Internet DRAFT - draft-wang-netmod-module-revision-management
draft-wang-netmod-module-revision-management
NETMOD Working Group M. Wang
Internet-Draft Q. Wu
Intended status: Standards Track Huawei
Expires: March 22, 2019 A. Wang
China Telecom
September 18, 2018
A YANG Data Model for module revision management
draft-wang-netmod-module-revision-management-01
Abstract
This document defines a YANG Data Model for module revision change
management. It is intended this model be used by vendors who support
multiple revisions of the same YANG module in their systems but
implement only one revision of a module. In addition, this document
introduces a new generic mechanism based on RPC, denoted as module-
revision-change, that allow datanode backwards compatibility
detection and provide a report on change type and change details of a
YANG module with two or multiple revisions that is defined in design
time., e.g.,identifies a place in the node hierarchy where data node
gets changed or new data gets inserted and indicate whether the
change to the data node is backward compatible.
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 March 22, 2019.
Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved.
Wang, et al. Expires March 22, 2019 [Page 1]
Internet-Draft Module Revision Management September 2018
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 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
2. Terminologies . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Design of YANG data model for module revision management . . 4
3.1. yang-modules . . . . . . . . . . . . . . . . . . . . . . 6
3.1.1. yang-modules/module . . . . . . . . . . . . . . . . . 6
3.1.2. yang-modules/change-log . . . . . . . . . . . . . . . 6
3.2. RPC definition for module revision change . . . . . . . . 6
3.2.1. Usage Example . . . . . . . . . . . . . . . . . . . . 6
4. YANG Extension for Purpose Marking . . . . . . . . . . . . . 8
4.1. Usage Example: Add New Function . . . . . . . . . . . . . 8
4.2. Usage example: Bug Fix . . . . . . . . . . . . . . . . . 10
5. Library Augmentation . . . . . . . . . . . . . . . . . . . . 12
6. Multiple revisions module management . . . . . . . . . . . . 13
7. Yang Data Model Definition . . . . . . . . . . . . . . . . . 13
8. Security Considerations . . . . . . . . . . . . . . . . . . . 21
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 22
11. Normative References . . . . . . . . . . . . . . . . . . . . 22
Appendix A. Example of Module Revision Management . . . . . . . 23
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 25
1. Introduction
The revised Network Management Datastore Architecture (NMDA) defines
a set of new datastores that each hold YANG-defined data [RFC7950]
and represent a different "viewpoint" on the data that is maintained
by a server. To support the NMDA, many modules may need to be
updated or restructured especially for some published non-NMDA
modules, the model should be republished with an NMDA-compatible
structure, deprecating non-NMDA constructs
[I-D.ietf-netmod-rfc6087bis]. Therefore, how to support hackward-
compatible and indicate the module's changes is an issue.
As described in [RFC7950] , a module name MUST NOT be changed when
definitions contained in a module are available to be imported by any
other module and are referenced in "import" statements via the module
Wang, et al. Expires March 22, 2019 [Page 2]
Internet-Draft Module Revision Management September 2018
name. In some case, when we make non-backward compatible updates,
the module name might be forced to change, according to[RFC7950]
module update rule.
In order to provide an easy way to indicate how backward-compatible a
given YANG module actually is, this document defines a YANG Data
Model for module revision change management. It is intended this
model be used by vendors who support multiple revisions of the same
YANG module in their systems but implement only one revision of a
module. In addition, this document introduces a new generic
mechanism based on RPC, denoted as module-revision-change, that allow
Datanode backwards compatibility detection and provide a report on
change type and change details of a YANG module with two or multiple
revisions that is defined in design time., e.g.,identifies a place in
the node hierarchy where data node gets changed or new data gets
inserted and indicate whether the change to the data node is backward
compatible.
In addition, in order to identify whether changes between two
revisions represent bug fixes, new functionality, or both, etc
[I-D.verdt-netmod-yang-versioning-reqs], this document also defines a
new YANG extension statement which can help the user to understand
the purpose of changing a specific node. See More details in section
4.
