NETCONF User Guide

Overview

NETCONF is an XML-based protocol used for configuration and monitoring devices in the network. The base NETCONF protocol is described in RFC-6241.

NETCONF in OpenDaylight:.

OpenDaylight supports the NETCONF protocol as a northbound server as well as a southbound plugin. It also includes a set of test tools for simulating NETCONF devices and clients.

Southbound (netconf-connector)

The NETCONF southbound plugin is capable of connecting to remote NETCONF devices and exposing their configuration/operational datastores, RPCs and notifications as MD-SAL mount points. These mount points allow applications and remote users (over RESTCONF) to interact with the mounted devices.

In terms of RFCs, the connector supports:

Netconf-connector is fully model-driven (utilizing the YANG modeling language) so in addition to the above RFCs, it supports any data/RPC/notifications described by a YANG model that is implemented by the device.

Tip

NETCONF southbound can be activated by installing odl-netconf-connector-all Karaf feature.

Netconf-connector configuration

NETCONF connectors are configured directly through the usage of the network-topology model. You can configure new NETCONF connectors both through the NETCONF server for MD-SAL (port 2830) or RESTCONF. This guide focuses on RESTCONF.

Important

Since 2022.09 Chlorine there is only one RESTCONF endpoint:

  • http://localhost:8181/rests is related to RFC-8040,
    can be activated by installing odl-restconf-nb Karaf feature.
Resources for configuration and operational datastores start /rests/data/,
e. g. GET http://localhost:8181/rests/data/network-topology:network-topology with response of both datastores. It’s allowed to use query parameters to distinguish between them.
e. g. GET http://localhost:8181/rests/data/network-topology:network-topology?content=config for configuration datastore
and GET http://localhost:8181/rests/data/network-topology:network-topology?content=nonconfig for operational datastore.
Also if a data node in the path expression is a YANG leaf-list or list node, the path segment has to be constructed by having leaf-list or list node name, followed by an “=” character, then followed by the leaf-list or list value. Any reserved characters must be percent-encoded.
e. g. GET http://localhost:8181/rests/data/network-topology:network-topology/topology=topology-netconf?content=config for retrieving data from configuration datastore for topology-netconf value of topology list.

Preconditions

  1. OpenDaylight is running

  2. In Karaf, you must have the odl-netconf-topology or odl-netconf-clustered-topology feature installed.

  3. Feature odl-restconf-nb must be installed

Spawning new NETCONF connectors

To create a new NETCONF connector you need to send the following PUT request to RESTCONF:

rfc8040

http://localhost:8181/rests/data/network-topology:network-topology/topology=topology-netconf/node=new-netconf-device

You could use the same body to create the new NETCONF connector with a POST without specifying the node in the URL:

rfc8040

http://localhost:8181/rests/data/network-topology:network-topology/topology=topology-netconf

Payload for password authentication:

Content-type: application/xml

Accept: application/xml

Authentication: admin:admin

<node xmlns="urn:TBD:params:xml:ns:yang:network-topology">
  <node-id>new-netconf-device</node-id>
  <host xmlns="urn:opendaylight:netconf-node-topology">127.0.0.1</host>
  <port xmlns="urn:opendaylight:netconf-node-topology">17830</port>
  <login-password-unencrypted xmlns="urn:opendaylight:netconf-node-topology">
    <username xmlns="urn:opendaylight:netconf-node-topology">admin</username>
    <password xmlns="urn:opendaylight:netconf-node-topology">admin</password>
  </login-password-unencrypted>
  <tcp-only xmlns="urn:opendaylight:netconf-node-topology">false</tcp-only>
  <!-- non-mandatory fields with default values, you can safely remove these if you do not wish to override any of these values-->
  <reconnect-on-changed-schema xmlns="urn:opendaylight:netconf-node-topology">false</reconnect-on-changed-schema>
  <connection-timeout-millis xmlns="urn:opendaylight:netconf-node-topology">20000</connection-timeout-millis>
  <max-connection-attempts xmlns="urn:opendaylight:netconf-node-topology">0</max-connection-attempts>
  <min-backoff-millis xmlns="urn:opendaylight:netconf-node-topology">2000</min-backoff-millis>
  <max-backoff-millis xmlns="urn:opendaylight:netconf-node-topology">1800000</max-backoff-millis>
  <backoff-multiplier xmlns="urn:opendaylight:netconf-node-topology">1.5</backoff-multiplier>
  <!-- keepalive-delay set to 0 turns off keepalives-->
  <keepalive-delay xmlns="urn:opendaylight:netconf-node-topology">120</keepalive-delay>
</node>

Note

You have the option to use the ‘login-password’ configuration for authentication as shown below:

"login-password": {
    "netconf-node-topology:username": "netconf",
    "netconf-node-topology:password": "c5R3aLBss7J8T2VC3pEeAQ=="
}

In OpenDaylight’s configuration, the AAAEncryptionServiceImpl generates a new encryption key with each application build. You can use this method if you have access to the current encryption key. Additionally, it is important to ensure that the entire password is encoded in base64 format and that its length is a multiple of 16 bytes for successful authentication.

There is also option of using key-based authentication instead of password. First we need to create key in datastore.

Adding a client private key credential to the netconf-keystore

POST HTTP/1.1
/rests/operations/netconf-keystore:add-keystore-entry
Content-Type: application/json
Accept: application/json

{
  "input": {
    "key-credential": [
      {
        "key-id": "example-client-key-id",
        "private-key": "PEM-format-private-key",
        "passphrase": "passphrase"
      }
    ]
  }
}

After we can use this key to create connector using this key.

Payload for key-based authentication via SSH:

Content-type: application/xml

Accept: application/xml

Authentication: admin:admin

<node xmlns="urn:TBD:params:xml:ns:yang:network-topology">
  <node-id>new-netconf-device</node-id>
  <host xmlns="urn:opendaylight:netconf-node-topology">127.0.0.1</host>
  <port xmlns="urn:opendaylight:netconf-node-topology">17830</port>
  <key-based xmlns="urn:opendaylight:netconf-node-topology">
    <username xmlns="urn:opendaylight:netconf-node-topology">admin</username>
    <key-id xmlns="urn:opendaylight:netconf-node-topology">key-id</password>
  </key-based>
  <tcp-only xmlns="urn:opendaylight:netconf-node-topology">false</tcp-only>
  <!-- non-mandatory fields with default values, you can safely remove these if you do not wish to override any of these values-->
  <reconnect-on-changed-schema xmlns="urn:opendaylight:netconf-node-topology">false</reconnect-on-changed-schema>
  <connection-timeout-millis xmlns="urn:opendaylight:netconf-node-topology">20000</connection-timeout-millis>
  <max-connection-attempts xmlns="urn:opendaylight:netconf-node-topology">0</max-connection-attempts>
  <min-backoff-millis xmlns="urn:opendaylight:netconf-node-topology">2000</min-backoff-millis>
  <max-backoff-millis xmlns="urn:opendaylight:netconf-node-topology">1800000</max-backoff-millis>
  <backoff-multiplier xmlns="urn:opendaylight:netconf-node-topology">1.5</backoff-multiplier>
  <!-- keepalive-delay set to 0 turns off keepalives-->
  <keepalive-delay xmlns="urn:opendaylight:netconf-node-topology">120</keepalive-delay>
</node>

Connecting via TLS protocol is similar to SSH. First setup keystore by using three RPCs from Configure device to connect over TLS protocol to add a client private key, associate a private key with a client and CA certificates chain and add a list of trusted CA and server certificates. Only after that we can process and create a new NETCONF connector you need to send the following PUT request.

