Network Working Group A. Bierman
Internet-Draft YumaWorks
Intended status: Standards Track M. Bjorklund
Expires: April 28, 2015 Tail-f Systems
K. Watsen
Juniper Networks
October 25, 2014
RESTCONF Protocol
draft-ietf-netconf-restconf-03
Abstract
This document describes an HTTP-based protocol that provides a
programmatic interface for accessing data defined in YANG, using the
datastores defined in NETCONF.
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-
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Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
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This Internet-Draft will expire on April 28, 2015.
Copyright Notice
Copyright (c) 2014 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
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to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Secure Transport . . . . . . . . . . . . . . . . . . . . 5
1.2. Simple Subset of NETCONF Functionality . . . . . . . . . 5
1.3. Data Model Driven API . . . . . . . . . . . . . . . . . . 6
1.4. Terminology . . . . . . . . . . . . . . . . . . . . . . . 7
1.4.1. NETCONF . . . . . . . . . . . . . . . . . . . . . . . 7
1.4.2. HTTP . . . . . . . . . . . . . . . . . . . . . . . . 8
1.4.3. YANG . . . . . . . . . . . . . . . . . . . . . . . . 9
1.4.4. Terms . . . . . . . . . . . . . . . . . . . . . . . . 9
1.4.5. URI Template . . . . . . . . . . . . . . . . . . . . 11
1.4.6. Tree Diagrams . . . . . . . . . . . . . . . . . . . . 11
2. Resources . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.1. RESTCONF Resource Types . . . . . . . . . . . . . . . . . 12
2.2. Resource Discovery . . . . . . . . . . . . . . . . . . . 12
2.3. API Resource . . . . . . . . . . . . . . . . . . . . . . 13
2.3.1. {+restconf}/data . . . . . . . . . . . . . . . . . . 13
2.3.2. {+restconf}/operations . . . . . . . . . . . . . . . 14
2.4. Datastore Resource . . . . . . . . . . . . . . . . . . . 14
2.4.1. Edit Collision Detection . . . . . . . . . . . . . . 15
2.5. Data Resource . . . . . . . . . . . . . . . . . . . . . . 15
2.5.1. Encoding YANG Instance Identifiers in the Request URI 16
2.5.2. Defaults Handling . . . . . . . . . . . . . . . . . . 18
2.6. Collection Resource . . . . . . . . . . . . . . . . . . . 19
2.7. Operation Resource . . . . . . . . . . . . . . . . . . . 19
2.7.1. Encoding Operation Input Parameters . . . . . . . . . 20
2.7.2. Encoding Operation Output Parameters . . . . . . . . 21
2.8. Schema Resource . . . . . . . . . . . . . . . . . . . . . 22
2.9. Stream Resource . . . . . . . . . . . . . . . . . . . . . 23
2.10. Errors Resource . . . . . . . . . . . . . . . . . . . . . 23
3. Operations . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.1. OPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.2. HEAD . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.3. GET . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.4. POST . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.4.1. Create Resource Mode . . . . . . . . . . . . . . . . 26
3.4.2. Invoke Operation Mode . . . . . . . . . . . . . . . . 27
3.5. PUT . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.6. PATCH . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.7. DELETE . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.8. Query Parameters . . . . . . . . . . . . . . . . . . . . 31
3.8.1. Query Parameter URIs . . . . . . . . . . . . . . . . 31
3.8.2. The "content" Query Parameter . . . . . . . . . . . . 32
3.8.3. The "depth" Query Parameter . . . . . . . . . . . . . 32
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3.8.4. The "select" Query Parameter . . . . . . . . . . . . 33
3.8.5. The "insert" Query Parameter . . . . . . . . . . . . 34
3.8.6. The "point" Query Parameter . . . . . . . . . . . . . 34
3.8.7. The "limit" Query Parameter . . . . . . . . . . . . . 35
3.8.8. The "offset" Query Parameter . . . . . . . . . . . . 35
3.8.9. The "filter" Query Parameter . . . . . . . . . . . . 36
3.8.10. The "start-time" Query Parameter . . . . . . . . . . 36
3.8.11. The "stop-time" Query Parameter . . . . . . . . . . . 37
4. Messages . . . . . . . . . . . . . . . . . . . . . . . . . . 38
4.1. Request URI Structure . . . . . . . . . . . . . . . . . . 38
4.2. RESTCONF Path Resolution . . . . . . . . . . . . . . . . 39
4.3. Message Headers . . . . . . . . . . . . . . . . . . . . . 40
4.4. Message Encoding . . . . . . . . . . . . . . . . . . . . 41
4.5. RESTCONF Meta-Data . . . . . . . . . . . . . . . . . . . 41
4.6. Return Status . . . . . . . . . . . . . . . . . . . . . . 42
4.7. Message Caching . . . . . . . . . . . . . . . . . . . . . 42
5. Notifications . . . . . . . . . . . . . . . . . . . . . . . . 42
5.1. Server Support . . . . . . . . . . . . . . . . . . . . . 42
5.2. Event Streams . . . . . . . . . . . . . . . . . . . . . . 43
5.3. Subscribing to Receive Notifications . . . . . . . . . . 45
5.3.1. NETCONF Event Stream . . . . . . . . . . . . . . . . 46
5.4. Receiving Event Notifications . . . . . . . . . . . . . . 46
6. Error Reporting . . . . . . . . . . . . . . . . . . . . . . . 48
6.1. Error Response Message . . . . . . . . . . . . . . . . . 49
7. RESTCONF module . . . . . . . . . . . . . . . . . . . . . . . 51
8. RESTCONF Monitoring . . . . . . . . . . . . . . . . . . . . . 57
8.1. restconf-state/capabilities . . . . . . . . . . . . . . . 58
8.2. restconf-state/streams . . . . . . . . . . . . . . . . . 58
8.3. RESTCONF Monitoring Module . . . . . . . . . . . . . . . 58
9. YANG Module Library . . . . . . . . . . . . . . . . . . . . . 62
9.1. modules . . . . . . . . . . . . . . . . . . . . . . . . . 63
9.1.1. modules/module . . . . . . . . . . . . . . . . . . . 63
9.2. YANG Library Module . . . . . . . . . . . . . . . . . . . 64
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 68
10.1. The "restconf" Relation Type . . . . . . . . . . . . . . 68
10.2. YANG Module Registry . . . . . . . . . . . . . . . . . . 68
10.3. application/yang Media Sub Types . . . . . . . . . . . . 69
10.4. NETCONF Capability URNs . . . . . . . . . . . . . . . . 70
11. Security Considerations . . . . . . . . . . . . . . . . . . . 70
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 71
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 71
13.1. Normative References . . . . . . . . . . . . . . . . . . 71
13.2. Informative References . . . . . . . . . . . . . . . . . 73
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 73
A.1. 02 - 03 . . . . . . . . . . . . . . . . . . . . . . . . . 73
A.2. 01 - 02 . . . . . . . . . . . . . . . . . . . . . . . . . 74
A.3. 00 - 01 . . . . . . . . . . . . . . . . . . . . . . . . . 75
A.4. bierman:restconf-04 to ietf:restconf-00 . . . . . . . . . 76
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Appendix B. Open Issues . . . . . . . . . . . . . . . . . . . . 76
Appendix C. Example YANG Module . . . . . . . . . . . . . . . . 76
C.1. example-jukebox YANG Module . . . . . . . . . . . . . . . 77
Appendix D. RESTCONF Message Examples . . . . . . . . . . . . . 82
D.1. Resource Retrieval Examples . . . . . . . . . . . . . . . 82
D.1.1. Retrieve the Top-level API Resource . . . . . . . . . 82
D.1.2. Retrieve The Server Module Information . . . . . . . 83
D.1.3. Retrieve The Server Capability Information . . . . . 84
D.2. Edit Resource Examples . . . . . . . . . . . . . . . . . 85
D.2.1. Create New Data Resources . . . . . . . . . . . . . . 85
D.2.2. Detect Resource Entity Tag Change . . . . . . . . . . 86
D.3. Query Parameter Examples . . . . . . . . . . . . . . . . 87
D.3.1. "content" Parameter . . . . . . . . . . . . . . . . . 87
D.3.2. "depth" Parameter . . . . . . . . . . . . . . . . . . 90
D.3.3. "select" Parameter . . . . . . . . . . . . . . . . . 93
D.3.4. "insert" Parameter . . . . . . . . . . . . . . . . . 94
D.3.5. "point" Parameter . . . . . . . . . . . . . . . . . . 95
D.3.6. "limit" Parameter . . . . . . . . . . . . . . . . . . 95
D.3.7. "offset" Parameter . . . . . . . . . . . . . . . . . 96
D.3.8. "filter" Parameter . . . . . . . . . . . . . . . . . 97
D.3.9. "start-time" Parameter . . . . . . . . . . . . . . . 98
D.3.10. "stop-time" Parameter . . . . . . . . . . . . . . . . 98
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 98
1. Introduction
There is a need for standard mechanisms to allow WEB applications to
access the configuration data, operational data, data-model specific
protocol operations, and notification events within a networking
device, in a modular and extensible manner.
This document describes an HTTP [RFC2616] based protocol called
RESTCONF, for accessing data defined in YANG [RFC6020], using
datastores defined in NETCONF [RFC6241].
The NETCONF protocol defines configuration datastores and a set of
Create, Retrieve, Update, Delete (CRUD) operations that can be used
to access these datastores. The YANG language defines the syntax and
semantics of datastore content, operational data, protocol
operations, and notification events. RESTCONF uses HTTP operations
to provide CRUD operations on a NETCONF datastore containing YANG-
defined data. Since NETCONF protocol operations are not relevant,
the user should not need any prior knowledge of NETCONF in order to
use RESTCONF.
Configuration data and state data are exposed as resources that can
be retrieved with the GET method. Resources representing
configuration data can be modified with the DELETE, PATCH, POST, and
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PUT methods. Data is encoded with either XML [W3C.REC-xml-20081126]
or JSON [RFC7158].
Data-model specific protocol operations defined with the YANG "rpc"
statement can be invoked with the POST method. Data-model specific
notification events defined with the YANG "notification" statement
can be accessed.
1.1. Secure Transport
RESTCONF relies on TLS [RFC2246] to provide privacy and data
integrity for its HTTP operations. More specifically, RESTCONF
requires HTTP over TLS (HTTPS) [RFC2818]. To ensure security,
RESTCONF clients MUST verify the RESTCONF server's X.509 certificate
using the path validation algorithm defined in section 6 of
[RFC5280]. Devices that do not support TLS will be unable to
implement RESTCONF.
1.2. Simple Subset of NETCONF Functionality
The framework and meta-model used for an HTTP-based API does not need
to mirror those used by the NETCONF protocol, but it needs to be
compatible with NETCONF. A simplified framework and protocol is
needed that utilizes the three NETCONF datastores (candidate,
running, startup), but hides the complexity of multiple datastores
from the client.
A simplified transaction model is needed that allows basic CRUD
operations on a hierarchy of conceptual resources. This represents a
limited subset of the transaction capabilities of the NETCONF
protocol.
Applications that require more complex transaction capabilities might
consider NETCONF instead of RESTCONF. The following transaction
features are not directly provided in RESTCONF:
o datastore locking (full or partial)
o candidate datastore
o startup datastore
o validate operation
o confirmed-commit procedure
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RESTCONF is not intended to replace NETCONF, but rather provide an
additional simplified interface that follows REST principles and is
compatible with a resource-oriented device abstraction.
The following figure shows the system components:
+-----------+ +-----------------+
| WEB app | <-------> | |
+-----------+ HTTP | network device |
| |
+-----------+ | +-----------+ |
| NMS app | <-------> | | datastore | |
+-----------+ NETCONF | +-----------+ |
+-----------------+
1.3. Data Model Driven API
RESTCONF combines the simplicity of the HTTP protocol with the
predictability and automation potential of a schema-driven API.
Using YANG, a client can predict all resource endpoints, much like
using URI Templates [RFC6570], but in a more holistic manner. This
strategy obviates the need for responses provided by the server to
contain HATEOAS links, originally described in Roy Fielding's
doctoral dissertation [rest-dissertation].
A REST client using HATEOAS principles would not use any data
modeling language to define the application-specific content of the
API. The client would discover each new child resource as it
traverses the URIs returned as Location IDs to discover the server
capabilities. This approach has 3 significant weaknesses with
regards to control of complex networking devices:
o inefficient performance: configuration APIs will be quite complex
and may require thousands of protocol messages to discover all the
schema information. Typically the data type information has to be
passed in the protocol messages, which is also wasteful overhead.
o no data model richness: without a data model, the schema-level
semantics and validation constraints are not available to the
application.
o no tool automation: API automation tools need some sort of content
schema to function. Such tools can automate various programming
and documentation tasks related to specific data models.
Data model modules such as YANG modules serve as an "API contract"
that will be honored by the server. An application designer can code
to the data model, knowing in advance important details about the
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exact protocol operations and datastore content a conforming server
implementation will support.
RESTCONF provides the YANG module capability information supported by
the server, in case the client wants to use it. The URIs for custom
protocol operations and datastore content are predictable, based on
the YANG module definitions.
Operational experience with CLI and SNMP indicates that operators
learn the 'location' of specific service or device related data and
do not expect such information to be arbitrary and discovered each
time the client opens a management session to a server.
The RESTCONF protocol operates on a conceptual datastore defined with
the YANG data modeling language. The server lists each YANG module
it supports under "/modules" defined in the "ietf-yang-library" YANG
module.
The conceptual datastore contents, data-model-specific operations and
notification events are identified by this set of YANG module
resources. All RESTCONF content identified as either a data
resource, operation resource, or event stream resource is defined
with the YANG language.
The classification of data as configuration or non-configuration is
derived from the YANG "config" statement. Data ordering behavior is
derived from the YANG "ordered-by" statement.
The RESTCONF datastore editing model is simple and direct, similar to
the behavior of the ":writable-running" capability in NETCONF. Each
RESTCONF edit of a datastore resource is activated upon successful
completion of the transaction.
1.4. 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].
1.4.1. NETCONF
The following terms are defined in [RFC6241]:
o candidate configuration datastore
o client
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o configuration data
o datastore
o configuration datastore
o protocol operation
o running configuration datastore
o server
o startup configuration datastore
o state data
o user
1.4.2. HTTP
The following terms are defined in [RFC2616]:
o entity tag
o fragment
o header line
o message body
o method
o path
o query
o request
o request URI
o response body
o resource
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1.4.3. 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
1.4.4. Terms
The following terms are used within this document:
o API resource: a resource with the media type "application/
yang.api+xml" or "application/yang.api+json". API resources can
only be edited by the server.
o collection resource: a resource with the media type "application/
yang.collection+xml" or "application/yang.collection+json".
Contains a set of data resources.
o data resource: a resource with the media type "application/
yang.data+xml" or "application/yang.data+json". Containers,
leafs, list entries and anyxml nodes can be data resources.
o datastore resource: a resource with the media type "application/
yang.datastore+xml" or "application/yang.datastore+json".
