Network Working Group A. Bierman
Internet-Draft YumaWorks
Intended status: Standards Track M. Bjorklund
Expires: June 17, 2016 Tail-f Systems
K. Watsen
Juniper Networks
December 15, 2015
YANG Patch Media Type
draft-ietf-netconf-yang-patch-07
Abstract
This document describes a method for applying patches to NETCONF
datastores using data defined with the YANG data modeling language.
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 June 17, 2016.
Copyright Notice
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.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
1.1.1. NETCONF . . . . . . . . . . . . . . . . . . . . . . . 3
1.1.2. HTTP . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1.3. YANG . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1.4. RESTCONF . . . . . . . . . . . . . . . . . . . . . . 4
1.1.5. YANG Patch . . . . . . . . . . . . . . . . . . . . . 5
1.1.6. Tree Diagrams . . . . . . . . . . . . . . . . . . . . 5
2. YANG Patch . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1. Target Resource . . . . . . . . . . . . . . . . . . . . . 6
2.2. yang-patch Input . . . . . . . . . . . . . . . . . . . . 6
2.3. yang-patch-status Output . . . . . . . . . . . . . . . . 7
2.4. Target Data Node . . . . . . . . . . . . . . . . . . . . 7
2.5. Edit Operations . . . . . . . . . . . . . . . . . . . . . 8
2.6. Error Handling . . . . . . . . . . . . . . . . . . . . . 8
2.7. yang-patch RESTCONF Capability . . . . . . . . . . . . . 9
3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . . . 9
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
4.1. YANG Module Registry . . . . . . . . . . . . . . . . . . 18
4.2. application/yang.patch Media Types . . . . . . . . . . . 18
4.3. application/yang.patch-status Media Types . . . . . . . . 18
4.4. RESTCONF Capability URNs . . . . . . . . . . . . . . . . 19
5. Security Considerations . . . . . . . . . . . . . . . . . . . 19
6. Normative References . . . . . . . . . . . . . . . . . . . . 19
Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 20
Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 21
B.1. v06 to v07 . . . . . . . . . . . . . . . . . . . . . . . 21
B.2. v05 to v06 . . . . . . . . . . . . . . . . . . . . . . . 21
B.3. v04 to v05 . . . . . . . . . . . . . . . . . . . . . . . 21
B.4. v03 to v04 . . . . . . . . . . . . . . . . . . . . . . . 21
B.5. v02 to v03 . . . . . . . . . . . . . . . . . . . . . . . 22
B.6. v01 to v02 . . . . . . . . . . . . . . . . . . . . . . . 22
B.7. v00 to v01 . . . . . . . . . . . . . . . . . . . . . . . 22
B.8. bierman:yang-patch-00 to ietf:yang-patch-00 . . . . . . . 23
Appendix C. Open Issues . . . . . . . . . . . . . . . . . . . . 23
Appendix D. Example YANG Module . . . . . . . . . . . . . . . . 23
D.1. YANG Patch Examples . . . . . . . . . . . . . . . . . . . 24
D.1.1. Add Resources: Error . . . . . . . . . . . . . . . . 24
D.1.2. Add Resources: Success . . . . . . . . . . . . . . . 27
D.1.3. Move list entry example . . . . . . . . . . . . . . . 29
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 29
1. Introduction
There is a need for standard mechanisms to patch NETCONF [RFC6241]
datastores which contain conceptual data that conforms to schema
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specified with YANG [RFC6020]. An "ordered edit list" approach is
needed to provide client developers with a simpler edit request
format that can be more efficient and also allow more precise client
control of the transaction procedure than existing mechanisms.
This document defines a media type for a YANG-based editing mechanism
that can be used with the HTTP PATCH method [RFC5789]. YANG Patch is
designed to support the RESTCONF protocol, defined in
[I-D.ietf-netconf-restconf].
1.1. Terminology
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].