Payload for key-based authentication via TLS:

Content-type: application/xml

Accept: application/xml

Authentication: admin:admin

<node xmlns="urn:TBD:params:xml:ns:yang:network-topology">
  <node-id>new-netconf-device</node-id>
  <host xmlns="urn:opendaylight:netconf-node-topology">127.0.0.1</host>
  <port xmlns="urn:opendaylight:netconf-node-topology">17830</port>
  <key-based xmlns="urn:opendaylight:netconf-node-topology">
    <username xmlns="urn:opendaylight:netconf-node-topology">admin</username>
    <key-id xmlns="urn:opendaylight:netconf-node-topology">key-id</password>
  </key-based>
  <tcp-only xmlns="urn:opendaylight:netconf-node-topology">false</tcp-only>
  <!-- non-mandatory fields with default values, you can safely remove these if you do not wish to override any of these values-->
  <reconnect-on-changed-schema xmlns="urn:opendaylight:netconf-node-topology">false</reconnect-on-changed-schema>
  <connection-timeout-millis xmlns="urn:opendaylight:netconf-node-topology">20000</connection-timeout-millis>
  <max-connection-attempts xmlns="urn:opendaylight:netconf-node-topology">0</max-connection-attempts>
  <min-backoff-millis xmlns="urn:opendaylight:netconf-node-topology">2000</min-backoff-millis>
  <max-backoff-millis xmlns="urn:opendaylight:netconf-node-topology">1800000</max-backoff-millis>
  <backoff-multiplier xmlns="urn:opendaylight:netconf-node-topology">1.5</backoff-multiplier>
  <!-- keepalive-delay set to 0 turns off keepalives-->
  <keepalive-delay xmlns="urn:opendaylight:netconf-node-topology">120</keepalive-delay>
  <protocol xmlns="urn:opendaylight:netconf-node-topology">
    <name xmlns="urn:opendaylight:netconf-node-topology">TLS</name>
  </protocol>
</node>

Note that the device name in <node-id> element must match the last element of the restconf URL.

Reconfiguring an existing connector

The steps to reconfigure an existing connector are exactly the same as when spawning a new connector. The old connection will be disconnected and a new connector with the new configuration will be created. This needs to be done with a PUT request because the node already exists. A POST request will fail for that reason.

Additionally, a PATCH request can be used to modify an existing configuration. Currently, only yang-patch (RFC-8072) is supported. The URL would be the same as the above PUT examples. Using JSON for the body, the headers needed for the request would be:

Headers:

  • Accept: application/yang-data+json

  • Content-Type: application/yang-patch+json

Example JSON payload to modify the password entry:

{
  "ietf-restconf:yang-patch" : {
    "patch-id" : "0",
    "edit" : [
      {
        "edit-id" : "edit1",
        "operation" : "merge",
        "target" : "",
        "value" : {
         "node": [
            {
             "node-id": "new-netconf-device",
             "netconf-node-topology:password" : "newpassword"
            }
         ]
        }
     }
    ]
  }
}

Deleting an existing connector

To remove an already configured NETCONF connector you need to send a DELETE request to the same PUT request URL that was used to create the device:

rfc8040

http://localhost:8181/rests/data/network-topology:network-topology/topology=topology-netconf/node=new-netconf-device

Note

No body is needed to delete the node/device

Connecting to a device not supporting NETCONF monitoring

The netconf-connector in OpenDaylight relies on ietf-netconf-monitoring support when connecting to remote NETCONF device. The ietf-netconf-monitoring support allows netconf-connector to list and download all YANG schemas that are used by the device. NETCONF connector can only communicate with a device if it knows the set of used schemas (or at least a subset). However, some devices use YANG models internally but do not support NETCONF monitoring. Netconf-connector can also communicate with these devices, but you have to side load the necessary yang models into OpenDaylight’s YANG model cache for netconf-connector. In general there are 2 situations you might encounter:

1. NETCONF device does not support ietf-netconf-monitoring but it does list all its YANG models as capabilities in HELLO message

This could be a device that internally uses only ietf-inet-types YANG model with revision 2010-09-24. In the HELLO message that is sent from this device there is this capability reported:

urn:ietf:params:xml:ns:yang:ietf-inet-types?module=ietf-inet-types&revision=2010-09-24

For such devices you only need to put the schema into folder cache/schema inside your Karaf distribution.

Important

The file with YANG schema for ietf-inet-types has to be called ietf-inet-types@2010-09-24.yang. It is the required naming format of the cache.

2. NETCONF device does not support ietf-netconf-monitoring and it does NOT list its YANG models as capabilities in HELLO message

Compared to device that lists its YANG models in HELLO message, in this case there would be no capability with ietf-inet-types in the HELLO message. This type of device basically provides no information about the YANG schemas it uses so its up to the user of OpenDaylight to properly configure netconf-connector for this device.

Netconf-connector has an optional configuration attribute called yang-module-capabilities and this attribute can contain a list of “YANG module based” capabilities. So by setting this configuration attribute, it is possible to override the “yang-module-based” capabilities reported in HELLO message of the device. To do this, we need to modify the configuration of netconf-connector like in the example below:

Content-type: application/xml

Accept: application/xml

Authentication: admin:admin

<node xmlns="urn:TBD:params:xml:ns:yang:network-topology">
  <node-id>r5</node-id>
  <host xmlns="urn:opendaylight:netconf-node-topology">127.0.0.1</host>
  <port xmlns="urn:opendaylight:netconf-node-topology">8305</port>
  <login-password-unencrypted xmlns="urn:opendaylight:netconf-node-topology">
    <username xmlns="urn:opendaylight:netconf-node-topology">root</username>
    <password xmlns="urn:opendaylight:netconf-node-topology">root</password>
  </login-password-unencrypted>
  <tcp-only xmlns="urn:opendaylight:netconf-node-topology">false</tcp-only>
  <keepalive-delay xmlns="urn:opendaylight:netconf-node-topology">30</keepalive-delay>
  <yang-module-capabilities xmlns="urn:opendaylight:netconf-node-topology">
    <override>true</override>
    <capability xmlns="urn:opendaylight:netconf-node-topology">
      urn:ietf:params:xml:ns:yang:ietf-inet-types?module=ietf-inet-types&amp;revision=2013-07-15
    </capability>
  </yang-module-capabilities>
</node>

Remember to also put the YANG schemas into the cache folder.

Note

For putting multiple capabilities, you just need to replicate the capability element inside yang-module-capability element. Capability element is modeled as a leaf-list. With this configuration, we would make the remote device report usage of ietf-inet-types in the eyes of netconf-connector.

Connecting to a device supporting only NETCONF 1.0

OpenDaylight is schema-based distribution and heavily depends on YANG models. However some legacy NETCONF devices are not schema-based and implement just RFC 4741. This type of device does not utilize YANG models internally and OpenDaylight does not know how to communicate with such devices, how to validate data, or what the semantics of data are.

NETCONF connector can communicate also with these devices, but the trade-offs are worsened possibilities in utilization of NETCONF mountpoints. Using RESTCONF with such devices is not supported. Also communicating with schemaless devices from application code is slightly different.

To connect to schemaless device, there is a optional configuration option in netconf-node-topology model called schemaless. You have to set this option to true.

Clustered NETCONF connector

To spawn NETCONF connectors that are cluster-aware you need to install the odl-netconf-clustered-topology karaf feature.

Warning

The odl-netconf-topology and odl-netconf-clustered-topology features are considered INCOMPATIBLE. They both manage the same space in the datastore and would issue conflicting writes if installed together.

Configuration of clustered NETCONF connectors works the same as the configuration through the topology model in the previous section.

When a new clustered connector is configured the configuration gets distributed among the member nodes and a NETCONF connector is spawned on each node. From these nodes a master is chosen which handles the schema download from the device and all the communication with the device. You will be able to read/write to/from the device from all slave nodes due to the proxy data brokers implemented.

You can use the odl-netconf-clustered-topology feature in a single node scenario as well but the code that uses akka will be used, so for a scenario where only a single node is used, odl-netconf-topology might be preferred.

Netconf-connector utilization

Once the connector is up and running, users can utilize the new mount point instance. By using RESTCONF or from their application code. This chapter deals with using RESTCONF and more information for app developers can be found in the developers guide or in the official tutorial application ncmount that can be found in the coretutorials project:

Reading data from the device

Just invoke (no body needed):

GET http://localhost:8181/rests/data/network-topology:network-topology/topology=topology-netconf/node=new-netconf-device/yang-ext:mount?content=nonconfig

This will return the entire content of operation datastore from the device. To view just the configuration datastore, change nonconfig in this URL to config.

