RFC XXXX: Network Management Datastore Architecture";
     }

     rpc get-data {
       description
         "Retrieve data from an NMDA datastore.";
       input {
         leaf datastore {
           type ncds:datastore;
           mandatory true;
           description

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             "Datastore from which to retrieve data.";
         }

         choice filter-spec {
           description
             "The content filter specification for this request.";

           anydata subtree-filter {
             description
               "This parameter identifies the portions of the
                target datastore to retrieve.";
             reference "RFC 6241, Section 6.";
           }
           leaf xpath-filter {
             if-feature nc:xpath;
             type yang:xpath1.0;
             description
               "This parameter contains an XPath expression
                identifying the portions of the target
                datastore to retrieve.";
           }
         }

         container where {
           description
             "Filter content with the specified criteria.  All given
              criteria are logically AND:ed.";

           leaf config {
             type boolean;
             description
               "Filter for nodes with the given value for their
                'config' property.";
           }
           leaf origin {
             if-feature origin;
             type identityref {
               base or:origin;
             }
             description
               "Filter based on 'origin' annotation.  A node matches the
                filter if its 'origin' annotation is derived from or
                equal to the given filter value.";
           }
         }

         leaf with-origin {
           when 'derived-from-or-self(../datastore, "or:operational")';

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           if-feature origin;
           type empty;
           description
             "If this parameter is present, the server will return
              the 'origin' annotation for the nodes that has one.";
         }

         uses ncwd:with-defaults-parameters;
       }

       output {
         anydata data {
           description
             "Copy of the source datastore subset which matched
              the filter criteria (if any).  An empty data
              container indicates that the request did not
              produce any results.";
         }
       }
     }

     rpc edit-data {
       description
         "Edit data in an NMDA datastore.";
       input {
         leaf datastore {
           type ncds:datastore;
           description
             "Datastore which data affects.";
         }
         leaf default-operation {
           type enumeration {
             enum "merge" {
               description
                 "The default operation is merge.";
             }
             enum "replace" {
               description
                 "The default operation is replace.";
             }
             enum "none" {
               description
                 "There is no default operation.";
             }
           }
           default "merge";
           description
             "The default operation to use.";

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         }
         choice edit-content {
           mandatory true;
           description
             "The content for the edit operation.";

           anydata config {
             description
               "Inline Config content.";
           }
           leaf url {
             if-feature nc:url;
             type inet:uri;
             description
               "URL based config content.";
           }
         }
       }
     }

     /*
      * Augment the lock and unlock operations with a
      * "datastore" parameter.
      */

     augment "/nc:lock/nc:input/nc:target/nc:config-target" {
       description
         "Add NMDA Datastore as target.";
       leaf datastore {
         type ncds:datastore;
         description
           "Datastore to lock.";
       }
     }
     augment "/nc:unlock/nc:input/nc:target/nc:config-target" {
       description
         "Add NMDA Datastore as target.";
       leaf datastore {
         type ncds:datastore;
         description
           "Datastore to unlock.";
       }
     }

     /*
      * Augment the validate operation with a
      * "datastore" parameter.
      */

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     augment "/nc:validate/nc:input/nc:source/nc:config-source" {
       description
         "Add NMDA Datastore as source.";
       leaf datastore {
         type ncds:datastore;
         description
           "Datastore to validate.";
       }
     }
   }

   <CODE ENDS>

4.  IANA Considerations

   This document registers one capability identifier URN from the
   "Network Configuration Protocol (NETCONF) Capability URNs" registry:

     Index           Capability Identifier
     -------------   ---------------------------------------------------
     :yang-library   urn:ietf:params:netconf:capability:yang-library:1.1

   This document registers a URI in the "IETF XML Registry" [RFC3688].
   Following the format in RFC 3688, the following registration has been
   made.

       URI: urn:ietf:params:xml:ns:yang:ietf-netconf-datastores

       Registrant Contact: The IESG.

       XML: N/A, the requested URI is an XML namespace.

   This document registers a YANG module in the "YANG Module Names"
   registry [RFC6020].

     name:         ietf-netconf-datastores
     namespace:    urn:ietf:params:xml:ns:yang:ietf-netconf-datastores
     prefix:       ncds
     reference:    RFC XXXX

5.  Security Considerations

   This document has no security considerations.

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6.  Informative References

   [I-D.ietf-netmod-revised-datastores]
              Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
              and R. Wilton, "Network Management Datastore
              Architecture", draft-ietf-netmod-revised-datastores-05
              (work in progress), October 2017.

   [I-D.nmdsdt-netconf-rfc7895bis]
              Bierman, A., Bjorklund, M., and K. Watsen, "YANG Library",
              draft-nmdsdt-netconf-rfc7895bis-01 (work in progress),
              July 2017.

   [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>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/info/rfc6241>.

   [RFC6243]  Bierman, A. and B. Lengyel, "With-defaults Capability for
              NETCONF", RFC 6243, DOI 10.17487/RFC6243, June 2011,
              <https://www.rfc-editor.org/info/rfc6243>.

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

Authors' Addresses

   Martin Bjorklund
   Tail-f Systems

   Email: mbj@tail-f.com

   Juergen Schoenwaelder
   Jacobs University

   Email: j.schoenwaelder@jacobs-university.de

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   Phil Shafer
   Juniper Networks

   Email: phil@juniper.net

   Kent Watsen
   Juniper Networks

   Email: kwatsen@juniper.net

   Robert Wilton
   Cisco Systems

   Email: rwilton@cisco.com

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