1.1.1. NETCONF
The following terms are defined in [RFC6241]:
o client
o configuration data
o datastore
o configuration datastore
o protocol operation
o running configuration datastore
o server
o state data
o user
1.1.2. HTTP
The following terms are defined in [RFC2616]:
o entity tag
o fragment
o header line
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o message body
o method
o path
o query
o request URI
o response body
1.1.3. YANG
The following terms are defined in [RFC6020]:
o container
o data node
o key leaf
o leaf
o leaf-list
o list
o presence container (or P-container)
o RPC operation (now called protocol operation)
o non-presence container (or NP-container)
o ordered-by system
o ordered-by user
1.1.4. RESTCONF
The following terms are defined in [I-D.ietf-netconf-restconf]:
o data resource
o datastore resource
o patch
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o RESTCONF capability
o target resource
1.1.5. YANG Patch
The following terms are used within this document:
o YANG Patch: a conceptual edit request using the "yang-patch" YANG
container, defined in Section 3. In HTTP, refers to a PATCH
method where the media type is "application/yang.patch+xml" or
"application/yang.patch+json".
o YANG Patch Status: a conceptual edit status response using the
YANG "yang-patch-status" container, defined in Section 3. In
HTTP, refers to a response message for a PATCH method, where the
message body is identified by the media type "application/
yang.patch-status+xml" or "application/yang.patch-status+json".
1.1.6. Tree Diagrams
A simplified graphical representation of the data model is used in
this document. The meaning of the symbols in these diagrams is as
follows:
o Brackets "[" and "]" enclose list keys.
o Abbreviations before data node names: "rw" means configuration
(read-write) and "ro" state data (read-only).
o Symbols after data node names: "?" means an optional node and "*"
denotes a "list" and "leaf-list".
o Parentheses enclose choice and case nodes, and case nodes are also
marked with a colon (":").
o Ellipsis ("...") stands for contents of subtrees that are not
shown.
2. YANG Patch
A "YANG Patch" is an ordered list of edits that are applied to the
target datastore by the server. The specific fields are defined in
the YANG module in Section 3.
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For RESTCONF, the YANG Patch operation is invoked by the client by
sending a PATCH method request with the YANG Patch media type. A
message body representing the YANG Patch input parameters MUST be
provided.
The RESTCONF server MUST return the Accept-Patch header in an OPTIONS
response, as specified in [RFC5789], which includes the media type
for YANG Patch.
A YANG Patch can be encoded in XML format according to
[W3C.REC-xml-20081126]. It can also be encoded in JSON, according to
"JSON Encoding of Data Modeled with YANG"
[I-D.ietf-netmod-yang-json]. If any meta-data needs to be sent in a
JSON message, it is encoded according to "Defining and Using Metadata
with YANG" [I-D.ietf-netmod-yang-metadata].
Example:
Accept-Patch: application/yang.patch
2.1. Target Resource
The YANG Patch operation uses a conceptual root within a NETCONF
configuration datastore to identity the patch point for the edit
operation. This root can be the datastore itself, or 1 or more data
nodes within the datastore.
For RESTCONF, the target resource is derived from the request URI.
2.2. yang-patch Input
A YANG patch is optionally identified by a unique "patch-id" and it
may have an optional comment. A patch is an ordered collection of
edits. Each edit is identified by an "edit-id" and it has an edit
operation (create, delete, insert, merge, move, replace, remove) that
is applied to the target resource. Each edit can be applied to a
sub-resource "target" within the target resource. If the operation
is "insert" or "move", then the "where" parameter indicates how the
node is inserted or moved. For values "before" and "after", the
"point" parameter specifies the data node insertion point.
A data element representing the YANG Patch is sent by the client to
specify the edit operation request. When used with the HTTP PATCH
method, this data is identified by the YANG Patch media type.