Writing configuration data to the device

In general, you cannot simply write any data you want to the device. The data have to conform to the YANG models implemented by the device. In this example we are adding a new interface-configuration to the mounted device (assuming the device supports Cisco-IOS-XR-ifmgr-cfg YANG model). In fact this request comes from the tutorial dedicated to the ncmount tutorial app.

POST http://localhost:8181/rests/data/network-topology:network-topology/topology=topology-netconf/node=new-netconf-device/yang-ext:mount/Cisco-IOS-XR-ifmgr-cfg:interface-configurations

<interface-configuration xmlns="http://cisco.com/ns/yang/Cisco-IOS-XR-ifmgr-cfg">
    <active>act</active>
    <interface-name>mpls</interface-name>
    <description>Interface description</description>
    <bandwidth>32</bandwidth>
    <link-status></link-status>
</interface-configuration>

Should return 200 response code with no body.

Tip

This call is transformed into a couple of NETCONF RPCs. Resulting NETCONF RPCs that go directly to the device can be found in the OpenDaylight logs after invoking log:set TRACE org.opendaylight.controller.sal.connect.netconf in the Karaf shell. Seeing the NETCONF RPCs might help with debugging.

This request is very similar to the one where we spawned a new netconf device. That’s because we used the loopback netconf-connector to write configuration data into config-subsystem datastore and config-subsystem picked it up from there.

Invoking custom RPC

Devices can implement any additional RPC and as long as it provides YANG models for it, it can be invoked from OpenDaylight. Following example shows how to invoke the get-schema RPC (get-schema is quite common among netconf devices). Invoke:

POST http://localhost:8181/rests/operations/network-topology:network-topology/topology=topology-netconf/node=new-netconf-device/yang-ext:mount/ietf-netconf-monitoring:get-schema

<input xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-monitoring">
  <identifier>ietf-yang-types</identifier>
  <version>2013-07-15</version>
</input>

This call should fetch the source for ietf-yang-types YANG model from the mounted device.

Receiving Netconf Device Notifications on a http client

Devices emit netconf alarms and notifications in certain situations, which can demand attention from Device Administration. The notifications are received as Netconf messages on an active Netconf session.

Opendaylight provides the way to stream the device notifications over a http session.

  • Step 1: Mount the device (assume node name is test_device)

  • Step 2: Wait for the device to be connected.

  • Step 3: Create the Subscription for notification on the active session.

POST
http://localhost:8181/rests/operations/network-topology:network-topology/topology=topology-netconf/node=test_device/yang-ext:mount/notifications:create-subscription
Content-Type: application/json
Accept: application/json

{
  "input": {
    "stream": "NETCONF"
   }
}

  • Step 4: Create the http Stream for the events.

POST
http://localhost:8181/rests/operations/odl-device-notification:subscribe-device-notification
Content-Type: application/json
Accept: application/json

{
  "input": {
     "path":"/network-topology:network-topology/topology[topology-id='topology-netconf']/node[node-id='test_device']"
  }
}

The response suggests the http url for reading the notifications.

{
   "odl-device-notification:output": {
        "stream-path": "http://localhost:8181/rests/notif/test_device?notificationType=test_device"
    }
}

  • Step 5: User can access the url in the response and the notifications will be as follows.

GET
http://localhost:8181/rests/notif/test_device?notificationType=test_device
Content-Type: application/xml
Accept: application/xml

: ping

: ping

: ping

: ping

: ping

data: <notification xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0"><eventTime>2022-06-17T07:01:08.60228Z</eventTime><netconf-session-start xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-notifications"><username>root</username><source-host>127.0.0.1</source-host><session-id>2</session-id></netconf-session-start></notification>

data: <notification xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0"><eventTime>2022-06-17T07:01:12.458258Z</eventTime><netconf-session-end xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-notifications"><username>root</username><source-host>127.0.0.1</source-host><termination-reason>closed</termination-reason><session-id>2</session-id></netconf-session-end></notification>

Change event notification subscription tutorial

Subscribing to data change notifications makes it possible to obtain notifications about data manipulation (insert, change, delete) which are done on any specified path of any specified datastore with specific scope. In following examples {odlAddress} is address of server where ODL is running and {odlPort} is port on which OpenDaylight is running. OpenDaylight offers two methods for receiving notifications: Server-Sent Events (SSE) and WebSocket. SSE is the default notification mechanism used in OpenDaylight.

SSE notifications subscription process

In this section we will learn what steps need to be taken in order to successfully subscribe to data change event notifications.

Create stream

In order to use event notifications you first need to call RPC that creates notification stream that you can later listen to. You need to provide three parameters to this RPC:

  • path: data store path that you plan to listen to. You can register listener on containers, lists and leaves.

  • datastore: data store type. OPERATIONAL or CONFIGURATION.

  • scope: Represents scope of data change. Possible options are:

    • BASE: only changes directly to the data tree node specified in the path will be reported

    • ONE: changes to the node and to direct child nodes will be reported

    • SUBTREE: changes anywhere in the subtree starting at the node will be reported

The RPC to create the stream can be invoked via RESTCONF like this:

OPERATION: POST
URI:  http://{odlAddress}:{odlPort}/rests/operations/sal-remote:create-data-change-event-subscription
HEADER: Content-Type=application/json
        Accept=application/json

{
    "input": {
        "path": "/toaster:toaster/toaster:toasterStatus",
        "sal-remote-augment:datastore": "OPERATIONAL",
        "sal-remote-augment:scope": "ONE"
    }
}

The response should look something like this:

{
    "sal-remote:output": {
        "stream-name": "data-change-event-subscription/toaster:toaster/toaster:toasterStatus/datastore=CONFIGURATION/scope=SUBTREE"
    }
}

stream-name is important because you will need to use it when you subscribe to the stream in the next step.

Note

Internally, this will create a new listener for stream-name if it did not already exist.

Subscribe to stream

In order to subscribe to stream and obtain SSE location you need to call GET on your stream path. The URI should generally be http://{odlAddress}:{odlPort}/rests/data/ietf-restconf-monitoring:restconf-state/streams/stream/{streamName}, where {streamName} is the stream-name parameter contained in response from create-data-change-event-subscription RPC from the previous step.

OPERATION: GET
URI: http://{odlAddress}:{odlPort}/rests/data/ietf-restconf-monitoring:restconf-state/streams/stream/data-change-event-subscription/toaster:toaster/datastore=CONFIGURATION/scope=SUBTREE

The subscription call may be modified with the following query parameters defined in the RESTCONF RFC:

In addition, the following ODL extension query parameter is supported:

odl-leaf-nodes-only:

If this parameter is set to “true”, create and update notifications will only contain the leaf nodes modified instead of the entire subscription subtree. This can help in reducing the size of the notifications.

odl-skip-notification-data:

If this parameter is set to “true”, create and update notifications will only contain modified leaf nodes without data. This can help in reducing the size of the notifications.

The response should look something like this:

{
    "subscribe-to-notification:location": "http://localhost:8181/rests/notif/data-change-event-subscription/network-topology:network-topology/datastore=CONFIGURATION/scope=SUBTREE"
}

Note

During this phase there is an internal check for to see if a listener for the stream-name from the URI exists. If not, new a new listener is registered with the DOM data broker.

Receive notifications

Once you got SSE location you can now connect to it and start receiving data change events. The request should look something like this:

curl -v -X GET  http://localhost:8181/rests/notif/data-change-event-subscription/toaster:toaster/toasterStatus/datastore=OPERATIONAL/scope=ONE  -H "Content-Type: text/event-stream" -H "Authorization: Basic YWRtaW46YWRtaW4="

WebSocket notifications subscription process

Enabling WebSocket notifications in OpenDaylight requires a manual setup before starting the application. The following steps can be followed to enable WebSocket notifications in OpenDaylight:

  1. Open the file org.opendaylight.restconf.nb.rfc8040.cfg, at etc/ folder inside your Karaf distribution. Or create in case it does not exist.

  2. Locate the use-sse configuration parameter and change its value from true to false. Or add use-sse=false as new line in case this parameter is not present.

