| Network Working Group | A. Bierman |
| Internet-Draft | YumaWorks |
| Intended status: Standards Track | M. Bjorklund |
| Expires: April 30, 2017 | Tail-f Systems |
| K. Watsen | |
| Juniper Networks | |
| October 27, 2016 |
RESTCONF Protocol
draft-ietf-netconf-restconf-18
This document describes an HTTP-based protocol that provides a programmatic interface for accessing data defined in YANG, using the datastore concepts defined in NETCONF.
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There is a need for standard mechanisms to allow Web applications to access the configuration data, state data, data-model-specific RPC operations, and event notifications within a networking device, in a modular and extensible manner.
This document defines an HTTP [RFC7230] based protocol called RESTCONF, for configuring data defined in YANG version 1 [RFC6020] or YANG version 1.1 [RFC7950], using the datastore concepts defined in NETCONF [RFC6241].
NETCONF defines configuration datastores and a set of Create, Retrieve, Update, Delete (CRUD) operations that can be used to access these datastores. NETCONF also defines a protocol for invoking these operations. The YANG language defines the syntax and semantics of datastore content, configuration, state data, RPC operations, and event notifications.
RESTCONF uses HTTP methods to provide CRUD operations on a conceptual datastore containing YANG-defined data, which is compatible with a server which implements NETCONF datastores.
If a RESTCONF server is co-located with a NETCONF server, then there are protocol interactions with the NETCONF protocol, which are described in Section 1.4. The RESTCONF server MAY provide access to specific datastores using operation resources, as described in Section 3.6. The RESTCONF protocol does not specify any mandatory operation resources. The semantics of each operation resource determine if and how datastores are accessed.
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 PUT methods. Data is encoded with either XML [W3C.REC-xml-20081126] or JSON [RFC7159].
Data-model-specific RPC operations defined with the YANG "rpc" or "action" statements can be invoked with the POST method. Data-model-specific event notifications defined with the YANG "notification" statement can be accessed.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].
The following terms are defined in [RFC6241]:
The following terms are defined in [RFC3986]:
The following terms are defined in [RFC7230]:
The following terms are defined in [RFC7231]:
The following terms are defined in [RFC7232]:
The following terms are defined in [RFC7950]:
The following terms are defined in [RFC5277]:
The following terms are used within this document:
Throughout this document, the URI template [RFC6570] syntax "{+restconf}" is used to refer to the RESTCONF root resource outside of an example. See Section 3.1 for details.
For simplicity, all of the examples in this document use "/restconf" as the discovered RESTCONF API root path. Many of the examples throughout the document are based on the "example‑jukebox" YANG module, defined in Appendix C.1.
Many protocol header lines and message-body text within examples throughout the document are split into multiple lines for display purposes only. When a line ends with backslash ('\') as the last character, the line is wrapped for display purposes. It is to be considered to be joined to the next line by deleting the backslash, the following line break, and the leading whitespace of the next line.
A simplified graphical representation of the data model is used in this document. The meaning of the symbols in these diagrams is as follows:
RESTCONF does not need to mirror the full functionality of the NETCONF protocol, but it does need to be compatible with NETCONF. RESTCONF achieves this by implementing a subset of the interaction capabilities provided by the NETCONF protocol, for instance, by eliminating datastores and explicit locking.
RESTCONF uses HTTP methods to implement the equivalent of NETCONF operations, enabling basic CRUD operations on a hierarchy of conceptual resources.
The HTTP POST, PUT, PATCH, and DELETE methods are used to edit data resources represented by YANG data models. These basic edit operations allow the running configuration to be altered by a RESTCONF client.
RESTCONF is not intended to replace NETCONF, but rather provide an HTTP interface that follows Representational State Transfer (REST) principles [rest-dissertation], and is compatible with the NETCONF datastore model.
RESTCONF combines the simplicity of the HTTP protocol with the predictability and automation potential of a schema-driven API. Knowing the YANG modules used by the server, a client can derive all management resource URLs and the proper structure of all RESTCONF requests and responses. This strategy obviates the need for responses provided by the server to contain Hypermedia as the Engine of Application State (HATEOAS) links, originally described in Roy Fielding's doctoral dissertation [rest-dissertation], because the client can determine the links it needs from the YANG modules.
RESTCONF utilizes the YANG Library [RFC7895] to allow a client to discover the YANG module conformance information for the server, in case the client wants to use it.
The server can optionally support retrieval of the YANG modules it uses, as identified in its YANG library. See Section 3.7 for details.
The URIs for data-model-specific RPC operations and datastore content are predictable, based on the YANG module definitions.
The RESTCONF protocol operates on a conceptual datastore defined with the YANG data modeling language. The server lists each YANG module it supports using the "ietf‑yang‑library" YANG module, defined in [RFC7895]. The server MUST implement the "ietf‑yang‑library" module, which MUST identify all the YANG modules used by the server, in the "modules‑state/module" list. The conceptual datastore contents, data-model-specific RPC operations and event notifications are identified by this set of YANG modules.
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. Non-configuration data is also called "state data".
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 data resource within the datastore resource is activated upon successful completion of the edit.
RESTCONF can be implemented on a device that supports the NETCONF protocol.
The following figure shows the system components if a RESTCONF server is co-located with a NETCONF server:
+-----------+ +-----------------+
| Web app | <-------> | |
+-----------+ RESTCONF | network device |
| |
+-----------+ | +-----------+ |
| NETCONF | <-------> | | datastore | |
| Client | NETCONF | | | |
+-----------+ | +-----------+ |
+-----------------+
The following figure shows the system components if a RESTCONF server is implemented in a device that does not have a NETCONF server:
+-----------+ +-----------------+
| Web app | <-------> | |
+-----------+ RESTCONF | network device |
| |
+-----------------+
There are interactions between the NETCONF protocol and RESTCONF protocol related to edit operations. It is possible that locks are in use on a RESTCONF server, even though RESTCONF cannot manipulate locks. In such a case, the RESTCONF protocol will not be granted write access to data resources within a datastore.
If the NETCONF server supports :writable-running, all edits to configuration nodes in {+restconf}/data are performed in the running configuration datastore. The URI template "{+restconf}" is defined in Section 1.1.6.
Otherwise, if the device supports :candidate, all edits to configuration nodes in {+restconf}/data are performed in the candidate configuration datastore. The candidate MUST be automatically committed to running immediately after each successful edit. Any edits from other sources that are in the candidate datastore will also be committed. If a confirmed commit procedure is in progress by any NETCONF client, then any new commit will act as the confirming commit. If the NETCONF server is expecting a "persist‑id" parameter to complete the confirmed commit procedure then the RESTCONF edit operation MUST fail with a "409 Conflict" status-line. There error-tag "in‑use" is returned in this case. The error-tag value "resource‑denied" is used in this case.
If the NETCONF server supports :startup, the RESTCONF server MUST automatically update the non-volatile startup configuration datastore, after the running datastore has been altered as a consequence of a RESTCONF edit operation.
If a datastore that would be modified by a RESTCONF operation has an active lock from a NETCONF client, the RESTCONF edit operation MUST fail with a "409 Conflict" status-line. There error-tag "in‑use" is returned in this case.
There are two extensibility mechanisms built into RESTCONF:
This document defines version 1 of the RESTCONF protocol. If a future version of this protocol is defined, then that document will specify how the new version of RESTCONF is identified. It is expected that a different RESTCONF root resource will be used which will be located using a different link relation (See Section 3.1).
The server will advertise all protocol versions that it supports in its host-meta data.
In this example, the server supports both RESTCONF version 1 and a fictitious version 2.
The client might send:
GET /.well-known/host-meta HTTP/1.1 Host: example.com Accept: application/xrd+xml
The server might respond:
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'/>
<Link rel='restconf2' href='/restconf2'/>
</XRD>
RESTCONF also supports a server-defined list of optional capabilities, which are listed by a server using the "ietf‑restconf‑monitoring" module defined in Section 9.3. This document defines several query parameters in Section 4.8. Each optional parameter has a corresponding capability URI defined in Section 9.1.1 that is advertised by the server if supported.
The "capabilities" list can identify any sort of server extension. Currently this extension mechanism is used to identify optional query parameters that are supported, but it is not limited to that purpose. For example, the "defaults" URI defined in Section 9.1.2 specifies a mandatory URI identifying server defaults handling behavior.
A new sub-resource type could be identified with a capability if it is optional to implement. Mandatory protocol features and new resource types require a new revision of the RESTCONF protocol.
HTTP [RFC7230] is an application layer protocol that may be layered on any reliable transport-layer protocol. RESTCONF is defined on top of HTTP, but due to the sensitive nature of the information conveyed, RESTCONF requires that the transport-layer protocol provides both data integrity and confidentiality. A RESTCONF server MUST support the TLS protocol [RFC5246], and SHOULD adhere to [RFC7525]. The RESTCONF protocol MUST NOT be used over HTTP without using the TLS protocol.
RESTCONF does not require a specific version of HTTP. However, it is RECOMMENDED that at least HTTP/1.1 [RFC7230] be supported by all implementations.
Given the nearly ubiquitous support for HTTP over TLS [RFC7230], RESTCONF implementations MUST support the "https" URI scheme, which has the IANA assigned default port 443.
RESTCONF servers MUST present an X.509v3 based certificate when establishing a TLS connection with a RESTCONF client. The use of X.509v3 based certificates is consistent with NETCONF over TLS [RFC7589].
The RESTCONF client MUST either use X.509 certificate path validation [RFC5280] to verify the integrity of the RESTCONF server's TLS certificate, or match the server’s TLS certificate with a certificate obtained by a trusted mechanism (e.g., a pinned certificate). If X.509 certificate path validation fails, and the presented X.509 certificate does not match a certificate obtained by a trusted mechanism, the connection MUST be terminated, as described in Section 7.2.1 of [RFC5246].
The RESTCONF client MUST check the identity of the server according to Section 3.1 of [RFC2818].
The RESTCONF server MUST authenticate client access to any protected resource. If the RESTCONF client is not authenticated, the server SHOULD send an HTTP response with "401 Unauthorized" status-line, as defined in Section 3.1 of [RFC7235]. The error-tag value "access‑denied" is used in this case.
To authenticate a client, a RESTCONF server SHOULD require TLS client certificate based authentication (Section 7.4.6 of [RFC5246]). If certificate based authentication is not feasible (e.g., because one cannot build the required PKI for clients) then an HTTP authentication MAY be used. In the latter case, one of the HTTP authentication schemes defined in the HTTP Authentication Scheme Registry (Section 5.1 in [RFC7235]) MUST be used.
A server MAY also support the combination of both client certificates and an HTTP client authentication scheme, with the determination of how to process this combination left as an implementation decision.
The RESTCONF client identity derived from the authentication mechanism used is hereafter known as the "RESTCONF username" and subject to the NETCONF Access Control Module (NACM) [RFC6536]. When a client certificate is presented, the RESTCONF username MUST be derived using the algorithm defined in Section 7 of [RFC7589]. For all other cases, when HTTP authentication is used, the RESTCONF username MUST be provided by the HTTP authentication scheme used.
The RESTCONF protocol operates on a hierarchy of resources, starting with the top-level API resource itself (Section 3.1). Each resource represents a manageable component within the device.
A resource can be considered as a collection of 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 a representation associated with a media type identifier, as represented by the "Content‑Type" header field in the HTTP response message. A resource has one or more representations, each associated with a different media type. When a representation of a resource is sent in an HTTP message, the associated media type is given in the "Content‑Type" header. 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.
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 RPC operations, top-level data nodes, and event notification messages supported by the server.
The RESTCONF protocol does not include a data resource discovery mechanism. Instead, the definitions within the YANG modules advertised by the server are used to construct an RPC operation or data resource identifier.
In line with the best practices defined by [RFC7320], 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. There MUST be exactly one "restconf" link relation returned by the device.
The client discovers this by getting the "/.well‑known/host‑meta" resource ([RFC6415]) and using the <Link> element containing the "restconf" attribute :
Example returning /restconf:
The client might send:
GET /.well-known/host-meta HTTP/1.1 Host: example.com Accept: application/xrd+xml
The server might respond:
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>
After discovering the RESTCONF API root, the client MUST use this value as the initial part of the path in the request URI, in any subsequent request for a RESTCONF resource.
In this example, the client would use the path "/restconf" as the RESTCONF root resource.
Example returning /top/restconf:
The client might send:
GET /.well-known/host-meta HTTP/1.1 Host: example.com Accept: application/xrd+xml
The server might respond:
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='/top/restconf'/>
</XRD>
In this example, the client would use the path "/top/restconf" as the RESTCONF root resource.