Represents a configuration datastore.
o edit operation: a RESTCONF operation on a data resource using the
POST, PUT, PATCH, or DELETE method.
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o event stream resource: This resource represents an SSE (Server-
Sent Events) event stream. The content consists of text using the
media type "text/event-stream", as defined by the HTML5
specification. Each event represents one <notification> message
generated by the server. It contains a conceptual system or data-
model specific event that is delivered within a notification event
stream. Also called a "stream resource".
o operation: the conceptual RESTCONF operation for a message,
derived from the HTTP method, request URI, headers, and message
body.
o operation resource: a resource with the media type "application/
yang.operation+xml" or "application/yang.operation+json".
o patch: a generic PATCH request on the target datastore or data
resource. The media type of the message body content will
identify the patch type in use.
o plain patch: a PATCH request where the media type is "application/
yang.data+xml" or "application/yang.data+json".
o query parameter: a parameter (and its value if any), encoded
within the query component of the request URI.
o retrieval request: a request using the GET or HEAD methods.
o target resource: the resource that is associated with a particular
message, identified by the "path" component of the request URI.
o unified datastore: A conceptual representation of the device
running configuration. The server will hide all NETCONF datastore
details for edit operations, such as the ":candidate" and
":startup" capabilities.
o schema resource: a resource with the media type "application/
yang". The YANG representation of the schema can be retrieved by
the client with the GET method.
o stream list: the set of data resource instances that describe the
event stream resources available from the server. This
information is defined in the "ietf-restconf-monitoring" module as
the "stream" list. It can be retrieved using the target resource
"{+restconf}/data/ietf-restconf-monitoring:restconf-state/streams/
stream". The stream list contains information about each stream,
such as the URL to retrieve the event stream data.
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1.4.5. URI Template
Throughout this document, the URI template [RFC6570] syntax
"{+restconf}" is used to refer to the RESTCONF API entry point
outside of an example. See @path-resolution@ for details.
All of the examples in this document assume "/restconf" as the
discovered RESTCONF API root path.
1.4.6. 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
data (read-write) and "ro" state data (read-only).
o Symbols after data node names: "?" means an optional node, "!"
means a presence container, 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. Resources
The RESTCONF protocol operates on a hierarchy of resources, starting
with the top-level API resource itself. Each resource represents a
manageable component within the device.
A resource can be considered a collection of conceptual data and the
set of allowed methods on that data. It can contain nested child
resources. The child resource types and methods allowed on them are
data-model specific.
A resource has its own media type identifier, represented by the
"Content-Type" header in the HTTP response message. A resource can
contain zero or more nested resources. A resource can be created and
deleted independently of its parent resource, as long as the parent
resource exists.
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All RESTCONF resources are defined in this document except datastore
contents, protocol operations, and notification events. The syntax
and semantics for these resource types are defined in YANG modules.
The RESTCONF resources are accessed via a set of URIs defined in this
document. The set of YANG modules supported by the server will
determine the data model specific operations, top-level data node
resources, and notification event messages supported by the server.
The resources used in the RESTCONF protocol are identified by the
"path" component in the request URI. Each operation is performed on
a target resource.
2.1. RESTCONF Resource Types
The RESTCONF protocol defines a set of application specific media
types to identify each of the available resource types. The
following resource types are defined in RESTCONF:
+------------+-----------------------------+
| Resource | Media Type |
+------------+-----------------------------+
| API | application/yang.api |
| Collection | application/yang.collection |
| Datastore | application/yang.datastore |
| Data | application/yang.data |
| Errors | application/yang.errors |
| Operation | application/yang.operation |
| Schema | application/yang |
+------------+-----------------------------+
RESTCONF Media Types
2.2. Resource Discovery
A client SHOULD start by retrieving the top-level API resource, using
the entry point URI defined in Section 4.2.
The RESTCONF protocol does not include a resource discovery
mechanism. Instead, the definitions within the YANG modules
advertised by the server are used to construct a predictable
operation or data resource identifier.
The "depth" query parameter (see Section 3.8.3) can be used to
control how many descendant levels should be included when retrieving
child resources. This parameter can be used with the GET method to
discover child resources within a particular resource.
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2.3. API Resource
The API resource contains the state and access points for the
RESTCONF features. It is the top-level resource and has the media
type "application/yang.api+xml" or "application/yang.api+json".
YANG Tree Diagram for "application/yang.api" Resource Type:
+--rw restconf
+--rw data
+--rw operations
The "restconf" grouping definition in the "ietf-restconf" module
defined in Section 7 is used to specify the structure and syntax of
the conceptual child resources within the API resource.
This resource has the following child resources:
+----------------+--------------------------------+
| Child Resource | Description |
+----------------+--------------------------------+
| data | Contains all data resources |
| operations | Data-model specific operations |
+----------------+--------------------------------+
RESTCONF API Resource
2.3.1. {+restconf}/data
This mandatory resource represents the combined configuration and
operational data resources that can be accessed by a client. It
cannot be created or deleted by the client. The datastore resource
type is defined in Section 2.4.
Example:
This example request by the client would retrieve only the non-
configuration data nodes that exist within the "library" resource,
using the "content" query parameter (see Section 3.8.2).
GET /restconf/data/example-jukebox:jukebox/library
?content=nonconfig HTTP/1.1
Host: example.com
Accept: application/yang.data+json,
application/yang.errors+json
The server might respond:
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HTTP/1.1 200 OK
Date: Mon, 23 Apr 2012 17:01:30 GMT
Server: example-server
Cache-Control: no-cache
Pragma: no-cache
Content-Type: application/yang.data+json
{
"example-jukebox:library" : {
"artist-count" : 42,
"album-count" : 59,
"song-count" : 374
}
}
2.3.2. {+restconf}/operations
This optional resource is a container that provides access to the
data-model specific protocol operations supported by the server. The
server MAY omit this resource if no data-model specific operations
are advertised.
Any data-model specific operations defined in the YANG modules
advertised by the server MAY be available as child nodes of this
resource.
Operation resources are defined in Section 2.7.
2.4. Datastore Resource
The "{+restconf}/data" subtree represents the datastore resource
type, which is a collection of configuration and operational data
nodes.
A "unified datastore" interface is used to simplify resource editing
for the client. The RESTCONF unified datastore is a conceptual
interface to the native configuration datastores that are present on
the device.
The underlying NETCONF datastores (i.e., candidate, running, startup)
can be used to implement the unified datastore, but the server design
is not limited to the exact datastore procedures defined in NETCONF.
The "candidate" and "startup" datastores are not visible in the
RESTCONF protocol. Transaction management and configuration
persistence are handled by the server and not controlled by the
client.
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A datastore resource can only be written directly with the PATCH
method. Only the configuration data resources within the datastore
resource can be edited directly with all methods.
Each RESTCONF edit of a datastore resource is saved to non-volatile
storage in an implementation-specific matter by the server. There is
no guarantee that configuration changes are saved immediately, or
that the saved configuration is always a mirror of the running
configuration.
2.4.1. Edit Collision Detection
Two "edit collision detection" mechanisms are provided in RESTCONF,
for datastore and data resources.
2.4.1.1. Timestamp
The last change time is maintained and the "Last-Modified" and "Date"
headers are returned in the response for a retrieval request. The
"If-Unmodified-Since" header can be used in edit operation requests
to cause the server to reject the request if the resource has been
modified since the specified timestamp.
The server MUST maintain a last-modified timestamp for this resource,
and return the "Last-Modified" header when this resource is retrieved
with the GET or HEAD methods. Only changes to configuration data
resources within the datastore affect this timestamp.
2.4.1.2. Entity tag
A unique opaque string is maintained and the "ETag" header is
returned in the response for a retrieval request. The "If-Match"
header can be used in edit operation requests to cause the server to
reject the request if the resource entity tag does not match the
specified value.
The server MUST maintain a resource entity tag for this resource, and
return the "ETag" header when this resource is retrieved with the GET
or HEAD methods. The resource entity tag MUST be changed to a new
previously unused value if changes to any configuration data
resources within the datastore are made.
2.5. Data Resource
A data resource represents a YANG data node that is a descendant node
of a datastore resource. Containers, leafs, list entries and anyxml
nodes are data resources.
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For configuration data resources, the server MAY maintain a last-
modified timestamp for the resource, and return the "Last-Modified"
header when it is retrieved with the GET or HEAD methods. If
maintained, the resource timestamp MUST be set to the current time
whenever the resource or any configuration resource within the
resource is altered.
For configuration data resources, the server MAY maintain a resource
entity tag for the resource, and return the "ETag" header when it is
retrieved as the target resource with the GET or HEAD methods. If
maintained, the resource entity tag MUST be updated whenever the
resource or any configuration resource within the resource is
altered.
A data resource can be retrieved with the GET method. Data resources
are accessed via the "{+restconf}/data" entry point. This sub-tree
is used to retrieve and edit data resources.
A configuration data resource can be altered by the client with some
or all of the edit operations, depending on the target resource and
the specific operation. Refer to Section 3 for more details on edit
operations.
The resource definition version for a data resource is identified by
the revision date of the YANG module containing the YANG definition
for the data resource, specified in the "{+restconf}/modules" sub-
tree.
2.5.1. Encoding YANG Instance Identifiers in the Request URI
In YANG, data nodes are named with an absolute XPath expression,
defined in [XPath] , starting from the document root to the target
resource. In RESTCONF, URL encoded Location header expressions are
used instead.
The YANG "instance-identifier" (i-i) data type is represented in
RESTCONF with the path expression format defined in this section.
+-------+-------------------------------------------+
| Name | Comments |
+-------+-------------------------------------------+
| point | Insertion point is always a full i-i |
| path | Request URI path is a full or partial i-i |
+-------+-------------------------------------------+
RESTCONF instance-identifier Type Conversion
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The "path" component of the request URI contains the absolute path
expression that identifies the target resource.
A predictable location for a data resource is important, since
applications will code to the YANG data model module, which uses
static naming and defines an absolute path location for all data
nodes.
A RESTCONF data resource identifier is not an XPath expression. It
is encoded from left to right, starting with the top-level data node,
according to the "api-path" rule in Section 2.5.1.1. The node name
of each ancestor of the target resource node is encoded in order,
ending with the node name for the target resource.
If a data node in the path expression is a YANG list node, then the
key values for the list (if any) MUST be encoded according to the
following rules.
o The key leaf values for a data resource representing a YANG list
MUST be encoded using one path segment [RFC3986].
o If there is only one key leaf value, the path segment is
constructed by having the list name followed by an "=" followed by
the single key leaf value.
o If there are multiple key leaf values, the value of each leaf
identified in the "key" statement is encoded in the order
specified in the YANG "key" statement, with a comma separating
them.
o All the components in the "key" statement MUST be encoded.
Partial instance identifiers are not supported.
o Quoted strings are supported in the key leaf values. Quoted
strings MUST be used to express empty strings. (example:
list=foo,'',baz).
o The "list-instance" ABNF rule defined in Section 2.5.1.1
represents the syntax of a list instance identifier.
o Resource URI values returned in Location headers for data
resources MUST identify the module name, even if there are no
conflicting local names when the resource is created. This
ensures the correct resource will be identified even if the server
loads a new module that the old client does not know about.
Examples:
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container top {
list list1 {
key "key1 key2 key3";
...
list list2 {
key "key4 key5";
...
leaf X { type string; }
}
}
For the above YANG definition, URI with key leaf values will be
encoded as follows (line wrapped for display purposes only):
/restconf/data/example-top:top/list1=key1val,key2val,key3val3/
list2=key4val,key5val/X
2.5.1.1. ABNF For Data Resource Identifiers
The "api-path" ABNF syntax is used to construct RESTCONF path
identifiers:
api-path = "/" |
("/" api-identifier
0*("/" (api-identifier | list-instance )))
api-identifier = [module-name ":"] identifier
module-name = identifier
list-instance = api-identifier "=" key-value ["," key-value]*
key-value = string
string = <a quoted or unquoted or empty string>
;; An identifier MUST NOT start with
;; (('X'|'x') ('M'|'m') ('L'|'l'))
identifier = (ALPHA / "_")
*(ALPHA / DIGIT / "_" / "-" / ".")
2.5.2. Defaults Handling
NETCONF has a rather complex model for handling default values for
leafs. RESTCONF attempts to avoid this complexity by restricting the
operations that can be applied to a resource. Applications that
require full control of defaults might consider NETCONF instead of
RESTCONF.
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If the target of a GET method is a data node that represents a leaf
that has a default value, and the leaf has not been given a value
yet, the server MUST return the default value that is in use by the
server.
If the target of a GET method is a data node that represents a
container or list that has any child resources with default values,
for the child resources that have not been given value yet, the
server MAY return the default values that are in use by the server.
2.6. Collection Resource
A collection resource contains a set of data resources. It is used
to represent a all instances or a subset of all instances in a YANG
list or leaf-list.
A collection resource can be retrieved with the GET method,
optionally with the query parameters "limit" (Section 3.8.7) and
"offset" (Section 3.8.8).
The "ietf-restconf" YANG module contains the "collection" grouping
which specifies the syntax of a collection resource.
2.7. Operation Resource
An operation resource represents an protocol operation defined with
the YANG "rpc" statement.
All operation resources share the same module namespace as any top-
level data resources, so the name of an operation resource cannot
conflict with the name of a top-level data resource defined within
the same module.
If 2 different YANG modules define the same "rpc" identifier, then
the module name MUST be used in the request URI. For example, if
"module-A" and "module-B" both defined a "reset" operation, then
invoking the operation from "module-A" would be requested as follows:
POST /restconf/operations/module-A:reset HTTP/1.1
Server example.com
Any usage of an operation resource from the same module, with the
same name, refers to the same "rpc" statement definition. This
behavior can be used to design protocol operations that perform the
same general function on different resource types.
If the "rpc" statement has an "input" section, then a message body
MAY be sent by the client in the request, otherwise the request
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message MUST NOT include a message body. If the "rpc" statement has
an "output" section, then a message body MAY be sent by the server in
the response. Otherwise the server MUST NOT include a message body
in the response message, and MUST send a "204 No Content" Status-Line
instead.
2.7.1. Encoding Operation Input Parameters
If the "rpc" statement has an "input" section, then the "input" node
is provided in the message body, corresponding to the YANG data
definition statements within the "input" section.
Example:
The following YANG definition is used for the examples in this
section.
rpc reboot {
input {
leaf delay {
units seconds;
type uint32;
default 0;
}
leaf message { type string; }
leaf language { type string; }
}
}
The client might send the following POST request message:
POST /restconf/operations/example-ops:reboot HTTP/1.1
Host: example.com
Content-Type: application/yang.operation+json
{
"example-ops:input" : {
"delay" : 600,
"message" : "Going down for system maintenance",
"language" : "en-US"
}
}
The server might respond:
HTTP/1.1 204 No Content
Date: Mon, 25 Apr 2012 11:01:00 GMT
Server: example-server
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2.7.2. Encoding Operation Output Parameters
If the "rpc" statement has an "output" section, then the "output"
node is provided in the message body, corresponding to the YANG data
definition statements within the "output" section.
