| Network Working Group | A. Bierman |
| Internet-Draft | YumaWorks |
| Intended status: Standards Track | M. Bjorklund |
| Expires: April 20, 2016 | Tail-f Systems |
| K. Watsen | |
| Juniper Networks | |
| October 18, 2015 |
YANG Module Library
draft-ietf-netconf-yang-library-02
This document describes a YANG library, which provides information about all the YANG modules used by a device to represent management and protocol information. A YANG library can be shared by multiple protocols within the same device. Simple caching mechanisms are needed to allow clients to minimize retrieval of this information.
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 April 20, 2016.
Copyright (c) 2015 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.
There is a need for standard mechanisms to identify the YANG modules and submodules that are in use by a server that utilizes YANG-based data abstractions. If a large number of YANG modules are utilized by the server, then the YANG library information needed can be relatively large. This information changes very infrequently, so it is important that clients be able to cache the YANG library and easily identify if their cache is out-of-date.
YANG library information can be different on every server, and can change at run-time or across a server reboot. Typically, a firmware upgrade is required to change the set of YANG modules used by a server.
The following information is needed by a client application (for each YANG module in the library) to fully utilize the YANG data modeling language:
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].
The following terms are defined in [RFC6241]:
The following terms are defined in [RFC6020]:
The following terms are used within this document:
A simplified graphical representation of the data model is used in this document. The meaning of the symbols in these diagrams is as follows:
The "ietf‑yang‑library" module provides information about the YANG library used by a server.
YANG Tree Diagram for "ietf‑yang‑library" module:
+--ro modules
+--ro module-set-id string
+--ro module* [name revision]
+--ro name yang:yang-identifier
+--ro revision union
+--ro schema? inet:uri
+--ro namespace inet:uri
+--ro feature* yang:yang-identifier
+--ro deviation* [name revision]
| +--ro name yang:yang-identifier
| +--ro revision union
+--ro conformance enumeration
+--ro submodules
+--ro submodule* [name revision]
+--ro name yang:yang-identifier
+--ro revision union
+--ro schema? inet:uri
This mandatory container holds the identifiers for the YANG data model modules supported by the server.
This mandatory leaf contains a unique implementation-specific identifier representing the current set of modules and submodules. This can for example be a checksum of all modules and submodules.
This leaf allows a client to fetch the module list once, cache them, and only re-fetch them if the value of this leaf has been changed.
This mandatory list contains one entry for each YANG data model module supported by the server. There MUST be an entry in this list for every YANG module that is used by the server.
The "ietf‑yang‑library" module defines monitoring information for the YANG modules used by a server.
The "ietf‑yang‑types" and "ietf‑inet‑types" modules from [RFC6991] are used by this module for some type definitions.
RFC Ed.: update the date below with the date of RFC publication and remove this note.
<CODE BEGINS> file "ietf-yang-library@2015-10-18.yang"
module ietf-yang-library {
namespace "urn:ietf:params:xml:ns:yang:ietf-yang-library";
prefix "yanglib";
import ietf-yang-types {
prefix yang;
}
import ietf-inet-types {
prefix inet;
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
WG Chair: Mehmet Ersue
<mailto:mehmet.ersue@nsn.com>
WG Chair: Mahesh Jethanandani
<mailto:mjethanandani@gmail.com>
Editor: Andy Bierman
<mailto:andy@yumaworks.com>
Editor: Martin Bjorklund
<mailto:mbj@tail-f.com>
Editor: Kent Watsen
<mailto:kwatsen@juniper.net>";
description
"This module contains monitoring information about the YANG
modules and submodules that are used within a YANG-based
server.
Copyright (c) 2015 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; see
the RFC itself for full legal notices.";
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
// RFC Ed.: remove this note
// Note: extracted from draft-ietf-netconf-yang-library-02.txt
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
revision 2015-10-18 {
description
"Initial revision.";
reference
"RFC XXXX: YANG Module Library.";
}
typedef revision-identifier {
type string {
pattern '\d{4}-\d{2}-\d{2}';
}
description
"Represents a specific date in YYYY-MM-DD format.";
}
grouping module {
description
"The module data structure is represented as a grouping
so it can be reused in configuration or another monitoring
data structure.";
grouping common-leafs {
description
"Common parameters for YANG modules and submodules.";
leaf name {
type yang:yang-identifier;
description
"The YANG module or submodule name.";
}
leaf revision {
type union {
type revision-identifier;
type string { length 0; }
}
description
"The YANG module or submodule revision date.