The client can now determine the operation resources supported by the the server. In this example a custom "play" operation is supported:
The client might send:
GET /top/restconf/operations HTTP/1.1 Host: example.com Accept: application/yang-data+json
The server might respond:
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2016 17:01:00 GMT
Server: example-server
Cache-Control: no-cache
Last-Modified: Sun, 22 Apr 2016 01:00:14 GMT
Content-Type: application/yang-data+json
{ "operations" : { "example-jukebox:play" : [null] } }
If the Extensible Resource Descriptor (XRD) contains more than one link relation, then only the relation named "restconf" is relevant to this specification.
Note that any given endpoint (host:port) can only support one RESTCONF server, due to the root resource discovery mechanism. This limits the number of RESTCONF servers that can run concurrently on a host, since each server must use a different port.
The RESTCONF protocol defines two application specific media types to identify representations of data which conforms to the schema for a particular YANG construct.
This document defines media types for XML and JSON serialization of YANG data. Other documents MAY define other media types for different serializations of YANG data. The "application/yang‑data+xml" media-type is defined in Section 11.3.1. The "application/yang‑data+json" media-type is defined in Section 11.3.2.
The API resource contains the RESTCONF root resource for the RESTCONF datastore and operation resources. It is the top-level resource located at {+restconf} and has the media type "application/yang‑data+xml" or "application/yang‑data+json".
YANG Tree Diagram for an API Resource:
+---- {+restconf}
+---- data
| ...
+---- operations?
| ...
+--ro yang-library-version string
The "yang‑api" YANG data template is defined using the "yang‑data" extension in the "ietf‑restconf" module, found in Section 8. It specifies the structure and syntax of the conceptual child resources within the API resource.
The API resource can be retrieved with the GET method.
The {+restconf} root resource name used in responses representing the root of the "ietf‑restconf" module MUST identify the "ietf‑restconf" YANG module. For example, a request to GET the root resource "/restconf" in JSON format will return a representation of the API resource named "ietf‑restconf:restconf".
This resource has the following child resources:
| Child Resource | Description |
|---|---|
| data | Contains all data resources |
| operations | Data-model-specific operations |
| yang-library-version | ietf-yang-library module date |
This mandatory resource represents the combined configuration and state 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 3.4.
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 4.8.1).
GET /restconf/data/example-jukebox:jukebox/library\
?content=nonconfig HTTP/1.1
Host: example.com
Accept: application/yang-data+xml
The server might respond:
HTTP/1.1 200 OK Date: Mon, 23 Apr 2016 17:01:30 GMT Server: example-server Cache-Control: no-cache Content-Type: application/yang-data+xml
<library xmlns="https://example.com/ns/example-jukebox">
<artist-count>42</artist-count>
<album-count>59</album-count>
<song-count>374</song-count>
</library>
This optional resource is a container that provides access to the data-model-specific RPC operations supported by the server. The server MAY omit this resource if no data-model-specific RPC operations are advertised.
Any data-model-specific RPC operations defined in the YANG modules advertised by the server MUST be available as child nodes of this resource.
The access point for each RPC operation is represented as an empty leaf. If an operation resource is retrieved, the empty leaf representation is returned by the server.
Operation resources are defined in Section 3.6.
This mandatory leaf identifies the revision date of the "ietf‑yang‑library" YANG module that is implemented by this server. Note that the revision date for the module version found in [RFC7895] is used.
Example:
GET /restconf/yang-library-version HTTP/1.1 Host: example.com Accept: application/yang-data+xml
The server might respond:
HTTP/1.1 200 OK Date: Mon, 23 Apr 2016 17:01:30 GMT Server: example-server Cache-Control: no-cache Content-Type: application/yang-data+xml
<yang-library-version
xmlns="urn:ietf:params:xml:ns:yang:ietf-yang-library">\
2016-06-21\
</yang-library-version>
The "{+restconf}/data" subtree represents the datastore resource, which is a collection of configuration data and state data nodes.
This resource type is an abstraction of the system's underlying datastore implementation. The client uses it to edit and retrieve data resources, as the conceptual root of all configuration and state data that is present on the device.
Configuration edit transaction management and configuration persistence are handled by the server and not controlled by the client. A datastore resource can be written directly with the POST and PATCH methods. Each RESTCONF edit of a datastore resource is saved to non-volatile storage by the server, if the server supports non-volatile storage of configuration data, as described in Section 1.4.
If the datastore resource represented by the "{+restconf}/data" subtree is retrieved, then the datastore and its contents are returned by the server. The datastore is represented by a node named "data" in the "ietf‑restconf" module namespace.
Two edit collision detection and prevention mechanisms are provided in RESTCONF for the datastore resource: a timestamp and an entity-tag. Any change to configuration data resources updates the timestamp and entity tag of the datastore resource. In addition, the RESTCONF server MUST return an error if the datastore is locked by an external source (e.g., NETCONF server).
The last change time is maintained and the "Last‑Modified" ([RFC7232], Section 2.2) header field is returned in the response for a retrieval request. The "If‑Unmodified‑Since" header field ([RFC7232], Section 3.4) 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 SHOULD maintain a last-modified timestamp for the datastore resource, defined in Section 3.4. This timestamp is only affected by configuration child data resources, and MUST NOT be updated for changes to non-configuration child data resources. Last-modified timestamps for data resources are discussed in Section 3.5.
If the RESTCONF server is colocated with a NETCONF server, then the last-modified timestamp MUST be for the "running" datastore. Note that it is possible other protocols can cause the last-modified timestamp to be updated. Such mechanisms are out of scope for this document.
The server MUST maintain a unique opaque entity-tag for the datastore resource and MUST return it in the "ETag" ([RFC7232], Section 2.3) header in the response for a retrieval request. The client MAY use an "If‑Match" header 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 an entity-tag for the top-level {+restconf}/data resource. This entity-tag is only affected by configuration data resources, and MUST NOT be updated for changes to non-configuration data. Entity-tags for data resources are discussed in Section 3.5. Note that each representation (e.g., XML vs. JSON) requires a different entity-tag.
If the RESTCONF server is colocated with a NETCONF server, then this entity-tag MUST be for the "running" datastore. Note that it is possible other protocols can cause the entity-tag to be updated. Such mechanisms are out of scope for this document.
Changes to configuration data resources affect the timestamp and entity-tag for that resource, any ancestor data resources, and the datastore resource.
For example, an edit to disable an interface might be done by setting the leaf "/interfaces/interface/enabled" to "false". The "enabled" data node and its ancestors (one "interface" list instance, and the "interfaces" container) are considered to be changed. The datastore is considered to be changed when any top-level configuration data node is changed (e.g., "interfaces").
A data resource represents a YANG data node that is a descendant node of a datastore resource. Each YANG-defined data node can be uniquely targeted by the request-line of an HTTP method. Containers, leafs, leaf-list entries, list entries, anydata and anyxml nodes are data resources.
The representation maintained for each data resource is the YANG defined subtree for that node. HTTP methods on a data resource affect both the targeted data node and all its descendants, if any.
A data resource can be retrieved with the GET method. Data resources are accessed via the "{+restconf}/data" URI. This sub-tree is used to retrieve and edit data resources.
For configuration data resources, the server MAY maintain a last-modified timestamp for the resource, and return the "Last‑Modified" header field when it is retrieved with the GET or HEAD methods.
The "Last‑Modified" header field can be used by a RESTCONF client in subsequent requests, within the "If‑Modified‑Since" and "If‑Unmodified‑Since" header fields.
If maintained, the resource timestamp MUST be set to the current time whenever the resource or any configuration resource within the resource is altered. If not maintained, then the resource timestamp for the datastore MUST be used instead. If the RESTCONF server is colocated with a NETCONF server, then the last-modified timestamp for a configuration data resource MUST represent the instance within the "running" datastore.
This timestamp is only affected by configuration data resources, and MUST NOT be updated for changes to non-configuration data.
For configuration data resources, the server SHOULD maintain a resource entity-tag for each resource, and return the "ETag" header field 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. If not maintained, then the resource entity-tag for the datastore MUST be used instead.
The "ETag" header field can be used by a RESTCONF client in subsequent requests, within the "If‑Match" and "If‑None‑Match" header fields.
This entity-tag is only affected by configuration data resources, and MUST NOT be updated for changes to non-configuration data. If the RESTCONF server is colocated with a NETCONF server, then the entity-tag for a configuration data resource MUST represent the instance within the "running" datastore.
In YANG, data nodes can be identified with an absolute XPath expression, defined in [XPath], starting from the document root to the target resource. In RESTCONF, URI-encoded path expressions are used instead.
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 encoded from left to right, starting with the top-level data node, according to the "api‑path" rule in Section 3.5.3.1. 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 node in the path is defined in another module than its parent node, or its parent is the datastore, then the module name followed by a colon character (":") MUST be prepended to the node name in the resource identifier. See Section 3.5.3.1 for details.
If a data node in the path expression is a YANG leaf-list node, then the leaf-list value MUST be encoded according to the following rules:
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:
Examples:
container top {
list list1 {
key "key1 key2 key3";
...
list list2 {
key "key4 key5";
...
leaf X { type string; }
}
}
leaf-list Y {
type uint32;
}
}
For the above YANG definition, the container "top" is defined in the "example‑top" YANG module, and a target resource URI for leaf "X" would be encoded as follows:
/restconf/data/example-top:top/list1=key1,key2,key3/\
list2=key4,key5/X
For the above YANG definition, a target resource URI for leaf-list "Y" would be encoded as follows:
/restconf/data/example-top:top/Y=instance-value
The following example shows how reserved characters are percent-encoded within a key value. The value of "key1" contains a comma, single-quote, double-quote, colon, double-quote, space, and forward slash. (,'":" /). Note that double-quote is not a reserved character and does not need to be percent-encoded. The value of "key2" is the empty string, and the value of "key3" is the string "foo".
Example URL:
/restconf/data/example-top:top/list1=%2C%27"%3A"%20%2F,,foo
The "api‑path" Augmented Backus-Naur Form (ABNF) syntax is used to construct RESTCONF path identifiers. Note that this syntax is used for all resources, and the API path starts with the RESTCONF root resource. Data resources are required to be identified under the subtree "+{restconf}/data".
An identifier is not allowed to start with the case-insensitive string "XML", according to YANG identifier rules. The syntax for "api‑identifier" and "key‑value" MUST conform to the JSON identifier encoding rules in Section 4 of [RFC7951]: The RESTCONF root resource path is required. Additional sub-resource identifiers are optional. The characters in a key value string are constrained, and some characters need to be percent-encoded, as described in Section 3.5.3.
api-path = root *("/" (api-identifier / list-instance))
root = string ;; replacement string for {+restconf}
api-identifier = [module-name ":"] identifier
module-name = identifier
list-instance = api-identifier "=" key-value *("," key-value)
key-value = string ;; constrained chars are percent-encoded
string = <an unquoted string>
identifier = (ALPHA / "_")
*(ALPHA / DIGIT / "_" / "-" / ".")
RESTCONF requires that a server report its default handling mode (see Section 9.1.2 for details). If the optional "with‑defaults" query parameter is supported by the server, a client may use it to control retrieval of default values (see Section 4.8.9 for details).
If a leaf or leaf-list is missing from the configuration and there is a YANG-defined default for that data resource, then the server MUST use the YANG-defined default as the configured value.
If the target of a GET method is a data node that represents a leaf or leaf-list that has a default value, and the leaf or leaf-list has not been instantiated yet, the server MUST return the default value(s) that are in use by the server. In this case, the server MUST ignore its basic-mode, described in Section 4.8.9, and return the default value.
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, in accordance with its reported default handing mode and query parameters passed by the client.
An operation resource represents an RPC operation defined with the YANG "rpc" statement or a data-model-specific action defined with a YANG "action" statement. It is invoked using a POST method on the operation resource.
An RPC operation is invoked as:
POST {+restconf}/operations/<operation>
The <operation> field identifies the module name and rpc identifier string for the desired operation.
For example, if "module‑A" defined a "reset" rpc operation, then invoking the operation would be requested as follows:
POST /restconf/operations/module-A:reset HTTP/1.1 Server: example.com
An action is invoked as:
POST {+restconf}/data/<data-resource-identifier>/<action>
where <data‑resource‑identifier> contains the path to the data node where the action is defined, and <action> is the name of the action.
For example, if "module‑A" defined a "reset‑all" action in the container "interfaces", then invoking this action would be requested as follows:
POST /restconf/data/module-A:interfaces/reset-all HTTP/1.1 Server: example.com
If the RPC operation is invoked without errors, and if the "rpc" or "action" statement has no "output" section, the response message MUST NOT include a message-body, and MUST send a "204 No Content" status-line instead.
All operation resources representing RPC operations supported by the server MUST be identified in the {+restconf}/operations subtree defined in Section 3.3.2. Operation resources representing YANG actions are not identified in this subtree since they are invoked using a URI within the {+restconf}/data subtree.