Example:
The following YANG definition is used for the examples in this
section.
rpc get-reboot-info {
output {
leaf reboot-time {
units seconds;
type uint32;
}
leaf message { type string; }
leaf language { type string; }
}
}
The client might send the following POST request message:
POST /restconf/operations/example-ops:get-reboot-info HTTP/1.1
Host: example.com
Accept: application/yang.operation+json,
application/yang.errors+json
The server might respond:
HTTP/1.1 200 OK
Date: Mon, 25 Apr 2012 11:10:30 GMT
Server: example-server
Content-Type: application/yang.operation+json
{
"example-ops:output" : {
"reboot-time" : 30,
"message" : "Going down for system maintenance",
"language" : "en-US"
}
}
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2.8. Schema Resource
If the server supports the "schema" leaf within the API then the
client can retrieve the YANG schema text for the associated YANG
module or submodule, using the GET method. First the client needs to
retrieve the URL for retrieving the schema.
The client might send the following GET request message:
GET /restconf/data/ietf-yang-library:modules/module=
example-jukebox,2014-07-03/schema HTTP/1.1
Host: example.com
Accept: application/yang.data+json,
application/yang.errors+json
The server might respond:
HTTP/1.1 200 OK
Date: Mon, 25 Apr 2012 11:10:30 GMT
Server: example-server
Content-Type: application/yang.data+json
{
"ietf-yang-library:schema":
"http://example.com/mymodules/example-jukebox/2014-07-03"
}
Next the client needs to retrieve the actual YANG schema.
The client might send the following GET request message:
GET http://example.com/mymodules/example-jukebox/2014-07-03
HTTP/1.1
Host: example.com
Accept: application/yang, application/yang.errors+json
The server might respond:
module example-jukebox {
namespace "http://example.com/ns/example-jukebox";
prefix "jbox";
// rest of YANG module content deleted...
}
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2.9. Stream Resource
A "stream" resource represents a source for system generated event
notifications. Each stream is created and modified by the server
only. A client can retrieve a stream resource or initiate a long-
poll server sent event stream, using the procedure specified in
Section 5.3.
A notification stream functions according to the NETCONF
Notifications specification [RFC5277]. The available streams can be
retrieved from the stream list, which specifies the syntax and
semantics of a stream resource.
2.10. Errors Resource
An "errors" resource is a collection of error information that is
sent as the message body in a server response message, if an error
occurs while processing a request message.
The "ietf-restconf" YANG module contains the "errors" grouping which
specifies the syntax and semantics of an errors resource. RESTCONF
error handling behavior is defined in Section 6.
3. Operations
The RESTCONF protocol uses HTTP methods to identify the CRUD
operation requested for a particular resource.
The following table shows how the RESTCONF operations relate to
NETCONF protocol operations:
+----------+-------------------------------------+
| RESTCONF | NETCONF |
+----------+-------------------------------------+
| OPTIONS | none |
| HEAD | none |
| GET | <get-config>, <get> |
| POST | <edit-config> (operation="create") |
| PUT | <edit-config> (operation="replace") |
| PATCH | <edit-config> (operation="merge") |
| DELETE | <edit-config> (operation="delete") |
+----------+-------------------------------------+
Table 1: CRUD Methods in RESTCONF
The NETCONF "remove" operation attribute is not supported by the HTTP
DELETE method. The resource must exist or the DELETE method will
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fail. The PATCH method is equivalent to a "merge" operation for a
plain patch.
Access control mechanisms may be used to limit what operations can be
used. In particular, RESTCONF is compatible with the NETCONF Access
Control Model (NACM) [RFC6536], as there is a specific mapping
between RESTCONF and NETCONF operations, defined in Table 1. The
resource path needs to be converted internally by the server to the
corresponding YANG instance-identifier. Using this information, the
server can apply the NACM access control rules to RESTCONF messages.
The server MUST NOT allow any operation to any resources that the
client is not authorized to access.
Implementation of all methods (except PATCH) are defined in
[RFC2616]. This section defines the RESTCONF protocol usage for each
HTTP method.
3.1. OPTIONS
The OPTIONS method is sent by the client to discover which methods
are supported by the server for a specific resource. If supported,
it SHOULD be implemented for all media types.
The server SHOULD implement this method, however the same information
could be extracted from the YANG modules and the RESTCONF protocol
specification.
If the PATCH method is supported, then the "Accept-Patch" header MUST
be supported, as defined in [RFC5789].
3.2. HEAD
The HEAD method is sent by the client to retrieve just the headers
that would be returned for the comparable GET method, without the
response body. It is supported for all resource types, except
operation resources.
The request MUST contain a request URI that contains at least the
entry point component. The same query parameters supported by the
GET method are supported by the HEAD method.
The access control behavior is enforced as if the method was GET
instead of HEAD. The server MUST respond the same as if the method
was GET instead of HEAD, except that no response body is included.
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3.3. GET
The GET method is sent by the client to retrieve data and meta-data
for a resource. It is supported for all resource types, except
operation resources. The request MUST contain a request URI that
contains at least the entry point component.
The server MUST NOT return any data resources for which the user does
not have read privileges. If the user is not authorized to read the
target resource, an error response containing a "403 Forbidden" or
"404 Not Found" Status-Line is returned to the client.
If the user is authorized to read some but not all of the target
resource, the unauthorized content is omitted from the response
message body, and the authorized content is returned to the client.
Example:
The client might request the response headers for a JSON
representation of the "library" resource:
GET /restconf/data/example-jukebox:jukebox/
library/artist=Foo%20Fighters/album HTTP/1.1
Host: example.com
Accept: application/yang.data+json,
application/yang.errors+json
The server might respond:
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2012 17:02:40 GMT
Server: example-server
Content-Type: application/yang.data+json
Cache-Control: no-cache
Pragma: no-cache
ETag: a74eefc993a2b
Last-Modified: Mon, 23 Apr 2012 11:02:14 GMT
{
"example-jukebox:album" : [
{
"name" : "Wasting Light",
"genre" : "example-jukebox:alternative",
"year" : 2011
}
]
}
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3.4. POST
The POST method is sent by the client to create a data resource or
invoke an operation resource. The server uses the target resource
media type to determine how to process the request.
+-----------+------------------------------------------------+
| Type | Description |
+-----------+------------------------------------------------+
| Datastore | Create a top-level configuration data resource |
| Data | Create a configuration data child resource |
| Operation | Invoke a protocol operation |
+-----------+------------------------------------------------+
Resource Types that Support POST
3.4.1. Create Resource Mode
If the target resource type is a datastore or data resource, then the
POST is treated as a request to create a resource or child resource.
The message body is expected to contain the content of a child
resource to create within the parent (target resource).
The "insert" and "point" query parameters are supported by the POST
method for datastore and data resource types, as specified in the
YANG definition in Section 7.
If the POST method succeeds, a "201 Created" Status-Line is returned
and there is no response message body. A "Location" header
identifying the child resource that was created MUST be present in
the response in this case.
If the user is not authorized to create the target resource, an error
response containing a "403 Forbidden" or "404 Not Found" Status-Line
is returned to the client. All other error responses are handled
according to the procedures defined in Section 6.
Example:
To create a new "jukebox" resource, the client might send:
POST /restconf/data HTTP/1.1
Host: example.com
Content-Type: application/yang.data+json
{ "example-jukebox:jukebox" : [null] }
If the resource is created, the server might respond as follows:
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HTTP/1.1 201 Created
Date: Mon, 23 Apr 2012 17:01:00 GMT
Server: example-server
Location: http://example.com/restconf/data/example-jukebox:jukebox
Last-Modified: Mon, 23 Apr 2012 17:01:00 GMT
ETag: b3a3e673be2
Refer to Appendix D.2.1 for more resource creation examples.
3.4.2. Invoke Operation Mode
If the target resource type is an operation resource, then the POST
method is treated as a request to invoke that operation. The message
body (if any) is processed as the operation input parameters. Refer
to Section 2.7 for details on operation resources.
If the POST request succeeds, a "200 OK" Status-Line is returned if
there is a response message body, and a "204 No Content" Status-Line
is returned if there is no response message body.
If the user is not authorized to invoke the target operation, an
error response containing a "403 Forbidden" or "404 Not Found"
Status-Line is returned to the client. All other error responses are
handled according to the procedures defined in Section 6.
Example:
In this example, the client is invoking the "play" operation defined
in the "example-jukebox" YANG module.
A client might send a "play" request as follows:
POST /restconf/operations/example-jukebox:play HTTP/1.1
Host: example.com
Content-Type: application/yang.operation+json
{
"example-jukebox:input" : {
"playlist" : "Foo-One",
"song-number" : 2
}
}
The server might respond:
HTTP/1.1 204 No Content
Date: Mon, 23 Apr 2012 17:50:00 GMT
Server: example-server
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3.5. PUT
The PUT method is sent by the client to create or replace the target
resource.
The only target resource media type that supports PUT is the data
resource. The message body is expected to contain the content used
to create or replace the target resource.
The "insert" (Section 3.8.5) and "point" (Section 3.8.6) query
parameters are supported by the PUT method for data resources.
Consistent with [RFC2616], if the PUT request creates a new resource,
a "201 Created" Status-Line is returned. If an existing resource is
modified, either "200 OK" or "204 No Content" are returned.
If the user is not authorized to create or replace the target
resource an error response containing a "403 Forbidden" or "404 Not
Found" Status-Line is returned to the client. All other error
responses are handled according to the procedures defined in
Section 6.
Example:
An "album" child resource defined in the "example-jukebox" YANG
module is replaced or created if it does not already exist.
To replace the "album" resource contents, the client might send as
follows. Note that the request URI header line is wrapped for
display purposes only:
PUT /restconf/data/example-jukebox:jukebox/
library/artist=Foo%20Fighters/album=Wasting%20Light HTTP/1.1
Host: example.com
Content-Type: application/yang.data+json
{
"example-jukebox:album" : {
"name" : "Wasting Light",
"genre" : "example-jukebox:alternative",
"year" : 2011
}
}
If the resource is updated, the server might respond:
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HTTP/1.1 204 No Content
Date: Mon, 23 Apr 2012 17:04:00 GMT
Server: example-server
Last-Modified: Mon, 23 Apr 2012 17:04:00 GMT
ETag: b27480aeda4c
3.6. PATCH
RESTCONF uses the HTTP PATCH method defined in [RFC5789] to provide
an extensible framework for resource patching mechanisms. It is
optional to implement by the server. Each patch type needs a unique
media type. Zero or more PATCH media types MAY be supported by the
server.
A plain patch is used to create or update a child resource within the
target resource. If the target resource instance does not exist, the
server MUST NOT create it.
If the PATCH request succeeds, a "200 OK" Status-Line is returned if
there is a message body, and "204 No Content" is returned if no
response message body is sent.
If the user is not authorized to alter the target resource an error
response containing a "403 Forbidden" or "404 Not Found" Status-Line
is returned to the client. All other error responses are handled
according to the procedures defined in Section 6.
Example:
To replace just the "year" field in the "album" resource (instead of
replacing the entire resource with the PUT method), the client might
send a plain patch as follows. Note that the request URI header line
is wrapped for display purposes only:
PATCH /restconf/data/example-jukebox:jukebox/
library/artist=Foo%20Fighters/album=Wasting%20Light HTTP/1.1
Host: example.com
Content-Type: application/yang.data+json
{
"example-jukebox:album" : {
"genre" : "example-jukebox:rock",
"year" : 2011
}
}
If the field is updated, the server might respond:
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HTTP/1.1 204 No Content
Date: Mon, 23 Apr 2012 17:49:30 GMT
Server: example-server
Last-Modified: Mon, 23 Apr 2012 17:49:30 GMT
ETag: b2788923da4c
The XML encoding for the same request might be:
PATCH /restconf/data/example-jukebox:jukebox/
library/artist=Foo%20Fighters/album=Wasting%20Light HTTP/1.1
Host: example.com
If-Match: b8389233a4c
Content-Type: application/yang.data+xml
<album xmlns="http://example.com/ns/example-jukebox">
<genre>example-jukebox:rock</genre>
<year>2011</year>
</album>
3.7. DELETE
The DELETE method is used to delete the target resource. If the
DELETE request succeeds, a "204 No Content" Status-Line is returned,
and there is no response message body.
If the user is not authorized to delete the target resource then an
error response containing a "403 Forbidden" or "404 Not Found"
Status-Line is returned to the client. All other error responses are
handled according to the procedures defined in Section 6.
Example:
To delete a resource such as the "album" resource, the client might
send:
DELETE /restconf/data/example-jukebox:jukebox/
library/artist=Foo%20Fighters/album=Wasting%20Light HTTP/1.1
Host: example.com
If the resource is deleted, the server might respond:
HTTP/1.1 204 No Content
Date: Mon, 23 Apr 2012 17:49:40 GMT
Server: example-server
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3.8. Query Parameters
Each RESTCONF operation allows zero or more query parameters to be
present in the request URI. The specific parameters that are allowed
depends on the resource type, and sometimes the specific target
resource used, in the request.
+------------+----------+-------------------------------------------+
| Name | Methods | Description |
+------------+----------+-------------------------------------------+
| content | GET | Select config and/or non-config data |
| | | resources |
| depth | GET | Request limited sub-tree depth in the |
| | | reply content |
| filter | GET | Boolean notification filter for event- |
| | | stream resources |
| insert | POST, | Insertion mode for user-ordered data |
| | PUT | resources |
| limit | GET | Number of entries to return for |
| | | collection resources |
| offset | GET | Starting point for collection resources |
| point | POST, | Insertion point for user-ordered data |
| | PUT | resources |
| select | GET | Request a subset of the target resource |
| | | contents |
| start-time | GET | Replay buffer start time for event-stream |
| | | resources |
| stop-time | GET | Replay buffer stop time for event-stream |
| | | resources |
+------------+----------+-------------------------------------------+
RESTCONF Query Parameters
Query parameters can be given in any order. Each parameter can
appear at most once in a request URI. A default value may apply if
the parameter is missing.
Refer to Appendix D.3 for examples of query parameter usage.
If vendors define additional query parameters, they SHOULD use a
prefix (such as the enterprise or organization name) for query
parameter names in order to avoid collisions with other parameters.
3.8.1. Query Parameter URIs
A new set of NETCONF Capability URNs are defined to identify the
specific query parameters supported by the server.