  3. Save the changes made to the org.opendaylight.restconf.nb.rfc8040.cfg file.

  4. Restart OpenDaylight if it is already running.

Once these steps are completed, WebSocket notifications will be enabled in OpenDaylight, and they can be used for receiving notifications instead of SSE.

WebSocket Notifications subscription process is the same as SSE until you receive a location of WebSocket. You can follow steps given above and after subscribing to a notification stream over WebSocket, you will receive a response indicating that the subscription was successful:

{
    "subscribe-to-notification:location": "ws://localhost:8181/rests/notif/data-change-event-subscription/network-topology:network-topology/datastore=CONFIGURATION/scope=SUBTREE"
}

You can use this WebSocket to listen to data change notifications. To listen to notifications you can use a JavaScript client or if you are using chrome browser you can use the Simple WebSocket Client.

Also, for testing purposes, there is simple Java application named WebSocketClient. The application is placed in the /restconf/websocket-client project. It accepts a WebSocket URI as an input parameter. After starting the utility (WebSocketClient class directly in Eclipse/InteliJ Idea) received notifications should be displayed in console.

Notifications are always in XML format and look like this:

<notification xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0">
    <eventTime>2014-09-11T09:58:23+02:00</eventTime>
    <data-changed-notification xmlns="urn:opendaylight:params:xml:ns:yang:controller:md:sal:remote">
        <data-change-event>
            <path xmlns:meae="http://netconfcentral.org/ns/toaster">/meae:toaster</path>
            <operation>updated</operation>
            <data>
               <!-- updated data -->
            </data>
        </data-change-event>
    </data-changed-notification>
</notification>

Example use case

The typical use case is listening to data change events to update web page data in real time. In this tutorial we will be using toaster as the base.

When you call make-toast RPC, it sets toasterStatus to “down” to reflect that the toaster is busy making toast. When it finishes, toasterStatus is set to “up” again. We will listen to these toaster status changes in data store and will reflect it on our web page in real-time thanks to WebSocket data change notification.

Simple javascript client implementation

We will create a simple JavaScript web application that will listen for updates on toasterStatus leaf and update some elements of our web page according to the new toaster status state.

Create stream

First you need to create stream that you are planning to subscribe to. This can be achieved by invoking “create-data-change-event-subscription” RPC on RESTCONF via AJAX request. You need to provide data store path that you plan to listen on, data store type and scope. If the request is successful you can extract the stream-name from the response and use that to subscribe to the newly created stream. The {username} and {password} fields represent the credentials that you use to connect to OpenDaylight via RESTCONF:

Note

The default user name and password are “admin”.

function createStream() {
    $.ajax(
        {
            url: 'http://{odlAddress}:{odlPort}/rests/operations/sal-remote:create-data-change-event-subscription',
            type: 'POST',
            headers: {
              'Authorization': 'Basic ' + btoa('{username}:{password}'),
              'Content-Type': 'application/json'
            },
            data: JSON.stringify(
                {
                    'input': {
                        'path': '/toaster:toaster/toaster:toasterStatus',
                        'sal-remote-augment:datastore': 'OPERATIONAL',
                        'sal-remote-augment:scope': 'ONE'
                    }
                }
            )
        }).done(function (data) {
            // this function will be called when ajax call is executed successfully
            subscribeToStream(data.output['stream-name']);
        }).fail(function (data) {
            // this function will be called when ajax call fails
            console.log("Create stream call unsuccessful");
        })
}

Subscribe to stream

The Next step is to subscribe to the stream. To subscribe to the stream you need to call GET on http://{odlAddress}:{odlPort}/rests/data/ietf-restconf-monitoring:restconf-state/streams/stream/{stream-name}. If the call is successful, you get WebSocket address for this stream in Location parameter inside response header. You can get response header by calling getResponseHeader(*Location)* on HttpRequest object inside done() function call:

function subscribeToStream(streamName) {
    $.ajax(
        {
            url: 'http://{odlAddress}:{odlPort}/rests/data/ietf-restconf-monitoring:restconf-state/streams/stream/' + streamName;
            type: 'GET',
            headers: {
              'Authorization': 'Basic ' + btoa('{username}:{password}'),
            }
        }
    ).done(function (data, textStatus, httpReq) {
        // we need function that has http request object parameter in order to access response headers.
        listenToNotifications(httpReq.getResponseHeader('Location'));
    }).fail(function (data) {
        console.log("Subscribe to stream call unsuccessful");
    });
}

Receive notifications

Once you have WebSocket server location you can now connect to it and start receiving data change events. You need to define functions that will handle events on WebSocket. In order to process incoming events from OpenDaylight you need to provide a function that will handle onmessage events. The function must have one parameter that represents the received event object. The event data will be stored in event.data. The data will be in an XML format that you can then easily parse using jQuery.

function listenToNotifications(socketLocation) {
    try {
        var notificatinSocket = new WebSocket(socketLocation);

        notificatinSocket.onmessage = function (event) {
            // we process our received event here
            console.log('Received toaster data change event.');
            $($.parseXML(event.data)).find('data-change-event').each(
                function (index) {
                    var operation = $(this).find('operation').text();
                    if (operation == 'updated') {
                        // toaster status was updated so we call function that gets the value of toasterStatus leaf
                        updateToasterStatus();
                        return false;
                    }
                }
            );
        }
        notificatinSocket.onerror = function (error) {
            console.log("Socket error: " + error);
        }
        notificatinSocket.onopen = function (event) {
            console.log("Socket connection opened.");
        }
        notificatinSocket.onclose = function (event) {
            console.log("Socket connection closed.");
        }
        // if there is a problem on socket creation we get exception (i.e. when socket address is incorrect)
    } catch(e) {
        alert("Error when creating WebSocket" + e );
    }
}

The updateToasterStatus() function represents function that calls GET on the path that was modified and sets toaster status in some web page element according to received data. After the WebSocket connection has been established you can test events by calling make-toast RPC via RESTCONF.

Note

for more information about WebSockets in JavaScript visit Writing WebSocket client applications

Netconf-connector + Netopeer

Netopeer (an open-source NETCONF server) can be used for testing/exploring NETCONF southbound in OpenDaylight.

Netopeer installation

A Docker container with netopeer will be used in this guide. To install Docker and start the netopeer image perform following steps:

  1. Install docker https://docs.docker.com/get-started/

  2. Start the netopeer image:

    docker run -it --name sysrepo -p 830:830 --rm sysrepo/sysrepo-netopeer2:latest

  3. Verify netopeer is running by invoking (netopeer should send its HELLO message right away:

    ssh root@localhost -p 830 -s netconf
(password root)

Mounting netopeer NETCONF server

Preconditions:

  • OpenDaylight is started with features odl-restconf-all and odl-netconf-connector-all.

  • Netopeer is up and running in docker

Now just follow the section: Spawning new NETCONF connectors for password authentication. In the payload change the:

  • name, e.g., to netopeer

  • username/password to your system credentials

  • ip to localhost

  • port to 830.

After netopeer is mounted successfully, its configuration can be read using RESTCONF by invoking:

GET http://localhost:8181/rests/data/network-topology:network-topology/topology=topology-netconf/node=netopeer/yang-ext:mount?content:config

Mounting netopeer NETCONF server using key-based authentication SSH

  1. Install docker https://docs.docker.com/get-started/

  2. Create RSA key pair - it will be user for connection.

  3. Start the netopeer image(this command will also copy you pub key into docker container):

    docker run -dt -p 830:830 -v {path-to-pub-key}:/home/{netopeer-username}/.ssh/authorized_keys sysrepo/sysrepo-netopeer2:latest netopeer2-server -d -v 2

  4. Verify netopeer is running by invoking (netopeer should send its HELLO message right away:

    ssh root@localhost -p 830 -s netconf
(password root)

Now just follow the section: Spawning new NETCONF connectors for key-based authentication(SSH) to create device. In the payload change the:

  • name, e.g., to netopeer

  • username/password to your system credentials

  • ip to localhost

  • port to 830.