2. Terminologies
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] and are not redefined
here:
o client
o notification
o server
The following terms are defined in [RFC7950] and are not redefined
here:
action
container
Wang, et al. Expires March 22, 2019 [Page 3]
Internet-Draft Module Revision Management September 2018
list
operation
3. Design of YANG data model for module revision management
The "ietf-module-revision-management" module provides per revision
the module change type and change details used by a server. This
module is defined using YANG version 1.1, but it supports the
description of YANG modules written in any revision of YANG.
All data nodes in "ietf-module-revision-management" are "config
false", and thus accessible in the operational state datastore.
Following is the YANG Tree Diagram for the "ietf-module-revision-
management" module:
Wang, et al. Expires March 22, 2019 [Page 4]
Internet-Draft Module Revision Management September 2018
module: ietf-module-revision
+--ro yang-modules
+--ro module* [name revision]
+--ro name yang:yang-identifier
+--ro revision yanglib:revision-identifier
+--ro backward-compatible? boolean
+--ro revision-change-log* [index]
+--ro index uint32
+--ro change-operation identityref
+--ro (yang-statements)?
+--:(data-definition-statement)
| +--ro data-definition
| +--ro target-node yang:xpath1.0
| +--ro location-point? yang:xpath1.0
| +--ro where? enumeration
| +--ro data-definition?
+--:(other-statement)
+--ro other-statement
+--ro statement-name? identityref
+--ro statement-definition?
+--ro substatements* [statement-name]
+--ro statement-name identityref
+--ro substatement-definition?
augment /yanglib:yang-library/yanglib:module-set/yanglib:module:
+--ro backward-compatible? boolean
augment /yanglib:yang-library/yanglib:module-set/yanglib:module/yanglib:submodule:
+--ro backward-compatible? boolean
rpcs:
+---x module-revision-change
+---w input
| +---w source module-name yang:yang-identifier
| +---w source-revision? yanglib:revision-identifier
| +---w target module-name yang:yang-identifier
| +---w target-revision? yanglib:revision-identifier
+--ro output
+--ro (status-response)?
| +--:(wrong-match)
| | +--ro wrong-match? empty
| +--ro data-nodes* [data-node-name]
| +--ro data-node-name string
| +--ro is-new-node? boolean
| +--ro change-operation? identityref
Wang, et al. Expires March 22, 2019 [Page 5]
Internet-Draft Module Revision Management September 2018
3.1. yang-modules
This container holds all per revision the module discrepancy
information used by a server.
3.1.1. yang-modules/module
This mandatory list contains one entry for each revision of each YANG
module that is used by the server. It is possible for multiple
revisions of the same module to be imported, in addition to an entry
for the revision that is implemented by the server. Multiple
revisions of the same module are either backward-compatible or non
backward-compatible.
3.1.2. yang-modules/change-log
This list contains one entry for each schema node change from
previous revision known by the server, and identifies schema node
change path,location, operation and associated with corresponding
schema node in the "change-log" list. Each revision of the YANG
module has multiple entries.
A change log is an ordered collection of changes that are applied to
one revision of YANG module. Each change is identified by an
"index", and it has an change operation ("create", "delete","move",
"modify") that is applied to the target resource. Each change can be
applied to a sub-resource "target" within the target resource. If
the operation is "move", then the "where" parameter indicates how the
node is moved. For values "before" and "after", the "point"
parameter specifies the data node insertion point.
Each entry within a change log MUST identify exactly one data
definition change or other statement change.
3.2. RPC definition for module revision change
The "module-revision-change" rpc statement is defined to retrieve the
schema data node changes between any two revisions of the same
module, i.e. the data node that get updated or newly added during
module revision change. This rpc statement takes module
identification information as input, and provides the list of data
nodes that make changes or are newly added in the later revision.