YANG Tree Diagram For "yang-patch" Container
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+--rw yang-patch
+--rw patch-id? string
+--rw comment? string
+--rw edit [edit-id]
+--rw edit-id string
+--rw operation enumeration
+--rw target target-resource-offset
+--rw point? target-resource-offset
+--rw where? enumeration
+--rw value
2.3. yang-patch-status Output
A data element representing the YANG Patch Status is returned to the
client to report the detailed status of the edit operation. When
used with the HTTP PATCH method, this data is identified by the YANG
Patch Status media type, and the syntax specification is defined in
Section 3.
YANG Tree Diagram For "yang-patch-status" Container:
+--rw yang-patch-status
+--rw patch-id? string
+--rw (global-status)?
| +--:(global-errors)
| | +--ro errors
| |
| +--:(ok)
| +--rw ok? empty
+--rw edit-status
+--rw edit [edit-id]
+--rw edit-id string
+--rw (edit-status-choice)?
+--:(ok)
| +--rw ok? empty
+--:(errors)
+--ro errors
2.4. Target Data Node
The target data node for each edit operation is determined by the
value of the target resource in the request and the "target" leaf
within each "edit" entry.
If the target resource specified in the request URI identifies a
datastore resource, then the path string in the "target" leaf is an
absolute path expression. The first node specified in the "target"
leaf is a top-level data node defined within a YANG module.
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If the target resource specified in the request URI identifies a data
resource, then the path string in the "target" leaf is a relative
path expression. The first node specified in the "target" leaf is a
child node of the data node associated with the target resource.
2.5. Edit Operations
Each YANG patch edit specifies one edit operation on the target data
node. The set of operations is aligned with the NETCONF edit
operations, but also includes some new operations.
+---------------+---------------------------------------------------+
| Operation | Description |
+---------------+---------------------------------------------------+
| create | create a new data resource if it does not already |
| | exist or error |
| delete | delete a data resource if it already exists or |
| | error |
| insert | insert a new user-ordered data resource |
| merge | merge the edit value with the target data |
| | resource; create if it does not already exist |
| move | re-order the target data resource |
| replace | replace the target data resource with the edit |
| | value |
| remove | remove a data resource if it already exists or no |
| | error |
+---------------+---------------------------------------------------+
YANG Patch Edit Operations
2.6. Error Handling
If a well-formed, schema-valid YANG Patch message is received, then
the server will process the supplied edits in ascending order. The
following error modes apply to the processing of this edit list:
All the specified edits MUST be applied or the target datastore
contents MUST be returned to its original state before the PATCH
method started.
The server will save the running datastore to non-volatile storage if
it has changed, after the edits have been successfully completed.
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2.7. yang-patch RESTCONF Capability
A URI is defined to identify the YANG Patch extension to the base
RESTCONF protocol. If the server supports the YANG Patch media type,
then the "yang-patch" RESTCONF capability defined in Section 4.4 MUST
be present in the "capability" leaf-list in the
"ietf-restconf-monitoring" module defined in
[I-D.ietf-netconf-restconf].
3. YANG Module
The "ietf-yang-patch" module defines conceptual definitions with the
'restconf-media-type' extension statements, which are not meant to be
implemented as datastore contents by a server.
The "ietf-restconf" module from [I-D.ietf-netconf-restconf] is used
by this module for the 'restconf-media-type' extension definition.
RFC Ed.: update the date below with the date of RFC publication and
remove this note.
<CODE BEGINS> file "ietf-yang-patch@2015-04-30.yang"
module ietf-yang-patch {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-yang-patch";
prefix "ypatch";
import ietf-yang-types { prefix yang; }
import ietf-restconf {
prefix rc;
revision-date 2015-10-18;
}
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>
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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 conceptual YANG specifications
for the YANG Patch and YANG Patch Status data structures.
Note that the YANG definitions within this module do not
represent configuration data of any kind.
The YANG grouping statements provide a normative syntax
for XML and JSON message encoding purposes.
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-patch-07.txt
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
revision 2015-12-15 {
description
"Initial revision.";
reference
"RFC XXXX: YANG Patch Media Type.";
}
typedef target-resource-offset {
type yang:xpath1.0;
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description
"Contains an XPath absolute path expression identifying
a sub-resource within the target resource.