After netopeer is mounted successfully, its configuration can be read using RESTCONF by invoking:

GET http://localhost:8181/rests/data/network-topology:network-topology/topology=topology-netconf/node=netopeer/yang-ext:mount?content:config

Mounting netopeer NETCONF server using key-based authentication TLS

  1. Install docker https://docs.docker.com/get-started/

  2. Run netopeer2

    docker pull sysrepo/sysrepo-netopeer2
docker run -it --name sysrepo -p 830:830 --rm sysrepo/sysrepo-netopeer2:latest

  3. Enable TLS communication on server netopeer2

    ssh root@localhost -p 830 -s netconf
(type password root)

    After successful connecting to netopeer2 setup your TLS configuration xml (See: https://github.com/CESNET/netopeer2/tree/master/example_configuration).

  4. Run ODL:

  • :~/netconf/karaf/target/assembly/bin$ ./karaf

  • feature:install odl-netconf-topology odl-restconf-nb-bierman02 odl-mdsal-apidocs

  1. Set up ODL netconf keystore

    To setup keystore is needed to send three RPCs from Configure device to connect over TLS protocol to add a client private key, associate a private key with a client and CA certificates chain and add a list of trusted CA and server certificates.

Now just follow the section: Spawning new NETCONF connectors for key-based authentication(TLS) to create device. In the payload change the:

  • name, e.g., to netopeer

  • username/password to your system credentials

  • ip to localhost

  • port to 830.

After netopeer is mounted successfully, its configuration can be read using RESTCONF by invoking:

GET http://localhost:8181/rests/data/network-topology:network-topology/topology=topology-netconf/node=netopeer/yang-ext:mount?content:config

Northbound (NETCONF servers)

OpenDaylight provides 2 types of NETCONF servers:

  • NETCONF server for config-subsystem (listening by default on port 1830)

    • Serves as a default interface for config-subsystem and allows users to spawn/reconfigure/destroy modules (or applications) in OpenDaylight

  • NETCONF server for MD-SAL (listening by default on port 2830)

    • Serves as an alternative interface for MD-SAL (besides RESTCONF) and allows users to read/write data from MD-SAL’s datastore and to invoke its rpcs (NETCONF notifications are not available in the Boron release of OpenDaylight)

Note

The reason for having 2 NETCONF servers is that config-subsystem and MD-SAL are 2 different components of OpenDaylight and require different approaches for NETCONF message handling and data translation. These 2 components will probably merge in the future.

Note

Since Nitrogen release, there has been performance regression in NETCONF servers accepting SSH connections. While opening a connection takes less than 10 seconds on Carbon, on Nitrogen time can increase up to 60 seconds. Please see https://jira.opendaylight.org/browse/ODLPARENT-112

NETCONF server for config-subsystem

This NETCONF server is the primary interface for config-subsystem. It allows the users to interact with config-subsystem in a standardized NETCONF manner.

In terms of RFCs, these are supported:

For regular users it is recommended to use RESTCONF + the controller-config loopback mountpoint instead of using pure NETCONF. How to do that is specific for each component/module/application in OpenDaylight and can be found in their dedicated user guides.

NETCONF server for MD-SAL

This NETCONF server is just a generic interface to MD-SAL in OpenDaylight. It uses the standard MD-SAL APIs and serves as an alternative to RESTCONF. It is fully model-driven and supports any data and rpcs that are supported by MD-SAL.

In terms of RFCs, these are supported:

Notifications over NETCONF are not supported in the Boron release.

Tip

Install NETCONF northbound for MD-SAL by installing feature: odl-netconf-mdsal in karaf. Default binding port is 2830.

Configuration

The default configuration can be found in file: 08-netconf-mdsal.xml. The file contains the configuration for all necessary dependencies and a single SSH endpoint starting on port 2830. There is also a (by default disabled) TCP endpoint. It is possible to start multiple endpoints at the same time either in the initial configuration file or while OpenDaylight is running.

The credentials for SSH endpoint can also be configured here, the defaults are admin/admin. Credentials in the SSH endpoint are not yet managed by the centralized AAA component and have to be configured separately.

Verifying MD-SAL’s NETCONF server

After the NETCONF server is available it can be examined by a command line ssh tool:

ssh admin@localhost -p 2830 -s netconf

The server will respond by sending its HELLO message and can be used as a regular NETCONF server from then on.

Mounting the MD-SAL’s NETCONF server

To perform this operation, just spawn a new netconf-connector as described in Spawning new NETCONF connectors. Just change the ip to “127.0.0.1” port to “2830” and its name to “controller-mdsal”.

Now the MD-SAL’s datastore can be read over RESTCONF via NETCONF by invoking:

GET http://localhost:8181/rests/data/network-topology:network-topology/topology=topology-netconf/node=controller-mdsal/yang-ext:mount?content:nonconfig

Note

This might not seem very useful, since MD-SAL can be accessed directly from RESTCONF or from Application code, but the same method can be used to mount and control other OpenDaylight instances by the “master OpenDaylight”.

NETCONF stress/performance measuring tool

This is basically a NETCONF client that puts NETCONF servers under heavy load of NETCONF RPCs and measures the time until a configurable amount of them is processed.

RESTCONF stress-performance measuring tool

Very similar to NETCONF stress tool with the difference of using RESTCONF protocol instead of NETCONF.

YANGLIB remote repository

There are scenarios in NETCONF deployment, that require for a centralized YANG models repository. YANGLIB plugin provides such remote repository.

To start this plugin, you have to install odl-yanglib feature. Then you have to configure YANGLIB either through RESTCONF or NETCONF. We will show how to configure YANGLIB through RESTCONF.

YANGLIB configuration

YANGLIB configuration works through OSGi Configuration Admin interface, in the org.opendaylight.netconf.yanglib configuration PID. There are three tuneables you can set:

  • cache-folder, which defaults to cache/schema

  • binding-address, which defaults to localhost

  • binding-port, which defaults to 8181

In order to change these settings, you can either modify the corresponding configuration file, etc/org.opendaylight.netconf.yanglib.cfg, for example:

::

cache-folder = cache/newSchema binding-address = localhost binding-port = 8181

Or use Karaf CLI:

::

opendaylight-user@root>config:edit org.opendaylight.netconf.yanglib opendaylight-user@root>config:property-set cache-folder cache/newSchema opendaylight-user@root>config:property-set binding-address localhost opendaylight-user@root>config:property-set binding-port 8181 opendaylight-user@root>config:update

This YANGLIB takes all YANG sources from the configured sources folder and for each generates URL in form:

http://localhost:8181/yanglib/schemas/{modelName}/{revision}

On this URL will be hosted YANG source for particular module.

YANGLIB instance also writes this URL along with source identifier to ietf-netconf-yang-library/modules-state/module list.

Netconf-connector with YANG library as fallback

There is an optional configuration in netconf-connector called yang-library. You can specify YANG library to be plugged as additional source provider into the mount’s schema repository. Since YANGLIB plugin is advertising provided modules through yang-library model, we can use it in mount point’s configuration as YANG library. To do this, we need to modify the configuration of netconf-connector by adding this XML

<yang-library xmlns="urn:opendaylight:netconf-node-topology">
  <yang-library-url xmlns="urn:opendaylight:netconf-node-topology">http://localhost:8181/rests/data/ietf-yang-library:modules-state</yang-library-url>
  <username xmlns="urn:opendaylight:netconf-node-topology">admin</username>
  <password xmlns="urn:opendaylight:netconf-node-topology">admin</password>
</yang-library>

This will register YANGLIB provided sources as a fallback schemas for particular mount point.

Restconf northbound configuration

Restconf-nb configuration works through OSGi Configuration Admin interface, in the org.opendaylight.restconf.nb.rfc8040 configuration PID. There are six tuneables you can set:

  • maximum-fragment-length, which defaults to 0

  • heartbeat-interval, which defaults to 10000

  • idle-timeout, which defaults to 30000

  • ping-executor-name-prefix, which defaults to ping-executor

  • max-thread-count, which defaults to 1

  • use-sse, which defaults to true

  • restconf, which defaults to rests

maximum-fragment-length — Maximum web-socket fragment length in number of Unicode code units (characters) (exceeded message length leads to fragmentation of messages)

heartbeat-interval — Interval in milliseconds between sending of ping control frames.

idle-timeout — Maximum idle time of web-socket session before the session is closed (milliseconds).

ping-executor-name-prefix — Name of thread group Ping Executor will be run with.

max-thread-count — Number of threads Ping Executor will be run with.

use-sse — In case of true access to notification streams will be via Server-Sent Events. Otherwise web-socket servlet will be initialized.

restconf — The value of RFC8040 restconf URI template, pointing to the root resource. Must not end with ‘/’.