If the "rpc" or "action" statement has an "input" section then instances of these input parameters are encoded in the module namespace where the "rpc" or "action" statement is defined, in an XML element or JSON object named "input", which is in the module namespace where the "rpc" or "action" statement is defined.
If the "rpc" or "action" statement has an "input" section and the "input" object tree contains any child data nodes which are considered mandatory nodes, then a message-body MUST be sent by the client in the request.
If the "rpc" or "action" statement has an "input" section and the "input" object tree does not contain any child nodes which are considered mandatory nodes, then a message-body MAY be sent by the client in the request.
If the "rpc" or "action" statement has no "input" section, the request message MUST NOT include a message-body.
Examples:
The following YANG module is used for the RPC operation examples in this section.
module example-ops {
namespace "https://example.com/ns/example-ops";
prefix "ops";
organization "Example, Inc.";
contact "support at example.com";
description "Example Operations Data Model Module";
revision "2016-07-07" {
description "Initial version.";
reference "example.com document 3-3373";
}
rpc reboot {
input {
leaf delay {
units seconds;
type uint32;
default 0;
}
leaf message { type string; }
leaf language { type string; }
}
}
rpc get-reboot-info {
output {
leaf reboot-time {
units seconds;
type uint32;
}
leaf message { type string; }
leaf language { type string; }
}
}
}
The following YANG module is used for the YANG action examples in this section.
module example-actions {
yang-version 1.1;
namespace "https://example.com/ns/example-actions";
prefix "act";
import ietf-yang-types { prefix yang; }
organization "Example, Inc.";
contact "support at example.com";
description "Example Actions Data Model Module";
revision "2016-07-07" {
description "Initial version.";
reference "example.com document 2-9973";
}
revision "2016-03-10";
container interfaces {
list interface {
key name;
leaf name { type string; }
action reset {
input {
leaf delay {
units seconds;
type uint32;
default 0;
}
}
}
action get-last-reset-time {
output {
leaf last-reset {
type yang:date-and-time;
mandatory true;
}
}
}
}
}
}
RPC Input Example:
The client might send the following POST request message to invoke the "reboot" RPC operation:
POST /restconf/operations/example-ops:reboot HTTP/1.1 Host: example.com Content-Type: application/yang-data+xml
<input xmlns="https://example.com/ns/example-ops">
<delay>600</delay>
<message>Going down for system maintenance</message>
<language>en-US</language>
</input>
The server might respond:
HTTP/1.1 204 No Content Date: Mon, 25 Apr 2016 11:01:00 GMT Server: example-server
The same example request message is shown here using JSON encoding:
POST /restconf/operations/example-ops:reboot HTTP/1.1
Host: example.com
Content-Type: application/yang-data+json
{
"example-ops:input" : {
"delay" : 600,
"message" : "Going down for system maintenance",
"language" : "en-US"
}
}
Action Input Example:
The client might send the following POST request message to invoke the "reset" action:
POST /restconf/data/example-actions:interfaces/\
interface=eth0/reset HTTP/1.1
Host: example.com
Content-Type: application/yang-data+xml
<input xmlns="https://example.com/ns/example-actions">
<delay>600</delay>
</input>
The server might respond:
HTTP/1.1 204 No Content Date: Mon, 25 Apr 2016 11:01:00 GMT Server: example-server
The same example request message is shown here using JSON encoding:
POST /restconf/data/example-actions:interfaces/\
interface=eth0/reset HTTP/1.1
Host: example.com
Content-Type: application/yang-data+json
{ "example-actions:input" : {
"delay" : 600
}
}
If the "rpc" or "action" statement has an "output" section then instances of these output parameters are encoded in the module namespace where the "rpc" or "action" statement is defined, in an XML element or JSON object named "output", which is in the module namespace where the "rpc" or "action" statement is defined.
If the RPC operation is invoked without errors, and if the "rpc" or "action" statement has an "output" section and the "output" object tree contains any child data nodes which are considered mandatory nodes, then a response message-body MUST be sent by the server in the response.
If the RPC operation is invoked without errors, and if the "rpc" or "action" statement has an "output" section and the "output" object tree does not contain any child nodes which are considered mandatory nodes, then a response message-body MAY be sent by the server in the response.
The request URI is not returned in the response. Knowledge of the request URI may be needed to associate the output with the specific "rpc" or "action" statement used in the request.
Examples:
RPC Output Example:
The "example‑ops" YANG module defined in Section 3.6.1 is used for this example.
The client might send the following POST request message to invoke the "get‑reboot‑info" operation:
POST /restconf/operations/example-ops:get-reboot-info HTTP/1.1 Host: example.com Accept: application/yang-data+json
The server might respond:
HTTP/1.1 200 OK
Date: Mon, 25 Apr 2016 11:10:30 GMT
Server: example-server
Content-Type: application/yang-data+json
{
"example-ops:output" : {
"reboot-time" : 30,
"message" : "Going down for system maintenance",
"language" : "en-US"
}
}
The same response is shown here using XML encoding:
HTTP/1.1 200 OK Date: Mon, 25 Apr 2016 11:10:30 GMT Server: example-server Content-Type: application/yang-data+xml
<output xmlns="https://example.com/ns/example-ops">
<reboot-time>30</reboot-time>
<message>Going down for system maintenance</message>
<language>en-US</language>
</output>
Action Output Example:
The "example‑actions" YANG module defined in Section 3.6.1 is used for this example.
The client might send the following POST request message to invoke the "get‑last‑reset‑time" action:
POST /restconf/data/example-actions:interfaces/\
interface=eth0/get-last-reset-time HTTP/1.1
Host: example.com
Accept: application/yang-data+json
The server might respond:
HTTP/1.1 200 OK
Date: Mon, 25 Apr 2016 11:10:30 GMT
Server: example-server
Content-Type: application/yang-data+json
{
"example-actions:output" : {
"last-reset" : "2015-10-10T02:14:11Z"
}
}
If any errors occur while attempting to invoke the operation or action, then an "errors" media type is returned with the appropriate error status.
If the RPC operation input is not valid, or the RPC operation is invoked but errors occur, then a message-body MUST be sent by the server, containing an "errors" resource, as defined in Section 3.9. A detailed example of an operation resource error response can be found in Section 3.6.3.
Using the "reboot" RPC operation from the example in Section 3.6.1, 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-data+xml
<input xmlns="https://example.com/ns/example-ops">
<delay>-33</delay>
<message>Going down for system maintenance</message>
<language>en-US</language>
</input>
The server might respond with an "invalid‑value" error:
HTTP/1.1 400 Bad Request Date: Mon, 25 Apr 2016 11:10:30 GMT Server: example-server Content-Type: application/yang-data+xml
<errors xmlns="urn:ietf:params:xml:ns:yang:ietf-restconf">
<error>
<error-type>protocol</error-type>
<error-tag>invalid-value</error-tag>
<error-path xmlns:ops="https://example.com/ns/example-ops">
/ops:input/ops:delay
</error-path>
<error-message>Invalid input parameter</error-message>
</error>
</errors>
The same response is shown here in JSON encoding:
HTTP/1.1 400 Bad Request
Date: Mon, 25 Apr 2016 11:10:30 GMT
Server: example-server
Content-Type: application/yang-data+json
{ "ietf-restconf:errors" : {
"error" : [
{
"error-type" : "protocol",
"error-tag" : "invalid-value",
"error-path" : "/example-ops:input/delay",
"error-message" : "Invalid input parameter",
}
]
}
}
The server can optionally support retrieval of the YANG modules it supports. If retrieval is supported, then the "schema" leaf MUST be present in the associated "module" list entry, defined in [RFC7895].
To retrieve a YANG module, a client first needs to get the URL for retrieving the schema, which is stored in the "schema" leaf. Note that there is no required structure for this URL. The URL value shown below is just an example.
The client might send the following GET request message:
GET /restconf/data/ietf-yang-library:modules-state/\
module=example-jukebox,2016-08-15/schema HTTP/1.1
Host: example.com
Accept: application/yang-data+json
The server might respond:
HTTP/1.1 200 OK
Date: Thu, 11 Feb 2016 11:10:30 GMT
Server: example-server
Content-Type: application/yang-data+json
{
"ietf-yang-library:schema" :
"https://example.com/mymodules/example-jukebox/2016-08-15"
}
Next the client needs to retrieve the actual YANG schema.
The client might send the following GET request message:
GET https://example.com/mymodules/example-jukebox/\
2016-08-15 HTTP/1.1
Host: example.com
Accept: application/yang
The server might respond:
HTTP/1.1 200 OK
Date: Thu, 11 Feb 2016 11:10:31 GMT
Server: example-server
Content-Type: application/yang
module example-jukebox {
// contents of YANG module deleted for this example...
}
An "event 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 6.3.
An event 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 the stream resources.
The "errors" YANG data template models 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. It is not considered as a resource type because no instances can be retrieved with a GET request.
The "ietf‑restconf" YANG module contains the "yang‑errors" YANG data template, that specifies the syntax and semantics of an "errors" container within a RESTCONF response. RESTCONF error handling behavior is defined in Section 7.
The RESTCONF protocol uses HTTP methods to identify the CRUD operations requested for a particular resource.
The following table shows how the RESTCONF operations relate to NETCONF protocol operations and for the NETCONF <edit‑config> operation, the "nc:operation" attribute.
| RESTCONF | NETCONF |
|---|---|
| OPTIONS | none |
| HEAD | none |
| GET | <get-config>, <get> |
| POST | <edit-config> (nc:operation="create") |
| POST | invoke an RPC operation |
| PUT | <edit-config> (nc:operation="create/replace") |
| PATCH | <edit-config> (nc:operation="merge") |
| DELETE | <edit-config> (nc:operation="delete") |
The "remove" edit operation attribute for the NETCONF <edit‑config> RPC operation is not supported by the HTTP DELETE method. The resource must exist or the DELETE method will fail. The PATCH method is equivalent to a "merge" edit operation when using a plain patch (see Section 4.6.1); other media-types may provide more granular control.
Access control mechanisms are used to limit what CRUD 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. 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 RESTCONF operation for any resources that the client is not authorized to access.
Implementation of all methods (except PATCH [RFC5789]) are defined in [RFC7231]. This section defines the RESTCONF protocol usage for each HTTP method.
The OPTIONS method is sent by the client to discover which methods are supported by the server for a specific resource (e.g., GET, POST, DELETE, etc.). The server MUST implement this method.
The "Accept‑Patch" header field MUST be supported and returned in the response to the OPTIONS request, as defined in [RFC5789].
The RESTCONF server MUST support the HEAD method. The HEAD method is sent by the client to retrieve just the header fields (which contain the metadata for a resource) that would be returned for the comparable GET method, without the response message-body. It is supported for all resources that support the GET method.
The request MUST contain a request URI that contains at least the root resource. 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 message-body is included.
The RESTCONF server MUST support the GET method. The GET method is sent by the client to retrieve data and metadata 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 root resource.
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 "401 Unauthorized" status-line SHOULD be returned. The error-tag value "access‑denied" is returned in this case. A server MAY return a "404 Not Found" status-line, as described in section 6.5.3 in [RFC7231]. The error-tag value "invalid‑value" is returned in this case.
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.
If any content is returned to the client, then the server MUST send a valid response message-body. More than one element MUST NOT be returned for XML encoding. If multiple elements are sent in a JSON message-body, then they MUST be sent as a JSON array. In this case any timestamp or entity-tag returned in the response MUST be associated with the first element returned.
If a retrieval request for a data resource representing a YANG leaf-list or list object identifies more than one instance, and XML encoding is used in the response, then an error response containing a "400 Bad Request" status-line MUST be returned by the server. The error-tag value "invalid‑value" is used in this case. Note that a non-configuration list is not required to defined any keys. In this case, retrieval of a single list instance is not possible.
If a retrieval request for a data resource represents an instance that does not exist, then an error response containing a "404 Not Found" status-line MUST be returned by the server. The error-tag value "invalid‑value" is used in this case.
If the target resource of a retrieval request is for an operation resource then a "405 Method Not Allowed" status-line MUST be returned by the server. The error-tag value "operation‑not‑supported" is used in this case.
Note that the way that access control is applied to data resources may not be completely compatible with HTTP caching. The Last-Modified and ETag header fields maintained for a data resource are not affected by changes to the access control rules for that data resource. It is possible for the representation of a data resource that is visible to a particular client to be changed without detection via the Last-Modified or ETag values.
