NETMOD Working Group Q. Wu
Internet-Draft R. Tao
Intended status: Standards Track R. Ranade
Expires: December 31, 2019 Huawei
June 29, 2019
NMDA Base Notification for Intent based configuration update
draft-wu-netmod-base-notification-nmda-03
Abstract
The Network Configuration Protocol (NETCONF)and RESTCONF provides
mechanisms to manipulate configuration datastores. NMDA introduces
additional datastores for systems that support more advanced
processing chains converting configuration to operational state.
However, client applications are not able to be aware of common
events in these additional datstores of the management system, such
as a intended configuration state change in NETCONF server or
RESTCONF server, that may impact management applications,especially
when a server is managed by multiple clients or management
applications. This document define a YANG module that allows a
client to receive additional notifications for some common system
events pertaining to the Network Management Datastore Architecture
(NMDA) defined in [RFC8342].
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 December 31, 2019.
Copyright Notice
Copyright (c) 2019 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 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. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2. NMDA Base Notifications for Intent based configuration Update 3
2.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. Data Model Design . . . . . . . . . . . . . . . . . . . . 5
2.3. Relation with NMDA Datastore Compare . . . . . . . . . . 6
2.4. Definitions . . . . . . . . . . . . . . . . . . . . . . . 7
3. Security Considerations . . . . . . . . . . . . . . . . . . . 13
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14
6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 14
7. Normative References . . . . . . . . . . . . . . . . . . . . 14
Appendix A. Changes between revisions . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
1. Introduction
The Network Configuration Protocol (NETCONF) [RFC6241] and RESTCONF
[RFC8040] provides mechanisms to manipulate configuration datastores.
NMDA introduces additional datastores (e.g.,<intended>,
<operational>) for systems that support more advanced processing
chains converting configuration to operational state. However,
client applications are not able to be aware of common events in
those additional datastores of the management system, e.g., there are
many background system activities (e.g.,system internal interactions
with hardware, interaction with protocols or other devices) that
happen during propagation of a configuration change to the software
and hardware components of a system. It is possible that some
configuration could not be applied to <operational> due to either
remnant Configuration, or missing resource, etc. There is a need for
user or an application (configuration) to know the origin of failed
configuration node and the reason why the configuration changes were
not applied.
This document define a YANG module that allows a client to receive
additional notifications for some common system events pertaining to
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the Network Management Datastore Architecture (NMDA) defined in
[RFC8342]. These notifications are designed to support the
monitoring of the base system events within the server and not
specific to any network management protocols such as NETCONF and
RESTCONF.
The solution presented in this document is backwards compatible with
[RFC6470].
1.1. Terminology
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.
The following terms are defined in [RFC8342] and are not redefined
here:
o operational state datastore
o running configuration datastore
o intended configuration datastore
2. NMDA Base Notifications for Intent based configuration Update
2.1. Overview
The YANG module in NETCONF Base Notifications [RFC6470] specifies the
following 5 event notifications for the 'NETCONF' stream to notify a
client application that the NETCONF server state has changed:
o netconf-config-change
o netconf-capability-change
o netconf-session-start
o netconf-session-end
o netconf-confirmed-commit
These event notifications used within the 'NETCONF' stream are
accessible to clients via the subscription mechanism described in
[RFC5277].
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This document introduces NMDA specific extension which allows a
client to receive 1 notifications for additional common system events
as follows:
apply-configuration-updated: Generated when a server with network
management protocol support interacts with hardware and detects
that a set of configurations are not applied or none of them are
not applied. Indicates the event and the current state of the
applied configuration or data inconsistency issue between intended
data initiated from the client and operational data saved in the
server. NMDA datastore compare [I-D.ietf-netmod-nmda-diff] can be
used to trigger consistency data check, i.e.,indicate the source
of configuration node and check which part of configuration data
is applied or which part of configuration data is not applied. A
server MAY report events for non-NETCONF management sessions (such
as RESTCONF,gPRC), using the 'session-id' value of zero.
The following figure shows event notification sequence defined in
this document.