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+---------+-------------------------------------------------+
| Name | URI |
+---------+-------------------------------------------------+
| content | urn:ietf:params:restconf:capability:content:1.0 |
| depth | urn:ietf:params:restconf:capability:depth:1.0 |
| filter | urn:ietf:params:restconf:capability:filter:1.0 |
| insert | urn:ietf:params:restconf:capability:insert:1.0 |
| page | urn:ietf:params:restconf:capability:page:1.0 |
| select | urn:ietf:params:restconf:capability:select:1.0 |
| replay | urn:ietf:params:restconf:capability:replay:1.0 |
+---------+-------------------------------------------------+
RESTCONF Query Parameter URIs
3.8.2. The "content" Query Parameter
The "content" parameter controls how descendant nodes of the
requested data nodes will be processed in the reply.
The allowed values are:
+-----------+-----------------------------------------------------+
| Value | Description |
+-----------+-----------------------------------------------------+
| config | Return only configuration descendant data nodes |
| nonconfig | Return only non-configuration descendant data nodes |
| all | Return all descendant data nodes |
+-----------+-----------------------------------------------------+
This parameter is only allowed for GET methods on datastore and data
resources. A 400 Bad Request error is returned if used for other
methods or resource types.
The default value is determined by the "config" statement value of
the requested data nodes. If the "config" value is "false", then the
default for the "content" parameter is "nonconfig". If "config" is
"true" then the default for the "content" parameter is "config".
If this query parameter is supported by the server, then the
"content" query parameter URI MUST be listed in the "capability"
leaf-list in Section 8.3.
3.8.3. The "depth" Query Parameter
The "depth" parameter is used to specify the number of nest levels
returned in a response for a GET method. The first nest-level
consists of the requested data node itself. Any child nodes which
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are contained within a parent node have a depth value that is 1
greater than its parent.
The value of the "depth" parameter is either an integer between 1 and
65535, or the string "unbounded". "unbounded" is the default.
This parameter is only allowed for GET methods on API, datastore, and
data resources. A 400 Bad Request error is returned if it used for
other methods or resource types.
By default, the server will include all sub-resources within a
retrieved resource, which have the same resource type as the
requested resource. Only one level of sub-resources with a different
media type than the target resource will be returned.
If this query parameter is supported by the server, then the "depth"
query parameter URI MUST be listed in the "capability" leaf-list in
Section 8.3.
3.8.4. The "select" Query Parameter
The "select" query parameter is used to optionally identify data
nodes within the target resource to be retrieved in a GET method.
The client can use this parameter to retrieve a subset of all nodes
in a resource.
A value of the "select" query parameter matches the following rule:
select-expr = path '(' select-expr / '*' ')' /
path ';' select-expr /
path
path = api-identifier [ '/' path ]
"api-identifier" is defined in Section 2.5.1.1.
";" is used to select multiple nodes. For example, to retrieve only
the "genre" and "year" of an album, use: "select=genre;year".
Parentheses are used to specify sub-selectors of a node. For
example, to retrieve only the "label" and "catalogue-number" of an
album, use: "select=admin(label;catalogue-number)".
"/" is used in a path to retrieve a child node of a node. For
example, to retrieve only the "label" of an album, use:
"select=admin/label".
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This parameter is only allowed for GET methods on api, datastore, and
data resources. A 400 Bad Request error is returned if used for
other methods or resource types.
If this query parameter is supported by the server, then the "select"
query parameter URI MUST be listed in the "capability" leaf-list in
Section 8.3.
3.8.5. The "insert" Query Parameter
The "insert" parameter is used to specify how a resource should be
inserted within a user-ordered list.
The allowed values are:
+--------+----------------------------------------------------------+
| Value | Description |
+--------+----------------------------------------------------------+
| first | Insert the new data as the new first entry. |
| last | Insert the new data as the new last entry. |
| before | Insert the new data before the insertion point, as |
| | specified by the value of the "point" parameter. |
| after | Insert the new data after the insertion point, as |
| | specified by the value of the "point" parameter. |
+--------+----------------------------------------------------------+
The default value is "last".
This parameter is only supported for the POST and PUT methods. It is
also only supported if the target resource is a data resource, and
that data represents a YANG list or leaf-list that is ordered by the
user.
If the values "before" or "after" are used, then a "point" query
parameter for the insertion parameter MUST also be present, or a 400
Bad Request error is returned.
If this query parameter is supported by the server, then the "insert"
query parameter URI MUST be listed in the "capability" leaf-list in
Section 8.3. The "point" query parameter MUST also be supported by
the server.
3.8.6. The "point" Query Parameter
The "point" parameter is used to specify the insertion point for a
data resource that is being created or moved within a user ordered
list or leaf-list.
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The value of the "point" parameter is of type
"data-resource-identifier", defined in the "ietf-restconf" YANG
module Section 7.
This parameter is only supported for the POST and PUT methods. It is
also only supported if the target resource is a data resource, and
that data represents a YANG list or leaf-list that is ordered by the
user.
If the "insert" query parameter is not present, or has a value other
than "before" or "after", then a 400 Bad Request error is returned.
This parameter contains the instance identifier of the resource to be
used as the insertion point for a POST or PUT method.
If the server includes the "insert" query parameter URI in the
"capability" leaf-list in Section 8.3, then the "point" query
parameter MUST be supported.
3.8.7. The "limit" Query Parameter
The "limit" parameter is used to restrict the number of data
resources to return in response to GET requests on collection
resources.
The value of the "limit" parameter is either an integer greater than
or equal to 1, or the string "unbounded". The string "unbounded" is
the default value.
If the server includes the "page" query parameter URI in the
"capability" leaf-list in Section 8.3, then the "limit" query
parameter MUST be supported.
3.8.8. The "offset" Query Parameter
The "offset" parameter is used to specify the first data resource to
return in response to GET requests on collection resources.
Resources instances are numbered with consecutive integers from 1 to
the number of resource instances.
The value of the "offset" parameter is an integer greater than or
equal to 1. The default value is 1.
If the server includes the "page" query parameter URI in the
"capability" leaf-list in Section 8.3, then the "offset" query
parameter MUST be supported.
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3.8.9. The "filter" Query Parameter
The "filter" parameter is used to indicate which subset of all
possible events are of interest. If not present, all events not
precluded by other parameters will be sent.
This parameter is only allowed for GET methods on a text/event-stream
data resource. A 400 Bad Request error is returned if used for other
methods or resource types.
The format of this parameter is an XPath 1.0 expression, and is
evaluated in the following context:
o The set of namespace declarations is the set of prefix and
namespace pairs for all supported YANG modules, where the prefix
is the YANG module name, and the namespace is as defined by the
"namespace" statement in the YANG module.
o The function library is the core function library defined in XPath
1.0.
o The set of variable bindings is empty.
o The context node is the root node.
The filter is used as defined in [RFC5277], section 3.6. If the
boolean result of the expression is true when applied to the
conceptual "notification" document root, then the notification event
is delivered to the client.
If this query parameter is supported by the server, then the "filter"
query parameter URI MUST be listed in the "capability" leaf-list in
Section 8.3.
3.8.10. The "start-time" Query Parameter
The "start-time" parameter is used to trigger the notification replay
feature and indicate that the replay should start at the time
specified. If the stream does not support replay, per the
"replay-support" attribute returned by stream list entry for the
stream resource, then the server MUST return the HTTP error code 400
Bad Request.
The value of the "start-time" parameter is of type "date-and-time",
defined in the "ietf-yang" YANG module [RFC6991].
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This parameter is only allowed for GET methods on a text/event-stream
data resource. A 400 Bad Request error is returned if used for other
methods or resource types.
If this parameter is not present, then a replay subscription is not
being requested. It is not valid to specify start times that are
later than the current time. If the value specified is earlier than
the log can support, the replay will begin with the earliest
available notification.
If this query parameter is supported by the server, then the "replay"
query parameter URI MUST be listed in the "capability" leaf-list in
Section 8.3. The "stop-time" query parameter MUST also be supported
by the server.
If the "replay-support" leaf is present in the "stream" entry
(defined in Section 8.3) then the server MUST support the
"start-time" and "stop-time" query parameters for that stream.
3.8.11. The "stop-time" Query Parameter
The "stop-time" parameter is used with the replay feature to indicate
the newest notifications of interest. This parameter MUST be used
with and have a value later than the "start-time" parameter.
The value of the "stop-time" parameter is of type "date-and-time",
defined in the "ietf-yang" YANG module [RFC6991].
This parameter is only allowed for GET methods on a text/event-stream
data resource. A 400 Bad Request error is returned if used for other
methods or resource types.
If this parameter is not present, the notifications will continue
until the subscription is terminated. Values in the future are
valid.
If this query parameter is supported by the server, then the "replay"
query parameter URI MUST be listed in the "capability" leaf-list in
Section 8.3. The "start-time" query parameter MUST also be supported
by the server.
If the "replay-support" leaf is present in the "stream" entry
(defined in Section 8.3) then the server MUST support the
"start-time" and "stop-time" query parameters for that stream.
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4. Messages
The RESTCONF protocol uses HTTP entities for messages. A single HTTP
message corresponds to a single protocol method. Most messages can
perform a single task on a single resource, such as retrieving a
resource or editing a resource. The exception is the PATCH method,
which allows multiple datastore edits within a single message.
4.1. Request URI Structure
Resources are represented with URIs following the structure for
generic URIs in [RFC3986].
A RESTCONF operation is derived from the HTTP method and the request
URI, using the following conceptual fields:
<OP> /<restconf>/<path>?<query>#<fragment>
^ ^ ^ ^ ^
| | | | |
method entry resource query fragment
M M O O I
M=mandatory, O=optional, I=ignored
<text> replaced by client with real values
o method: the HTTP method identifying the RESTCONF operation
requested by the client, to act upon the target resource specified
in the request URI. RESTCONF operation details are described in
Section 3.
o entry: the root of the RESTCONF API configured on this HTTP
server, discovered by getting the ".well-known/host-meta"
resource, as described in Section 4.2.
o resource: the path expression identifying the resource that is
being accessed by the operation. If this field is not present,
then the target resource is the API itself, represented by the
media type "application/yang.api".
o query: the set of parameters associated with the RESTCONF message.
These have the familiar form of "name=value" pairs. All query
parameters are optional to implement by the server and optional to
use by the client. Each query parameter is identified by a URI.
The server MUST list the query parameter URIs it supports in the
"capabilities" list defined in Section 8.3.
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There is a specific set of parameters defined, although the server
MAY choose to support query parameters not defined in this document.
The contents of the any query parameter value MUST be encoded
according to [RFC2396], section 3.4. Any reserved characters MUST be
encoded with escape sequences, according to [RFC2396], section 2.4.
o fragment: This field is not used by the RESTCONF protocol.
When new resources are created by the client, a "Location" header is
returned, which identifies the path of the newly created resource.
The client MUST use this exact path identifier to access the resource
once it has been created.
The "target" of an operation is a resource. The "path" field in the
request URI represents the target resource for the operation.
4.2. RESTCONF Path Resolution
In line the best practices defined by [get-off-my-lawn], RESTCONF
enables deployments to specify where the RESTCONF API is located.
When first connecting to a RESTCONF server, a RESTCONF client MUST
determine the root of the RESTCONF API. The client discovers this by
getting the "/.well-known/host-meta" resource ([RFC6415]) and using
the <Link> element containing the "restconf" attribute :
Request
-------
GET /.well-known/host-meta users HTTP/1.1
Host: example.com
Accept: application/xrd+xml
Response
--------
HTTP/1.1 200 OK
Content-Type: application/xrd+xml
Content-Length: nnn
<XRD xmlns='http://docs.oasis-open.org/ns/xri/xrd-1.0'>
<Link rel='restconf' href='/restconf'/>
</XRD>
Once discovering the RESTCONF API root, the client MUST prepend it to
any subsequent request to a RESTCONF resource. For instance, using
the "/restconf" path discovered above, the client can now determine
the operations supported by the the server:
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Request
-------
GET /restconf/operations HTTP/1.1
Host: example.com
Accept: application/yang.api+json,
application/yang.errors+json
Response
--------
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2012 17:01:00 GMT
Server: example-server
Cache-Control: no-cache
Pragma: no-cache
Last-Modified: Sun, 22 Apr 2012 01:00:14 GMT
Content-Type: application/yang.api+json
{ "operations" : { "play" : [ null ] } }
4.3. Message Headers
There are several HTTP header lines utilized in RESTCONF messages.
Messages are not limited to the HTTP headers listed in this section.
HTTP defines which header lines are required for particular
circumstances. Refer to each operation definition section in
Section 3 for examples on how particular headers are used.
There are some request headers that are used within RESTCONF, usually
applied to data resources. The following tables summarize the
headers most relevant in RESTCONF message requests:
+---------------------+---------------------------------------------+
| Name | Description |
+---------------------+---------------------------------------------+
| Accept | Response Content-Types that are acceptable |
| Content-Type | The media type of the request body |
| Host | The host address of the server |
| If-Match | Only perform the action if the entity |
| | matches ETag |
| If-Modified-Since | Only perform the action if modified since |
| | time |
| If-Unmodified-Since | Only perform the action if un-modified |
| | since time |
+---------------------+---------------------------------------------+
RESTCONF Request Headers
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The following tables summarize the headers most relevant in RESTCONF
message responses:
+---------------+---------------------------------------------------+
| Name | Description |
+---------------+---------------------------------------------------+
| Allow | Valid actions when 405 error returned |
| Cache-Control | The cache control parameters for the response |
| Content-Type | The media type of the response body |
| Date | The date and time the message was sent |
| ETag | An identifier for a specific version of a |
| | resource |
| Last-Modified | The last modified date and time of a resource |
| Location | The resource identifier for a newly created |
| | resource |
+---------------+---------------------------------------------------+
RESTCONF Response Headers
4.4. Message Encoding
RESTCONF messages are encoded in HTTP according to RFC 2616. The
"utf-8" character set is used for all messages. RESTCONF message
content is sent in the HTTP message body.
Content is encoded in either JSON or XML format. A server MUST
support XML encoding and MAY support JSON encoding. XML encoding
rules for data nodes are defined in [RFC6020]. The same encoding
rules are used for all XML content. JSON encoding rules are defined
in [I-D.ietf-netmod-json]. This encoding is valid JSON, but also has
special encoding rules to identify module namespaces and provide
consistent type processing of YANG data.
Request input content encoding format is identified with the Content-
Type header. This field MUST be present if a message body is sent by
the client.
Response output content encoding format is identified with the Accept
header in the request, or if is not specified, the request input
encoding format is used. If there was no request input, then the
default output encoding is XML. File extensions encoded in the
request are not used to identify format encoding.
4.5. RESTCONF Meta-Data
The RESTCONF protocol needs to retrieve the same meta-data that is
used in the NETCONF protocol. Information about default leafs, last-
modified timestamps, etc. are commonly used to annotate
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representations of the datastore contents. This meta-data is not
defined in the YANG schema because it applies to the datastore, and
is common across all data nodes.
This information is encoded as attributes in XML. JSON encoding of
meta-data is defined in [I-D.lhotka-netmod-yang-metadata].