Example:
The client might request the response header fields for an XML representation of the a specific "album" resource:
GET /restconf/data/example-jukebox:jukebox/\
library/artist=Foo%20Fighters/album=Wasting%20Light HTTP/1.1
Host: example.com
Accept: application/yang-data+xml
The server might respond:
HTTP/1.1 200 OK Date: Mon, 23 Apr 2016 17:02:40 GMT Server: example-server Content-Type: application/yang-data+xml Cache-Control: no-cache ETag: "a74eefc993a2b" Last-Modified: Mon, 23 Apr 2016 11:02:14 GMT
<album xmlns="http://example.com/ns/example-jukebox"
xmlns:jbox="http://example.com/ns/example-jukebox">
<name>Wasting Light</name>
<genre>jbox:alternative</genre>
<year>2011</year>
</album>
Refer to Appendix D.1 for more resource retrieval examples.
The RESTCONF server MUST support the POST method. The POST method is sent by the client to create a data resource or invoke an operation resource. The server uses the target resource 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 an RPC operation |
If the target resource type is a datastore or data resource, then the POST is treated as a request to create a top-level resource or child resource, respectively. The message-body is expected to contain the content of a child resource to create within the parent (target resource). The message-body MUST contain exactly one instance of the expected data resource. The data-model for the child tree is the subtree as defined by YANG for the child resource.
The "insert" Section 4.8.5 and "point" Section 4.8.6 query parameters MUST be supported by the POST method for datastore and data resources. These parameters are only allowed if the list or leaf-list is ordered-by user.
If the POST method succeeds, a "201 Created" status-line is returned and there is no response message-body. A "Location" header field identifying the child resource that was created MUST be present in the response in this case.
If the data resource already exists, then the POST request MUST fail and a "409 Conflict" status-line MUST be returned. The error-tag value "resource‑denied" is used in this case.
If the user is not authorized to create the target resource, an error response containing a "403 Forbidden" status-line SHOULD be returned. The error-tag value "access‑denied" is used in this case. A server MAY return a "404 Not Found" status-line, as described in section 6.5.3 in [RFC7231]. The error-tag value "invalid‑value" is used in this case. All other error responses are handled according to the procedures defined in Section 7.
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" : {} }
If the resource is created, the server might respond as follows:
HTTP/1.1 201 Created
Date: Mon, 23 Apr 2016 17:01:00 GMT
Server: example-server
Location: https://example.com/restconf/data/\
example-jukebox:jukebox
Last-Modified: Mon, 23 Apr 2016 17:01:00 GMT
ETag: "b3a3e673be2"
Refer to Appendix D.2.1 for more resource creation examples.
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 3.6 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" status-line SHOULD be returned. The error-tag value "access‑denied" is used in this case. A server MAY return a "404 Not Found" status-line, as described in section 6.5.3 in [RFC7231]. All other error responses are handled according to the procedures defined in Section 7.
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-data+json
{
"example-jukebox:input" : {
"playlist" : "Foo-One",
"song-number" : 2
}
}
The server might respond:
HTTP/1.1 204 No Content Date: Mon, 23 Apr 2016 17:50:00 GMT Server: example-server
The RESTCONF server MUST support the PUT method. The PUT method is sent by the client to create or replace the target data resource. A request message-body MUST be present, representing the new data resource, or the server MUST return "400 Bad Request" status-line. The error-tag value "invalid‑value" is used in this case.
Both the POST and PUT methods can be used to create data resources. The difference is that for POST, the client does not provide the resource identifier for the resource that will be created. The target resource for the POST method for resource creation is the parent of the new resource. The target resource for the PUT method for resource creation is the new resource.
The PUT method MUST be supported for data and datastore resources. A PUT on the datastore resource is used to replace the entire contents of the datastore. A PUT on a data resource only replaces that data resource within the datastore.
The "insert" (Section 4.8.5) and "point" (Section 4.8.6) query parameters MUST be supported by the PUT method for data resources. These parameters are only allowed if the list or leaf-list is ordered-by user.
Consistent with [RFC7231], if the PUT request creates a new resource, a "201 Created" status-line is returned. If an existing resource is modified, a "204 No Content" status-line is returned.
If the user is not authorized to create or replace the target resource an error response containing a "403 Forbidden" status-line SHOULD be returned. The error-tag value "access‑denied" is used in this case.
A server MAY return a "404 Not Found" status-line, as described in section 6.5.3 in ^RFC7231^. The error-tag value "invalid-value" is used in this case. All other error responses are handled according to the procedures defined in ^error-reporting^.
If the target resource represents a YANG leaf-list, then the PUT method MUST NOT change the value of the leaf-list instance.
If the target resource represents a YANG list instance, then the key leaf values in message-body representation MUST be the same as the key leaf values in the request URI. The PUT method MUST NOT be used to change the key leaf values for a data resource instance.
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:
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:
HTTP/1.1 204 No Content Date: Mon, 23 Apr 2016 17:04:00 GMT Server: example-server Last-Modified: Mon, 23 Apr 2016 17:04:00 GMT ETag: "b27480aeda4c"
The same request is shown here using XML encoding:
PUT /restconf/data/example-jukebox:jukebox/\
library/artist=Foo%20Fighters/album=Wasting%20Light HTTP/1.1
Host: example.com
Content-Type: application/yang-data+xml
<album xmlns="http://example.com/ns/example-jukebox"
xmlns:jbox="http://example.com/ns/example-jukebox">
<name>Wasting Light</name>
<genre>jbox:alternative</genre>
<year>2011</year>
</album>
Refer to Appendix D.2.4 for an example using the PUT method to replace the contents of the datastore resource.
The RESTCONF server MUST support the PATCH method for a plain patch, and MAY support additional media types. The PATCH media types supported by a server can be discovered by the client by sending an OPTIONS request, and examining the Accept-Patch header field in the response. (see Section 4.1).
RESTCONF uses the HTTP PATCH method defined in [RFC5789] to provide an extensible framework for resource patching mechanisms. Each patch mechanism needs a unique media type.
This document defines one patch mechanism (Section 4.6.1). Another patch mechanism, the YANG PATCH mechanism, is defined in [I-D.ietf-netconf-yang-patch]. Other patch mechanisms may be defined by future specifications.
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" status-line SHOULD be returned. A server MAY return a "404 Not Found" status-line, as described in section 6.5.3 in [RFC7231]. The error-tag value "invalid‑value" is used in this case. All other error responses are handled according to the procedures defined in Section 7.
The plain patch mechanism merges the contents of the message-body with the target resource. The message-body for a plain patch MUST be present and MUST be represented by the media type "application/yang‑data+xml" or "application/yang‑data+json".
Plain patch can be used to create or update, but not delete, a child resource within the target resource. Please see [I-D.ietf-netconf-yang-patch] for an alternate media-type supporting the ability to delete child resources. The YANG Patch Media Type allows multiple sub-operations (e.g., merge, delete) within a single PATCH method.
If the target resource represents a YANG leaf-list, then the PATCH method MUST NOT change the value of the leaf-list instance.
If the target resource represents a YANG list instance, then the key leaf values in message-body representation MUST be the same as the key leaf values in the request URI. The PATCH method MUST NOT be used to change the key leaf values for a data resource instance.
After the plain patch is processed by the server a response will be returned to the client, as specified in Section 4.6.
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.
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">
<year>2011</year>
</album>
If the field is updated, the server might respond:
HTTP/1.1 204 No Content Date: Mon, 23 Apr 2016 17:49:30 GMT Server: example-server Last-Modified: Mon, 23 Apr 2016 17:49:30 GMT ETag: "b2788923da4c"
The RESTCONF server MUST support the DELETE method. The DELETE method is used to delete the target resource. If the DELETE request succeeds, a "204 No Content" status-line is returned.
If the user is not authorized to delete the target resource then an error response containing a "403 Forbidden" status-line SHOULD be returned. The error-tag value "access‑denied" is returned in this case. A server MAY return a "404 Not Found" status-line, as described in section 6.5.3 in [RFC7231]. The error-tag value "invalid‑value" is returned in this case. All other error responses are handled according to the procedures defined in Section 7.
If the target resource represents a configuration leaf-list or list data node, then it MUST represent a single YANG leaf-list or list instance. The server MUST NOT use the DELETE method to delete more than one such instance.
Example:
To delete the "album" resource with the key "Wasting Light", 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 2016 17:49:40 GMT Server: example-server
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, HEAD | Select config and/or non-config data resources |
| depth | GET, HEAD | Request limited sub-tree depth in the reply content |
| fields | GET, HEAD | Request a subset of the target resource contents |
| filter | GET, HEAD | Boolean notification filter for event stream resources |
| insert | POST, PUT | Insertion mode for ordered-by user data resources |
| point | POST, PUT | Insertion point for ordered-by user data resources |
| start-time | GET, HEAD | Replay buffer start time for event stream resources |
| stop-time | GET, HEAD | Replay buffer stop time for event stream resources |
| with-defaults | GET, HEAD | Control retrieval of default values |
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.
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" status-line is returned if used for other methods or resource types.
If this query parameter is not present, the default value is "all". This query parameter MUST be supported by the server.
The "depth" parameter is used to limit the depth of subtrees returned by the server. Data nodes with a depth value greater than the "depth" parameter are not returned in a response for a GET method.
The requested data node has a depth level of '1'. If the "fields" parameter (Section 4.8.3) is used to select descendant data nodes, then these nodes and all their ancestor nodes have a depth value of 1. (This has the effect of including the nodes specified by the fields, even if the "depth" value is less than the actual depth level of the specified fields.) Any other child node has 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" status-line 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. The exception is the datastore resource. If this resource type is retrieved then by default the datastore and all child data resources are returned.
If the "depth" query parameter URI is listed in the "capability" leaf-list in Section 9.3, then the server supports the "depth" query parameter.
The "fields" 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.
The server will return a message-body representing the target resource, with descendant nodes pruned as specified in the "fields‑expr" value. The server does not return a set of separate sub-resources.
A value of the "fields" query parameter matches the following rule:
fields-expr = path '(' fields-expr ')' /
path ';' fields-expr /
path
path = api-identifier [ '/' path ]
"api‑identifier" is defined in Section 3.5.3.1.
";" is used to select multiple nodes. For example, to retrieve only the "genre" and "year" of an album, use: "fields=genre;year".
Parentheses are used to specify sub-selectors of a node. Note that there is no path separator character '/' between a "path" field and left parenthesis character '('.
For example, assume the target resource is the "album" list. To retrieve only the "label" and "catalogue‑number" of the "admin" container within an album, use: "fields=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: "fields=admin/label".
This parameter is only allowed for GET methods on api, datastore, and data resources. A "400 Bad Request" status-line is returned if used for other methods or resource types.
If the "fields" query parameter URI is listed in the "capability" leaf-list in Section 9.3, then the server supports the "fields" 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 an event stream resource. A "400 Bad Request" status-line is returned if used for other methods or resource types.
The format of this parameter is an XPath 1.0 expression [XPath], and is evaluated in the following context:
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 event notification is delivered to the client.
If the "filter" query parameter URI is listed in the "capability" leaf-list in Section 9.3, then the server supports the "filter" query parameter.
The "insert" parameter is used to specify how a resource should be inserted within a ordered-by user 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 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" status-line is returned.
The "insert" query parameter MUST be supported by the server.
The "point" parameter is used to specify the insertion point for a data resource that is being created or moved within an ordered-by user list or leaf-list.
The value of the "point" parameter is a string that identifies the path to the insertion point object. The format is the same as a target resource URI string.
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 user.
If the "insert" query parameter is not present, or has a value other than "before" or "after", then a "400 Bad Request" status-line is returned.
This parameter contains the instance identifier of the resource to be used as the insertion point for a POST or PUT method.
The "point" query parameter MUST be supported by the server.
The "start‑time" parameter is used to trigger the notification replay feature defined in [RFC5277] 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 a "400 Bad Request" status-line.
The value of the "start‑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" status-line 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. A client can obtain a server's current time by examining the "Date" header field that the server returns in response messages, according to [RFC7231].
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 9.3, anf the "stop‑time" query parameter MUST also be supported by the server.
If the "replay‑support" leaf has the value 'true' in the "stream" entry (defined in Section 9.3) then the server MUST support the "start‑time" and "stop‑time" query parameters for that stream.
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" status-line 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 9.3, and 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 9.3) then the server MUST support the "start‑time" and "stop‑time" query parameters for that stream.
The "with‑defaults" parameter is used to specify how information about default data nodes should be returned in response to GET requests on data resources.
If the server supports this capability, then it MUST implement the behavior in Section 4.5.1 of [RFC6243], except applied to the RESTCONF GET operation, instead of the NETCONF operations.
| Value | Description |
|---|---|
| report-all | All data nodes are reported |
| trim | Data nodes set to the YANG default are not reported |
| explicit | Data nodes set to the YANG default by the client are reported |
| report-all-tagged | All data nodes are reported and defaults are tagged |
If the "with‑defaults" parameter is set to "report‑all" then the server MUST adhere to the defaults reporting behavior defined in Section 3.1 of [RFC6243].