The document root for this XPath expression is the
target resource that is specified in the
protocol operation (e.g., the URI for the PATCH request).";
}
rc:restconf-media-type "application/yang.patch" {
uses yang-patch;
}
rc:restconf-media-type "application/yang.patch-status" {
uses yang-patch-status;
}
grouping yang-patch {
description
"A grouping that contains a YANG container
representing the syntax and semantics of a
YANG Patch edit request message.";
container yang-patch {
description
"Represents a conceptual sequence of datastore edits,
called a patch. Each patch is given a client-assigned
patch identifier. Each edit MUST be applied
in ascending order, and all edits MUST be applied.
If any errors occur, then the target datastore MUST NOT
be changed by the patch operation.
YANG datastore validation (defined in RFC 6020, section
8.3.3) is performed before any edits have been applied
to the running datastore.
It is possible for a datastore constraint violation to occur
due to any node in the datastore, including nodes not
included in the edit list. Any validation errors MUST
be reported in the reply message.";
reference
"RFC 6020, section 8.3.";
leaf patch-id {
type string;
description
"An arbitrary string provided by the client to identify
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the entire patch. This value SHOULD be present in any
audit logging records generated by the server for the
patch. Error messages returned by the server pertaining
to this patch will be identified by this patch-id value.";
}
leaf comment {
type string;
description
"An arbitrary string provided by the client to describe
the entire patch. This value SHOULD be present in any
audit logging records generated by the server for the
patch.";
}
list edit {
key edit-id;
ordered-by user;
description
"Represents one edit within the YANG Patch
request message. The edit list is applied
in the following manner:
- The first edit is conceptually applied to a copy
of the existing target datastore, e.g., the
running configuration datastore.
- Each ascending edit is conceptually applied to
the result of the previous edit(s).
- After all edits have been successfully processed,
the result is validated according to YANG constraints.
- If successful, the server will attempt to apply
the result to the target datastore. ";
leaf edit-id {
type string;
description
"Arbitrary string index for the edit.
Error messages returned by the server pertaining
to a specific edit will be identified by this
value.";
}
leaf operation {
type enumeration {
enum create {
description
"The target data node is created using the
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supplied value, only if it does not already
exist.";
}
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.";
}
}
mandatory true;
description
"The datastore operation requested for the associated
edit entry";
}
leaf target {
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type target-resource-offset;
mandatory true;
description
"Identifies the target data resource for the edit
operation.";
}
leaf point {
when "(../operation = 'insert' or ../operation = 'move') "
+ "and (../where = 'before' or ../where = 'after')" {
description
"Point leaf only applies for insert or move
operations, before or after an existing entry.";
}
type target-resource-offset;
description
"The absolute URL path for the data node that is being
used as the insertion point or move point for the
target of this edit entry.";
}
leaf where {
when "../operation = 'insert' or ../operation = 'move'" {
description
"Where leaf only applies for insert or move
operations.";
}
type enumeration {
enum before {
description
"Insert or move a data node before the data resource
identified by the 'point' parameter.";
}
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.";
}
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}
default last;
description
"Identifies where a data resource will be inserted or
moved. YANG only allows these operations for
list and leaf-list data nodes that are ordered-by
user.";
}
anydata value {
when "../operation = 'create' "
+ "or ../operation = 'merge' "
+ "or ../operation = 'replace' "
+ "or ../operation = 'insert'" {
description
"Value node only used for create, merge,
replace, and insert operations";
}
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 will contain one instance of foo:
<value>
<foo xmlns='example-foo-namespace'>
<a>some value</a>
<b>42</b>
</foo>
</value>
";
}
}
}
} // grouping yang-patch
grouping yang-patch-status {
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description
"A grouping that contains a YANG container
representing the syntax and semantics of
YANG Patch status response message.";
container yang-patch-status {
description
"A container representing the response message
sent by the server after a YANG Patch edit
request message has been processed.";
leaf patch-id {
type string;
description
"The patch-id value used in the request";
}
choice global-status {
description
"Report global errors or complete success.