4.6. Return Status
Each message represents some sort of resource access. An HTTP
"Status-Line" header line is returned for each request. If a 4xx or
5xx range status code is returned in the Status-Line, then the error
information will be returned in the response, according to the format
defined in Section 6.1.
4.7. Message Caching
Since the datastore contents change at unpredictable times, responses
from a RESTCONF server generally SHOULD NOT be cached.
The server SHOULD include a "Cache-Control" header in every response
that specifies whether the response should be cached. A "Pragma"
header specifying "no-cache" MAY also be sent in case the
"Cache-Control" header is not supported.
Instead of using HTTP caching, the client SHOULD track the "ETag"
and/or "Last-Modified" headers returned by the server for the
datastore resource (or data resource if the server supports it). A
retrieval request for a resource can include the "If-None-Match" and/
or "If-Modified-Since" headers, which will cause the server to return
a "304 Not Modified" Status-Line if the resource has not changed.
The client MAY use the HEAD method to retrieve just the message
headers, which SHOULD include the "ETag" and "Last-Modified" headers,
if this meta-data is maintained for the target resource.
5. Notifications
The RESTCONF protocol supports YANG-defined event notifications. The
solution preserves aspects of NETCONF Event Notifications [RFC5277]
while utilizing the Server-Sent Events [W3C.CR-eventsource-20121211]
transport strategy.
5.1. Server Support
A RESTCONF server is not required to support RESTCONF notifications.
Clients may determine if a server supports RESTCONF notifications by
using the HTTP operation OPTIONS, HEAD, or GET on the stream list.
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The server does not support RESTCONF notifications if an HTTP error
code is returned (e.g., 404 Not Found).
5.2. Event Streams
A RESTCONF server that supports notifications will populate a stream
resource for each notification delivery service access point. A
RESTCONF client can retrieve the list of supported event streams from
a RESTCONF server using the GET operation on the stream list.
The "restconf-state/streams" container definition in the
"ietf-restconf-monitoring" module (defined in Section 8.3) is used to
specify the structure and syntax of the conceptual child resources
within the "streams" resource.
For example:
The client might send the following request:
GET /restconf/data/ietf-restconf-monitoring:restconf-state/
streams HTTP/1.1
Host: example.com
Accept: application/yang.data+xml,
application/yang.errors+xml
The server might send the following response:
HTTP/1.1 200 OK
Content-Type: application/yang.api+xml
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<streams
xmlns="urn:ietf:params:xml:ns:yang:ietf-restconf-monitoring">
<stream>
<name>NETCONF</name>
<description>default NETCONF event stream
</description>
<replay-support>true</replay-support>
<replay-log-creation-time>
2007-07-08T00:00:00Z
</replay-log-creation-time>
<encoding>
<type>xml</type>
<events>http://example.com/streams/NETCONF</events>
</encoding>
<encoding>
<type>json</type>
<events>http://example.com/streams/NETCONF-JSON</events>
</encoding>
</stream>
<stream>
<name>SNMP</name>
<description>SNMP notifications</description>
<replay-support>false</replay-support>
<encoding>
<type>xml</type>
<events>http://example.com/streams/SNMP</events>
</encoding>
</stream>
<stream>
<name>syslog-critical</name>
<description>Critical and higher severity
</description>
<replay-support>true</replay-support>
<replay-log-creation-time>
2007-07-01T00:00:00Z
</replay-log-creation-time>
<encoding>
<type>xml</type>
<events>
http://example.com/streams/syslog-critical
</events>
</encoding>
</stream>
</streams>
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5.3. Subscribing to Receive Notifications
RESTCONF clients can determine the URL for the subscription resource
(to receive notifications) by sending an HTTP GET request for the
"events" leaf with the stream list entry. The value returned by the
server can be used for the actual notification subscription.
The client will send an HTTP GET request for the URL returned by the
server with the "Accept" type "text/event-stream".
The server will treat the connection as an event stream, using the
Server Sent Events [W3C.CR-eventsource-20121211] transport strategy.
The server MAY support query parameters for a GET method on this
resource. These parameters are specific to each notification stream.
For example:
The client might send the following request:
GET /restconf/data/ietf-restconf-monitoring:restconf-state/
streams/stream=NETCONF/encoding=xml/events HTTP/1.1
Host: example.com
Accept: application/yang.data+xml,
application/yang.errors+xml
The server might send the following response:
HTTP/1.1 200 OK
Content-Type: application/yang.api+xml
<events
xmlns="urn:ietf:params:xml:ns:yang:ietf-restconf-monitoring">
http://example.com/streams/NETCONF
</events>
The RESTCONF client can then use this URL value to start monitoring
the event stream:
GET /streams/NETCONF HTTP/1.1
Host: example.com
Accept: text/event-stream
Cache-Control: no-cache
Connection: keep-alive
A RESTCONF client MAY request the server compress the events using
the HTTP header field "Accept-Encoding". For instance:
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GET /streams/NETCONF HTTP/1.1
Host: example.com
Accept: text/event-stream
Cache-Control: no-cache
Connection: keep-alive
Accept-Encoding: gzip, deflate
5.3.1. NETCONF Event Stream
The server SHOULD support the "NETCONF" notification stream defined
in [RFC5277]. For this stream, RESTCONF notification subscription
requests MAY specify parameters indicating the events it wishes to
receive. These query parameters are optional to implement, and only
available if the server supports them.
+------------+---------+-------------------------+
| Name | Section | Description |
+------------+---------+-------------------------+
| start-time | 3.8.10 | replay event start time |
| stop-time | 3.8.11 | replay event stop time |
| filter | 3.8.9 | boolean content filter |
+------------+---------+-------------------------+
NETCONF Stream Query Parameters
The semantics and syntax for these query parameters are defined in
the sections listed above. The YANG encoding MUST be converted to
URL-encoded string for use in the request URI.
Refer to Appendix D.3.8 for filter parameter examples.
5.4. Receiving Event Notifications
RESTCONF notifications are encoded according to the definition of the
event stream. The NETCONF stream defined in [RFC5277] is encoded in
XML format.
The structure of the event data is based on the "notification"
element definition in section 4 of [RFC5277]. It MUST conform to the
"notification" YANG container definition in Section 7.
An example SSE notification encoded using XML:
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data: <notification
data: xmlns="urn:ietf:params:xml:ns:yang:ietf-restconf">
data: <event-time>2013-12-21T00:01:00Z</event-time>
data: <event xmlns="http://example.com/event/1.0">
data: <event-class>fault</event-class>
data: <reporting-entity>
data: <card>Ethernet0</card>
data: </reporting-entity>
data: <severity>major</severity>
data: </event>
data: </notification>
An example SSE notification encoded using JSON:
data: {
data: "ietf-restconf:notification": {
data: "event-time": "2013-12-21T00:01:00Z",
data: "example-mod:event": {
data: "event-class": "fault",
data: "reporting-entity": { "card": "Ethernet0" },
data: "severity": "major"
data: }
data: }
data: }
Alternatively, since neither XML nor JSON are whitespace sensitive,
the above messages can be encoded onto a single line. For example:
For example: ('\' line wrapping added for formatting only)
XML:
data: <notification xmlns="urn:ietf:params:xml:ns:yang:ietf-rest\
conf"><event-time>2013-12-21T00:01:00Z</event-time><event xmlns="\
http://example.com/event/1.0"><event-class>fault</event-class><re\
portingEntity><card>Ethernet0</card></reporting-entity><severity>\
major</severity></event></notification>
JSON:
data: {"ietf-restconf:notification":{"event-time":"2013-12-21\
T00:01:00Z","example-mod:event":{"event-class": "fault","repor\
tingEntity":{"card":"Ethernet0"},"severity":"major"}}}
The SSE specifications supports the following additional fields:
event, id and retry. A RESTCONF server MAY send the "retry" field
and, if it does, RESTCONF clients SHOULD use it. A RESTCONF server
SHOULD NOT send the "event" or "id" fields, as there are no
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meaningful values that could be used for them that would not be
redundant to the contents of the notification itself. RESTCONF
servers that do not send the "id" field also do not need to support
the HTTP header "Last-Event-Id". RESTCONF servers that do send the
"id" field MUST still support the "startTime" query parameter as the
preferred means for a client to specify where to restart the event
stream.
6. Error Reporting
HTTP Status-Lines are used to report success or failure for RESTCONF
operations. The <rpc-error> element returned in NETCONF error
responses contains some useful information. This error information
is adapted for use in RESTCONF, and error information is returned for
"4xx" class of status codes.
The following table summarizes the return status codes used
specifically by RESTCONF operations:
+---------------------------+---------------------------------------+
| Status-Line | Description |
+---------------------------+---------------------------------------+
| 100 Continue | POST accepted, 201 should follow |
| 200 OK | Success with response body |
| 201 Created | POST to create a resource success |
| 202 Accepted | POST to create a resource accepted |
| 204 No Content | Success without response body |
| 304 Not Modified | Conditional operation not done |
| 400 Bad Request | Invalid request message |
| 403 Forbidden | Access to resource denied |
| 404 Not Found | Resource target or resource node not |
| | found |
| 405 Method Not Allowed | Method not allowed for target |
| | resource |
| 409 Conflict | Resource or lock in use |
| 412 Precondition Failed | Conditional method is false |
| 413 Request Entity Too | too-big error |
| Large | |
| 414 Request-URI Too Large | too-big error |
| 415 Unsupported Media | non RESTCONF media type |
| Type | |
| 500 Internal Server Error | operation-failed |
| 501 Not Implemented | unknown-operation |
| 503 Service Unavailable | Recoverable server error |
+---------------------------+---------------------------------------+
HTTP Status Codes used in RESTCONF
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Since an operation resource is defined with a YANG "rpc" statement, a
mapping between the NETCONF <error-tag> value and the HTTP status
code is needed. The specific error condition and response code to
use are data-model specific and might be contained in the YANG
"description" statement for the "rpc" statement.
+-------------------------+-------------+
| <error-tag> | status code |
+-------------------------+-------------+
| in-use | 409 |
| invalid-value | 400 |
| too-big | 413 |
| missing-attribute | 400 |
| bad-attribute | 400 |
| unknown-attribute | 400 |
| bad-element | 400 |
| unknown-element | 400 |
| unknown-namespace | 400 |
| access-denied | 403 |
| lock-denied | 409 |
| resource-denied | 409 |
| rollback-failed | 500 |
| data-exists | 409 |
| data-missing | 409 |
| operation-not-supported | 501 |
| operation-failed | 500 |
| partial-operation | 500 |
| malformed-message | 400 |
+-------------------------+-------------+
Mapping from error-tag to status code
6.1. Error Response Message
When an error occurs for a request message on a data resource or an
operation resource, and a "4xx" class of status codes (except for
status code "403 Forbidden"), then the server SHOULD send a response
body containing the information described by the "errors" container
definition within the YANG module Section 7. The Content-Type of
this response message MUST be application/yang.errors.
YANG Tree Diagram for <errors> Data:
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+--ro errors
+--ro error
+--ro error-type enumeration
+--ro error-tag string
+--ro error-app-tag? string
+--ro (error-node)?
| +--:(error-path)
| | +--ro error-path? instance-identifier
| +--:(error-urlpath)
| +--ro error-urlpath? data-resource-identifier
+--ro error-message? string
+--ro error-info
The semantics and syntax for RESTCONF error messages are defined in
the "errors" YANG grouping in Section 7.
Examples:
The following example shows an error returned for an "lock-denied"
error on a datastore resource.
POST /restconf/operations/example-ops:lock-datastore HTTP/1.1
Host: example.com
The server might respond:
HTTP/1.1 409 Conflict
Date: Mon, 23 Apr 2012 17:11:00 GMT
Server: example-server
Content-Type: application/yang.errors+json
{
"ietf-restconf:errors": {
"error": {
"error-type": "protocol",
"error-tag": "lock-denied",
"error-message": "Lock failed, lock already held"
}
}
}
The following example shows an error returned for a "data-exists"
error on a data resource. The "jukebox" resource already exists so
it cannot be created.
The client might send:
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POST /restconf/data/example-jukebox:jukebox HTTP/1.1
Host: example.com
The server might respond:
HTTP/1.1 409 Conflict
Date: Mon, 23 Apr 2012 17:11:00 GMT
Server: example-server
Content-Type: application/yang.errors+json
{
"ietf-restconf:errors": {
"error": {
"error-type": "protocol",
"error-tag": "data-exists",
"error-urlpath": "http://example.com/restconf/data/
example-jukebox:jukebox",
"error-message":
"Data already exists, cannot create new resource"
}
}
}
7. RESTCONF module
The "ietf-restconf" module defines conceptual definitions within
groupings, which are not meant to be implemented as datastore
contents by a server. The "restconf" container is not intended to be
implemented as a top-level data node (under the "/restconf/data"
entry point).
The "ietf-yang-types" module from [RFC6991] is used by this module
for some type definitions.
RFC Ed.: update the date below with the date of RFC publication and
remove this note.
<CODE BEGINS> file "ietf-restconf@2014-10-25.yang"
module ietf-restconf {
namespace "urn:ietf:params:xml:ns:yang:ietf-restconf";
prefix "rc";
import ietf-yang-types { prefix yang; }
organization
"IETF NETCONF (Network Configuration) Working Group";
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contact
"WG Web: <http://tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
WG Chair: Bert Wijnen
<mailto:bertietf@bwijnen.net>
WG Chair: Mehmet Ersue
<mailto:mehmet.ersue@nsn.com>
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 message and error content that is used in
RESTCONF protocol messages. A conceptual container
representing the RESTCONF API nodes is also defined
for the media type application/yang.api.
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) 2014 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
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// Note: extracted from draft-ietf-netconf-restconf-03.txt
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
revision 2014-10-25 {
description
"Initial revision.";
reference
"RFC XXXX: RESTCONF Protocol.";
}
typedef data-resource-identifier {
type string {
length "1 .. max";
}
description
"Contains a Data Resource Identifier formatted string
to identify a specific data resource instance.
The document root for all data resources is a
datastore resource container. Each top-level YANG
data nodes supported by the server will be represented
as a child node of the document root.
The canonical representation of a data resource identifier
includes the full server specification that is returned
in the Location header when a new data resource is created
with the POST method.
The abbreviated representation does not contain any server
location identification. Instead the identifier will start
with the '/' character to represent the datastore document
root for the data resource instance.
The server MUST accept either representation and SHOULD
return the canonical representation in any response message.";
reference
"RFC XXXX: [sec. 5.3.1.1 ABNF For Data Resource Identifiers]";
}
grouping errors {
description
"A grouping that contains a YANG container
representing the syntax and semantics of a
YANG Patch errors report within a response message.";
container errors {
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description
"Represents an error report returned by the server if
a request results in an error.";
list error {
description
"An entry containing information about one
specific error that occurred while processing
a RESTCONF request.";
reference "RFC 6241, Section 4.3";
leaf error-type {
type enumeration {
enum transport {
description "The transport layer";
}
enum rpc {
description "The rpc or notification layer";
}
enum protocol {
description "The protocol operation layer";
}
enum application {
description "The server application layer";
}
}
mandatory true;
description
"The protocol layer where the error occurred.";
}
leaf error-tag {
type string;
mandatory true;
description
"The enumerated error tag.";
}
leaf error-app-tag {
type string;
description
"The application-specific error tag.";
}
choice error-node {
description
"The server will return the location of the error node
in a format that is appropriate for the protocol.