If the "with‑defaults" parameter is set to "trim" then the server MUST adhere to the defaults reporting behavior defined in Section 3.2 of [RFC6243].
If the "with‑defaults" parameter is set to "explicit" then the server MUST adhere to the defaults reporting behavior defined in Section 3.3 of [RFC6243].
If the "with‑defaults" parameter is set to "report‑all‑tagged" then the server MUST adhere to the defaults reporting behavior defined in Section 3.4 of [RFC6243]. Metadata is reported by the server as specified in Section 5.3. The XML encoding for the "default" attribute sent by the server for default nodes is defined in section 6 of [RFC6243]. The JSON encoding for the "default" attribute MUST use the same values as defined in [RFC6243], but encoded according to the rules in [RFC7952]. The module name "ietf‑netconf‑with‑defaults" MUST be used for the "default" attribute.
If the "with‑defaults" parameter is not present then the server MUST adhere to the defaults reporting behavior defined in its "basic‑mode" parameter for the "defaults" protocol capability URI, defined in Section 9.1.2.
If the server includes the "with‑defaults" query parameter URI in the "capability" leaf-list in Section 9.3, then the "with‑defaults" query parameter MUST be supported.
Since the server does not report the "also‑supported" parameter as described in section 4.3 of [RFC6243], it is possible that some values for the "with‑defaults" parameter will not be supported. If the server does not support the requested value of the "with‑defaults" parameter, the server MUST return a response with a "400 Bad Request" status-line. The error-tag value "invalid‑value" is used in this case.
The RESTCONF protocol uses HTTP 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.
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>
^ ^ ^ ^
| | | |
method entry resource query
M M O O
M=mandatory, O=optional
where:
<OP> is the HTTP method
<restconf> is the RESTCONF root resource
<path> is the Target Resource URI
<query> is the query parameter list
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 [RFC3986], Section 3.4. Any reserved characters MUST be percent-encoded, according to [RFC3986], section 2.1 and 2.5.
Note that the fragment component not used by the RESTCONF protocol. The fragment is excluded from the target URI by a server, as described in section 5.1 of [RFC7230].
When new resources are created by the client, a "Location" header field is returned, which identifies the path of the newly created resource. The client uses this exact path identifier to access the resource once it has been created.
The "target" of a RESTCONF operation is a resource. The "path" field in the request URI represents the target resource for the RESTCONF operation.
Refer to Appendix D for examples of RESTCONF Request URIs.
RESTCONF messages are encoded in HTTP according to [RFC7230]. 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 one of either XML or JSON encoding. A server MAY support both XML and JSON encoding. A client will need to support both XML and JSON to interoperate with all RESTCONF servers.
XML encoding rules for data nodes are defined in [RFC7950]. The same encoding rules are used for all XML content. JSON encoding rules are defined in [RFC7951]. Additional JSON encoding rules for metadata are defined in [RFC7952]. 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 field. This field MUST be present if a message-body is sent by the client.
The server MUST support the "Accept" header field and "406 Not Acceptable" status-line, as defined in [RFC7231]. The response output content encoding formats that the client will accept are identified with the Accept header field in the request. If it is not specified, the request input encoding format SHOULD be used, or the server MAY choose any supported content encoding format.
If there was no request input, then the default output encoding is XML or JSON, depending on server preference. File extensions encoded in the request are not used to identify format encoding.
A client can determine if the RESTCONF server supports an encoding format by sending a request using a specific format in the Content-Type and/or Accept header field. If the server does not support the requested input encoding for a request, then it MUST return an error response with a '415 Unsupported Media Type' status-line. If the server does not support any of the requested output encodings for a request, then it MUST return an error response with a '406 Not Acceptable' status-line.
The RESTCONF protocol needs to support retrieval of the same metadata that is used in the NETCONF protocol. Information about default leafs, last-modified timestamps, etc. are commonly used to annotate representations of the datastore contents.
With the XML encoding, the metadata is encoded as attributes in XML, according to section 3.3 of [W3C.REC-xml-20081126]. With the JSON encoding, the metadata is encoded as specified in [RFC7952].
The following examples are based on the example in Appendix D.3.9. The "report‑all‑tagged" mode for the "with‑defaults" query parameter requires that a "default" attribute be returned for default nodes. This example shows that attribute for the "mtu" leaf .
GET /restconf/data/interfaces/interface=eth1
?with-defaults=report-all-tagged HTTP/1.1
Host: example.com
Accept: application/yang-data+xml
The server might respond as follows.
HTTP/1.1 200 OK Date: Mon, 23 Apr 2016 17:01:00 GMT Server: example-server Content-Type: application/yang-data+xml
<interface
xmlns="urn:example.com:params:xml:ns:yang:example-interface">
<name>eth1</name>
<mtu xmlns:wd="urn:ietf:params:xml:ns:netconf:default:1.0"
wd:default="true">1500</mtu>
<status>up</status>
</interface>
Note that RFC 6243 defines the "default" attribute with XSD, not YANG, so the YANG module name has to be assigned instead of derived from the YANG module. The value "ietf‑netconf‑with‑defaults" is assigned for JSON metadata encoding.
GET /restconf/data/interfaces/interface=eth1\
?with-defaults=report-all-tagged HTTP/1.1
Host: example.com
Accept: application/yang-data+json
The server might respond as follows.
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2016 17:01:00 GMT
Server: example-server
Content-Type: application/yang-data+json
{
"example:interface" : [
{
"name" : "eth1",
"mtu" : 1500,
"@mtu" : {
"ietf-netconf-with-defaults:default" : true
},
"status" : "up"
}
]
}
Each message represents some sort of resource access. An HTTP "status‑line" header field is returned for each request. If a "4xx" range status code is returned in the status-line, then the error information SHOULD be returned in the response, according to the format defined in Section 7.1. If a "5xx" range status code is returned in the status-line, then the error information MAY be returned in the response, according to the format defined in Section 7.1. If a 1xx, 2xx, or 3xx range status code is returned in the status-line, then error information MUST NOT be returned in the response, since these ranges do not represent error conditions.
Since the datastore contents change at unpredictable times, responses from a RESTCONF server generally SHOULD NOT be cached.
The server MUST include a "Cache‑Control" header field in every response that specifies whether the response should be cached.
Instead of relying on HTTP caching, the client SHOULD track the "ETag" and/or "Last‑Modified" header fields 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" header fields, 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 header fields, which SHOULD include the "ETag" and "Last‑Modified" header fields, if this metadata is maintained for the target resource.
Note that the way that access control is applied to data resources the values in the Last-Modified and ETag headers maintained for a data resource may not be reliable, as described in Section 4.3.
The RESTCONF protocol supports YANG-defined event notifications. The solution preserves aspects of NETCONF Event Notifications [RFC5277] while utilizing the Server-Sent Events [W3C.REC-eventsource-20150203] transport strategy.
A RESTCONF server MAY support RESTCONF notifications. Clients may determine if a server supports RESTCONF notifications by using the HTTP method OPTIONS, HEAD, or GET on the stream list. The server does not support RESTCONF notifications if an HTTP error code is returned (e.g., "404 Not Found" status-line).
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 method on the stream list.
The "restconf‑state/streams" container definition in the "ietf‑restconf‑monitoring" module (defined in Section 9.3) 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
The server might send the following response:
HTTP/1.1 200 OK Content-Type: application/yang-data+xml
<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>
<access>
<encoding>xml</encoding>
<location>https://example.com/streams/NETCONF\
</location>
</access>
<access>
<encoding>json</encoding>
<location>https://example.com/streams/NETCONF-JSON\
</location>
</access>
</stream>
<stream>
<name>SNMP</name>
<description>SNMP notifications</description>
<replay-support>false</replay-support>
<access>
<encoding>xml</encoding>
<location>https://example.com/streams/SNMP</location>
</access>
</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>
<access>
<encoding>xml</encoding>
<location>\
https://example.com/streams/syslog-critical\
</location>
</access>
</stream>
</streams>
RESTCONF clients can determine the URL for the subscription resource (to receive notifications) by sending an HTTP GET request for the "location" 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.REC-eventsource-20150203] transport strategy.
The server MAY support query parameters for a GET method on this resource. These parameters are specific to each event stream.
For example:
The client might send the following request:
GET /restconf/data/ietf-restconf-monitoring:restconf-state/\
streams/stream=NETCONF/access=xml/location HTTP/1.1
Host: example.com
Accept: application/yang-data+xml
The server might send the following response:
HTTP/1.1 200 OK Content-Type: application/yang-data+xml
<location
xmlns="urn:ietf:params:xml:ns:yang:ietf-restconf-monitoring">\
https://example.com/streams/NETCONF\
</location>
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 that the server compress the events using the HTTP header field "Accept‑Encoding". For instance:
GET /streams/NETCONF HTTP/1.1 Host: example.com Accept: text/event-stream Cache-Control: no-cache Connection: keep-alive Accept-Encoding: gzip, deflate
The server SHOULD support the "NETCONF" event stream defined in section 3.2.3 of [RFC5277]. The notification messages for this stream are encoded in XML.
The server MAY support additional streams which represent the semantic content of the NETCONF event stream, but using a representation with a different media type.
The server MAY support the "start‑time", "stop‑time", and "filter" query parameters, defined in Section 4.8. Refer to Appendix D.3.6 for filter parameter examples.
RESTCONF notifications are encoded according to the definition of the event stream.
The structure of the event data is based on the "notification" element definition in Section 4 of [RFC5277]. It MUST conform to the schema for the "notification" element in Section 4 of [RFC5277] using the XML namespace as defined in the XSD as follows:
urn:ietf:params:xml:ns:netconf:notification:1.0
For JSON encoding purposes, the module name for the "notification" element is "ietf‑restconf".
Two child nodes within the "notification" container are expected, representing the event time and the event payload. The "eventTime" node is defined within the same XML namespace as the "notification" element. It is defined to be within the "ietf‑restconf" module namespace for JSON encoding purposes.
The name and namespace of the payload element are determined by the YANG module containing the notification-stmt representing the notification message.
In the following example, the YANG module "example‑mod" is used:
module example-mod {
namespace "http://example.com/event/1.0";
prefix ex;
notification event {
leaf event-class { type string; }
container reporting-entity {
leaf card { type string; }
}
leaf severity { type string; }
}
}
An example SSE event notification encoded using XML:
data: <notification data: xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0"> data: <eventTime>2013-12-21T00:01:00Z</eventTime> 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 event notification encoded using JSON:
data: {
data: "ietf-restconf:notification" : {
data: "eventTime" : "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:
XML:
data: <notification xmlns="urn:ietf:params:xml:ns:netconf:notif\
ication:1.0"><eventTime>2013-12-21T00:01:00Z</eventTime><event \
xmlns="http://example.com/event/1.0"><event-class>fault</event-\
class><reportingEntity><card>Ethernet0</card></reporting-entity>\
<severity>major</severity></event></notification>
JSON:
data: {"ietf-restconf:notification":{"eventTime":"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 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 field "Last‑Event‑Id". RESTCONF servers that do send the "id" field SHOULD support the "start‑time" query parameter as the preferred means for a client to specify where to restart the event stream.
HTTP status codes are used to report success or failure for RESTCONF operations. The error information that NETCONF error responses contain in the <rpc‑error> element is adapted for use in RESTCONF, and an <errors> data tree information is returned for "4xx" and "5xx" class of status codes.
Since an operation resource is defined with a YANG "rpc" statement, and an action is defined with a YANG "action" statement, a mapping from the NETCONF <error‑tag> value to the HTTP status code is needed. The specific error-tag and response code to use are data-model-specific and might be contained in the YANG "description" statement for the "action" or "rpc" statement.
| error-tag | status code |
|---|---|
| in-use | 409 |
| invalid-value | 400, 404 or 406 |
| (request) too-big | 413 |
| (response) too-big | 400 |
| missing-attribute | 400 |
| bad-attribute | 400 |
| unknown-attribute | 400 |
| bad-element | 400 |
| unknown-element | 400 |
| unknown-namespace | 400 |
| access-denied | 401, 403 |
| lock-denied | 409 |
| resource-denied | 409 |
| rollback-failed | 500 |
| data-exists | 409 |
| data-missing | 409 |
| operation-not-supported | 405 or 501 |
| operation-failed | 412 or 500 |
| partial-operation | 500 |
| malformed-message | 400 |
When an error occurs for a request message on any resource type, and the status code that will be returned is in the "4xx" range (except for status code "403 Forbidden"), then the server SHOULD send a response message-body containing the information described by the "yang‑errors" YANG data template within the "ietf‑restconf" module, found in Section 8. The Content-Type of this response message MUST be "application/yang‑data", plus optionally a structured syntax name suffix.
