Is it possible to validate configuration context using custom validation rules?

[olafayomi]

Hi all,

I'm trying to validate configuration context data for devices and I was wondering if it's possible to do that with custom validation rules?
I'm trying to check that certain fields/values are defined in the configuration context data before it is applied to a device.

Currently, I'm doing something along these lines but I'm not sure if that is the right approach for what I want to do.

from extras.validators import CustomValidator
from typing import Any
import logging

logger = logging.getLogger('netbox.plugins')

class DeviceAddrsValidator(CustomValidator):
    def validate(self, instance: Any, request: Any) -> None:
        """
        Validate modifications to devices and their configuration context data.

        Args:
            instance: The device object being validated
            request: The HTTP request object

        Returns:
            None

        Raises:
            ValidationError: If validation fails
        """
        from dcim.models import Interface
        from dcim.models import Device
        from django.db.models import QuerySet

        ifaces = Interface.objects.filter(device_id=instance.id)
        conf_ctx = instance.get_config_context()
        roles = ['Leaf', 'Spine', 'Switch', 'oob-mgmt-switch']

        if 'inband_management' in config_context:
            inband_mgmt_present = True
            inband_iface_name =  conf_ctx['inband_management']['interface']

            if isinstance(inband_iface_name, list):
                self.fail(f"There can only be one inband-management interface")
        else:
            inband_mgmt_present = False

       if 'dns' in conf_ctx:
          if not isinstance(dns['servers'], list):
              self.fail(f"No DNS servers in config context")
      else:
          self.fail(f"DNS data not in config context")