Support of Versioning in YANG Notifications Subscription
draft-tgraf-netconf-yang-notifications-versioning-00
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| Authors | Thomas Graf , Benoît Claise , Alex Huang Feng | ||
| Last updated | 2022-10-20 | ||
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draft-tgraf-netconf-yang-notifications-versioning-00
Network Working Group T. Graf
Internet-Draft Swisscom
Intended status: Standards Track B. Claise
Expires: 23 April 2023 Huawei
A. Huang Feng
INSA-Lyon
20 October 2022
Support of Versioning in YANG Notifications Subscription
draft-tgraf-netconf-yang-notifications-versioning-00
Abstract
This document extends the YANG notifications subscription mechanism
to specify the YANG module semantic version at the subscription.
Then, a new extension with new metadata of the YANG push update
notification header is proposed.
Requirements Language
The key words "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.
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 23 April 2023.
Copyright Notice
Copyright (c) 2022 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 (https://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 Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Extend the Datastore Selection . . . . . . . . . . . . . . . 3
3. Extend the Metadata in Streaming Update . . . . . . . . . . . 4
4. The "ietf-yang-push-metadata" Module . . . . . . . . . . . . 6
4.1. Data Model Overview . . . . . . . . . . . . . . . . . . . 6
4.2. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 7
5. Security Considerations . . . . . . . . . . . . . . . . . . . 10
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
8.1. Normative References . . . . . . . . . . . . . . . . . . 11
8.2. Informative References . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13
1. Introduction
In order to process the received YANG push notification messages
described in section 3.7 of [RFC8641] at the YANG push receiver, a
semantic reference to the YANG module and the XPath or subtree is
needed to determine the data types for each field and which part of
the YANG module the metrics are expose from.
This specification applies to the YANG push configured subscriptions
defined in Section 2.5 of [RFC8639], where a publisher is configured
to stream notification out of band, as opposed to dynamic
subscriptions defined in Section 2.4 of [RFC8641], where the
subscriber can initiate and modify the subscription dynamically in-
band. In the latter case, the subscriber knows already all the
subscriber YANG-related information, which it has to know in order to
configure the subscription.
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This semantic reference is available during the subscription period
described in Section 3.6 of [RFC8641] where for each subscription a
locally unique subscription ID described in Section 4.3.2 of
[RFC8641] is being issued and streamed as metadata with the
notification message in the YANG push message header. This implies
that the YANG receiver needs to lookup the subscription inventory for
a subscription ID in each notification message to determine the YANG
module name, namespace, and filter definitions.
The semantics can change between different YANG module revisions.
The YANG module version statement is specified in Section 7.1.2 of
[RFC6020] and states that the newer revision needs to be backward
compatible to the previous revision. Section 3.1 of
[I-D.ietf-netmod-yang-module-versioning] specifies that newer
semantic versions introduced in [I-D.ietf-netmod-yang-semver] MAY not
be backward compatible to the previous version when indicated with
non-backwards-compatible keyword.
The YANG notifications subscription mechanism defined in [RFC8641]
does not allow to specify the YANG module revision. When a network
node is upgraded, the subscribed YANG module revision MAY have
updated and might, consequently, break the data processing pipeline
since the YANG push receiver may not be aware of this change.
This documents extends the current YANG notifications subscription
mechanism to allow to subscribe to a specific revision or latest
semantic version to which the YANG module version needs to be
backward compatible to and advertises its specific YANG module
revision inband. Besides the existing Subscription ID, the YANG
module name, namespace, revision and filtering metadata is added to
the YANG push notification header to lift the YANG push receiver need
to lookup the subscription inventory information.
2. Extend the Datastore Selection
The YANG notifications subscription OPTIONALLY can be restricted to
the following YANG module revision for future capabilities:
latest: Restricts the subscription to the latest YANG module
revision.
revision: Restricts the subscription to a specific YANG module
revision. Example 2014-05-08.
latest-compatible-semversion: Restricts the subscription to the
latest compatible YANG module semantic version referenced to.
Example 2.0.0.