The client SHOULD specify the desired encoding(s) for response messages by specifying the appropriate media-type(s) in the Accept header. If the client did not specify an Accept header, then the same structured syntax name suffix used in the request message SHOULD be used, or the server MAY choose any supported message encoding format. If there is no request message the server MUST select "application/yang‑data+xml" or "application/yang‑data+json", depending on server preference. All of the examples in this document, except for the one below, assume that XML encoding will be returned if there is an error.
YANG Tree Diagram for <errors> data:
+---- errors
+---- error*
+---- error-type enumeration
+---- error-tag string
+---- error-app-tag? string
+---- error-path? instance-identifier
+---- error-message? string
+---- error-info?
The semantics and syntax for RESTCONF error messages are defined with the "yang‑errors" YANG data template extension, found in Section 8.
Examples:
The following example shows an error returned for an "lock‑denied" error that can occur if a NETCONF client has locked a datastore. The RESTCONF client is attempting to delete a data resource. Note that an Accept header field is used to specify the desired encoding for the error message. There would be no response message-body content if this operation was successful.
DELETE /restconf/data/example-jukebox:jukebox/\
library/artist=Foo%20Fighters/album=Wasting%20Light HTTP/1.1
Host: example.com
Accept: application/yang-data+json
The server might respond:
HTTP/1.1 409 Conflict
Date: Mon, 23 Apr 2016 17:11:00 GMT
Server: example-server
Content-Type: application/yang-data+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:
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 2016 17:11:00 GMT Server: example-server Content-Type: application/yang-data+xml
<errors xmlns="urn:ietf:params:xml:ns:yang:ietf-restconf">
<error>
<error-type>protocol</error-type>
<error-tag>data-exists</error-tag>
<error-path
xmlns:rc="urn:ietf:params:xml:ns:yang:ietf-restconf"
xmlns:jbox="https://example.com/ns/example-jukebox">\
/rc:restconf/rc:data/jbox:jukebox
</error-path>
<error-message>
Data already exists, cannot create new resource
</error-message>
</error>
</errors>
The "ietf‑restconf" module defines conceptual definitions within an extension and two groupings, which are not meant to be implemented as datastore contents by a server. E.g., the "restconf" container is not intended to be implemented as a top-level data node (under the "/restconf/data" URI).
Note that the "ietf‑restconf" module does not have any protocol-accessible objects, so no YANG tree diagram is shown.
RFC Ed.: update the date below with the date of RFC publication and remove this note.
<CODE BEGINS> file "ietf-restconf@2016-08-15.yang"
module ietf-restconf {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-restconf";
prefix "rc";
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
Author: Andy Bierman
<mailto:andy@yumaworks.com>
Author: Martin Bjorklund
<mailto:mbj@tail-f.com>
Author: Kent Watsen
<mailto:kwatsen@juniper.net>";
description
"This module contains conceptual YANG specifications
for basic RESTCONF media type definitions used in
RESTCONF protocol messages.
Note that the YANG definitions within this module do not
represent configuration data of any kind.
The 'restconf-media-type' YANG extension statement
provides a normative syntax for XML and JSON message
encoding purposes.
Copyright (c) 2016 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
// RFC Ed.: remove this note
// Note: extracted from draft-ietf-netconf-restconf-17.txt
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
revision 2016-08-15 {
description
"Initial revision.";
reference
"RFC XXXX: RESTCONF Protocol.";
}
extension yang-data {
argument name {
yin-element true;
}
description
"This extension is used to specify a YANG data template which
represents conceptual data defined in YANG. It is
intended to describe hierarchical data independent of
protocol context or specific message encoding format.
Data definition statements within a yang-data extension
specify the generic syntax for the specific YANG data
template, whose name is the argument of the yang-data
extension statement.
Note that this extension does not define a media-type.
A specification using this extension MUST specify the
message encoding rules, including the content media type.
The mandatory 'name' parameter value identifies the YANG
data template that is being defined. It contains the
template name.
This extension is ignored unless it appears as a top-level
statement. It MUST contain data definition statements
that result in exactly one container data node definition.
An instance of a YANG data template can thus be translated
into an XML instance document, whose top-level element
corresponds to the top-level container.
The module name and namespace value for the YANG module using
the extension statement is assigned to instance document data
conforming to the data definition statements within
this extension.
The sub-statements of this extension MUST follow the
'data-def-stmt' rule in the YANG ABNF.
The XPath document root is the extension statement itself,
such that the child nodes of the document root are
represented by the data-def-stmt sub-statements within
this extension. This conceptual document is the context
for the following YANG statements:
- must-stmt
- when-stmt
- path-stmt
- min-elements-stmt
- max-elements-stmt
- mandatory-stmt
- unique-stmt
- ordered-by
- instance-identifier data type
The following data-def-stmt sub-statements are constrained
when used within a yang-data-resource extension statement.
- The list-stmt is not required to have a key-stmt defined.
- The if-feature-stmt is ignored if present.
- The config-stmt is ignored if present.
- The available identity values for any 'identityref'
leaf or leaf-list nodes is limited to the module
containing this extension statement, and the modules
imported into that module.
";
}
rc:yang-data yang-errors {
uses errors;
}
rc:yang-data yang-api {
uses restconf;
}
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 {
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.";
}
leaf error-path {
type instance-identifier;
description
"The YANG instance identifier associated
with the error node.";
}
leaf error-message {
type string;
description
"A message describing the error.";
}
anydata error-info {
description
"This anydata value MUST represent a container with
zero or more data nodes representing additional
error information.";
}
}
}
}
grouping restconf {
description
"Conceptual grouping representing the RESTCONF
root resource.";
container restconf {
description
"Conceptual container representing the RESTCONF
root resource.";
container data {
description
"Container representing the datastore resource.
Represents the conceptual root of all state data
and configuration data supported by the server.
The child nodes of this container can be any data
resource which are defined as top-level data nodes
from the YANG modules advertised by the server in
the ietf-yang-library module.";
}
container operations {
description
"Container for all operation resources.
Each resource is represented as an empty leaf with the
name of the RPC operation from the YANG rpc statement.
For example, the 'system-restart' RPC operation defined
in the 'ietf-system' module would be represented as
an empty leaf in the 'ietf-system' namespace. This is
a conceptual leaf, and will not actually be found in
the module:
module ietf-system {
leaf system-reset {
type empty;
}
}
To invoke the 'system-restart' RPC operation:
POST /restconf/operations/ietf-system:system-restart
To discover the RPC operations supported by the server:
GET /restconf/operations
In XML the YANG module namespace identifies the module:
<system-restart
xmlns='urn:ietf:params:xml:ns:yang:ietf-system' />
In JSON the YANG module name identifies the module:
{ 'ietf-system:system-restart' : [null] }
";
}
leaf yang-library-version {
type string {
pattern '\d{4}-\d{2}-\d{2}';
}
config false;
mandatory true;
description
"Identifies the revision date of the ietf-yang-library
module that is implemented by this RESTCONF server.
Indicates the year, month, and day in YYYY-MM-DD
numeric format.";
}
}
}
}
<CODE ENDS>
The "ietf‑restconf‑monitoring" module provides information about the RESTCONF protocol capabilities and event streams available from the server. A RESTCONF server MUST implement the "ietf‑restconf‑monitoring" module.
YANG tree diagram for "ietf‑restconf‑monitoring" module:
+--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 access* [encoding]
+--ro encoding string
+--ro location inet:uri
This mandatory container holds the RESTCONF protocol capability URIs supported by the server.
The server MAY maintain a last-modified timestamp for this container, and return the "Last‑Modified" header field when this data node is retrieved with the GET or HEAD methods. Note that the last-modified timestamp for the datastore resource is not affected by changes to this subtree.
The server SHOULD maintain an entity-tag for this container, and return the "ETag" header field when this data node is retrieved with the GET or HEAD methods. Note that the entity-tag for the datastore resource is not affected by changes to this subtree.
The server MUST include a "capability" URI leaf-list entry for the "defaults" mode used by the server, defined in Section 9.1.2.
The server MUST include a "capability" URI leaf-list entry identifying each supported optional protocol feature. This includes optional query parameters and MAY include other capability URIs defined outside this document.
A new set of RESTCONF Capability URIs are defined to identify the specific query parameters (defined in Section 4.8) supported by the server.
The server MUST include a "capability" leaf-list entry for each optional query parameter that it supports.
| Name | Section | URI |
|---|---|---|
| depth | 4.8.2 | urn:ietf:params:restconf:capability:depth:1.0 |
| fields | 4.8.3 | urn:ietf:params:restconf:capability:fields:1.0 |
| filter | 4.8.4 | urn:ietf:params:restconf:capability:filter:1.0 |
| replay | 4.8.7 4.8.8 | urn:ietf:params:restconf:capability:replay:1.0 |
| with-defaults | 4.8.9 | urn:ietf:params:restconf:capability:with-defaults:1.0 |
This URI identifies the "basic‑mode" defaults handling mode that is used by the server for processing default leafs in requests for data resources. This protocol capability URI MUST be supported by the server, and MUST be listed in the "capability" leaf-list in Section 9.3.
| Name | URI |
|---|---|
| defaults | urn:ietf:params:restconf:capability:defaults:1.0 |
The URI MUST contain a query parameter named "basic‑mode" with one of the values listed below:
| Value | Description |
|---|---|
| report-all | No data nodes are considered default |
| trim | Values set to the YANG default-stmt value are default |
| explicit | Values set by the client are never considered default |
The "basic‑mode" definitions are specified in the "With-Defaults Capability for NETCONF" [RFC6243].
If the "basic‑mode" is set to "report‑all" then the server MUST adhere to the defaults handling behavior defined in Section 2.1 of [RFC6243].
If the "basic‑mode" is set to "trim" then the server MUST adhere to the defaults handling behavior defined in Section 2.2 of [RFC6243].
If the "basic‑mode" is set to "explicit" then the server MUST adhere to the defaults handling behavior defined in Section 2.3 of [RFC6243].
Example: (split for display purposes only)
urn:ietf:params:restconf:capability:defaults:1.0?
basic-mode=explicit
This optional container provides access to the event streams supported by the server. The server MAY omit this container if no 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 3.8. Notifications are defined in Section 6.
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.
RFC Ed.: update the date below with the date of RFC publication and remove this note.
<CODE BEGINS> file "ietf-restconf-monitoring@2016-08-15.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>
Author: Andy Bierman
<mailto:andy@yumaworks.com>
Author: Martin Bjorklund
<mailto:mbj@tail-f.com>
Author: Kent Watsen
<mailto:kwatsen@juniper.net>";
description
"This module contains monitoring information for the
RESTCONF protocol.
Copyright (c) 2016 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
// RFC Ed.: remove this note
// Note: extracted from draft-ietf-netconf-restconf-17.txt
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
revision 2016-08-15 {
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;
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;
default false;
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 access {
key encoding;
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 'text/event-stream' is expected
for all event streams. This list identifies the
sub-types supported for this stream.";
leaf encoding {
type string;
description
"This is the secondary encoding format within the
'text/event-stream' encoding used by all streams.
The type 'xml' is supported for XML encoding.
The type 'json' is supported for JSON encoding.";
}
leaf location {
type inet:uri;
mandatory true;
description
"Contains a URL that represents the entry point
for establishing notification delivery via server
sent events.";
}
}
}
}
}
}
<CODE ENDS>
The "ietf‑yang‑library" module defined in [RFC7895] 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.
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 this list are defined in the "module" YANG list statement in [RFC7895].
Note that there are no protocol accessible objects in the "ietf‑restconf" module to implement, but it is possible that a server will list the "ietf‑restconf" module in the YANG library if it is imported (directly or indirectly) by an implemented module.
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: RFCXXXX
`
This document registers two URIs as namespaces in the IETF XML registry [RFC3688]. Following the format in RFC 3688, the following registration is requested:
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.
This document registers two YANG modules in the YANG Module Names registry [RFC6020]:
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: RFCXXXX 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: RFCXXXX
Type name: application
Subtype name: yang-data+xml
Required parameters: None
Optional parameters: None
Encoding considerations: 8-bit
Each conceptual YANG data node is encoded according to the
XML Encoding Rules and Canonical Format for the specific
YANG data node type defined in [RFC7950].
// RFC Ed.: replace 'NN' in Section NN of [RFCXXXX] with the
// section number for Security Considerations
// Replace 'XXXX' in Section NN of [RFCXXXX] with the actual
// RFC number, and remove this note.
Security considerations: Security considerations related
to the generation and consumption of RESTCONF messages
are discussed in Section NN of [RFCXXXX].