3.2.1. Usage Example
For example, there are two revisions of the same module, the yang
codes are shown as below:
Wang, et al. Expires March 22, 2019 [Page 6]
Internet-Draft Module Revision Management September 2018
module example-a{
yang-version 1.1;
namespace "urn:example:a";
prefix "a";
organization "foo.";
contact "fo@example.com";
description
"foo.";
revision 2017-12-01 {
description "Initial revision.";
}
container system {
leaf host-name {
type string;
description
"Hostname for this system.";
}
}
}
module example-a{
yang-version 1.1;
namespace "urn:example:a";
prefix "a";
organization "foo.";
contact "fo@example.com";
description
"foo.";
revision 2017-12-20{
description "Initial revision.";
}
container system {
leaf host-name {
type string;
description
"Hostname for this system.";
}
leaf b {
type string;
description
"foo";
}
Wang, et al. Expires March 22, 2019 [Page 7]
Internet-Draft Module Revision Management September 2018
}
If we initiate a "module-revision-change" RPC to retrieve the changes
between two revisions of module "a", the NETCONF XML example are
shown as below:
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<module-revision-change xmlns="http://example.com/system">
<module-name>example-a</module-namee>
<source-revisions>1.0.0</source-revisions>
<target-revisions>2.0.0</target-revisions>
</module-revision-change>
</rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<data-nodes>
<id>0001</id>
<data-node-name>b</data-node-name>
<is-new-node>true</is-new-node>
<data-node-change>major-change</data-node-change>
</data-nodes>
</rpc-reply>
4. YANG Extension for Purpose Marking
In order to identify whether changes between two revisions represent
bug fixes, new functionality, or both, etc
[I-D.verdt-netmod-yang-versioning-reqs], purpose marking are defined
via the YANG extension "mr:purpose". This YANG extension statement
is defined in the module "ietf-module-revision" (Section 7). This
YANG extension can help the user to understand the purpose of
changing a specific node.
4.1. Usage Example: Add New Function
For example, there is a YANG data model "example-a", the yang codes
are shown as below:
Wang, et al. Expires March 22, 2019 [Page 8]
Internet-Draft Module Revision Management September 2018
module example-a{
yang-version 1.1;
namespace "urn:example:a";
prefix "a";
organization "foo.";
contact "fo@example.com";
description
"foo.";
revision 2017-12-01 {
description "Initial revision.";
}
container system {
leaf host-name {
type string;
description
"Hostname for this system.";
}
}
}
When the author of "example-a" designs a new revision to add some new
attributes, the "mr:purpose" marking can be used to mark the purpose
of the updates. For example:
Wang, et al. Expires March 22, 2019 [Page 9]
Internet-Draft Module Revision Management September 2018
module example-a{
yang-version 1.1;
namespace "urn:example:a";
prefix "a";
organization "foo.";
contact "fo@example.com";
description
"foo.";
revision 2017-12-20{
description "Initial revision.";
}
container system {
leaf host-name {
type string;
description
"Hostname for this system.";
}
leaf b {
type string;
mr:purpose "new-function";
description
"foo";
}
}
4.2. Usage example: Bug Fix
For example, there are some bugs in a published model "example-b",
the yang codes are shown as below:
Wang, et al. Expires March 22, 2019 [Page 10]
Internet-Draft Module Revision Management September 2018
module example-b{
yang-version 1.1;
namespace "urn:example:b";
prefix "b";
organization "foo.";
contact "fo@example.com";
description
"foo.";
revision 2017-12-01 {
description "Initial revision.";
}
container system {
leaf host-name {
type uint32;
description
"Hostname for this system.";
}
}
}
The following updates allow to fix bugs in a backward-compatible way:
Wang, et al. Expires March 22, 2019 [Page 11]
Internet-Draft Module Revision Management September 2018
module example-b{
yang-version 1.1;
namespace "urn:example:b";
prefix "b";
organization "foo.";
contact "fo@example.com";
description
"foo.";
revision 2017-12-01 {
description "Initial revision.";
}
container system {
leaf host-name-update {
type string;
mr:purpose "bug-fix";
description
"Hostname for this system.";
}
leaf host-name {
type uint32;
status deprecated;
description
"Hostname for this system.";
}
}
}
5. Library Augmentation
Backward compatibility for each revision of YANG module can also be
read using the yang library [I-D.ietf-netconf-rfc7895bis] if a server
supports both YANG library and the augmentation defined below. If a
server supports indication of backward compatibility forone revision
of and the YANG module, it SHOULD also support the "ietf-module-
revision" module.