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If nothing is specified, latest YANG module version is implied.
3. Extend the Metadata in Streaming Update
Along with the subscribed content, besides the Subcription ID, the
following metadata objects are part of a "push-update" or "push-
change-update" notification.
module: Describes the YANG module name for the related streamed
content.
namespace: Describes the YANG module namespace as specified in
Section 7.1.3 of [RFC6020] for the related streamed content.
revision: Describes the YANG module revision as specified in
Section 7.1.2 of [RFC6020] for the related streamed content.
revision-label: Describes the YANG module semantic version as
specified in [I-D.ietf-netmod-yang-semver] for the related
streamed content.
datastore-xpath-filter: Describes the YANG module xpath filter as
specified in Section 6.4 of [RFC6020] for the related streamed
content.
datastore-subtree-filter: Describes the YANG module subtree filter
as specified in Section 6 of [RFC6241] for the related streamed
content.
Figure 1 provides an example of a notification message with the YANG
module name, revision, revision label and datastore-xpath-filter for
a subscription tracking the operational status of a single Ethernet
interface (per [RFC8343]). This notification message is encoded XML
[W3C.REC-xml-20081126] over the Network Configuration Protocol
(NETCONF) as per [RFC8640].
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<notification xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0">
<eventTime>2022-09-02T10:59:55.32Z</eventTime>
<push-update xmlns="urn:ietf:params:xml:ns:yang:ietf-yang-push">
<id>101</id>
<module>ietf-interfaces</module>
<namespace>urn:ietf:params:xml:ns:yang:ietf-interfaces</namespace>
<revision>2014-05-08</revision>
<revision-label>1.0.0</revision-label>
<datastore-xpath-filter>ietf-interfaces:interfaces</datastore-xpath-filter>
<datastore-contents>
<interfaces xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces">
<interface>
<name>eth0</name>
<oper-status>up</oper-status>
</interface>
</interfaces>
</datastore-contents>
</push-update>
</notification>
Figure 1: XML Push Example for a Periodical Notification Message
Figure 2 provides an example of a JSON encoded, [RFC8259],
notification message over HTTPS-based [I-D.ietf-netconf-https-notif]
or UDP-based [I-D.ietf-netconf-udp-notif] transport for the same
subscription.
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{
"ietf-notification:notification": {
"eventTime": "2022-09-02T10:59:55.32Z",
"ietf-yang-push:push-update": {
"id": 101,{
"module": "ietf-interfaces",{
"namespace": "urn:ietf:params:xml:ns:yang:ietf-interfaces",{
"revision": "2014-05-08",{
"revision-label": "1.0.0",{
"datastore-xpath-filter": "ietf-interfaces:interfaces",
"datastore-contents": {
"ietf-interfaces:interface": {
"name": {
"eth0": {
"oper-status": "up",
}
}
}
}
}
}
}
}
}
}
}
Figure 2: JSON Push Example for a Periodical Notification Message
4. The "ietf-yang-push-metadata" Module
4.1. Data Model Overview
This YANG module augments the "ietf-yang-push" module to add
subcription metadata into the "push-update" and "push-change-update"
notification and the ability to define the "revision" and "revision-
label" in the "establish-subscription" and "modify-subscription" in
the datastore push subscription.
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module: ietf-yang-push-metadata
augment /yp:push-update:
+--ro module? string
+--ro namespace? string
+--ro revision? rev:revision-date-or-label
+--ro revision-label? ysver:version
+--ro datastore-xpath-filter? yang:xpath1.0 {sn:xpath}?
+--ro datastore-subtree-filter? <anydata> {sn:subtree}?
augment /yp:push-change-update:
+--ro module? string
+--ro namespace? string
+--ro revision? rev:revision-date-or-label
+--ro revision-label? ysver:version
+--ro datastore-xpath-filter? yang:xpath1.0 {sn:xpath}?