Additional security considerations are specific to the
semantics of particular YANG data models. Each YANG module
is expected to specify security considerations for the
YANG data defined in that module.
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
Interoperability considerations: [RFCXXXX] specifies the
format of conforming messages and the interpretation
thereof.
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
Published specification: RFC XXXX
Applications that use this media type: Instance document
data parsers used within a protocol or automation tool
that utilize YANG defined data structures.
Fragment identifier considerations: Fragment identifiers for
this type are not defined. All YANG data nodes are
accessible as resources using the path in the request URI.
Additional information:
Deprecated alias names for this type: N/A
Magic number(s): N/A
File extension(s): None
Macintosh file type code(s): "TEXT"
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
Person & email address to contact for further information: See
Authors' Addresses section of [RFCXXXX].
Intended usage: COMMON
Restrictions on usage: N/A
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
Author: See Authors' Addresses section of [RFCXXXX].
Change controller: Internet Engineering Task Force
(mailto:iesg&ietf.org).
Provisional registration? (standards tree only): no
Type name: application
Subtype name: yang-data+json
Required parameters: None
Optional parameters: None
Encoding considerations: 8-bit
Each conceptual YANG data node is encoded according to
[RFC7951]. A data annotation is encoded according to
[RFC7952].
// RFC Ed.: replace 'NN' in Section NN of [RFCXXXX] with the
// section number for Security Considerations
// Replace 'XXXX' in Section NN of [RFCXXXX] with the actual
// RFC number, and remove this note.
Security considerations: Security considerations related
to the generation and consumption of RESTCONF messages
are discussed in Section NN of [RFCXXXX].
Additional security considerations are specific to the
semantics of particular YANG data models. Each YANG module
is expected to specify security considerations for the
YANG data defined in that module.
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
Interoperability considerations: [RFCXXXX] specifies the format
of conforming messages and the interpretation thereof.
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
Published specification: RFC XXXX
Applications that use this media type: Instance document
data parsers used within a protocol or automation tool
that utilize YANG defined data structures.
Fragment identifier considerations: The syntax and semantics
of fragment identifiers are the same as specified for the
"application/json" media type.
Additional information:
Deprecated alias names for this type: N/A
Magic number(s): N/A
File extension(s): None
Macintosh file type code(s): "TEXT"
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
Person & email address to contact for further information: See
Authors' Addresses section of [RFCXXXX].
Intended usage: COMMON
Restrictions on usage: N/A
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
Author: See Authors' Addresses section of [RFCXXXX].
Change controller: Internet Engineering Task Force
(mailto:iesg&ietf.org).
Provisional registration? (standards tree only): no
[Note to RFC Editor:
The RESTCONF Protocol Capability Registry does not yet exist;
Need to ask IANA to create it; remove this note for publication
]
This document defines a registry for RESTCONF capability identifiers. The name of the registry is "RESTCONF Capability URNs". The review policy for this registry is "IETF Review". The registry shall record for each entry:
This document registers several capability identifiers in "RESTCONF Capability URNs" registry:
Index
Capability Identifier
------------------------
:defaults
urn:ietf:params:restconf:capability:defaults:1.0
:depth
urn:ietf:params:restconf:capability:depth:1.0
:fields
urn:ietf:params:restconf:capability:fields:1.0
:filter
urn:ietf:params:restconf:capability:filter:1.0
:replay
urn:ietf:params:restconf:capability:replay:1.0
:with-defaults
urn:ietf:params:restconf:capability:with-defaults:1.0
IANA has registered a new URN sub-namespace within the IETF URN Sub-namespace for Registered Protocol Parameter Identifiers defined in [RFC3553].
Registry Name: restconf
Specification: RFC XXXX
// RFC Ed.: replace XXXX with RFC number and remove this note
Repository: RESTCONF Capability URNs registry (Section 11.4)
Index value: Sub-parameters MUST be specified in UTF-8, using
standard URI encoding where necessary.
Section 2.1 states "A RESTCONF server MUST support the TLS protocol [RFC5246]". This language leaves open the possibility that a RESTCONF server might also support future versions of the TLS protocol. Of specific concern, TLS 1.3 [I-D.ietf-tls-tls13] introduces support for 0-RTT handshakes that can lead to security issues for REST APIs, as described in the Appendix of the TLS 1.3 specification. It is therefore RECOMMENDED that RESTCONF servers do not support 0-RTT at all (not even for idempotent requests) until an update to this RFC guides otherwise.
Section 2.5 recommends TLS client certificate based authentication, but allows the use of any authentication scheme defined in the HTTP Authentication Scheme Registry. Implementations need to be aware that the strength of these methods vary greatly, and that some may be considered experimental. Selection of any of these schemes SHOULD be performed after reading the Security Considerations section of the RFC associated with the scheme’s registry entry.
The "ietf‑restconf‑monitoring" YANG module defined in this memo is designed to be accessed via the NETCONF protocol [RFC6241]. The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. The NETCONF access control model [RFC6536] provides the means to restrict access for particular NETCONF users to a pre-configured subset of all available NETCONF protocol operations and content.
The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC5246]. The RESTCONF protocol uses the NETCONF access control model [RFC6536], which provides the means to restrict access for particular RESTCONF users to a preconfigured subset of all available RESTCONF protocol operations and content.
This section provides security considerations for the resources defined by the RESTCONF protocol. Security considerations for HTTPS are defined in [RFC7230]. RESTCONF does not specify which YANG modules a server needs to support, except the "ietf‑restconf‑monitoring" module. Security considerations for the other modules manipulated by RESTCONF can be found in the documents defining those YANG modules.
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. There are many patterns of attack that have been observed through operational practice with existing management interfaces. It would be wise for implementers to research them, and take them into account when implementing this protocol.
Different environments may well allow different rights prior to and then after authentication. When a RESTCONF operation is not properly authorized, the RESTCONF server MUST return a "401 Unauthorized" status-line. 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. Note that it is possible for a client to detect configuration changes in data resources it is not authorized to access by monitoring changes in the ETag and Last-Modified header fields returned by the server for the datastore resource.
A RESTCONF server implementation SHOULD attempt to prevent system disruption due to excessive resource consumption required to fulfill edit requests via the POST, PUT, and PATCH methods. It may be possible to construct an attack on such a RESTCONF server, which attempts to consume all available memory or other resource types.
The authors would like to thank the following people for their contributions to this document: Ladislav Lhotka, Juergen Schoenwaelder, Rex Fernando, Robert Wilton, and Jonathan Hansford.
The authors would like to thank the following people for their excellent technical reviews of this document: Mehmet Ersue, Mahesh Jethanandani, Qin Wu, Joe Clarke, Bert Wijnen, Ladislav Lhotka, Rodney Cummings, Frank Xialiang, Tom Petch, Robert Sparks, Balint Uveges, Randy Presuhn, Sue Hares, Mark Nottingham, Benoit Claise, Dale Worley, and Lionel Morand.
Contributions to this material by Andy Bierman are based upon work supported by the United States Army, Space & Terrestrial Communications Directorate (S&TCD) under Contract No. W15P7T-13-C-A616. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of The Space & Terrestrial Communications Directorate (S&TCD).
| [I-D.ietf-netconf-yang-patch] | Bierman, A., Bjorklund, M. and K. Watsen, "YANG Patch Media Type", Internet-Draft draft-ietf-netconf-yang-patch-12, October 2016. |
| [I-D.ietf-tls-tls13] | Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", Internet-Draft draft-ietf-tls-tls13-18, October 2016. |
| [rest-dissertation] | Fielding, R., "Architectural Styles and the Design of Network-based Software Architectures", 2000. |
| [RFC2818] | Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000. |
-- RFC Ed.: remove this section before publication.
The RESTCONF issue tracker can be found here: https://github.com/netconf-wg/restconf/issues
This release addresses github issues #61, #62, #63, #65, #66, and #67.
-- RFC Ed.: remove this section before publication.
The RESTCONF issues are tracked on github.com:
https://github.com/netconf-wg/restconf/issues
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:
+---x play
+--ro input
+--ro playlist string
+--ro song-number uint32
module example-jukebox {
namespace "http://example.com/ns/example-jukebox";
prefix "jbox";
organization "Example, Inc.";
contact "support at example.com";
description "Example Jukebox Data Model Module";
revision "2016-08-15" {
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;
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
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
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.";
}
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 instance-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 {
type uint32;
mandatory true;
description "Song number in playlist to play";
}
}
}
}
The examples within this document use the normative YANG module "ietf‑restconf" defined in Section 8 and the non-normative example YANG module "example‑jukebox" defined in Appendix C.1.
This section shows some typical RESTCONF message exchanges.
The client starts by retrieving the RESTCONF root resource:
GET /.well-known/host-meta HTTP/1.1 Host: example.com Accept: application/xrd+xml
The server might respond:
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>
The client may then retrieve the top-level API resource, using the root resource "/restconf".
GET /restconf HTTP/1.1 Host: example.com Accept: application/yang-data+json
The server might respond as follows:
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2016 17:01:00 GMT
Server: example-server
Content-Type: application/yang-data+json
{
"ietf-restconf:restconf" : {
"data" : {},
"operations" : {},
"yang-library-version" : "2016-06-21"
}
}
To request that the response content to be encoded in XML, the "Accept" header can be used, as in this example request:
GET /restconf HTTP/1.1 Host: example.com Accept: application/yang-data+xml
The server will return the same conceptual data either way, which might be as follows :
HTTP/1.1 200 OK Date: Mon, 23 Apr 2016 17:01:00 GMT Server: example-server Cache-Control: no-cache Content-Type: application/yang-data+xml
<restconf xmlns="urn:ietf:params:xml:ns:yang:ietf-restconf">
<data/>
<operations/>
<yang-library-version>2016-06-21</yang-library-version>
</restconf>
It is possible the YANG library module will change over time. The client can retrieve the revision date of the ietf-yang-library supported by the server from the API resource, as described in the previous section.
In this example the client is retrieving the modules information from the server in JSON format:
GET /restconf/data/ietf-yang-library:modules-state HTTP/1.1 Host: example.com Accept: application/yang-data+json
The server might respond as follows:
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2016 17:01:00 GMT
Server: example-server
Cache-Control: no-cache
Last-Modified: Sun, 22 Apr 2016 01:00:14 GMT
Content-Type: application/yang-data+json
{
"ietf-yang-library:modules-state" : {
"module-set-id" : "5479120c17a619545ea6aff7aa19838b036ebbd7",
"module" : [
{
"name" : "foo",
"revision" : "2012-01-02",
"schema" : "https://example.com/modules/foo/2012-01-02",
"namespace" : "http://example.com/ns/foo",
"feature" : [ "feature1", "feature2" ],
"deviation" : [
{
"name" : "foo-dev",
"revision" : "2012-02-16"
}
],
"conformance-type" : "implement"
},
{
"name" : "ietf-yang-library",
"revision" : "2016-06-21",
"schema" : "https://example.com/modules/\
ietf-yang-library/2016-06-21",
"namespace" :
"urn:ietf:params:xml:ns:yang:ietf-yang-library",
"conformance-type" : "implement"
},
{
"name" : "foo-types",
"revision" : "2012-01-05",
"schema" :
"https://example.com/modules/foo-types/2012-01-05",
"namespace" : "http://example.com/ns/foo-types",
"conformance-type" : "import"
},
{
"name" : "bar",
"revision" : "2012-11-05",
"schema" : "https://example.com/modules/bar/2012-11-05",
"namespace" : "http://example.com/ns/bar",
"feature" : [ "bar-ext" ],
"conformance-type" : "implement",
"submodule" : [
{
"name" : "bar-submod1",
"revision" : "2012-11-05",
"schema" :
"https://example.com/modules/bar-submod1/2012-11-05"
},
{
"name" : "bar-submod2",
"revision" : "2012-11-05",
"schema" :
"https://example.com/modules/bar-submod2/2012-11-05"
}
]
}
]
}
}
In this example the client is retrieving the capability information from the server in XML format, and the server supports all the RESTCONF query parameters, plus one vendor parameter:
GET /restconf/data/ietf-restconf-monitoring:restconf-state/\
capabilities HTTP/1.1
Host: example.com
Accept: application/yang-data+xml
The server might respond as follows:
HTTP/1.1 200 OK Date: Mon, 23 Apr 2016 17:02:00 GMT Server: example-server Cache-Control: no-cache Last-Modified: Sun, 22 Apr 2016 01:00:14 GMT Content-Type: application/yang-data+xml
<capabilities
xmlns="urn:ietf:params:xml:ns:yang:ietf-restconf-monitoring">
<capability>\
urn:ietf:params:restconf:capability:defaults:1.0?\
basic-mode=explicit\
</capability>
<capability>\
urn:ietf:params:restconf:capability:with-defaults:1.0\
</capability>
<capability>\
urn:ietf:params:restconf:capability:depth:1.0\
</capability>
<capability>\
urn:ietf:params:restconf:capability:fields:1.0\
</capability>
<capability>\
urn:ietf:params:restconf:capability:filter:1.0\
</capability>
<capability>\
urn:ietf:params:restconf:capability:start-time:1.0\
</capability>
<capability>\
urn:ietf:params:restconf:capability:stop-time:1.0\
</capability>
<capability>\
http://example.com/capabilities/myparam\
</capability>
</capabilities>
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"
}
]
}
If the resource is created, the server might respond as follows:
HTTP/1.1 201 Created
Date: Mon, 23 Apr 2016 17:02:00 GMT
Server: example-server
Location: https://example.com/restconf/data/\
example-jukebox:jukebox/library/artist=Foo%20Fighters
Last-Modified: Mon, 23 Apr 2016 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:
POST /restconf/data/example-jukebox:jukebox/\
library/artist=Foo%20Fighters HTTP/1.1
Host: example.com
Content-Type: application/yang-data+xml
<album xmlns="http://example.com/ns/example-jukebox">
<name>Wasting Light</name>
<year>2011</year>
</album>
If the resource is created, the server might respond as follows:
HTTP/1.1 201 Created
Date: Mon, 23 Apr 2016 17:03:00 GMT
Server: example-server
Location: https://example.com/restconf/data/\
example-jukebox:jukebox/library/artist=Foo%20Fighters/\
album=Wasting%20Light
Last-Modified: Mon, 23 Apr 2016 17:03:00 GMT
ETag: "b8389233a4c"
In this example, the server just supports the datastore last-changed timestamp. After the previous request, the client has cached the "Last‑Modified" header and the Location header from the response to provide in the following request to patch an "album" list entry with key value "Wasting Light". Only the "genre" field is being updated.