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If no specific node within the request message body
caused the error then this choice will not be present.";
leaf error-path {
type instance-identifier;
description
"The YANG instance identifier associated
with the error node. This leaf will only be
present if the error node is not a data resource,
e.g., the error node is an input parameter
for an operation resource.";
}
leaf error-urlpath {
type data-resource-identifier;
description
"The target data resource identifier associated
with the error node. This leaf will only be
present if the error node is associated with
a data resource (either within the server or
in the request message).";
}
}
leaf error-message {
type string;
description
"A message describing the error.";
}
anyxml error-info {
description
"Arbitrary XML that represents a container
of additional information for the error report.";
}
}
}
} // grouping errors
grouping restconf {
description
"Conceptual container representing the
application/yang.api resource type.";
container restconf {
description
"Conceptual container representing the
application/yang.api resource type.";
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container data {
description
"Container representing the application/yang.datastore
resource type. Represents the conceptual root of all
operational data and configuration data supported by
the server. The child nodes of this container can be
any data resource (application/yang.data), which are
defined as top-level data nodes from the YANG modules
advertised by the server in the ietf-restconf-monitoring
module.";
}
container operations {
description
"Container for all operation resources
(application/yang.operation),
Each resource is represented as an empty leaf with the
name of the RPC operation from the YANG rpc statement.
E.g.;
POST /restconf/operations/show-log-errors
leaf show-log-errors {
type empty;
}
";
}
} // container restconf
} // grouping restconf
grouping collection {
description
"Conceptual container representing the
application/yang.collection resource type.";
container collection {
description
"Container representing the application/yang.collection
resource type.";
}
} // grouping collection
grouping notification {
description
"Contains the notification message wrapper definition.";
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container notification {
description
"RESTCONF notification message wrapper.";
leaf event-time {
type yang:date-and-time;
mandatory true;
description
"The time the event was generated by the
event source.";
reference
"RFC 5277, section 4, <eventTime> element.";
}
/* The YANG-specific notification container is encoded
* after the 'event-time' element. The format
* corresponds to the notificationContent element
* in RFC 5277, section 4. For example:
*
* module example-one {
* ...
* notification event1 { ... }
*
* }
*
* Encoded as element 'event1' in the namespace
* for module 'example-one'.
*/
}
} // grouping notification
}
<CODE ENDS>
8. RESTCONF Monitoring
The "ietf-restconf-monitoring" module provides information about the
RESTCONF protocol capabilities and notification event streams
available from the server. Implementation is mandatory for RESTCONF
servers, if any protocol capabilities or notification event streams
are supported.
YANG Tree Diagram for "ietf-restconf-monitoring" module:
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+--ro restconf-state
+--ro capabilities
| +--ro capability* inet:uri
+--ro streams
+--ro stream* [name]
+--ro name string
+--ro description? string
+--ro replay-support? boolean
+--ro replay-log-creation-time? yang:date-and-time
+--ro encoding* [type]
+--ro type string
+--ro events inet:uri
8.1. restconf-state/capabilities
This mandatory container holds the RESTCONF protocol capability URIs
supported by the server.
The server MUST maintain a last-modified timestamp for this
container, and return the "Last-Modified" header when this data node
is retrieved with the GET or HEAD methods.
The server SHOULD maintain an entity-tag for this container, and
return the "ETag" header when this data node is retrieved with the
GET or HEAD methods.
8.2. restconf-state/streams
This optional container provides access to the notification event
streams supported by the server. The server MAY omit this container
if no notification event streams are supported.
The server will populate this container with a stream list entry for
each stream type it supports. Each stream contains a leaf called
"events" which contains a URI that represents an event stream
resource.
Stream resources are defined in Section 2.9. Notifications are
defined in Section 5.
8.3. RESTCONF Monitoring Module
The "ietf-restconf-monitoring" module defines monitoring information
for the RESTCONF protocol.
The "ietf-yang-types" and "ietf-inet-types" modules from [RFC6991]
are used by this module for some type definitions.
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RFC Ed.: update the date below with the date of RFC publication and
remove this note.
<CODE BEGINS> file "ietf-restconf-monitoring@2014-10-25.yang"
module ietf-restconf-monitoring {
namespace "urn:ietf:params:xml:ns:yang:ietf-restconf-monitoring";
prefix "rcmon";
import ietf-yang-types { prefix yang; }
import ietf-inet-types { prefix inet; }
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
WG Chair: Bert Wijnen
<mailto:bertietf@bwijnen.net>
WG Chair: Mehmet Ersue
<mailto:mehmet.ersue@nsn.com>
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 monitoring information for the
RESTCONF protocol.
Copyright (c) 2014 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).
Bierman, et al. Expires April 28, 2015 [Page 59]
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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-restconf-03.txt
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
revision 2014-10-25 {
description
"Initial revision.";
reference
"RFC XXXX: RESTCONF Protocol.";
}
container restconf-state {
config false;
description
"Contains RESTCONF protocol monitoring information.";
container capabilities {
description
"Contains a list of protocol capability URIs";
leaf-list capability {
type inet:uri;
description "A RESTCONF protocol capability URI.";
}
}
container streams {
description
"Container representing the notification event streams
supported by the server.";
reference
"RFC 5277, Section 3.4, <streams> element.";
list stream {
key name;
description
"Each entry describes an event stream supported by
the server.";
leaf name {
type string;
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description "The stream name";
reference "RFC 5277, Section 3.4, <name> element.";
}
leaf description {
type string;
description "Description of stream content";
reference
"RFC 5277, Section 3.4, <description> element.";
}
leaf replay-support {
type boolean;
description
"Indicates if replay buffer supported for this stream.
If 'true', then the server MUST support the 'start-time'
and 'stop-time' query parameters for this stream.";
reference
"RFC 5277, Section 3.4, <replaySupport> element.";
}
leaf replay-log-creation-time {
when "../replay-support" {
description
"Only present if notification replay is supported";
}
type yang:date-and-time;
description
"Indicates the time the replay log for this stream
was created.";
reference
"RFC 5277, Section 3.4, <replayLogCreationTime>
element.";
}
list encoding {
key type;
min-elements 1;
description
"The server will create an entry in this list for each
encoding format that is supported for this stream.
The media type 'application/yang.stream' is expected
for all event streams. This list identifies the
sub-types supported for this stream.";
leaf type {
type string;
description
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"This is the secondary encoding format within the
'text/event-stream' encoding used by all streams.
The type 'xml' is supported for the media type
'application/yang.stream+xml'. The type 'json'
is supported for the media type
'application/yang.stream+json'.";
}
leaf events {
type inet:uri;
mandatory true;
description
"Contains a URL that represents the entry point
for establishing notification delivery via server
sent events.";
}
}
}
}
}
}
<CODE ENDS>
9. YANG Module Library
The "ietf-yang-library" module provides information about the YANG
modules and submodules used by the RESTCONF server. Implementation
is mandatory for RESTCONF servers. All YANG modules and submodules
used by the server MUST be identified in the YANG module library.
YANG Tree Diagram for "ietf-yang-library" module:
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+--ro modules
+--ro module-set-id? string
+--ro module* [name revision]
+--ro name yang:yang-identifier
+--ro revision union
+--ro schema? inet:uri
+--ro namespace inet:uri
+--ro feature* yang:yang-identifier
+--ro deviation* yang:yang-identifier
+--ro conformance boolean
+--ro submodules
+--ro submodule* [name revision]
+--ro name yang:yang-identifier
+--ro revision union
+--ro schema? inet:uri
9.1. modules
This mandatory container holds the identifiers for the YANG data
model modules supported by the server.
The server MUST maintain a last-modified timestamp for this
container, and return the "Last-Modified" header when this data node
is retrieved with the GET or HEAD methods.
The server SHOULD maintain an entity-tag for this container, and
return the "ETag" header when this data node is retrieved with the
GET or HEAD methods.
9.1.1. modules/module
This mandatory list contains one entry for each YANG data model
module supported by the server. There MUST be an instance of this
list for every YANG module that is used by the server.
The contents of the "module" list are defined in the "module" YANG
list statement in Section 9.2.
The server MAY maintain a last-modified timestamp for each instance
of this list entry, and return the "Last-Modified" header when this
data node is retrieved with the GET or HEAD methods. If not
supported then the timestamp for the parent "modules" container MAY
be used instead.
The server MAY maintain an entity-tag for each instance of this list
entry, and return the "ETag" header when this data node is retrieved
with the GET or HEAD methods. If not supported then the timestamp
for the parent "modules" container MAY be used instead.
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9.2. YANG Library Module
The "ietf-yang-library" module defines monitoring information for the
YANG modules used by a RESTCONF server.
The "ietf-yang-types" and "ietf-inet-types" modules from [RFC6991]
are used by this module for some type definitions.
RFC Ed.: update the date below with the date of RFC publication and
remove this note.
<CODE BEGINS> file "ietf-yang-library@2014-10-25.yang"
module ietf-yang-library {
namespace "urn:ietf:params:xml:ns:yang:ietf-yang-library";
prefix "yanglib";
import ietf-yang-types { prefix yang; }
import ietf-inet-types { prefix inet; }
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
WG Chair: Bert Wijnen
<mailto:bertietf@bwijnen.net>
WG Chair: Mehmet Ersue
<mailto:mehmet.ersue@nsn.com>
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 monitoring information about the YANG
modules and submodules that are used within a RESTCONF
server.
Copyright (c) 2014 IETF Trust and the persons identified as
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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-restconf-03.txt
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
revision 2014-10-25 {
description
"Initial revision.";
reference
"RFC XXXX: RESTCONF Protocol.";
}
typedef revision-identifier {
type string {
pattern '\d{4}-\d{2}-\d{2}';
}
description
"Represents a specific date in YYYY-MM-DD format.
TBD: make pattern more precise to exclude leading zeros.";
}
grouping module {
description
"The module data structure is represented as a grouping
so it can be reused in configuration or another monitoring
data structure.";
grouping common-leafs {
description
"Common parameters for YANG modules and submodules.";
leaf name {
type yang:yang-identifier;
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description "The YANG module or submodule name.";
}
leaf revision {
type union {
type revision-identifier;
type string { length 0; }
}
description
"The YANG module or submodule revision date.
An empty string is used if no revision statement
is present in the YANG module or submodule.";
}
leaf schema {
type inet:uri;
description
"Contains a URL that represents the YANG schema
resource for this module or submodule.
This leaf will only be present if there is a URL
available for retrieval of the schema for this entry.";
}
}
list module {
key "name revision";
description
"Each entry represents one module currently
supported by the server.";
uses common-leafs;
leaf namespace {
type inet:uri;
mandatory true;
description
"The XML namespace identifier for this module.";
}
leaf-list feature {
type yang:yang-identifier;
description
"List of YANG feature names from this module that are
supported by the server.";
}
leaf-list deviation {
type yang:yang-identifier;
description
"List of YANG deviation module names used by this
server to modify the conformance of the module
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associated with this entry.";
}
leaf conformance {
type boolean;
mandatory true;
description
"If 'true', then the server is claiming conformance to
the YANG module identified in this entry.
If 'false', then the server is not claiming any
conformance for the YANG module identified by this
entry. The module may be needed for reusable definitions
such as extensions, features, identifies, typedefs,
or groupings.";
}
container submodules {
description
"Contains information about all the submodules used
by the parent module entry";
list submodule {
key "name revision";
description
"Each entry represents one submodule within the
parent module.";
uses common-leafs;
}
}
} // list module
} // grouping module
container modules {
config false;
description
"Contains YANG module monitoring information.";
leaf module-set-id {
type string;
description
"Contains a server-specific identifier representing
the current set of modules and submodules. The
server MUST change the value of this leaf if the
information represented by the 'module' list instances
has changed.";
}
uses module;
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}
}
<CODE ENDS>
10. IANA Considerations
10.1. The "restconf" Relation Type
This specification registers the "restconf" relation type in the Link
Relation Type Registry defined by [RFC5988]:
Relation Name: restconf
Description: Identifies the root of RESTCONF API as configured
on this HTTP server. The "restconf" relation
defines the root of the API defined in RFCXXXX.
Subsequent revisions of RESTCONF will use alternate
relation values to support protocol versioning.
Reference: RFC XXXX
`
10.2. YANG Module Registry
This document registers three URIs 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-restconf
Registrant Contact: The NETMOD WG of the IETF.
XML: N/A, the requested URI is an XML namespace.
URI: urn:ietf:params:xml:ns:yang:ietf-restconf-monitoring
Registrant Contact: The NETMOD WG of the IETF.
XML: N/A, the requested URI is an XML namespace.
URI: urn:ietf:params:xml:ns:yang:ietf-yang-library
Registrant Contact: The NETMOD WG of the IETF.
XML: N/A, the requested URI is an XML namespace.
This document registers three YANG modules in the YANG Module Names
registry [RFC6020].
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name: ietf-restconf
namespace: urn:ietf:params:xml:ns:yang:ietf-restconf
prefix: rc
// RFC Ed.: replace XXXX with RFC number and remove this note
reference: RFC XXXX
name: ietf-restconf-monitoring
namespace: urn:ietf:params:xml:ns:yang:ietf-restconf-monitoring
prefix: rcmon
// RFC Ed.: replace XXXX with RFC number and remove this note
reference: RFC XXXX
name: ietf-yang-library
namespace: urn:ietf:params:xml:ns:yang:ietf-yang-library
prefix: yanglib
// RFC Ed.: replace XXXX with RFC number and remove this note
reference: RFC XXXX
10.3. application/yang Media Sub Types
The parent MIME media type for RESTCONF resources is application/
yang, which is defined in [RFC6020]. This document defines the
following sub-types for this media type.
- api
- data
- datastore
- collection
- errors
- operation
- stream
Type name: application
Subtype name: yang.xxx
Required parameters: TBD
Optional parameters: TBD
Encoding considerations: TBD
Security considerations: TBD
Interoperability considerations: TBD
// RFC Ed.: replace XXXX with RFC number and remove this note
Published specification: RFC XXXX
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10.4. NETCONF Capability URNs
This document registers several capability identifiers in "Network
Configuration Protocol (NETCONF) Capability URNs" registry
Index
Capability Identifier
------------------------
:content
urn:ietf:params:restconf:capability:content:1.0
:depth
urn:ietf:params:restconf:capability:depth:1.0
:filter
urn:ietf:params:restconf:capability:filter:1.0
:insert
urn:ietf:params:restconf:capability:insert:1.0
:page
urn:ietf:params:restconf:capability:page:1.0
:select
urn:ietf:params:restconf:capability:select:1.0
:replay
urn:ietf:params:restconf:capability:replay:1.0
11. Security Considerations
This section provides security considerations for the resources
defined by the RESTCONF protocol. Security considerations for HTTPS
are defined in [RFC2818]. Security considerations for the content
manipulated by RESTCONF can be found in the documents defining data
models.