If there is no case selected then errors
are reported in the edit-status container.";
case global-errors {
uses rc:errors;
description
"This container will be present if global
errors unrelated to a specific edit occurred.";
}
leaf ok {
type empty;
description
"This leaf will be present if the request succeeded
and there are no errors reported in the edit-status
container.";
}
}
container edit-status {
description
"This container will be present if there are
edit-specific status responses to report.
If all edits succeeded and the 'global-status'
returned is 'ok', then a server MAY omit this
container";
list edit {
key edit-id;
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description
"Represents a list of status responses,
corresponding to edits in the YANG Patch
request message. If an edit entry was
skipped or not reached by the server,
then this list will not contain a corresponding
entry for that edit.";
leaf edit-id {
type string;
description
"Response status is for the edit list entry
with this edit-id value.";
}
choice edit-status-choice {
description
"A choice between different types of status
responses for each edit entry.";
leaf ok {
type empty;
description
"This edit entry was invoked without any
errors detected by the server associated
with this edit.";
}
case errors {
uses rc:errors;
description
"The server detected errors associated with the
edit identified by the same edit-id value.";
}
}
}
}
}
} // grouping yang-patch-status
}
<CODE ENDS>
4. IANA Considerations
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4.1. YANG Module Registry
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-patch
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-patch
namespace: urn:ietf:params:xml:ns:yang:ietf-yang-patch
prefix: ypatch
// RFC Ed.: replace XXXX with RFC number and remove this note
reference: RFC XXXX
4.2. application/yang.patch Media Types
The MIME media type for a YANG Patch document is application/
yang.patch.
Type name: application
Subtype name: yang.patch
Required parameters: none
Optional parameters: none
Encoding considerations: 8-bit
Security considerations: See Section 5 of RFC XXXX
Interoperability considerations: none
// RFC Ed.: replace XXXX with RFC number and remove this note
Published specification: RFC XXXX
4.3. application/yang.patch-status Media Types
The MIME media type for a YANG Patch status document is application/
yang.patch-status.
Type name: application
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Subtype name: yang.patch-status
Required parameters: none
Optional parameters: none
Encoding considerations: 8-bit
Security considerations: See Section 5 of RFC XXXX
Interoperability considerations: none
// RFC Ed.: replace XXXX with RFC number and remove this note
Published specification: RFC XXXX
4.4. RESTCONF Capability URNs
This document registers one capability identifier in "RESTCONF
Protocol Capability URNs" registry
Index
Capability Identifier
------------------------
:yang-patch
urn:ietf:params:restconf:capability:yang-patch:1.0
5. Security Considerations
The YANG Patch media type does not introduce any significant new
security threats, beyond what is described in
[I-D.ietf-netconf-restconf]. This document defines edit processing
instructions for a variant of the PATCH method, as used within the
RESTCONF protocol.
It is important for server implementations to carefully validate all
the edit request parameters in some manner. If the entire YANG Patch
request cannot be completed, then no configuration changes to the
system are done.
A server implementation SHOULD attempt to prevent system disruption
due to partial processing of the YANG Patch edit list. It may be
possible to construct an attack on such a server, which relies on the
edit processing order mandated by YANG Patch.
6. Normative References
[I-D.ietf-netconf-restconf]
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Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", draft-ietf-netconf-restconf-08 (work in
progress), October 2015.
[I-D.ietf-netmod-yang-json]
Lhotka, L., "JSON Encoding of Data Modeled with YANG",
draft-ietf-netmod-yang-json-06 (work in progress), October
2015.
[I-D.ietf-netmod-yang-metadata]
Lhotka, L., "Defining and Using Metadata with YANG",
draft-ietf-netmod-yang-metadata-02 (work in progress),
September 2015.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
January 2004.