+--ro datastore-subtree-filter? <anydata> {sn:subtree}?
augment /sn:establish-subscription/sn:input/sn:target:
+-- revision? rev:revision-date-or-label
+-- revision-label? ysver:version
augment /sn:modify-subscription/sn:input/sn:target:
+-- revision? rev:revision-date-or-label
+-- revision-label? ysver:version
augment /sn:subscription-started/sn:target:
+-- revision? rev:revision-date-or-label
+-- revision-label? ysver:version
augment /sn:subscription-modified/sn:target:
+-- revision? rev:revision-date-or-label
+-- revision-label? ysver:version
augment /sn:subscriptions/sn:subscription/sn:target:
+--rw revision? rev:revision-date-or-label
+--rw revision-label? ysver:version
4.2. YANG Module
The YANG module has six leaves augmenting the model of YANG-push
[RFC8641].
<CODE BEGINS> file "ietf-yang-push-metadata@2022-10-10.yang"
module ietf-yang-push-metadata {
yang-version 1.1;
namespace
"urn:ietf:params:xml:ns:yang:ietf-yang-push-metadata";
prefix ypm;
import ietf-yang-types {
prefix yang;
reference
"RFC 6991: Common YANG Data Types";
}
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import ietf-subscribed-notifications {
prefix sn;
reference
"RFC 8639: Subscription to YANG Notifications";
}
import ietf-yang-push {
prefix yp;
reference
"RFC 8641: Subscription to YANG Notifications for Datastore Updates";
}
import ietf-yang-revisions {
prefix rev;
reference
"RFC XXXX: draft-ietf-netmod-yang-module-versioning-06, Updated YANG
Module Revision Handling";
}
import ietf-yang-semver {
prefix ysver;
reference
"RFC XXXX: draft-ietf-netmod-yang-semver-07, YANG Semantic Versioning";
}
organization "IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http:/tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
Authors: Thomas Graf
<mailto:thomas.graf@swisscom.com>
Benoit Claise
<mailto:benoit.claise@huawei.com>
Alex Huang Feng
<mailto:alex.huang-feng@insa-lyon.fr>";
description
"Defines YANG push event notification header with metadata.
Copyright (c) 2022 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 Revised BSD License set forth in Section
4.c of the IETF Trust's Legal Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see the RFC
itself for full legal notices.";
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revision 2022-09-21 {
description
"First revision";
reference
"RFC XXXX: Support of Versioning in YANG Notifications Subscription";
}
feature yang-push-metadata-supported {
description
"This feature indicates the YANG Notifications have the metadata
defined in this YANG module.";
}
grouping yang-push-module-version {
leaf revision {
type rev:revision-date-or-label;
description
"This references the YANG module revision of the sent notification.";
}
leaf revision-label {
type ysver:version;
description
"This references the YANG module semversion of the sent notification.";
}
}
grouping yang-push-metadata {
leaf module {
type string;
description
"This references the YANG module of the sent notification.";
}
leaf namespace {
type string;
description
"This references the YANG module namespace of the sent notification.";
}
uses ypm:yang-push-module-version;
leaf datastore-xpath-filter {
type yang:xpath1.0;
if-feature "sn:xpath";
description
"This references the YANG module xpath of the sent notification.";
}
anydata datastore-subtree-filter {
if-feature "sn:subtree";
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description
"This references the YANG module subtree of the sent notification.";
}
}
// Event notifications
augment "/yp:push-update" {
description
"This augmentation adds the module, the namespace, the revision, the
semversion, the xpath and the subtree in the push-update notification";
uses ypm:yang-push-metadata;
}
augment "/yp:push-change-update" {
description
"This augmentation adds the module, the namespace, the revision, the
semversion, the xpath and the subtree in the push-change-update notification";
uses ypm:yang-push-metadata;
}
// Subscription parameters
augment "/sn:establish-subscription/sn:input/sn:target" {
uses ypm:yang-push-module-version;
}
augment "/sn:modify-subscription/sn:input/sn:target" {
uses ypm:yang-push-module-version;
}
// Subscription notifications
augment "/sn:subscription-started/sn:target" {
uses ypm:yang-push-module-version;
}
augment "/sn:subscription-modified/sn:target" {
uses ypm:yang-push-module-version;
}
// Subscription container
augment "/sn:subscriptions/sn:subscription/sn:target" {
uses ypm:yang-push-module-version;
}
}
<CODE ENDS>
5. Security Considerations
The security considerations for the YANG notifications subscription
mechanism are described in [RFC8641]. This documents adds no
additional security considerations.