In order to change these settings, you can either modify the corresponding configuration file, org.opendaylight.restconf.nb.rfc8040.cfg, for example:

maximum-fragment-length=0
heartbeat-interval=10000
idle-timeout=30000
ping-executor-name-prefix=ping-executor
max-thread-count=1
use-sse=true
restconf=rests

Or use Karaf CLI:

opendaylight-user@root>config:edit org.opendaylight.restconf.nb.rfc8040
opendaylight-user@root>config:property-set maximum-fragment_length 0
opendaylight-user@root>config:property-set heartbeat-interval 10000
opendaylight-user@root>config:property-set idle-timeout 30000
opendaylight-user@root>config:property-set ping-executor-name-prefix "ping-executor"
opendaylight-user@root>config:property-set max-thread-count 1
opendaylight-user@root>config:property-set use-sse true
opendaylight-user@root>config:property-set restconf "rests"
opendaylight-user@root>config:update

NETCONF Call Home

Call Home Installation

ODL Call-Home server is installed in Karaf by installing karaf feature odl-netconf-callhome-ssh. RESTCONF feature is recommended for configuring Call Home & testing its functionality.

feature:install odl-netconf-callhome-ssh

Note

In order to test Call Home functionality we recommend Netopeer or Netopeer2. See Netopeer Call Home or Netopeer2 to learn how to enable call-home on Netopeer.

Northbound Call-Home API

The northbound Call Home API is used for administering the Call-Home Server. The following describes this configuration.

Global Configuration

Important

The global configuration is not a part of the RFC 8071 and, therefore, subject to change.

Configuring global credentials

The ODL Call-Home server allows user to configure global credentials, which will be used for devices connecting over SSH transport protocol that do not have device-specific credentials configured.

This is done by creating /odl-netconf-callhome-server:netconf-callhome-server/global/credentials with username and passwords specified.

Configuring global username & passwords to try

PUT HTTP/1.1
/rests/data/odl-netconf-callhome-server:netconf-callhome-server/global/credentials
Content-Type: application/json
Accept: application/json

{
  "credentials":
  {
    "username": "example",
    "passwords": [ "first-password-to-try", "second-password-to-try" ]
  }
}
Configuring to accept any ssh server key using global credentials

By default Netconf Call-Home Server accepts only incoming connections from allowed devices /odl-netconf-callhome-server:netconf-callhome-server/allowed-devices, if user desires to allow all incoming connections, it is possible to set accept-all-ssh-keys to true in /odl-netconf-callhome-server:netconf-callhome-server/global.

The name of these devices in netconf-topology will be in format ip-address:port. For naming devices see Device-Specific Configuration.

Allowing unknown devices to connect

This is a debug feature and should not be used in production. Besides being an obvious security issue, this also causes the Call-Home Server to drastically increase its output to the log.

PUT HTTP/1.1
/rests/data/odl-netconf-callhome-server:netconf-callhome-server/global/accept-all-ssh-keys
Content-Type: application/json
Accept: application/json

{
    "accept-all-ssh-keys": "true"
}

Device-Specific Configuration

Netconf Call Home server supports both of the secure transports used by the Network Configuration Protocol (NETCONF) - Secure Shell (SSH), and Transport Layer Security (TLS).

Configure device to connect over SSH protocol

Netconf Call Home Server uses device provided SSH server key (host key) to identify device. The pairing of name and server key is configured in /odl-netconf-callhome-server:netconf-callhome-server/allowed-devices. This list is colloquially called a allowlist.

If the Call-Home Server finds the SSH host key in the allowlist, it continues to negotiate a NETCONF connection over an SSH session. If the SSH host key is not found, the connection between the Call Home server and the device is dropped immediately. In either case, the device that connects to the Call home server leaves a record of its presence in the operational store.

Configuring Device with Device-specific Credentials

Adding specific device to the allowed list is done by creating /odl-netconf-callhome-server:netconf-callhome-server/allowed-devices/device={device} with device-id and connection parameters inside the ssh-client-params container.

Configuring Device with Credentials

PUT HTTP/1.1
/rests/data/odl-netconf-callhome-server:netconf-callhome-server/allowed-devices/device=example
Content-Type: application/json
Accept: application/json

{
  "device": {
    "unique-id": "example",
    "ssh-client-params": {
      "credentials": {
        "username": "example",
        "passwords": [ "password" ]
      },
      "host-key": "AAAAB3NzaC1yc2EAAAADAQABAAABAQDHoH1jMjltOJnCt999uaSfc48ySutaD3ISJ9fSECe1Spdq9o9mxj0kBTTTq+2V8hPspuW75DNgN+V/rgJeoUewWwCAasRx9X4eTcRrJrwOQKzb5Fk+UKgQmenZ5uhLAefi2qXX/agFCtZi99vw+jHXZStfHm9TZCAf2zi+HIBzoVksSNJD0VvPo66EAvLn5qKWQD4AdpQQbKqXRf5/W8diPySbYdvOP2/7HFhDukW8yV/7ZtcywFUIu3gdXsrzwMnTqnATSLPPuckoi0V2jd8dQvEcu1DY+rRqmqu0tEkFBurlRZDf1yhNzq5xWY3OXcjgDGN+RxwuWQK3cRimcosH"
    }
  }
}
Configuring Device with Global Credentials

It is possible to omit username and password for ssh-client-params, in such case values from global credentials will be used.

Example of configuring device

PUT HTTP/1.1
/rests/data/odl-netconf-callhome-server:netconf-callhome-server/allowed-devices/device=example
Content-Type: application/json
Accept: application/json

{
  "device": {
    "unique-id": "example",
    "ssh-client-params": {
      "host-key": "AAAAB3NzaC1yc2EAAAADAQABAAABAQDHoH1jMjltOJnCt999uaSfc48ySutaD3ISJ9fSECe1Spdq9o9mxj0kBTTTq+2V8hPspuW75DNgN+V/rgJeoUewWwCAasRx9X4eTcRrJrwOQKzb5Fk+UKgQmenZ5uhLAefi2qXX/agFCtZi99vw+jHXZStfHm9TZCAf2zi+HIBzoVksSNJD0VvPo66EAvLn5qKWQD4AdpQQbKqXRf5/W8diPySbYdvOP2/7HFhDukW8yV/7ZtcywFUIu3gdXsrzwMnTqnATSLPPuckoi0V2jd8dQvEcu1DY+rRqmqu0tEkFBurlRZDf1yhNzq5xWY3OXcjgDGN+RxwuWQK3cRimcosH"
    }
  }
}
Deprecated configuration models for devices accessed with SSH protocol

With RFC 8071 alignment and adding support for TLS transport following configuration models have been marked deprecated.

Configuring Device with Global Credentials

Example of configuring device

PUT HTTP/1.1
/rests/data/odl-netconf-callhome-server:netconf-callhome-server/allowed-devices/device=example
Content-Type: application/json
Accept: application/json

{
  "device": {
    "unique-id": "example",
    "ssh-host-key": "AAAAB3NzaC1yc2EAAAADAQABAAABAQDHoH1jMjltOJnCt999uaSfc48ySutaD3ISJ9fSECe1Spdq9o9mxj0kBTTTq+2V8hPspuW75DNgN+V/rgJeoUewWwCAasRx9X4eTcRrJrwOQKzb5Fk+UKgQmenZ5uhLAefi2qXX/agFCtZi99vw+jHXZStfHm9TZCAf2zi+HIBzoVksSNJD0VvPo66EAvLn5qKWQD4AdpQQbKqXRf5/W8diPySbYdvOP2/7HFhDukW8yV/7ZtcywFUIu3gdXsrzwMnTqnATSLPPuckoi0V2jd8dQvEcu1DY+rRqmqu0tEkFBurlRZDf1yhNzq5xWY3OXcjgDGN+RxwuWQK3cRimcosH"
  }
}
Configuring Device with Device-specific Credentials

Call Home Server also allows the configuration of credentials per device basis. This is done by introducing credentials container into the device-specific configuration. Format is same as in global credentials.