The tree associated with the defined augmentation is:
Wang, et al. Expires March 22, 2019 [Page 12]
Internet-Draft Module Revision Management September 2018
module: ietf-module-revisions
augment /yanglib:yang-library/yanglib:modules/yanglib:module:
+--ro backward-compatible? bool
augment /yanglib:yanglibrary/yanglib:modules/yanglib:module
/yanglib:submodule:
+--ro backward-compatible? bool
6. Multiple revisions module management
As experience is gained with a module, it may be desirable to support
multiple revisions of that module in their systems but implement one
revision of a module at each time. To indicate the details changes
of that module, e.g., identifies schema node change path,location,
operation and associated with corresponding schema node, it will be
desirable to use 'ietf-module-revision' defined in this document to
manage all the revisions of that module and keep track of module
change discrepancy in different revision, especially when the new
revision is not backward compatible with previous revision.
7. Yang Data Model Definition
<CODE BEGINS> file "ietf-module-revision@2018-08-08.yang"
module ietf-module-revision {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-module-revision";
prefix ml;
import ietf-yang-library {
prefix yanglib;
}
import ietf-yang-types {
prefix yang;
}
organization
"IETF Network Modeling (NETMOD) Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/netmod/>
WG List: <mailto:netmod@ietf.org>
Author: Qin Wu
<mailto:bill.wu@huawei.com>
Zitao Wang
<mailto:wangzitao@huawei.com>";
description
Wang, et al. Expires March 22, 2019 [Page 13]
Internet-Draft Module Revision Management September 2018
"This YANG module defines an module log.";
revision 2018-08-08 {
description
"Initial revision.";
reference "RFC XXXX: Using Metadata with YANG for Module revisions";
}
identity operation-type {
description
"Abstract base identity for the operation type ";
}
identity create {
base operation-type;
description
"Denotes create new data nodes";
}
identity delete {
base operation-type;
description
"Denotes delete the target node";
}
identity move {
base operation-type;
description
"Denote move the target node.";
}
identity modify {
base operation-type;
description
"Denote modify the target data node.";
}
identity statement-type {
description
"Base identity for statement type";
}
identity feature-statement {
base statement-type;
description
"feature statement, if this type be chose, it means that the
feature or if-feature statement been modified";
}
Wang, et al. Expires March 22, 2019 [Page 14]
Internet-Draft Module Revision Management September 2018
identity identity-statement {
base statement-type;
description
"identity statement, if this type be chose, it means that the
identity statement been modified, for example, add new identity, etc.";
}
identity grouping-statement {
base statement-type;
description
"grouping statement, if this type be chose, it means that the grouping
statement been modified.";
}
identity typedef-statement {
base statement-type;
description
"typedef statement, if this type be chose, it means that the typedef
statement been modified.";
}
identity augment-statement {
base statement-type;
description
"augment statement, if this type be chose, it means that the augment
statement been modified.";
}
identity rpc-statement {
base statement-type;
description
"rpc statement, if this type be chose, it means that the rpc
statement been modified.";
}
identity notification-statement {
base statement-type;
description
"notification statement, if this type be chose, it means that the notification
statement been modified.";
}
extension purpose {
argument name;
description
"The purpose can be used to mark the data nodes change purpose.