An empty string is used if no revision statement
is present in the YANG module or submodule.";
}
}
grouping schema-leaf {
description
"Common schema leaf parameter for modules and submodules.";
leaf schema {
type inet:uri;
description
"Contains a URL that represents the YANG schema
resource for this module or submodule.
This leaf will only be present if there is a URL
available for retrieval of the schema for this entry.";
}
}
list module {
key "name revision";
description
"Each entry represents one module currently
supported by the server.";
uses common-leafs;
uses schema-leaf;
leaf namespace {
type inet:uri;
mandatory true;
description
"The XML namespace identifier for this module.";
}
leaf-list feature {
type yang:yang-identifier;
description
"List of YANG feature names from this module that are
supported by the server.";
}
list deviation {
key "name revision";
description
"List of YANG deviation module names and revisions
used by this server to modify the conformance of
the module associated with this entry. Note that
the same module can be used for deviations for
multiple modules, so the same entry MAY appear
within multiple 'module' entries.
If the deviation module is available for download
from the server then a 'module' entry for that module
will exist, with the same name and revision values.
The 'conformance' value will be 'implement' for
the deviation module.";
uses common-leafs;
}
leaf conformance {
type enumeration {
enum implement {
description
"Indicates the server implements one or more
protocol-accessible objects defined in the
YANG module identified in this entry. This includes
deviation statements defined in the module.
For YANG 1.1 modules, there MUST NOT be more than
one module entry for a particular module name.
For YANG 1.1 modules that use the import statement
without specifying a revision date, the implemented
revision of the imported module MUST be used.
If the imported module is not implemented, then
the most recent revision of the imported module
used by the server (and contained in the module list)
MUST be used.
For YANG 1.0 modules, there SHOULD NOT be more than
one module entry for a particular module name.";
}
enum import {
description
"Indicates the server imports reusable definitions from
the specified revision of the module, but does not
implement any protocol accessible objects from this
revision.
Multiple module entries for the same module name MAY
exist. This can occur if multiple modules import the
same module, but specify different revision-dates in
the import statements.
For import statements that do not specify a revision
date, the most recent revision in the library SHOULD
be used by the server.";
}
}
mandatory true;
description
"Indicates the type of conformance the server is claiming
for the YANG module identified by this entry.";
}
container submodules {
description
"Contains information about all the submodules used
by the parent module entry";
list submodule {
key "name revision";
description
"Each entry represents one submodule within the
parent module.";
uses common-leafs;
uses schema-leaf;
}
}
} // list module
} // grouping module
container modules {
config false;
description
"Contains YANG module monitoring information.";
leaf module-set-id {
type string;
mandatory true;
description
"Contains a server-specific identifier representing
the current set of modules and submodules. The
server MUST change the value of this leaf if the
information represented by the 'module' list instances
has changed.";
}
uses module;
}
}
<CODE ENDS>
This document registers one URI in the IETF XML registry [RFC3688]. Following the format in RFC 3688, the following registration is requested to be made.
URI: urn:ietf:params:xml:ns:yang:ietf-yang-library
Registrant Contact: The NETMOD WG of the IETF.
XML: N/A, the requested URI is an XML namespace.
This document registers one YANG module in the YANG Module Names registry [RFC6020].
name: ietf-yang-library namespace: urn:ietf:params:xml:ns:yang:ietf-yang-library prefix: yanglib // RFC Ed.: replace XXXX with RFC number and remove this note reference: RFC XXXX
The YANG module defined in this memo is designed to be accessed via the NETCONF protocol [RFC6241]. The lowest NETCONF layer is the secure transport layer and the mandatory-to-implement secure transport is SSH [RFC6242].
Some of the readable data nodes in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or notification) to these data nodes. These are the subtrees and data nodes and their sensitivity/vulnerability:
Contributions to this material by Andy Bierman are based upon work supported by the The Space & Terrestrial Communications Directorate (S&TCD) under Contract No. W15P7T-13-C-A616. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of The Space & Terrestrial Communications Directorate (S&TCD).
| [RFC2119] | Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. |
| [RFC3688] | Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, January 2004. |
| [RFC6020] | Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, October 2010. |
| [RFC6241] | Enns, R., Bjorklund, M., Schoenwaelder, J. and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, June 2011. |
| [RFC6242] | Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, June 2011. |
| [RFC6991] | Schoenwaelder, J., "Common YANG Data Types", RFC 6991, July 2013. |
-- RFC Ed.: remove this section before publication.
-- RFC Ed.: remove this section before publication.
The YANG Library issue tracker can be found here:
https://github.com/netconf-wg/yang-library/issues