Configuring Device with Credentials

PUT HTTP/1.1
/rests/data/odl-netconf-callhome-server:netconf-callhome-server/allowed-devices/device=example
Content-Type: application/json
Accept: application/json

{
  "device": {
    "unique-id": "example",
    "credentials": {
      "username": "example",
      "passwords": [ "password" ]
    },
    "ssh-host-key": "AAAAB3NzaC1yc2EAAAADAQABAAABAQDHoH1jMjltOJnCt999uaSfc48ySutaD3ISJ9fSECe1Spdq9o9mxj0kBTTTq+2V8hPspuW75DNgN+V/rgJeoUewWwCAasRx9X4eTcRrJrwOQKzb5Fk+UKgQmenZ5uhLAefi2qXX/agFCtZi99vw+jHXZStfHm9TZCAf2zi+HIBzoVksSNJD0VvPo66EAvLn5qKWQD4AdpQQbKqXRf5/W8diPySbYdvOP2/7HFhDukW8yV/7ZtcywFUIu3gdXsrzwMnTqnATSLPPuckoi0V2jd8dQvEcu1DY+rRqmqu0tEkFBurlRZDf1yhNzq5xWY3OXcjgDGN+RxwuWQK3cRimcosH"
  }
}

Configure device to connect over TLS protocol

Netconf Call Home Server allows devices to use TLS transport protocol to establish a connection towards the NETCONF device. This communication requires proper setup to make two-way TLS authentication possible for client and server.

The initial step is to configure certificates and keys for two-way TLS by storing them within the netconf-keystore.

Adding a client private key credential to the netconf-keystore

POST HTTP/1.1
/rests/operations/netconf-keystore:add-keystore-entry
Content-Type: application/json
Accept: application/json

{
  "input": {
    "key-credential": [
      {
        "key-id": "example-client-key-id",
        "private-key": "PEM-format-private-key",
        "passphrase": "passphrase"
      }
    ]
  }
}

Associate a private key with a client and CA certificates chain

POST HTTP/1.1
/rests/operations/netconf-keystore:add-private-key
Content-Type: application/json
Accept: application/json

{
  "input": {
    "private-key": [
      {
        "name": "example-client-key-id",
        "data": "key-data",
        "certificate-chain": [
          "certificate-data"
        ]
      }
    ]
  }
}

Add a list of trusted CA and server certificates

POST HTTP/1.1
/rests/operations/netconf-keystore:add-trusted-certificate
Content-Type: application/json
Accept: application/json

{
  "input": {
    "trusted-certificate": [
      {
        "name": "example-ca-certificate",
        "certificate": "ca-certificate-data"
      },
      {
        "name": "example-server-certificate",
        "certificate": "server-certificate-data"
      }
    ]
  }
}

In a second step, it is required to create an allowed device associated with a server certificate and client key. The server certificate will be used to identify and pin the NETCONF device during SSL handshake and should be unique among the allowed devices.

Add device configuration for TLS protocol to allowed devices list

PUT HTTP/1.1
/rests/data/odl-netconf-callhome-server:netconf-callhome-server/allowed-devices/device=example-device
Content-Type: application/json
Accept: application/json

{
  "device": {
    "unique-id": "example-device",
    "tls-client-params": {
      "key-id": "example-client-key-id",
      "certificate-id": "example-server-certificate"
    }
  }
}

Operational Status

Once an entry is made on the config side of “allowed-devices”, the Call-Home Server will populate a corresponding operational device that is the same as the config device but has an additional status. By default, this status is DISCONNECTED. Once a device calls home, this status will change to one of:

CONNECTED — The device is currently connected and the NETCONF mount is available for network management.

FAILED_AUTH_FAILURE — The last attempted connection was unsuccessful because the Call-Home Server was unable to provide the acceptable credentials of the device. The device is also disconnected and not available for network management.

FAILED_NOT_ALLOWED — The last attempted connection was unsuccessful because the device was not recognized as an acceptable device. The device is also disconnected and not available for network management.

FAILED — The last attempted connection was unsuccessful for a reason other than not allowed to connect or incorrect client credentials. The device is also disconnected and not available for network management.

DISCONNECTED — The device is currently disconnected.

Rogue Devices

Devices that are not on the allowlist might try to connect to the Call-Home Server. In these cases, the server will keep a record by instantiating an operational device. There will be no corresponding config device for these rogues. They can be identified readily because their device id, rather than being user-supplied, will be of the form “address:port”. Note that if a device calls back multiple times, there will only be a single operatinal entry (even if the port changes); these devices are recognized by their unique host key.

Southbound Call-Home API

The Call-Home Server listens for incoming TCP connections and assumes that the other side of the connection is a device calling home via a NETCONF connection with SSH for management. The server uses port 4334 by default and this can be configured via a blueprint configuration file.

The device must initiate the connection and the server will not try to re-establish the connection in case of a drop. By requirement, the server cannot assume it has connectivity to the device due to NAT or firewalls among others.

Reading data with selected fields

Overview

If user would like to read only selected fields from a NETCONF device, it is possible to use the fields query parameter that is described by RFC-8040. RESTCONF parses content of query parameter into format that is accepted by NETCONF subtree filtering - filtering of data is done on NETCONF server, not on NETCONF client side. This approach optimizes network traffic load, because data in which user doesn’t have interest, is not transferred over network.

Next advantages:

  • using single RESTCONF request and single NETCONF RPC for reading multiple subtrees

  • possibility to read only selected fields under list node across multiple hierarchies (it cannot be done without proper selection API)

Note

More information about fields query parameter: RFC 8071

Preparation of data

For demonstration, we will define next YANG model:

module test-module {
    yang-version 1.1;
    namespace "urn:opendaylight:test-module";
    prefix "tm";
    revision "2023-02-16";

    container root {
        container simple-root {
            leaf leaf-a {
                type string;
            }
            leaf leaf-b {
                type string;
            }
            leaf-list ll {
                type string;
            }
            container nested {
                leaf sample-x {
                    type boolean;
                }
                leaf sample-y {
                    type boolean;
                }
            }
        }

        container list-root {
            leaf branch-ab {
                type int32;
            }
            list top-list {
                key "key-1 key-2";
                ordered-by user;
                leaf key-1 {
                    type string;
                }
                leaf key-2 {
                    type string;
                }
                container next-data {
                    leaf switch-1 {
                        type empty;
                    }
                    leaf switch-2 {
                        type empty;
                    }
                }
                list nested-list {
                    key "identifier";
                    leaf identifier {
                        type string;
                    }
                    leaf foo {
                        type int32;
                    }
                }
            }
        }
    }
}

Follow the NETCONF testtool instructions to save this schema and run it with testtool.