The name argument can be specified in the following recommended mode
Wang, et al. Expires March 22, 2019 [Page 15]
Internet-Draft Module Revision Management September 2018
- bug-fix, which can help user to understand the data nodes' changes present bug fix,
- new-function, which can help user to understand the data nodes' changes present new function,
- nmda-conform, which can help user to understand the data nodes' changes conform to NMDA,
and note that the user can argument the purpose name according to their sepcific requirements.";
}
grouping data-definition {
container data-definition {
leaf target-node {
type yang:xpath1.0;
mandatory true;
description
"Identifies the target data node for update.
Notice that, if the update-type equal to move or delete,
this target-node must point to the data node of old version.
\t
For example, suppose the target node is a YANG leaf named a,
and the previous version is:
\t
container foo {
leaf a { type string; }
leaf b { type int32; }
}
\t
the new version is:
container foo {
leaf b {type int32;}
}
\t
Therefore, the targe-node should be /foo/a.";
}
leaf location-point {
type yang:xpath1.0;
description
"Identifies the location point where the updates happened.";
}
leaf where {
when "derived-from-or-self(../../change-operation, 'move')" {
description
"This leaf only applies for 'move'
updates.";
}
type enumeration {
enum "before" {
description
"Insert or move a data node before the data resource
identified by the 'point' parameter.";
Wang, et al. Expires March 22, 2019 [Page 16]
Internet-Draft Module Revision Management September 2018
}
enum "after" {
description
"Insert or move a data node after the data resource
identified by the 'point' parameter.";
}
enum "first" {
description
"Insert or move a data node so it becomes ordered
as the first entry.";
}
enum "last" {
description
"Insert or move a data node so it becomes ordered
as the last entry.";
}
}
default "last";
description
"Identifies where a data resource will be inserted
or moved.";
}
anydata data-definition {
when "derived-from-or-self(../../change-operation, 'modify')" {
description
"This nodes only be present when
the 'change-operation' equal to 'modify'.";
}
description
"This nodes used for present the definitions before updated.
And this nodes only be present when
the 'change-operation' equal to 'modify'.";
}
description
"Container for data statement";
}
description
"Grouping for data definition";
}
grouping other-statement {
container other-statement {
leaf statement-name {
type identityref {
base statement-type;
}
description
"Statement name, for example, identity, feature, typedef, etc.";
Wang, et al. Expires March 22, 2019 [Page 17]
Internet-Draft Module Revision Management September 2018
}
anydata statement-definition {
description
"This nodes used for present new the definitions.";
}
list substatements {
key "statement-name";
leaf statement-name {
type identityref {
base statement-type;
}
description
"Statement name, for example, identity, feature, typedef, etc.";
}
anydata substatement-definition {
description
"This nodes used for present new the definitions.";
}
description
"List for substatements updates";
}
description
"Container for header statement updates";
}
description
"Grouping for header statement";
}
grouping change-log {
list revision-change-log {
key "index";
leaf index {
type uint32;
description
"Index for module change log";
}
leaf change-operation {
type identityref {
base operation-type;
}
mandatory true;
description
"This leaf indicate the change operation, such as create, move, delete, modify, etc.";
}
choice yang-statements {
description
"Choice for various YANG statements that have been impacted.";
case data-definition-statement {
Wang, et al. Expires March 22, 2019 [Page 18]
Internet-Draft Module Revision Management September 2018
uses data-definition;
}
case other-statement {
uses other-statement;
}
}
description
"List for module revision change log";
}
description
"Grouping for module revision change log";
}
container yang-modules {
config false;
list module {
key "name revision";
leaf name {
type yang:yang-identifier;
description
"The YANG module or submodule name.";
}
leaf revision {
type yanglib:revision-identifier;
description
"The YANG module or submodule revision date. If no revision
statement is present in the YANG module or submodule, this
leaf is not instantiated.";
}
leaf backward-compatible {
type boolean;
description
"Indicates whether it is a backward compatible version.
