nova/doc/notification_samples/instance-update-tags-action.json

{
    "event_type": "instance.update",
    "payload": {
        "$ref":"common_payloads/InstanceUpdatePayload.json#",
        "nova_object.data": {
            "tags": ["tag1"]
        }
    },
    "priority": "INFO",
    "publisher_id": "nova-api:fake-mini"
}