NETCONF Model for NMDA
draft-dsdt-nmda-netconf-00

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 draft details those new operations.

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 http://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 5, 2018.

Copyright Notice

Copyright (c) 2017 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 (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 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
• 1.1. Keywords
• 1.2. Terminology
• 2. The NMDA Model for NETCONF
• 2.1. Operations
• 2.1.1. The <get‑data> Operation
• 2.1.2. The <edit‑data> Operation
• 2.2. Augmentations to the Base NETCONF Model
• 2.3. RPCs and Actions
• 3. YANG Model
• 4. IANA Considerations
• 5. Security Considerations
• 6. Informative References
• Appendix A. Examples
• Authors' Addresses

1. Introduction

This document provides a YANG model that adds NETCONF ([RFC6241]) support for the emerging "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.

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 target 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 mirrors the "filter" parameter of the "get‑config" operation, but it is modified to use "type anydata" for configuration content, rather than the "get‑config"'s use of "type anyxml".

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 Attribute

The "get‑data" operation adds a new boolean parameter named "origin", which requests that the server return the "origin" information as detailed in the NMDA. This parameter is only valid for <operational> and any datastores with identities derived from the "operational" identity.

Data from <operational> can come from multiple sources. The server should return the most accurate value for the "origin" attribute as possible, indicating the source of the operational value.

When encoding the origin attribute for a hierarchy of returned nodes, the origin attribute may be omitted when the value matches that of the parent node.

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 "target" 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.

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 operation and actions is <operational>.

3. YANG Model

<CODE BEGINS> file "ietf-netconf-datastores@2017-06-30.yang"

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

  import ietf-inet-types {
    prefix inet;
  }
  import ietf-datastores {
    prefix ds;
  }
  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
           <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 2017-06-30 {
    description
      "Initial revision.";
    reference "RFC XXXX: NETCONF Support for NMDA";
  }

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

  rpc get-data {
    description
      "Get data from an NMDA datastore";
    input {
      leaf source {
        type ncds:datastore;
        description
          "Datastore from which to retrieve data.";
      }
      anydata filter {
        description
          "Subtree or XPath filter to use.";
        nc:get-filter-element-attributes;
      }
    }
    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 target {
        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.";
      }
      uses ncwd:with-defaults-parameters;
      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.
   */

  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 has no actions for IANA.

5. Security Considerations

This document has no security considerations.

6. Informative References

Appendix A. Examples

Authors' Addresses