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6. IANA Considerations
This document has no IANA actions.
7. Acknowledgements
The authors would like to thank xxx for their review and valuable
comments.
8. References
8.1. Normative References
[I-D.ietf-netmod-yang-module-versioning]
Wilton, R., Rahman, R., Lengyel, B., Clarke, J., and J.
Sterne, "Updated YANG Module Revision Handling", Work in
Progress, Internet-Draft, draft-ietf-netmod-yang-module-
versioning-06, 10 July 2022,
<https://www.ietf.org/archive/id/draft-ietf-netmod-yang-
module-versioning-06.txt>.
[I-D.ietf-netmod-yang-semver]
Clarke, J., Wilton, R., Rahman, R., Lengyel, B., Sterne,
J., and B. Claise, "YANG Semantic Versioning", Work in
Progress, Internet-Draft, draft-ietf-netmod-yang-semver-
07, 10 July 2022, <https://www.ietf.org/archive/id/draft-
ietf-netmod-yang-semver-07.txt>.
[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>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<https://www.rfc-editor.org/info/rfc6020>.
[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>.
[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>.
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[RFC8639] Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard,
E., and A. Tripathy, "Subscription to YANG Notifications",
RFC 8639, DOI 10.17487/RFC8639, September 2019,
<https://www.rfc-editor.org/info/rfc8639>.
[RFC8641] Clemm, A. and E. Voit, "Subscription to YANG Notifications
for Datastore Updates", RFC 8641, DOI 10.17487/RFC8641,
September 2019, <https://www.rfc-editor.org/info/rfc8641>.
8.2. Informative References
[I-D.ietf-netconf-https-notif]
Jethanandani, M. and K. Watsen, "An HTTPS-based Transport
for YANG Notifications", Work in Progress, Internet-Draft,
draft-ietf-netconf-https-notif-12, 22 August 2022,
<https://www.ietf.org/archive/id/draft-ietf-netconf-https-
notif-12.txt>.
[I-D.ietf-netconf-udp-notif]
Zheng, G., Zhou, T., Graf, T., Francois, P., Feng, A. H.,
and P. Lucente, "UDP-based Transport for Configured
Subscriptions", Work in Progress, Internet-Draft, draft-
ietf-netconf-udp-notif-08, 12 September 2022,
<https://www.ietf.org/archive/id/draft-ietf-netconf-udp-
notif-08.txt>.
[RFC8259] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
Interchange Format", STD 90, RFC 8259,
DOI 10.17487/RFC8259, December 2017,
<https://www.rfc-editor.org/info/rfc8259>.
[RFC8343] Bjorklund, M., "A YANG Data Model for Interface
Management", RFC 8343, DOI 10.17487/RFC8343, March 2018,
<https://www.rfc-editor.org/info/rfc8343>.
[RFC8640] Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard,
E., and A. Tripathy, "Dynamic Subscription to YANG Events
and Datastores over NETCONF", RFC 8640,
DOI 10.17487/RFC8640, September 2019,
<https://www.rfc-editor.org/info/rfc8640>.
[W3C.REC-xml-20081126]
Bray, T., Paoli, J., Sperberg-McQueen, M., Maler, E., and
F. Yergeau, "Extensible Markup Language (XML) 1.0 (Fifth
Edition)", World Wide Web Consortium Recommendation REC-
xml-20081126, November 2008,
<https://www.w3.org/TR/2008/REC-xml-20081126>.
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Authors' Addresses
Thomas Graf
Swisscom
Binzring 17
CH-8045 Zurich
Switzerland
Email: thomas.graf@swisscom.com
Benoit Claise
Huawei
Email: benoit.claise@huawei.com
Alex Huang Feng
INSA-Lyon
Lyon
France
Email: alex.huang-feng@insa-lyon.fr
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