+----------------------------+
|Server (device) |
| |
| |
| +----------+ |
| | Intended | |
+------------+ | | datastore| |
| | | +----------+ |
|+----------+| | ^ |
|| Intended || | | |
|| config || | v |
|+----------+| | +-------------+ |
| |<----------------------> | | |
| Client | <nmda-diff> rpc | NETCONF | |
| (app) | | | engine | |
| |<---------------------- | | |
| | <intent-configuration +-------------+ |
| | -update> notification / \ |
+------------+ | / \ |
| / \ |
|+------------++---------+ |
|| Operational||system |+ |
|| datastore ||software ||+ |
|| ||component||| |
|+------------++---------+|| |
| +---------+| |
| +---------+ |
+----------------------------+
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These notification messages are accessible to clients via either the
subscription mechanism described in [RFC5277] or dynamic subscription
mechanism and configured subscription mechanism described in [I-
D.ietf-netconf-netconf-event-notifications].
2.2. Data Model Design
The data model is defined in the ietf-nmda-notifications YANG module.
Its structure is shown in the following figure. The notation syntax
follows [RFC8340].
notifications:
+---n intent-configuration-update
+--ro app-tag? string
+--ro src-ds? identityref
+--ro dst-ds? identifyref
+--ro (filter-spec)?
| +--:(subtree-filter)
| | +--ro subtree-filter? <anydata>
| +--:(xpath-filter)
| +--ro xpath-filter? yang:xpath1.0 {nc:xpath}?
|--ro apply-result enumeration
+--ro fail-applied-object* [edit-id]
+--ro edit-id string
+--ro operation enumeration
+--ro object? ypatch:target-resource-offset
+--ro value? <anydata>
+--ro errors
+--ro error* []
+--ro error-type enumeration
+--ro error-tag string
+--ro error-app-tag? string
+--ro error-path? instance-identifier
+--ro error-message? string
+--ro error-info? <anydata>
The following are examples of a apply-configuration-updated
notification message:
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<notification xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0">
<eventTime>2017-06-16T16:30:59.137045+09:00</eventTime>
<intent-configuration-update xmlns="urn:ietf:params:xml:ns:yang:ietf-nmda-notifications">
<app-tag>ds--module-a</app-tag>
<datastore>intended</datastore>
<datastore>operational</datastore>
<fail-applied-object>
<edit-id>1<edit-id>
<operation>merge</operation>
<target>/ietf-interfaces:interfaces-state</target>
<value>
<interfaces-state xmlns="http://foo.com/ietf-interfaces">
<interface>
<name>eth0</name>
<oper-status>down</oper-status>
</interface>
</interfaces-state>
</value>
</fail-applied-object>
<fail-applied-object>
<edit-id>2<edit-id>
<target>/ietf-system:system</target>
<errors>
<error-type>protocol</error-type>
<error-tag>mis-resource</error-tag>
<error-path xmlns:ops="https://example.com/ns/ietf-system">\
\/if:interfaces-state\
\</error-path>
<error-message>refer to resources that are not \
\available or otherwise not physically present.\
\</error-message>
</errors>
</fail-applied-object>
</intent-configuration-update>
</notification>
2.3. Relation with NMDA Datastore Compare
NMDA datastore compare [I-D.ietf-netmod-nmda-diff] could be used to
check which part of configuration data is applied or which part of
configuration data is not applied,e.g.,If a client creates an
interface "et-0/0/0" but the interface does not physically exist at
this point, the interface will appear in <intended> but does not does
not exist in the <operational>. By comparing configuration
difference between <intended> and <operational>, the interface that
is not applied can be sorted out. Unlike [I-D.ietf-netmod-nmda-
diff], the notification message only focuses on the configuration
data that is not applied and the reason why the configuration changes
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were not applied. Also system internal interactions with hardware is
needed within the server to make sure fail applied object is caused
by mis-resource or remnant Configuration, etc.
2.4. Definitions
This section presents the YANG module defined in this document. This
module imports data types from the 'ietf-datastores' module defined
in [RFC8342] and 'ietf-inet-types' module defined in [RFC6021].