If this parameter is set to true, it means that this version is
a backwards compatible version";
}
uses change-log;
description
"List for module updated log";
}
description
"This container present the modules updated log.";
}
augment "/yanglib:yang-library/yanglib:module-set/yanglib:module" {
description
"Augment the yang library with backward compatibility indication.";
leaf backward-compatible {
type boolean;
Wang, et al. Expires March 22, 2019 [Page 19]
Internet-Draft Module Revision Management September 2018
description
"backward compatibility indication.";
}
}
augment "/yanglib:yang-library/yanglib:module-set/yanglib:module/yanglib:submodule" {
description
"Augment the yang library with backward compatibility indication.";
leaf backward-compatible {
type boolean;
description
"backward compatibility indication.";
}
}
rpc module-revision-change {
description
"Module Node change query operation.";
input {
leaf source-module-name {
type yang:yang-identifier;
mandatory true;
description
"The Source YANG module or submodule name.";
}
leaf source-revision {
type yanglib:revision-identifier;
description
"The Source YANG module revision date. If no revision
statement is present in the YANG module or submodule, this
leaf is not instantiated.";
}
leaf target-module-name {
type yang:yang-identifier;
mandatory true;
description
"The Target YANG module or submodule name.";
}
leaf target-revision {
type yanglib:revision-identifier;
description
"The target YANG module revision date. If no revision
statement is present in the YANG module or submodule, this
leaf is not instantiated.";
}
}
output {
choice status-response{
leaf wrong-match{
type empty;
Wang, et al. Expires March 22, 2019 [Page 20]
Internet-Draft Module Revision Management September 2018
description
"This leaf indicates that two modules have nothing in common.";
}
list data-nodes {
key "data-node-name";
description
"Each entry represents a data node of a given module that
have been changed from source revision of
a module to target revision of the module.";
leaf data-node-name {
type string;
description
"a data node name of a given module that
has been changed.";
}
leaf is-new-node {
type boolean;
description
"indicate the data node is newly introduced node in the target revision.";
}
leaf change-operation {
type identityref {
base operation-type;
}
description
"This leaf indicate the change operation,
such as create, move, delete, modify, etc.";
}
}
}
}
}
}
<CODE ENDS>
8. Security Considerations
This document defines a mechanism that is put at a place in the node
hierarchy where data node gets changed or new data gets inserted and
indicate whether the change to the data node is backward compatible
and as such doesn't introduce new security issues.
9. IANA Considerations
This document registers a URI in the IETF XML registry [RFC3688].
Following the format in [RFC3688], the following registration is
requested to be made:
Wang, et al. Expires March 22, 2019 [Page 21]
Internet-Draft Module Revision Management September 2018
---------------------------------------------------------------------
URI: urn:ietf:params:xml:ns:yang:ietf-module-revision
Registrant Contact: The NETMOD WG of the IETF.
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-module-revision
Namespace: urn:ietf:params:xml:ns:yang:ietf-module-revision
Prefix: md
Reference: RFC xxxx
---------------------------------------------------------------------
10. Acknowledgements
This work is motivated from the discussions of module version in IETF
100 Singapore meeting. Thanks to Juergen Schoenwaelder and Adrian
Farrel for useful comments on this work.
11. Normative References
[I-D.ietf-netconf-rfc7895bis]
Bierman, A., Bjorklund, M., Schoenwaelder, J., Watsen, K.,
and R. Wilton, "YANG Library", draft-ietf-netconf-
rfc7895bis-04 (work in progress), January 2018.
[I-D.ietf-netmod-rfc6087bis]
Bierman, A., "Guidelines for Authors and Reviewers of YANG
Data Model Documents", draft-ietf-netmod-rfc6087bis-15
(work in progress), December 2017.
