Network Working Group M. Bjorklund
Internet-Draft Tail-f Systems
Updates: 7950 (if approved) J. Schoenwaelder
Intended status: Standards Track Jacobs University
Expires: March 19, 2018 P. Shafer
K. Watsen
Juniper Networks
R. Wilton
Cisco Systems
September 15, 2017
NETCONF Model for NMDA
draft-dsdt-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
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 March 19, 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
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
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 . . . . . . . . . 4
2.3. RPCs and Actions . . . . . . . . . . . . . . . . . . . . 5
2.4. YANG Library Capability . . . . . . . . . . . . . . . . . 5
3. YANG Model . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
5. Security Considerations . . . . . . . . . . . . . . . . . . . 11
6. Informative References . . . . . . . . . . . . . . . . . . . 11
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 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 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 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 Attribute
The "get-data" operation adds a new boolean parameter named
"with-origin", which requests that the server returns 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.
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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>.
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".
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;
}
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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
<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
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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 source {
type ncds:datastore;
mandatory true;
description
"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.";
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}
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(../source, "or:operational")';
if-feature origin;
type boolean;
default false;
description
"If this parameter is 'true', the server will return
the 'origin' annotation for the nodes that has one.";
}
uses ncwd:with-defaults-parameters;
}
output {
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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.";
}
choice edit-content {
mandatory true;
description
"The content for the edit operation.";
anydata config {
description
"Inline Config content.";
}
leaf url {
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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.";
}
}
}
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<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.
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-04
(work in progress), August 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.
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[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>.
Appendix A. Examples
Authors' Addresses
Martin Bjorklund
Tail-f Systems
Email: mbj@tail-f.com
Juergen Schoenwaelder
Jacobs University
Email: j.schoenwaelder@jacobs-university.de
Phil Shafer
Juniper Networks
Email: phil@juniper.net
Kent Watsen
Juniper Networks
Email: kwatsen@juniper.net
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Robert Wilton
Cisco Systems
Email: rwilton@cisco.com
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