<CODE BEGINS> file "ietf-nmda-notifications@2019-06-19.yang"
module ietf-nmda-notifications {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-nmda-notifications";
prefix ndn;
import ietf-datastores {
prefix ds;
}
import ietf-inet-types { prefix inet; }
import ietf-yang-types { prefix yang;}
import ietf-yang-patch {
prefix ypatch;
}
import ietf-netconf {
prefix nc;
}
import ietf-restconf { prefix rc;}
organization
"IETF NETMOD (Network Modeling) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netmod/>
WG List: <mailto:netmod@ietf.org>
Editor: Qin Wu
<mailto:bill.wu@huawei.com>
Editor: Rohit R Ranade
<mailto:rohitrranade@huawei.com>";
description
"This module defines a YANG data model for use with the
NETCONF and RESTCONF protocol that allows the client to
receive additional common event notifications related to NMDA.
Copyright (c) 2012 IETF Trust and the persons identified as
the document authors. 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; see
the RFC itself for full legal notices.";
revision 2019-06-19 {
description
"Initial version.";
reference "RFC xxx: NETCONF Base Notifications for NMDA";
}
typedef session-id-or-zero-type {
type uint32;
description
"NETCONF Session Id or Zero to indicate none";
}
feature error-info {
description
"This feature must
also be enabled for that session if error-info
can be advertised by the server. Otherwise,
this feature must not be enabled.";
}
grouping common-session-parms {
description
"Common session parameters to identify a
management session or internal interaction
on a set of configuration data.";
leaf username {
type string;
description
"Name of the user for the session.";
}
leaf source-host {
type inet:ip-address;
description
"Address of the remote host for the session.";
}
leaf session-id {
type session-id-or-zero-type;
description
"Identifier of the session.
A NETCONF session MUST be identified by a non-zero value.
A non-NETCONF session MAY be identified by the value zero.";
}
leaf app-tag {
type string;
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description
"The application tag used to identify the managment session
or internal interaction on a set of configuration data.";
}
}
notification intent-configuration-updated {
description
"Generated when a server detects that a
intended configuration applied event has occurred. Indicates
the event and the current state of the intended data applying
procedure in progress.";
reference "RFC 8342, Section 5";
uses common-session-parms;
leaf src-ds {
type identityref {
base ds:datastore;
}
description
"Indicates which datastore is
source of edit-data operation.";
}
leaf dst-ds {
type identityref {
base ds:datastore;
}
description
"Indicates which datastore is
target of edit-data operation.";
}
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: Network Configuration Protocol, Section 6.";
}
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.
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If the expression returns a node-set, all nodes in the
node-set are selected by the filter. Otherwise, if the
expression does not return a node-set, then the get-data
operation fails.
The expression is evaluated in the following XPath
context:
o The set of namespace declarations are those in
scope on the 'xpath-filter' leaf element.
o The set of variable bindings is empty.
o The function library is the core function library,
and the XPath functions defined in section 10 in
RFC 7950.
o The context node is the root node of the target
datastore.";
}
}
leaf apply-result {
type enumeration {
enum "partial-fail" {
description
"A set of configuration data is not applied.";
}
enum "fail" {
description
" None of configuration data is applied.";
}
enum "sucess" {
description
" All configuration data is applied.";
}
}
description
"Configuration data apply result.";
}
list fail-applied-object {
when "../apply-result = 'partial-fail'";
key edit-id;
ordered-by user;
leaf edit-id {
type string;
description
"Response status is for the 'edit' list entry
with this 'edit-id' value.";
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}
leaf operation {
type enumeration {
enum create {
description
"The target data node is created using the supplied
value, only if it does not already exist. The
'target' leaf identifies the data node to be
created, not the parent data node.";
}
enum delete {
description
"Delete the target node, only if the data resource
currently exists; otherwise, return an error.";
}
enum insert {
description
"Insert the supplied value into a user-ordered
list or leaf-list entry. The target node must
represent a new data resource. If the 'where'
parameter is set to 'before' or 'after', then
the 'point' parameter identifies the insertion
point for the target node.";
}
enum merge {
description
"The supplied value is merged with the target data
node.";
}
enum move {
description
"Move the target node. Reorder a user-ordered
list or leaf-list. The target node must represent
an existing data resource. If the 'where' parameter
is set to 'before' or 'after', then the 'point'
parameter identifies the insertion point to move
the target node.";
}
enum replace {
description
"The supplied value is used to replace the target
data node.";
}
enum remove {
description
"Delete the target node if it currently exists.";
}
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}
mandatory true;
description
"The datastore operation requested for the associated
'edit' entry.";
}
leaf target {
type ypatch:target-resource-offset;
description
"Topmost node associated with the configuration change.
