Cisco NX-OS RESTCONF is an HTTP -based protocol for configuring data that are defined in YANG version 1, using datastores defined in NETCONF.

NETCONF defines configuration datastores and a set of Create, Retrieve, Update, and Delete (CRUD) operations that can be used to access these datastores. The YANG language defines the syntax and semantics of datastore content, operational data, protocol operations, and event notifications.

Cisco NX-OS RESTCONF uses HTTP operations to provide CRUD operations on a conceptual datastore containing YANG-defined data. This data is compatible with a server which implements NETCONF datastores.

The RESTCONF protocol supports both XML and JSON payload encodings. User authentication is done through the HTTP Basic Authentication.

The following table shows the Protocol operations that the Cisco NX-OS RESTCONF Agent supports:

This feature provides access to ephemeral data. Ephemeral data is high volume data. DME provides a batching mechanism to retrieve the data so that each batch is of a manageable size in terms of memory usage. The size of the batch is the number of MOs to be retrieved.

You can find information about which data is ephemeral by the comment "Ephemeral data" in the published Cisco-NX-OS-device.yang file.

The output from ephemeral data is returned, if and only if the URI in the request points to:

• A leaf from ephemeral data

• A container or list with ephemeral data children

• An empty container that is used to wrap a list that has direct ephemeral data children

System level GET queries do not return ephemeral data.

For write operations such as POST, PUT, PATCH, or DELETE, RESTCONF would emit the relevant accounting log. It would include both the original received request, as well as the eventual changes applied to the switch.

You can see the accounting log using the show accounting log command.

Consider the following example request:

curl -s -L --request POST --user admin: --header 'Content-Type: application/yang.data+json' --url “restconf/data/Cisco-NX-OS-device:System/intf-items/lb-items/LbRtdIf-list=lo10” --data-raw @request.txt

Payload:
<descr>test</descr>

Or 

{"descr":"test"}

The accounting log shall include the following items:

• Changes Applied to the Switch:

  Item	Description
  Context	Session ID and user
  Operation	COMMIT/ABORT
  Database	Running or Candidate
  ConfigMO	MO tree’s text representation. Up to 3K characters.
  Status	SUCCESS/FAILED

  Example:

  Wed Jun 29 13:53:37 
  2022:type=update:id=3180018864:user=admin:cmd=(COMMIT),database=[running],configMo=[
  <topSystem childAction="" dn="sys" status="created,modified"><interfaceEntity childAction=""
  rn="intf" status="created,modified"><l3LbRtdIf childAction="" descr="test" id="lo10" rn="lb-
  [lo10]" status="created,modified"/></interfaceEntity></topSystem>] (SUCCESS)

• Original Received Request:

  Item	Description
  Context	Session ID and user
  Operation	RESTCONF:POST, RESTCONF:PUT, RESTCONF:PATCH, RESTCONF:DELETE
  Source IP	RESTCONF Client IP
  URL	HTTP URL
  Payload	Received XML/JSON Request. Up to 3K characters.
  Status	SUCCESS/FAILED

  Example:

  Wed Jun 29 13:53:37 
  2022:type=update:id=3180018864:user=admin:cmd=(RESTCONF:POST),sourceIp=[192.168.1.2],
  url=[/restconf/data/Cisco-NX-OS-device:System/intf-items/lb-items/LbRtdIf-
  list=lo10],payload=[<descr>test</descr>] (SUCCESS)

In case of failed request, based on the failed scenarios, a user may not observe both the logs.

• Invalid Request:

  The invalid request would be rejected without making a configuration change, thus only the original request would be logged.

  Example:

  Wed Jun 29 20:16:26 
  2022:type=update:id=3180018864:user=admin:cmd=(RESTCONF:POST),
  sourceIp=[192.168.1.2],url=[/restconf/data/Cisco-NX-OS-device:System/intf-items/lb-items/LbRtdIf-
  list=lo10],payload=[<descr>test</descr>] (FAILED)

• Request Fails due to Various Configuration Restrictions:

  In this case, both the failed configuration attempt and the original request would be logged.

  Example:

  Wed Jun 29 20:32:01 
  2022:type=update:id=3180018864:user=admin:cmd=(COMMIT),database=[running],
  configMo=[<topSystem childAction="" dn="sys" status="created,modified"><telemetryEntity 
  childAction="" rn="tm" status="created,modified"><telemetryCertificate childAction=""
  filename="foo" hostname="foo" rn="certificate" status="created,modified"
  trustpoint="test"/></telemetryEntity></topSystem>] (FAILED)

  Wed Jun 29 20:32:01 
  2022:type=update:id=3180018864:user=admin:cmd=(RESTCONF:PATCH),
  sourceIp=[192.168.1.2],url=[/restconf/data/Cisco-NX-OS-device:System/tm-items/certificate-
  items],payload=[<trustpoint>test</trustpoint><hostname>foo</hostname><filename>
  foo</filename>] (FAILED)