[RFC5789] Dusseault, L. and J. Snell, "PATCH Method for HTTP", RFC
5789, March 2010.
[RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the
Network Configuration Protocol (NETCONF)", RFC 6020,
October 2010.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, June 2011.
[RFC7158] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
Interchange Format", RFC 7158, March 2013.
[W3C.REC-xml-20081126]
Yergeau, F., Maler, E., Paoli, J., Sperberg-McQueen, C.,
and T. Bray, "Extensible Markup Language (XML) 1.0 (Fifth
Edition)", World Wide Web Consortium Recommendation REC-
xml-20081126, November 2008,
<http://www.w3.org/TR/2008/REC-xml-20081126>.
Appendix A. Acknowledgements
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The authors would like to thank the following people for their
contributions to this document: Rex Fernando.
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).
Appendix B. Change Log
-- RFC Ed.: remove this section before publication.
The YANG Patch issue tracker can be found here: https://github.com/
netconf-wg/yang-patch/issues
B.1. v06 to v07
o converted YANG module to YANG 1.1
o changed anyxml value to anydata value
o updated import revision date for ietf-restconf
o updated revision date for ietf-yang-patch because import-by-
revision date needed to be changed
B.2. v05 to v06
o changed errors example so a full request and error response is
shown in XML format
o fixed error-path to match instance-identifier encoding for both
XML and JSON
o added references for YANG to JSON and YANG Metadata drafts
o clarified that YANG JSON drafts are used for encoding, not plain
JSON
B.3. v04 to v05
o updated reference to RESTCONF
B.4. v03 to v04
o removed NETCONF specific text
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o changed data-resource-offset typedef from a relative URI to an
XPath absolute path expression
o clarified insert operation
o removed requirement that edits MUST be applied in ascending order
o change SHOULD keep datastore unchanged on error to MUST (this is
required by HTTP PATCH)
o removed length restriction on 'comment' leaf
o updated YANG tree for example-jukebox library
B.5. v02 to v03
o added usage of restconf-media-type extension to map the yang-patch
and yang-patch-status groupings to media types
o added yang-patch RESTCONF capability URI
o Added sub-section for terms used from RESTCONF
o filled in security considerations section
B.6. v01 to v02
o Reversed order of change log
o Clarified anyxml structure of "value" parameter within a YANG
patch request (github issue #1)
o Updated RESTCONF reference
o Added note to open issues section to check github instead
B.7. v00 to v01
o Added text requiring support for Accept-Patch header, and removed
'Identification of YANG Patch capabilities' open issue.
o Removed 'location' leaf from yang-patch-status grouping
o Removed open issue 'Protocol independence' because the location
leaf was removed.
o Removed open issue 'RESTCONF coupling' because there is no concern
about a normative reference to RESTCONF. There may need to be a
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YANG 1.1 mechanism to allow protocol template usage (instead of
grouping wrapper).
o Removed open issue 'Is the delete operation needed'. It was
decided that both delete and remove should remain as operations
and clients can choose which one to use. This is not an
implementation burden on the server.
o Removed open issue 'global-errors needed'. It was decided that
they are needed as defined because the global <ok/> is needed and
the special key value for edit=global error only allows for 1
global error.
o Removed open issue 'Is location leaf needed'. It was decided that
it is not needed so this leaf has been removed.
o Removed open issue 'Bulk editing support in yang-patch-status'.
The 'location' leaf has been removed so this issue is no longer
applicable.
o Removed open issue 'Edit list mechanism'. Added text to the
'edit' list description-stmt about how the individual edits must
be processed. There is no concern about duplicate edits which
cause intermediate results to be altered by subsequent edits in
the same edit list.
B.8. bierman:yang-patch-00 to ietf:yang-patch-00
o Created open issues section
Appendix C. Open Issues
-- RFC Ed.: remove this section before publication.