A server SHOULD set this object to the node within
the datastore that is being altered. A server MAY
set this object to one of the ancestors of the actual
node that was changed, or omit this object, if the
exact node is not known.";
}
anydata value {
description
"Value used for this edit operation. The anydata 'value'
contains the target resource associated with the
'target' leaf.
For example, suppose the target node is a YANG container
named foo:
container foo {
leaf a { type string; }
leaf b { type int32; }
}
The 'value' node contains one instance of foo:
<value>
<foo xmlns='example-foo-namespace'>
<a>some value</a>
<b>42</b>
</foo>
</value>
";
}
uses rc:errors {if-feature error-info;}
description
"List for fail applied objects that is not applied. ";
}
}
}
<CODE ENDS>
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3. Security Considerations
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, defined in [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:
/intent-configuration-update:
Event type itself indicates that intent based configuration has
been updated. This event could alert an attacker that a datastore
may have been altered.
/intent-configuration-updated/apply-result:
Indicates the specific intent based configuration update event
state change that occurred. A value of 'success' probably
indicates that intent based configuration has been applied
successfully.
4. IANA Considerations
This document registers one XML namespace URN in the 'IETF XML
registry', following the format defined in [RFC3688]:
URI: urn:ietf:params:xml:ns:yang:ietf-nmda-notifications
Registrant Contact: The IESG.
XML: N/A, the requested URI is an XML namespace.
This document registers one module name in the 'YANG Module Names'
registry, defined in [RFC7950]:
name: ietf-nmda-notifications
prefix: ndn
namespace: urn:ietf:params:xml:ns:yang:ietf-nmda-notifications
RFC: xxxx
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5. Acknowledgements
Thanks to Juergen Schoenwaelder, Alex Clemm,Carey Timothy and Andy
Berman, Sterne Jason to review this draft and Thank Xiaojian Ding
provide important input to the initial version of this document.
6. Contributors
Chong Feng
Huawei
Email:frank.fengchong@huawei.com
7. Normative References
[I-D.ietf-netmod-nmda-diff]
Clemm, A., Qu, Y., Tantsura, J., and A. Bierman,
"Comparison of NMDA datastores", draft-ietf-netmod-nmda-
diff-01 (work in progress), May 2019.
[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>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC5277] Chisholm, S. and H. Trevino, "NETCONF Event
Notifications", RFC 5277, DOI 10.17487/RFC5277, July 2008,
<https://www.rfc-editor.org/info/rfc5277>.
[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>.
[RFC6021] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6021, DOI 10.17487/RFC6021, October 2010,
<https://www.rfc-editor.org/info/rfc6021>.
[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>.
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[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<https://www.rfc-editor.org/info/rfc6242>.
[RFC6470] Bierman, A., "Network Configuration Protocol (NETCONF)
Base Notifications", RFC 6470, DOI 10.17487/RFC6470,
February 2012, <https://www.rfc-editor.org/info/rfc6470>.
[RFC8072] Bierman, A., Bjorklund, M., and K. Watsen, "YANG Patch
Media Type", RFC 8072, DOI 10.17487/RFC8072, February
2017, <https://www.rfc-editor.org/info/rfc8072>.
[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
and R. Wilton, "Network Management Datastore Architecture
(NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
<https://www.rfc-editor.org/info/rfc8342>.
Appendix A. Changes between revisions
v01 - v03
o Change notification name into intent-configuration update.
o Change title into NMDA Base event for intent based configuration
update.
o Clarify the usage of NMDA base event and relation with NMDA diff
work.
v01 - v00
o Add application tag support and use additional parameters to
identify management session.
o Remove apply-intended-start and apply-intended-end two
notifications since they are not needed based on discussion.
Authors' Addresses
Qin Wu
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: bill.wu@huawei.com
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Ran Tao
Huawei
Email: taoran20@huawei.com
Rohit R Ranade
Huawei
Divyashree Techno Park, Whitefield
Bangalore, Karnataka 560066
India
Email: rohitrranade@huawei.com
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