Basic Delete ANC Policy Notification Example

This sample registers and outputs messages received for Cisco Adaptive Network Control (ANC) delete policy notifications via DXL and Cisco pxGrid.

Prerequisites

• The samples configuration step has been completed (see Samples Configuration).

• The DXL fabric to which the client will connect has been bridged to Cisco pxGrid.

• The Python client has been authorized to receive DXL Cisco pxGrid Notifications (see Authorize Client to Use Cisco pxGrid via DXL).

• ANC Delete Policy notifications from pxGrid have been enabled (see Enable Cisco pxGrid Notifications for DXL).

• An ANC policy has been configured. The policy could be created by logging into the Cisco Identity Services Engine (ISE) web interface and performing the following steps:

  • Navigate to Operations → Adaptive Network Control → Policy List.
  • On the List screen, click on the Add button.
  • On the List → New screen, enter test_policy in the name field, select QUARANTINE in the Action field, and press the Submit button.

Running

To run this sample execute the sample/basic/basic_anc_delete_policy_notification_example.py script as follows:

python sample/basic/basic_anc_delete_policy_notification_example.py

After the example starts up, the initial output should appear similar to the following:

Waiting for delete policy events...

To generate a delete policy notification, delete an ANC policy on the server. The policy could be deleted by logging into the ISE web interface and performing the following steps:

• Navigate to Operations → Adaptive Network Control → Policy List.
• On the List screen, check the box next to the policy name -- for example: test_policy -- and press the Trash drop down.
• Press the Selected item in the Trash drop down to delete the policy.

A message similar to the following should appear in the output of the notification example:

{
    "action": [
        "Quarantine"
    ],
    "name": "test_policy"
}

Details

The majority of the sample code is shown below:

# Create the client
with DxlClient(config) as dxl_client:

    # Connect to the fabric
    dxl_client.connect()

    logger.info("Connected to DXL fabric.")

    # Create client wrapper
    client = CiscoPxGridClient(dxl_client)

    class MyAncDeletePolicyCallback(AncDeletePolicyCallback):
        def on_delete_policy(self, delete_dict):
            print("on_delete_policy\n" +
                  MessageUtils.dict_to_json(delete_dict, pretty_print=True))

    # Attach callback for 'delete policy' events
    client.anc.add_delete_policy_callback(MyAncDeletePolicyCallback())

    # Wait forever
    print("Waiting for delete policy events...")
    while True:
        time.sleep(60)

Once a connection is established to the DXL fabric, a dxlciscopxgridclient.client.CiscoPxGridClient instance is created which will be used to communicate with Cisco pxGrid.

Next, the dxlciscopxgridclient.client.AncClientCategory.add_delete_policy_callback() method is invoked to register a callback for delete policy event notifications.

When an delete policy event occurs, the on_delete_policy method in the MyAncDeletePolicyCallback class is invoked. The delete_dict parameter passed into the callback, a dictionary (dict) which contains the content of the event notification, is displayed.