Refer to the github issue tracker for any open issues:
https://github.com/netconf-wg/yang-patch/issues [1]
Appendix D. Example YANG Module
The example YANG module used in this document represents a simple
media jukebox interface. The "example-jukebox" YANG module is
defined in [I-D.ietf-netconf-restconf].
YANG Tree Diagram for "example-jukebox" Module:
+--rw jukebox!
+--rw library
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| +--rw artist* [name]
| | +--rw name string
| | +--rw album* [name]
| | +--rw name string
| | +--rw genre? identityref
| | +--rw year? uint16
| | +--rw admin
| | | +--rw label? string
| | | +--rw catalogue-number? string
| | +--rw song* [name]
| | +--rw name string
| | +--rw location string
| | +--rw format? string
| | +--rw length? uint32
| +--ro artist-count? uint32
| +--ro album-count? uint32
| +--ro song-count? uint32
+--rw playlist* [name]
| +--rw name string
| +--rw description? string
| +--rw song* [index]
| +--rw index uint32
| +--rw id leafref
+--rw player
+--rw gap? decimal64
rpcs:
+---x play
+--ro input
+--ro playlist string
+--ro song-number uint32
D.1. YANG Patch Examples
This section includes RESTCONF examples. Most examples are shown in
JSON encoding [RFC7158], and some are shown in XML encoding
[W3C.REC-xml-20081126].
D.1.1. Add Resources: Error
The following example shows several songs being added to an existing
album. Each edit contains one song. The first song already exists,
so an error will be reported for that edit. The rest of the edits
were not attempted, since the first edit failed. The XML encoding is
used in this example.
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Request from client:
PATCH /restconf/data/example-jukebox:jukebox/
library/artist=Foo%20Fighters/album=Wasting%20Light HTTP/1.1
Host: example.com
Accept: application/yang.patch-status+xml
Content-Type: application/yang.patch+xml
<yang-patch xmlns="urn:ietf:params:xml:ns:yang:ietf-yang-patch">
<patch-id>add-songs-patch</patch-id>
<edit>
<edit-id>edit1</edit-id>
<operation>create</operation>
<target>/song</target>
<value>
<song xmlns="http://example.com/ns/example-jukebox">
<name>Bridge Burning</name>
<location>/media/bridge_burning.mp3</location>
<format>MP3</format>
<length>288</length>
</song>
</value>
</edit>
<edit>
<edit-id>edit2</edit-id>
<operation>create</operation>
<target>/song</target>
<value>
<song xmlns="http://example.com/ns/example-jukebox">
<name>Rope</name>
<location>/media/rope.mp3</location>
<format>MP3</format>
<length>259</length>
</song>
</value>
</edit>
<edit>
<edit-id>edit3</edit-id>
<operation>create</operation>
<target>/song</target>
<value>
<song xmlns="http://example.com/ns/example-jukebox">
<name>Dear Rosemary</name>
<location>/media/dear_rosemary.mp3</location>
<format>MP3</format>
<length>269</length>
</song>
</value>
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</edit>
</yang-patch>
XML Response from server:
HTTP/1.1 409 Conflict
Date: Mon, 23 Apr 2012 13:01:20 GMT
Server: example-server
Last-Modified: Mon, 23 Apr 2012 13:01:20 GMT
Content-Type: application/yang.patch-status+xml
<yang-patch-status
xmlns="urn:ietf:params:xml:ns:yang:ietf-yang-patch">
<patch-id>add-songs-patch</patch-id>
<edit-status>
<edit>
<edit-id>edit1</edit-id>
<errors>
<error>
<error-type>application</error-type>
<error-tag>data-exists</error-tag>
<error-path
xmlns:jb="http://example.com/ns/example-jukebox">
/jb:jukebox/jb:library
/jb:artist[jb:name='Foo Fighters']
/jb:album[jb:name='Wasting Light']
/jb:song[jb:name='Burning Light']
</error-path>
<error-message>
Data already exists, cannot be created
</error-message>
</error>
</errors>
</edit>
</edit-status>
</yang-patch-status>
JSON Response from server:
The following response is shown in JSON format to highlight the
difference in the "error-path" object encoding. For JSON, the
instance-identifier encoding in the "JSON Encoding of YANG
Data" draft is used. The "error-path" string is wrapped for
display purposes.