This document does not specify an authentication scheme, but it does
require that an authenticated NETCONF username be associated with
each HTTP request. The authentication scheme MAY be implemented in
the underlying transport layer (e.g., client certificates) or within
the HTTP layer (e.g., Basic Auth, OAuth, etc.). RESTCONF does not
itself define an authentication mechanism, authentication MUST occur
in a lower layer. Implementors SHOULD provide a comprehensive
authorization scheme with RESTCONF and ensure that the resulting
NETCONF username is made available to the RESTCONF server.
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Authorization of individual user access to operations and data MAY be
configured via NETCONF Access Control Model (NACM) [RFC6536], as
specified in Section 3. Other authorization models MAY be used, but
are outside of the scope of this document.
Configuration information is by its very nature sensitive. Its
transmission in the clear and without integrity checking leaves
devices open to classic eavesdropping and false data injection
attacks. Configuration information often contains passwords, user
names, service descriptions, and topological information, all of
which are sensitive. Because of this, this protocol SHOULD be
implemented carefully with adequate attention to all manner of attack
one might expect to experience with other management interfaces.
Different environments may well allow different rights prior to and
then after authentication. When an operation is not properly
authorized, the RESTCONF server MUST return HTTP error status code
401 Unauthorized. Note that authorization information can be
exchanged in the form of configuration information, which is all the
more reason to ensure the security of the connection.
12. Acknowledgements
The authors would like to thank for following for lively discussions
on list and in the halls (ordered by last name): Rex Fernando
13. References
13.1. Normative References
[I-D.ietf-netmod-json]
Lhotka, L., "Modeling JSON Text with YANG", draft-ietf-
netmod-yang-json-01 (work in progress), October 2014.
[I-D.lhotka-netmod-yang-metadata]
Lhotka, L., "Defining and Using Metadata with YANG",
draft-lhotka-netmod-yang-metadata-00 (work in progress),
September 2014.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2246] Dierks, T. and C. Allen, "The TLS Protocol, Version 1.0",
RFC 2246, January 1999.
[RFC2396] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifiers (URI): Generic Syntax", RFC 2396,
August 1998.
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[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.
[RFC2818] Rescorla, E., "The IETF XML Registry", RFC 2818, May 2000.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
January 2004.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66, RFC
3986, January 2005.
[RFC5277] Chisholm, S. and H. Trevino, "NETCONF Event
Notifications", RFC 5277, July 2008.
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and T. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, May 2008.
[RFC5789] Dusseault, L. and J. Snell, "PATCH Method for HTTP", RFC
5789, March 2010.
[RFC5988] Nottingham, M., "Web Linking", RFC 5988, October 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.
[RFC6415] Hammer-Lahav, E. and B. Cook, "Web Host Metadata", RFC
6415, October 2011.
[RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration
Protocol (NETCONF) Access Control Model", RFC 6536, March
2012.
[RFC6570] Gregorio, J., Fielding, R., Hadley, M., Nottingham, M.,
and D. Orchard, "URI Template", RFC 6570, March 2012.
[RFC6991] Schoenwaelder, J., "Common YANG Data Types", RFC 6991,
July 2013.
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[RFC7158] Bray, T., Ed., "The JSON Data Interchange Format", RFC
7158, March 2013.
[W3C.CR-eventsource-20121211]
Hickson, I., "Server-Sent Events", World Wide Web
Consortium CR CR-eventsource-20121211, December 2012,
<http://www.w3.org/TR/2012/CR-eventsource-20121211>.
[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>.
[get-off-my-lawn]
Nottingham, M., "URI Design and Ownership", Best Current
Practice draft-ietf-appsawg-uri-get-off-my-lawn-05, May
2014.
[rest-dissertation]
Fielding, R., "Architectural Styles and the Design of
Network-based Software Architectures", 2000.
13.2. Informative References
[XPath] Clark, J. and S. DeRose, "XML Path Language (XPath)
Version 1.0", World Wide Web Consortium Recommendation
REC-xpath-19991116, November 1999,
<http://www.w3.org/TR/1999/REC-xpath-19991116>.
Appendix A. Change Log
-- RFC Ed.: remove this section before publication.
A.1. 02 - 03
o added collection resource
o added "page" query parameter capability
o added "limit" and "offset" query parameters, which are available
if the "page" capability is supported
o added "stream list" term
o fixed bugs in some examples
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o added "encoding" list within the "stream" list to allow different
<events> URLs for XML and JSON encoding.
o made XML MUST implement and JSON MAY implement for servers
o re-add JSON notification examples (previously removed)
o updated JSON references
A.2. 01 - 02
o moved query parameter definitions from the YANG module back to the
plain text sections
o made all query parameters optional to implement
o defined query parameter capability URI
o moved 'streams' to new YANG module (ietf-restconf-monitoring)
o added 'capabilities' container to new YANG module (ietf-restconf-
monitoring)
o moved 'modules' container to new YANG module (ietf-yang-library)
o added new leaf 'module-set-id' (ietf-yang-library)
o added new leaf 'conformance' (ietf-yang-library)
o changed 'schema' leaf to type inet:uri that returns the location
of the YANG schema (instead of returning the schema directly)
o changed 'events' leaf to type inet:uri that returns the location
of the event stream resource (instead of returning events
directly)
o changed examples for yang.api resource since the monitoring
information is no longer in this resource
o closed issue #1 'select parameter' since no objections to the
proposed syntax
o closed "encoding of list keys" issue since no objection to new
encoding of list keys in a target resource URI.
o moved open issues list to the issue tracker on github
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A.3. 00 - 01
o fixed content=nonconfig example (non-config was incorrect)
o closed open issue 'message-id'. There is no need for a message-id
field, and RFC 2392 does not apply.
o closed open issue 'server support verification'. The headers used
by RESTCONF are widely supported.
o removed encoding rules from section on RESTCONF Meta-Data. This
is now defined in "I-D.lhotka-netmod-json".
o added media type application/yang.errors to map to errors YANG
grouping. Updated error examples to use new media type.
o closed open issue 'additional datastores'. Support may be added
in the future to identify new datastores.
o closed open issue 'PATCH media type discovery'. The section on
PATCH has an added sentence on the Accept-Patch header.
o closed open issue 'YANG to resource mapping'. Current mapping of
all data nodes to resources will be used in order to allow
mandatory DELETE support. The PATCH operation is optional, as
well as the YANG Patch media type.
o closed open issue '_self links for HATEOAS support'. It was
decided that they are redundant because they can be derived from
the YANG module for the specific data.
o added explanatory text for the 'select' parameter.
o added RESTCONF Path Resolution section for discovering the root of
the RESTCONF API using the /.well-known/host-meta.
o added an "error" media type to for structured error messages
o added Secure Transport section requiring TLS
o added Security Considerations section
o removed all references to "REST-like"
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A.4. bierman:restconf-04 to ietf:restconf-00
o updated open issues section
Appendix B. Open Issues
-- RFC Ed.: remove this section before publication.
The RESTCONF issues are tracked on github.com:
https://github.com/netconf-wg/restconf/issues
Appendix C. Example YANG Module
The example YANG module used in this document represents a simple
media jukebox interface.
YANG Tree Diagram for "example-jukebox" Module
+--rw jukebox?
+--rw library
| +--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 instance-identifier
+--rw player
+--rw gap? decimal64
rpcs:
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+---x play
+--ro input
+--ro playlist string
+--ro song-number uint32
C.1. example-jukebox YANG Module
module example-jukebox {
namespace "http://example.com/ns/example-jukebox";
prefix "jbox";
import ietf-restconf { prefix rc; }
organization "Example, Inc.";
contact "support at example.com";
description "Example Jukebox Data Model Module";
revision "2014-07-03" {
description "Initial version.";
reference "example.com document 1-4673";
}
identity genre {
description "Base for all genre types";
}
// abbreviated list of genre classifications
identity alternative {
base genre;
description "Alternative music";
}
identity blues {
base genre;
description "Blues music";
}
identity country {
base genre;
description "Country music";
}
identity jazz {
base genre;
description "Jazz music";
}
identity pop {
base genre;
description "Pop music";
}
identity rock {
base genre;
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description "Rock music";
}
container jukebox {
presence
"An empty container indicates that the jukebox
service is available";
description
"Represents a jukebox resource, with a library, playlists,
and a play operation.";
container library {
description "Represents the jukebox library resource.";
list artist {
key name;
description
"Represents one artist resource within the
jukebox library resource.";
leaf name {
type string {
length "1 .. max";
}
description "The name of the artist.";
}
list album {
key name;
description
"Represents one album resource within one
artist resource, within the jukebox library.";
leaf name {
type string {
length "1 .. max";
}
description "The name of the album.";
}
leaf genre {
type identityref { base genre; }
description
"The genre identifying the type of music on
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the album.";
}
leaf year {
type uint16 {
range "1900 .. max";
}
description "The year the album was released";
}
container admin {
description
"Administrative information for the album.";
leaf label {
type string;
description "The label that released the album.";
}
leaf catalogue-number {
type string;
description "The album's catalogue number.";
}
}
list song {
key name;
description
"Represents one song resource within one
album resource, within the jukebox library.";
leaf name {
type string {
length "1 .. max";
}
description "The name of the song";
}
leaf location {
type string;
mandatory true;
description
"The file location string of the
media file for the song";
}
leaf format {
type string;
description
"An identifier string for the media type
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for the file associated with the
'location' leaf for this entry.";
}
leaf length {
type uint32;
units "seconds";
description
"The duration of this song in seconds.";
}
} // end list 'song'
} // end list 'album'
} // end list 'artist'
leaf artist-count {
type uint32;
units "songs";
config false;
description "Number of artists in the library";
}
leaf album-count {
type uint32;
units "albums";
config false;
description "Number of albums in the library";
}
leaf song-count {
type uint32;
units "songs";
config false;
description "Number of songs in the library";
}
} // end library
list playlist {
key name;
description
"Example configuration data resource";
leaf name {
type string;
description
"The name of the playlist.";
}
leaf description {
type string;
description
"A comment describing the playlist.";
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}
list song {
key index;
ordered-by user;
description
"Example nested configuration data resource";
leaf index { // not really needed
type uint32;
description
"An arbitrary integer index for this
playlist song.";
}
leaf id {
type rc:data-resource-identifier;
mandatory true;
description
"Song identifier. Must identify an instance of
/jukebox/library/artist/album/song/name.";
}
}
}
container player {
description
"Represents the jukebox player resource.";
leaf gap {
type decimal64 {
fraction-digits 1;
range "0.0 .. 2.0";
}
units "tenths of seconds";
description "Time gap between each song";
}
}
}
rpc play {
description "Control function for the jukebox player";
input {
leaf playlist {
type string;
mandatory true;
description "playlist name";
}
leaf song-number {
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type uint32;
mandatory true;
description "Song number in playlist to play";
}
}
}
}
Appendix D. RESTCONF Message Examples
The examples within this document use the normative YANG module
defined in Section 7 and the non-normative example YANG module
defined in Appendix C.1.
This section shows some typical RESTCONF message exchanges.
D.1. Resource Retrieval Examples
D.1.1. Retrieve the Top-level API Resource
The client may start by retrieving the top-level API resource, using
the entry point URI "{+restconf}".
GET /restconf HTTP/1.1
Host: example.com
Accept: application/yang.api+json,
application/yang.errors+json
The server might respond as follows:
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2012 17:01:00 GMT
Server: example-server
Content-Type: application/yang.api+json
{
"ietf-restconf:restconf": {
"data" : [ null ],
"operations" : {
"play" : [ null ]
}
}
}
To request that the response content to be encoded in XML, the
"Accept" header can be used, as in this example request:
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GET /restconf HTTP/1.1
Host: example.com
Accept: application/yang.api+xml,
application/yang.errors+xml
The server will return the same response either way, which might be
as follows :
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2012 17:01:00 GMT
Server: example-server
Cache-Control: no-cache
Pragma: no-cache
Content-Type: application/yang.api+xml
<restconf xmlns="urn:ietf:params:xml:ns:yang:ietf-restconf">
<data/>
<operations>
<play xmlns="http://example.com/ns/example-jukebox"/>
</operations>
</restconf>
D.1.2. Retrieve The Server Module Information
In this example the client is retrieving the modules information from
the server in JSON format:
GET /restconf/data/ietf-yang-library:modules HTTP/1.1
Host: example.com
Accept: application/yang.data+json,
application/yang.errors+json
The server might respond as follows.
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2012 17:01:00 GMT
Server: example-server
Cache-Control: no-cache
Pragma: no-cache
Last-Modified: Sun, 22 Apr 2012 01:00:14 GMT
Content-Type: application/yang.data+json
{
"ietf-yang-library:modules": {
"module": [
{
"name" : "foo",
"revision" : "2012-01-02",
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"schema" : "http://example.com/mymodules/foo/2012-01-02",
"namespace" : "http://example.com/ns/foo",
"feature" : [ "feature1", "feature2" ],
"conformance" : true
},
{
"name" : "foo-types",
"revision" : "2012-01-05",
"schema" :
"http://example.com/mymodules/foo-types/2012-01-05",
"schema" : [null],
"namespace" : "http://example.com/ns/foo-types",
"conformance" : false
},
{
"name" : "bar",
"revision" : "2012-11-05",
"schema" : "http://example.com/mymodules/bar/2012-11-05",
"namespace" : "http://example.com/ns/bar",
"feature" : [ "bar-ext" ],
"conformance" : true,
"submodule" : [
{
"name" : "bar-submod1",
"revision" : "2012-11-05",
"schema" :
"http://example.com/mymodules/bar-submod1/2012-11-05"
},
{
"name" : "bar-submod2",
"revision" : "2012-11-05",
"schema" :
"http://example.com/mymodules/bar-submod2/2012-11-05"
}
]
}
]
}
}
D.1.3. Retrieve The Server Capability Information
In this example the client is retrieving the capability information
from the server in JSON format, and the server supports all the
RESTCONF query parameters, plus one vendor parameter:
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GET /restconf/data/ietf-restconf-monitoring:restconf-state/
capabilities HTTP/1.1
Host: example.com
Accept: application/yang.data+json,
application/yang.errors+json
The server might respond as follows.