Mounting NETCONF device that runs on NETCONF testtool:

curl --location --request PUT 'http://127.0.0.1:8181/rests/data/network-topology:network-topology/topology=topology-netconf/node=testtool' \
--header 'Authorization: Basic YWRtaW46YWRtaW4=' \
--header 'Content-Type: application/json' \
--data-raw '{
    "node": [
        {
            "node-id": "testtool",
            "netconf-node-topology:host": "127.0.0.1",
            "netconf-node-topology:port": 17830,
            "netconf-node-topology:keepalive-delay": 100,
            "netconf-node-topology:tcp-only": false,
            "netconf-node-topology:login-password-unencrypted": {
                "netconf-node-topology:username": "admin",
                "netconf-node-topology:password": "admin"
            },
        }
    ]
}'

Setting initial configuration on NETCONF device:

curl --location --request PUT 'http://127.0.0.1:8181/rests/data/network-topology:network-topology/topology=topology-netconf/node=testtool/yang-ext:mount/test-module:root' \
--header 'Authorization: Basic YWRtaW46YWRtaW4=' \
--header 'Content-Type: application/json' \
--data-raw '{
    "root": {
        "simple-root": {
            "leaf-a": "asddhg",
            "leaf-b": "ffffff",
            "ll": [
                "str1",
                "str2",
                "str3"
            ],
            "nested": {
                "sample-x": true,
                "sample-y": false
            }
        },
        "list-root": {
            "branch-ab": 5,
            "top-list": [
                {
                    "key-1": "ka",
                    "key-2": "kb",
                    "next-data": {
                        "switch-1": [
                            null
                        ],
                        "switch-2": [
                            null
                        ]
                    },
                    "nested-list": [
                        {
                            "identifier": "f1",
                            "foo": 1
                        },
                        {
                            "identifier": "f2",
                            "foo": 10
                        },
                        {
                            "identifier": "f3",
                            "foo": 20
                        }
                    ]
                },
                {
                    "key-1": "kb",
                    "key-2": "ka",
                    "next-data": {
                        "switch-1": [
                            null
                        ]
                    },
                    "nested-list": [
                        {
                            "identifier": "e1",
                            "foo": 1
                        },
                        {
                            "identifier": "e2",
                            "foo": 2
                        },
                        {
                            "identifier": "e3",
                            "foo": 3
                        }
                    ]
                },
                {
                    "key-1": "kc",
                    "key-2": "ke",
                    "next-data": {
                        "switch-2": [
                            null
                        ]
                    },
                    "nested-list": [
                        {
                            "identifier": "q1",
                            "foo": 13
                        },
                        {
                            "identifier": "q2",
                            "foo": 14
                        },
                        {
                            "identifier": "q3",
                            "foo": 15
                        }
                    ]
                }
            ]
        }
    }
}'

Examples

  1. Reading whole leaf-list ‘ll’ and leaf ‘nested/sample-x’ under ‘simple-root’ container.

RESTCONF request:

curl --location --request GET 'http://localhost:8181/rests/data/network-topology:network-topology/topology=topology-netconf/node=testtool/yang-ext:mount/test-module:root/simple-root?content=config&fields=ll;nested/sample-x' \
--header 'Authorization: Basic YWRtaW46YWRtaW4=' \
--header 'Cookie: JSESSIONID=node01h4w82eorc1k61866b71qjgj503.node0'

Generated NETCONF RPC request:

<rpc message-id="m-18" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
    <get-config>
        <source>
            <running/>
        </source>
        <filter xmlns:ns0="urn:ietf:params:xml:ns:netconf:base:1.0" ns0:type="subtree">
            <root xmlns="urn:ietf:params:xml:ns:yang:test-model">
                <simple-root>
                    <ll/>
                    <nested>
                        <sample-x/>
                    </nested>
                </simple-root>
            </root>
        </filter>
    </get-config>
</rpc>

Note

Using fields query parameter it is also possible to read whole leaf-list or list without necessity to specify value / key predicate (without reading parent entity). Such scenario is not permitted in RFC-8040 paths alone - fields query parameter can be used as workaround for this case.

RESTCONF response:

{
    "test-module:simple-root": {
        "ll": [
            "str3",
            "str1",
            "str2"
        ],
        "nested": {
            "sample-x": true
        }
    }
}

  1. Reading all identifiers of ‘nested-list’ under all elements of ‘top-list’.

RESTCONF request:

curl --location --request GET 'http://localhost:8181/rests/data/network-topology:network-topology/topology=topology-netconf/node=testtool/yang-ext:mount/test-module:root/list-root?content=config&fields=top-list(nested-list/identifier)' \
--header 'Authorization: Basic YWRtaW46YWRtaW4=' \
--header 'Cookie: JSESSIONID=node01h4w82eorc1k61866b71qjgj503.node0'

Generated NETCONF RPC request:

<rpc message-id="m-27" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
    <get-config>
        <source>
            <running/>
        </source>
        <filter xmlns:ns0="urn:ietf:params:xml:ns:netconf:base:1.0" ns0:type="subtree">
            <root xmlns="urn:ietf:params:xml:ns:yang:test-model">
                <list-root>
                    <top-list>
                        <nested-list>
                            <identifier/>
                        </nested-list>
                        <key-1/>
                        <key-2/>
                    </top-list>
                </list-root>
            </root>
        </filter>
    </get-config>
</rpc>

Note

NETCONF client automatically fetches values of list keys since they are required for correct deserialization of NETCONF response and at the end serialization of response to RESTCONF response (JSON/XML).

RESTCONF response:

{
    "test-module:list-root": {
        "top-list": [
            {
                "key-1": "ka",
                "key-2": "kb",
                "nested-list": [
                    {
                        "identifier": "f3"
                    },
                    {
                        "identifier": "f2"
                    },
                    {
                        "identifier": "f1"
                    }
                ]
            },
            {
                "key-1": "kb",
                "key-2": "ka",
                "nested-list": [
                    {
                        "identifier": "e3"
                    },
                    {
                        "identifier": "e2"
                    },
                    {
                        "identifier": "e1"
                    }
                ]
            },
            {
                "key-1": "kc",
                "key-2": "ke",
                "nested-list": [
                    {
                        "identifier": "q3"
                    },
                    {
                        "identifier": "q2"
                    },
                    {
                        "identifier": "q1"
                    }
                ]
            }
        ]
    }
}

  1. Reading value of leaf ‘branch-ab’ and all values of leaves ‘switch-1’ that are placed under ‘top-list’ list elements.

RESTCONF request:

curl --location --request GET 'http://localhost:8181/rests/data/network-topology:network-topology/topology=topology-netconf/node=testtool/yang-ext:mount/test-module:root/list-root?content=config&fields=branch-ab;top-list/next-data/switch-1' \
--header 'Authorization: Basic YWRtaW46YWRtaW4=' \
--header 'Cookie: JSESSIONID=node01jx6o5thwae9t1ft7c2zau5zbz4.node0'

Generated NETCONF RPC request:

<rpc message-id="m-42" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
    <get-config>
        <source>
            <running/>
        </source>
        <filter xmlns:ns0="urn:ietf:params:xml:ns:netconf:base:1.0" ns0:type="subtree">
            <root xmlns="urn:ietf:params:xml:ns:yang:test-model">
                <list-root>
                    <branch-ab/>
                    <top-list>
                        <next-data>
                            <switch-1/>
                        </next-data>
                        <key-1/>
                        <key-2/>
                    </top-list>
                </list-root>
            </root>
        </filter>
    </get-config>
</rpc>

RESTCONF response:

{
    "test-module:list-root": {
        "branch-ab": 5,
        "top-list": [
            {
                "key-1": "ka",
                "key-2": "kb",
                "next-data": {
                    "switch-1": [
                        null
                    ]
                }
            },
            {
                "key-1": "kb",
                "key-2": "ka",
                "next-data": {
                    "switch-1": [
                        null
                    ]
                }
            },
            {
                "key-1": "kc",
                "key-2": "ke"
            }
        ]
    }
}

RESTCONF OpenAPI

Overview

The OpenAPI provides full API for configurational data which can be edited (by POST, PUT, PATCH and DELETE). For operational data we only provide GET API. For the majority of requests you can see only config data in examples. That’s because we can show only one example per request. The exception when you can see operational data in an example is when data are representing an operational (config false) container with no config data in it.

Using the OpenAPI Explorer through HTTP

  1. Install OpenApi into Karaf by installing karaf feature:

$ feature:install odl-restconf-openapi

  1. Navigate to OpenAPI in your web browser which is available at URLs:

Note

In the URL links for OpenAPI, change localhost to the IP/Host name of your actual server.

  1. Enter the username and password. By default the credentials are admin/admin.

  2. Select any model to try out.

  3. Select any available request to try out.

  4. Click on the Try it out button.

  5. Provide any required parameters or edit request body.

  6. Click the Execute button.

  7. You can see responses to the given request.

OpenAPI Explorer can also be used for connected device. How to connect a device can be found here.

OpenAPI URLs in that case would look like this:

Note

The URL links for OpenAPI are made for device with name 17830-sim-device and model toaster with 2009-11-20 revision and need to be changed accordingly to connected device.