PATCH /restconf/data/example-jukebox:jukebox/\
library/artist=Foo%20Fighters/album=Wasting%20Light/\
genre HTTP/1.1
Host: example.com
If-Unmodified-Since: Mon, 23 Apr 2016 17:03:00 GMT
Content-Type: application/yang-data+json
{ "example-jukebox:genre" : "example-jukebox:alternative" }
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 2016 19:01:00 GMT Server: example-server Last-Modified: Mon, 23 Apr 2016 17:45:00 GMT ETag: "b34aed893a4c"
In this example, assume there is a top-level data resource named "system" from the example-system module, and this container has a child leaf called "enable‑jukebox‑streaming":
container system {
leaf enable-jukebox-streaming {
type boolean;
}
}
In this example PATCH is used by the client to modify 2 top-level resources at once, in order to enable jukebox streaming and add an "album" sub-resource to each of 2 "artist" resources:
PATCH /restconf/data HTTP/1.1 Host: example.com Content-Type: application/yang-data+xml
<data xmlns="urn:ietf:params:xml:ns:yang:ietf-restconf">
<system xmlns="http://example.com/ns/example-system">
<enable-jukebox-streaming>true</enable-jukebox-streaming>
</system>
<jukebox xmlns="http://example.com/ns/example-jukebox">
<library>
<artist>
<name>Foo Fighters</name>
<album>
<name>One by One</name>
<year>2012</year>
</album>
</artist>
<artist>
<name>Nick Cave and the Bad Seeds</name>
<album>
<name>Tender Prey</name>
<year>1988</year>
</album>
</artist>
</library>
</jukebox>
</data>
In this example, the entire configuration datastore contents are being replaced. Any child nodes not present in the <data> element but present in the server will be deleted.
PUT /restconf/data HTTP/1.1 Host: example.com Content-Type: application/yang-data+xml
<data xmlns="urn:ietf:params:xml:ns:yang:ietf-restconf">
<jukebox xmlns="http://example.com/ns/example-jukebox">
<library>
<artist>
<name>Foo Fighters</name>
<album>
<name>One by One</name>
<year>2012</year>
</album>
</artist>
<artist>
<name>Nick Cave and the Bad Seeds</name>
<album>
<name>Tender Prey</name>
<year>1988</year>
</album>
</artist>
</library>
</jukebox>
</data>
In this example, the client modifies one data node by adding an "album" sub-resource by sending a PATCH for the data resource:
PATCH /restconf/data/example-jukebox:jukebox/library/\
artist=Nick%20Cave%20and%20the%20Bad%20Seeds HTTP/1.1
Host: example.com
Content-Type: application/yang-data+xml
<artist xmlns="http://example.com/ns/example-jukebox">
<name>Nick Cave and the Bad Seeds</name>
<album>
<name>The Good Son</name>
<year>1990</year>
</album>
</artist>
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
To retrieve all the child resources, the "content" parameter is set to "all", or omitted, since this is the default value. The client might send:
GET /restconf/data/example-events:events?\
content=all HTTP/1.1
Host: example.com
Accept: application/yang-data+json
The server might respond:
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2016 17:11:30 GMT
Server: example-server
Cache-Control: 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". 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
The server might respond:
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2016 17:11:30 GMT
Server: example-server
Last-Modified: Mon, 23 Apr 2016 13:01:20 GMT
ETag: "eeeada438af"
Cache-Control: 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
The server might respond:
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2016 17:11:30 GMT
Server: example-server
Cache-Control: no-cache
Content-Type: application/yang-data+json
{
"example-events:events" : {
"event" : [
{
"name" : "interface-up",
"event-count" : 42
},
{
"name" : "interface-down",
"event-count" : 4
}
]
}
}
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.
The depth parameter starts counting levels at the level of the target resource that is specified, so that a depth level of "1" includes just the target resource level itself. A depth level of "2" includes the target resource level and its child nodes.
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".
GET /restconf/data/example-jukebox:jukebox?\
depth=unbounded HTTP/1.1
Host: example.com
Accept: application/yang-data+json
The server might respond:
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2016 17:11:30 GMT
Server: example-server
Cache-Control: 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" : "/example-jukebox:jukebox/library\
/artist[name='Foo Figthers']\
/album[name='Wasting Light']\
/song[name=Rope']"
},
{
"index" : 2,
"id" : "/example-jukebox:jukebox/library\
/artist[name='Foo Figthers']\
/album[name='Wasting Light']\
/song[name=Bridge Burning']"
}
]
}
],
"player" : {
"gap" : 0.5
}
}
}
Example 2: depth=1
To determine if 1 or more resource instances exist for a given target resource, the value one is used.
GET /restconf/data/example-jukebox:jukebox?depth=1 HTTP/1.1 Host: example.com Accept: application/yang-data+json
The server might respond:
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2016 17:11:30 GMT
Server: example-server
Cache-Control: no-cache
Content-Type: application/yang-data+json
{
"example-jukebox:jukebox" : {}
}
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
The server might respond:
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2016 17:11:30 GMT
Server: example-server
Cache-Control: no-cache
Content-Type: application/yang-data+json
{
"example-jukebox:jukebox" : {
"library" : {
"artist" : {}
},
"playlist" : [
{
"name" : "Foo-One",
"description" : "example playlist 1",
"song" : {}
}
],
"player" : {
"gap" : 0.5
}
}
}
In this example the client is retrieving the datastore resource in JSON format, but retrieving only the "modules‑state/module" list, and only the "name" and "revision" nodes from each list entry. Note that top node returned by the server matches the target resource node (which is "data" in this example). The "module‑set‑id" leaf is not returned because it is not selected in the fields expression.
GET /restconf/data?fields=ietf-yang-library:modules-state/\
module(name;revision) HTTP/1.1
Host: example.com
Accept: application/yang-data+json
The server might respond as follows.
[RFC Editor Note: Adjust the date for ietf-restconf-monitoring below to the date in the published ietf-restconf-monitoring YANG module, and remove this note.]
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2016 17:01:00 GMT
Server: example-server
Content-Type: application/yang-data+json
{
"ietf-restconf:data" : {
"ietf-yang-library:modules-state" : {
"module" : [
{
"name" : "example-jukebox",
"revision" : "2015-06-04"
},
{
"name" : "ietf-inet-types",
"revision" : "2013-07-15"
},
{
"name" : "ietf-restconf-monitoring",
"revision" : "2016-03-16"
},
{
"name" : "ietf-yang-library",
"revision" : "2016-06-21"
},
{
"name" : "ietf-yang-types",
"revision" : "2013-07-15"
}
]
}
}
}
In this example, a new first song 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[name='Foo Figthers']\
/album[name='Wasting Light']\
/song[name=Rope']"
}
]
}
Response from server:
HTTP/1.1 201 Created
Date: Mon, 23 Apr 2016 13:01:20 GMT
Server: example-server
Last-Modified: Mon, 23 Apr 2016 13:01:20 GMT
Location: https://example.com/restconf/data/\
example-jukebox:jukebox/playlist=Foo-One/song=1
ETag: "eeeada438af"
In this example, the client is inserting a new song entry in the "Foo‑One" playlist after the first song.
Request from client:
POST /restconf/data/example-jukebox:jukebox/\
playlist=Foo-One?insert=after&point=\
%2Fexample-jukebox%3Ajukebox\
%2Fplaylist%3DFoo-One%2Fsong%3D1 HTTP/1.1
Host: example.com
Content-Type: application/yang-data+json
{
"example-jukebox:song" : [
{
"index" : 2,
"id" : "/example-jukebox:jukebox/library\
/artist[name='Foo Figthers']\
/album[name='Wasting Light']\
/song[name=Bridge Burning']"
}
]
}
Response from server:
HTTP/1.1 201 Created
Date: Mon, 23 Apr 2016 13:01:20 GMT
Server: example-server
Last-Modified: Mon, 23 Apr 2016 13:01:20 GMT
Location: https://example.com/restconf/data/\
example-jukebox:jukebox/playlist=Foo-One/song=2
ETag: "abcada438af"
The following URIs show some examples of notification filter specifications:
// filter = /event/event-class='fault'
GET /streams/NETCONF?filter=%2Fevent%2Fevent-class%3D'fault'
// filter = /event/severity<=4
GET /streams/NETCONF?filter=%2Fevent%2Fseverity%3C%3D4
// filter = /linkUp|/linkDown
GET /streams/SNMP?filter=%2FlinkUp%7C%2FlinkDown
// filter = /*/reporting-entity/card!='Ethernet0'
GET /streams/NETCONF?\
filter=%2F*%2Freporting-entity%2Fcard%21%3D'Ethernet0'
// filter = /*/email-addr[contains(.,'company.com')]
GET /streams/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 /streams/NETCONF?\
filter=(%2Fexample-mod%3Aevent1%2Fname%3D'joe'%20and\
%20%2Fexample-mod%3Aevent1%2Fstatus%3D'online')
// To get notifications from just two modules (e.g., m1 + m2)
// filter=(/m1:* or /m2:*)
GET /streams/NETCONF?filter=(%2Fm1%3A*%20or%20%2Fm2%3A*)
The following URI shows an example of the "start‑time" query parameter:
// start-time = 2014-10-25T10:02:00Z GET /streams/NETCONF?start-time=2014-10-25T10%3A02%3A00Z
The following URI shows an example of the "stop‑time" query parameter:
// start-time = 2014-10-25T10:02:00Z
// stop-time = 2014-10-25T12:31:00Z
GET /mystreams/NETCONF?start-time=2014-10-25T10%3A02%3A00Z\
&stop-time=2014-10-25T12%3A31%3A00Z
Assume the server implements the module "example" defined in Appendix A.1 of [RFC6243]. Assume the server's datastore is as defined in Appendix A.2 of [RFC6243].
If the server defaults-uri basic-mode is "trim", the the following request for interface "eth1" might be as follows:
Without query parameter:
GET /restconf/data/example:interfaces/interface=eth1 HTTP/1.1 Host: example.com Accept: application/yang-data+json
The server might respond as follows.
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2016 17:01:00 GMT
Server: example-server
Content-Type: application/yang-data+json
{
"example:interface" : [
{
"name" : "eth1",
"status" : "up"
}
]
}
Note that the "mtu" leaf is missing because it is set to the default "1500", and the server defaults handling basic-mode is "trim".
With query parameter:
GET /restconf/data/example:interfaces/interface=eth1\
?with-defaults=report-all HTTP/1.1
Host: example.com
Accept: application/yang-data+json
The server might respond as follows.
HTTP/1.1 200 OK
Date: Mon, 23 Apr 2016 17:01:00 GMT
Server: example-server
Content-Type: application/yang-data+json
{
"example:interface" : [
{
"name" : "eth1",
"mtu" : 1500,
"status" : "up"
}
]
}
Note that the server returns the "mtu" leaf because the "report‑all" mode was requested with the "with‑defaults" query parameter.