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2012 17:02:00 GMT
Server: example-server
Cache-Control: no-cache
Pragma: no-cache
Last-Modified: Sun, 22 Apr 2012 01:00:14 GMT
Content-Type: application/yang.data+json
{
"ietf-restconf-monitoring:capabilities": {
"capability": [
"urn:ietf:params:restconf:capability:content:1.0",
"urn:ietf:params:restconf:capability:depth:1.0",
"urn:ietf:params:restconf:capability:filter:1.0",
"urn:ietf:params:restconf:capability:insert:1.0",
"urn:ietf:params:restconf:capability:point:1.0",
"urn:ietf:params:restconf:capability:select:1.0",
"urn:ietf:params:restconf:capability:start-time:1.0",
"urn:ietf:params:restconf:capability:stop-time:1.0",
"http://example.com/capabilities/myparam"
]
}
}
D.2. Edit Resource Examples
D.2.1. Create New Data Resources
To create a new "artist" resource within the "library" resource, the
client might send the following request.
POST /restconf/data/example-jukebox:jukebox/library HTTP/1.1
Host: example.com
Content-Type: application/yang.data+json
{ "example-jukebox:artist" : {
"name" : "Foo Fighters"
}
}
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If the resource is created, the server might respond as follows.
Note that the "Location" header line is wrapped for display purposes
only:
HTTP/1.1 201 Created
Date: Mon, 23 Apr 2012 17:02:00 GMT
Server: example-server
Location: http://example.com/restconf/data/
example-jukebox:jukebox/library/artist=Foo%20Fighters
Last-Modified: Mon, 23 Apr 2012 17:02:00 GMT
ETag: b3830f23a4c
To create a new "album" resource for this artist within the "jukebox"
resource, the client might send the following request. Note that the
request URI header line is wrapped for display purposes only:
POST /restconf/data/example-jukebox:jukebox/
library/artist=Foo%20Fighters HTTP/1.1
Host: example.com
Content-Type: application/yang.data+json
{
"example-jukebox:album" : {
"name" : "Wasting Light",
"genre" : "example-jukebox:alternative",
"year" : 2012 # note this is the wrong date
}
}
If the resource is created, the server might respond as follows.
Note that the "Location" header line is wrapped for display purposes
only:
HTTP/1.1 201 Created
Date: Mon, 23 Apr 2012 17:03:00 GMT
Server: example-server
Location: http://example.com/restconf/data/
example-jukebox:jukebox/library/artist=Foo%20Fighters/
album=Wasting%20Light
Last-Modified: Mon, 23 Apr 2012 17:03:00 GMT
ETag: b8389233a4c
D.2.2. Detect Resource Entity Tag Change
In this example, the server just supports the mandatory datastore
last-changed timestamp. The client has previously retrieved the
"Last-Modified" header and has some value cached to provide in the
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following request to patch an "album" list entry with key value
"Wasting Light". Only the "year" field is being updated.
PATCH /restconf/data/example-jukebox:jukebox/
library/artist=Foo%20Fighters/album=Wasting%20Light/year
HTTP/1.1
Host: example.com
Accept: application/yang.data+json,
application/yang.errors+json
If-Unmodified-Since: Mon, 23 Apr 2012 17:01:00 GMT
Content-Type: application/yang.data+json
{ "example-jukebox:year" : "2011" }
In this example the datastore resource has changed since the time
specified in the "If-Unmodified-Since" header. The server might
respond:
HTTP/1.1 412 Precondition Failed
Date: Mon, 23 Apr 2012 19:01:00 GMT
Server: example-server
Last-Modified: Mon, 23 Apr 2012 17:45:00 GMT
ETag: b34aed893a4c
D.3. Query Parameter Examples
D.3.1. "content" Parameter
The "content" parameter is used to select the type of data child
resources (configuration and/or not configuration) that are returned
by the server for a GET method request.
In this example, a simple YANG list that has configuration and non-
configuration child resources.
container events
list event {
key name;
leaf name { type string; }
leaf description { type string; }
leaf event-count {
type uint32;
config false;
}
}
}
Example 1: content=all
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To retrieve all the child resources, the "content" parameter is set
to "all". The client might send:
GET /restconf/data/example-events:events?content=all
HTTP/1.1
Host: example.com
Accept: application/yang.data+json,
application/yang.errors+json
The server might respond:
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2012 17:11:30 GMT
Server: example-server
Cache-Control: no-cache
Pragma: no-cache
Content-Type: application/yang.data+json
{
"example-events:events" : {
"event" : [
{
"name" : "interface-up",
"description" : "Interface up notification count",
"event-count" : 42
},
{
"name" : "interface-down",
"description" : "Interface down notification count",
"event-count" : 4
}
]
}
}
Example 2: content=config
To retrieve only the configuration child resources, the "content"
parameter is set to "config" or omitted since this is the default
value. Note that the "ETag" and "Last-Modified" headers are only
returned if the content parameter value is "config".
GET /restconf/data/example-events:events?content=config
HTTP/1.1
Host: example.com
Accept: application/yang.data+json,
application/yang.errors+json
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The server might respond:
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2012 17:11:30 GMT
Server: example-server
Last-Modified: Mon, 23 Apr 2012 13:01:20 GMT
ETag: eeeada438af
Cache-Control: no-cache
Pragma: no-cache
Content-Type: application/yang.data+json
{
"example-events:events" : {
"event" : [
{
"name" : "interface-up",
"description" : "Interface up notification count"
},
{
"name" : "interface-down",
"description" : "Interface down notification count"
}
]
}
}
Example 3: content=nonconfig
To retrieve only the non-configuration child resources, the "content"
parameter is set to "nonconfig". Note that configuration ancestors
(if any) and list key leafs (if any) are also returned. The client
might send:
GET /restconf/data/example-events:events?content=nonconfig
HTTP/1.1
Host: example.com
Accept: application/yang.data+json,
application/yang.errors+json
The server might respond:
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HTTP/1.1 200 OK
Date: Mon, 23 Apr 2012 17:11:30 GMT
Server: example-server
Cache-Control: no-cache
Pragma: no-cache
Content-Type: application/yang.data+json
{
"example-events:events" : {
"event" : [
{
"name" : "interface-up",
"event-count" : 42
},
{
"name" : "interface-down",
"event-count" : 4
}
]
}
}
D.3.2. "depth" Parameter
The "depth" parameter is used to limit the number of levels of child
resources that are returned by the server for a GET method request.
This example shows how different values of the "depth" parameter
would affect the reply content for retrieval of the top-level
"jukebox" data resource.
Example 1: depth=unbounded
To retrieve all the child resources, the "depth" parameter is not
present or set to the default value "unbounded". Note that some
strings are wrapped for display purposes only.
GET /restconf/data/example-jukebox:jukebox?depth=unbounded
HTTP/1.1
Host: example.com
Accept: application/yang.data+json,
application/yang.errors+json
The server might respond:
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2012 17:11:30 GMT
Server: example-server
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Cache-Control: no-cache
Pragma: no-cache
Content-Type: application/yang.data+json
{
"example-jukebox:jukebox" : {
"library" : {
"artist" : [
{
"name" : "Foo Fighters",
"album" : [
{
"name" : "Wasting Light",
"genre" : "example-jukebox:alternative",
"year" : 2011,
"song" : [
{
"name" : "Wasting Light",
"location" :
"/media/foo/a7/wasting-light.mp3",
"format" : "MP3",
"length" " 286
},
{
"name" : "Rope",
"location" : "/media/foo/a7/rope.mp3",
"format" : "MP3",
"length" " 259
}
]
}
]
}
]
},
"playlist" : [
{
"name" : "Foo-One",
"description" : "example playlist 1",
"song" : [
{
"index" : 1,
"id" : "http://example.com/restconf/data/
example-jukebox:jukebox/library/artist=
Foo%20Fighters/album/Wasting%20Light/
song/Rope"
},
{
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"index" : 2,
"id" : "http://example.com/restconf/data/
example-jukebox:jukebox/library/artist=
Foo%20Fighters/album/Wasting%20Light/song/
Bridge%20Burning"
}
]
}
],
"player" : {
"gap" : 0.5
}
}
}
Example 2: depth=1
To determine if 1 or more resource instances exist for a given target
resource, the value "1" is used.
GET /restconf/data/example-jukebox:jukebox?depth=1 HTTP/1.1
Host: example.com
Accept: application/yang.data+json,
application/yang.errors+json
The server might respond:
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2012 17:11:30 GMT
Server: example-server
Cache-Control: no-cache
Pragma: no-cache
Content-Type: application/yang.data+json
{
"example-jukebox:jukebox" : [null]
}
Example 3: depth=3
To limit the depth level to the target resource plus 2 child resource
layers the value "3" is used.
GET /restconf/data/example-jukebox:jukebox?depth=3 HTTP/1.1
Host: example.com
Accept: application/yang.data+json,
application/yang.errors+json
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The server might respond:
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2012 17:11:30 GMT
Server: example-server
Cache-Control: no-cache
Pragma: no-cache
Content-Type: application/yang.data+json
{
"example-jukebox:jukebox" : {
"library" : {
"artist" : [ null ]
},
"playlist" : [
{
"name" : "Foo-One",
"description" : "example playlist 1",
"song" : [ null ]
}
],
"player" : {
"gap" : 0.5
}
}
}
D.3.3. "select" Parameter
In this example the client is retrieving the API resource, but
selecting only the "name" and "revision" nodes from each module, in
JSON format:
GET /restconf/data?select=modules/module(name;revision) HTTP/1.1
Host: example.com
Accept: application/yang.data+json,
application/yang.errors+json
The server might respond as follows.
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HTTP/1.1 200 OK
Date: Mon, 23 Apr 2012 17:01:00 GMT
Server: example-server
Content-Type: application/yang.data+json
{
"ietf-yang-library:modules": {
"module": [
{
"name" : "example-jukebox",
"revision" : "2014-07-03"
},
{
"name" : "ietf-restconf-monitoring",
"revision" : "2014-10-25"
},
{
"name" : "ietf-yang-library",
"revision" : "2014-10-25"
}
]
}
}
D.3.4. "insert" Parameter
In this example, a new first entry in the "Foo-One" playlist is being
created.
Request from client:
POST /restconf/data/example-jukebox:jukebox/
playlist=Foo-One?insert=first HTTP/1.1
Host: example.com
Content-Type: application/yang.data+json
{
"example-jukebox:song" : {
"index" : 1,
"id" : "/example-jukebox:jukebox/library/
artist=Foo%20Fighters/album/Wasting%20Light/song/Rope"
}
}
Response from server:
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HTTP/1.1 201 Created
Date: Mon, 23 Apr 2012 13:01:20 GMT
Server: example-server
Last-Modified: Mon, 23 Apr 2012 13:01:20 GMT
Location: http://example.com/restconf/data/
example-jukebox:jukebox/playlist=Foo-One/song=1
ETag: eeeada438af
D.3.5. "point" Parameter
In this example, the client is inserting a new "song" resource within
an "album" resource after another song. The request URI is split for
display purposes only.
Request from client:
POST /restconf/data/example-jukebox:jukebox/
library/artist=Foo%20Fighters/album/Wasting%20Light?
insert=after&point=%2Fexample-jukebox%3Ajukebox%2F
library%2Fartist%2FFoo%20Fighters%2Falbum%2F
Wasting%20Light%2Fsong%2FBridge%20Burning HTTP/1.1
Host: example.com
Content-Type: application/yang.data+json
{
"example-jukebox:song" : {
"name" : "Rope",
"location" : "/media/foo/a7/rope.mp3",
"format" : "MP3",
"length" : 259
}
}
Response from server:
HTTP/1.1 204 No Content
Date: Mon, 23 Apr 2012 13:01:20 GMT
Server: example-server
Last-Modified: Mon, 23 Apr 2012 13:01:20 GMT
ETag: abcada438af
D.3.6. "limit" Parameter
In this example, the client requests the first two "album" resources
for a given artist:
Request from client:
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GET /restconf/data/example-jukebox:jukebox/
library/artist=Foo%20Fighters/album/?limit=2 HTTP/1.1
Host: example.com
Content-Type: application/yang.collection+xml
Response from server:
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2012 17:01:00 GMT
Server: example-server
Cache-Control: no-cache
Pragma: no-cache
Content-Type: application/yang.collection+xml
<collection xmlns="urn:ietf:params:xml:ns:yang:ietf-restconf"
<album xmlns="http://example.com/ns/example-jukebox">
<name>Foo Fighters</name>
<year>1995</year>
...
</album>
<album xmlns="http://example.com/ns/example-jukebox">
<name>The Color and the Shape</name>
<year>1997</year>
...
</album>
</collection>
D.3.7. "offset" Parameter
In this example, the client requests the next two albums, i.e., two
albums starting from two.
Request from client:
GET /restconf/data/example-jukebox:jukebox/
library/artist=Foo%20Fighters/album/?limit=2&offset=2 HTTP/1.1
Host: example.com
Content-Type: application/yang.collection+json
Response from server:
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HTTP/1.1 200 OK
Date: Mon, 23 Apr 2012 17:02:00 GMT
Server: example-server
Cache-Control: no-cache
Pragma: no-cache
Content-Type: application/yang.collection+json
{
"collection": {
"example-jukebox:album" : [
{
"year" : 1999,
"name" : "There is Nothing Left to Loose",
...
},
{
"year" : 2002,
"name" : "One by One",
...
}
]
}
}
D.3.8. "filter" Parameter
The following URIs show some examples of notification filter
specifications (lines wrapped for display purposes only):
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// filter = /event/event-class='fault'
GET /mystreams/NETCONF?filter=%2Fevent%2Fevent-class%3D'fault'
// filter = /event/severity<=4
GET /mystreams/NETCONF?filter=%2Fevent%2Fseverity%3C%3D4
// filter = /linkUp|/linkDown
GET /mystreams/SNMP?filter=%2FlinkUp%7C%2FlinkDown
// filter = /*/reporting-entity/card!='Ethernet0'
GET /mystreams/NETCONF?
filter=%2F*%2Freporting-entity%2Fcard%21%3D'Ethernet0'
// filter = /*/email-addr[contains(.,'company.com')]
GET /mystreams/critical-syslog?
filter=%2F*%2Femail-addr[contains(.%2C'company.com')]
// Note: the module name is used as prefix.
// filter = (/example-mod:event1/name='joe' and
// /example-mod:event1/status='online')
GET /mystreams/NETCONF?
filter=(%2Fexample-mod%3Aevent1%2Fname%3D'joe'%20and
%20%2Fexample-mod%3Aevent1%2Fstatus%3D'online')
D.3.9. "start-time" Parameter
// start-time = 2014-10-25T10:02:00Z
GET /mystreams/NETCONF?start-time=2014-10-25T10%3A02%3A00Z
D.3.10. "stop-time" Parameter
// stop-time = 2014-10-25T12:31:00Z
GET /mystreams/NETCONF?stop-time=2014-10-25T12%3A31%3A00Z
Authors' Addresses
Andy Bierman
YumaWorks
Email: andy@yumaworks.com
Martin Bjorklund
Tail-f Systems
Email: mbj@tail-f.com
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Kent Watsen
Juniper Networks
Email: kwatsen@juniper.net
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