HTTP/1.1 409 Conflict
Date: Mon, 23 Apr 2012 13:01:20 GMT
Server: example-server
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Last-Modified: Mon, 23 Apr 2012 13:01:20 GMT
Content-Type: application/yang.patch-status+json
{
"ietf-yang-patch:yang-patch-status" : {
"patch-id" : "add-songs-patch",
"edit-status" : {
"edit" : [
{
"edit-id" : "edit1",
"errors" : {
"error" : [
{
"error-type": "application",
"error-tag": "data-exists",
"error-path": "/example-jukebox:jukebox/library
/artist[name='Foo Fighters']
/album[name='Wasting Light']
/song[name='Burning Light']",
"error-message":
"Data already exists, cannot be created"
}
]
}
}
]
}
}
}
D.1.2. Add Resources: Success
The following example shows several songs being added to an existing
album.
o Each of 2 edits contains one song.
o Both edits succeed and new sub-resources are created
Request from client:
PATCH /restconf/data/example-jukebox:jukebox/
library/artist=Foo%20Fighters/album=Wasting%20Light
HTTP/1.1
Host: example.com
Accept: application/yang.patch-status+json
Content-Type: application/yang.patch+json
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{
"ietf-yang-patch:yang-patch" : {
"patch-id" : "add-songs-patch-2",
"edit" : [
{
"edit-id" : "edit1",
"operation" : "create",
"target" : "/song",
"value" : {
"song" : {
"name" : "Rope",
"location" : "/media/rope.mp3",
"format" : "MP3",
"length" : 259
}
}
},
{
"edit-id" : "edit2",
"operation" : "create",
"target" : "/song",
"value" : {
"song" : {
"name" : "Dear Rosemary",
"location" : "/media/dear_rosemary.mp3",
"format" : "MP3",
"length" : 269
}
}
}
]
}
}
Response from server:
HTTP/1.1 200 Success
Date: Mon, 23 Apr 2012 13:01:20 GMT
Server: example-server
Last-Modified: Mon, 23 Apr 2012 13:01:20 GMT
Content-Type: application/yang.patch-status+json
{
"ietf-yang-patch:yang-patch-status" : {
"patch-id" : "add-songs-patch-2",
"ok" : [null]
}
}
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D.1.3. Move list entry example
The following example shows a song being moved within an existing
playlist. Song "1" in playlist "Foo-One" is being moved after song
"3" in the playlist. The operation succeeds, so a non-error reply
example can be shown.
Request from client:
PATCH /restconf/data/example-jukebox:jukebox/
playlist=Foo-One HTTP/1.1
Host: example.com
Accept: application/yang.patch-status+json
Content-Type: application/yang.patch+json
{
"ietf-yang-patch:yang-patch" : {
"patch-id" : "move-song-patch",
"comment" : "Move song 1 after song 3",
"edit" : [
{
"edit-id" : "edit1",
"operation" : "move",
"target" : "/song/1",
"point" : "/song3",
"where" : "after"
}
]
}
}
Response from server:
HTTP/1.1 400 OK
Date: Mon, 23 Apr 2012 13:01:20 GMT
Server: example-server
Last-Modified: Mon, 23 Apr 2012 13:01:20 GMT
Content-Type: application/yang.patch-status+json
{
"ietf-restconf:yang-patch-status" : {
"patch-id" : "move-song-patch",
"ok" : [null]
}
}
Authors' Addresses
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Andy Bierman
YumaWorks
Email: andy@yumaworks.com
Martin Bjorklund
Tail-f Systems
Email: mbj@tail-f.com
Kent Watsen
Juniper Networks
Email: kwatsen@juniper.net
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