[I-D.verdt-netmod-yang-versioning-reqs]
Clarke, J., "YANG Module Versioning Requirements", draft-
verdt-netmod-yang-versioning-reqs-00 (work in progress),
July 2018.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", March 1997.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
Wang, et al. Expires March 22, 2019 [Page 22]
Internet-Draft Module Revision Management September 2018
[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>.
[RFC7223] Bjorklund, M., "A YANG Data Model for Interface
Management", RFC 7223, DOI 10.17487/RFC7223, May 2014,
<https://www.rfc-editor.org/info/rfc7223>.
[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>.
[RFC7952] Lhotka, L., "Defining and Using Metadata with YANG",
RFC 7952, DOI 10.17487/RFC7952, August 2016,
<https://www.rfc-editor.org/info/rfc7952>.
Appendix A. Example of Module Revision Management
This section provides an example to generate XML snippet of ietf-
module-revision based on the changes between the new revision of
interface model as specified in [draft-ietf-netmod-rfc7223bis] and
the old revision of interface model as specified in [RFC7223].
<yang-modules>
<module>
<name>ietf-interfaces</name>
<revision>2018-01-09</revision>
<backwards-compatible>false</backwards-compatible>
<revision-change-log>
<index>0001</index>
<change-operation>delete</change-operation>
<yang-statements>
<data-definition-statement>
<data-definition>
<target>/if:interfaces-state</target>
</data-definition>
</data-definition-statement>
</yang-statements>
</revision-change-log>
<revision-change-log>
<index>0002</index>
<change-operation>create</change-operation>
<yang-statements>
<other-statement>
<statement>
<statement-name>feature-statement</statement-name>
Wang, et al. Expires March 22, 2019 [Page 23]
Internet-Draft Module Revision Management September 2018
<statement-definition>
feature if-mib {
description
"This feature indicates that the device implements
the IF-MIB.";
reference
"RFC 2863: The Interfaces Group MIB";
}
</statement-definition>
</statement>
</other-statement>
</yang-statements>
</revision-change-log>
<revision-change-log>
<index>0003</index>
<change-operation>modify</change-operation>
<yang-statements>
<data-definition-statement>
<data-definition>
<target>
/if:interfaces/if:interface/if:link-up-down-trap-enable
</target>
<data-node>
leaf link-up-down-trap-enable {
if-feature if-mib; // add if-feature statement
type enumeration {
....
</data-node>
</data-definition>
</data-definition-statement>
</yang-statements>
</revision-change-log>
<revision-change-log>
<index>0004</index>
<change-operation>move</change-operation>
<yang-statements>
<data-definition-statement>
<data-definition>
<target>
/if:interfaces-state/if:interface/if:admin-status
</target>
<location-point>
/if:interfaces/if:interface/link-up-down-trap-enable
</location-point>
<where>after</where>
</data-definition-statement>
Wang, et al. Expires March 22, 2019 [Page 24]
Internet-Draft Module Revision Management September 2018
</yang-statements>
</revision-change-log>
<revision-change-log>
<index>0005</index>
<change-operation>move</change-operation>
<yang-statements>
<data-definition-statement>
<data-definition>
<target>
/if:interfaces-state/if:interface/if:statistics
</target>
<location-point>
/if:interfaces/if:interface/if:speed
</location-point>
<where>after</where>
</data-definition-statement>
</yang-statements>
</revision-change-log>
.......
</module>
</yang-modules>
Authors' Addresses
Michael Wang
Huawei Technologies,Co.,Ltd
101 Software Avenue, Yuhua District
Nanjing 210012
China
Email: wangzitao@huawei.com
Qin Wu
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: bill.wu@huawei.com
Wang, et al. Expires March 22, 2019 [Page 25]
Internet-Draft Module Revision Management September 2018
Aijun Wang
China Telecom
Beiqijia Town, Changping District
Beijing, Beijing 102209
China
Email: wangaj.bri@chinatelecom.cn
Wang, et al. Expires March 22, 2019 [Page 26]
