Django RQ admin shows errors for circuit webhooks

[funzoneq]

Environment

• Python version: 3.6.4
• NetBox version: 2.4.8

Steps to Reproduce

Create a webhook for circuits with the following settings:

Object type: Circuits -> Circuit
Name: test_circuit_hook
Type: Update
URL: https://example.com/webhook/
HTTP Content type: JSON
No secret
Enabled
SSL Verification enabled.
-> Save

Create a test circuit:

cid: test-001
Provider: test provider
Type: Internet
Status: Active
Tenant: Test tenant
Install_date, commit_rate, description, comments empty
No custom fields
Save the circuit.

No go back and edit the circuit. Change the cid to test-002. This will trigger the webhook. It doesn't matter if it fails or succeeds.

Go to the Django Admin -> Django RQ -> Queues -> Failed or Succeeded jobs list

Select a job for the circuit:

It throws a django error page:

<class 'django.db.models.fields.related_descriptors.RelatedObjectDoesNotExist'>

Circuit has no provider.

The object definitely has a provider assigned to it:

15:54:33 default: extras.webhooks_worker.process_webhook(<Webhook: test_hook_arnoud>, {'package': OrderedDict([('id', 10), ('url', '/api/tenancy/packages/10/'), ('name', 'L3-500m_500m'), ('slug', 'l3-500m_500m')]), 'install_date': None, 'created': '2018-11-27', 'custom_fields': {'script_time_circuit': None, 'EPLVlanId': None}, 'commit_rate': None, 'type': OrderedDict([('id', 3), ('url', '/api/circuits/circuit-types/3/'), ('name', 'Customer'), ('slug', 'customer')]), 'description': '', 'status': {'value': 3, 'label': 'Provisioning'}, 'tags': [], 'cid': 'test-circuit', 'provider': OrderedDict([('id', 12), ('url', '/api/circuits/providers/12/'), ('name', 'OpenFiber'), ('slug', 'openfiber')]), 'last_updated': '2018-11-28T15:54:33.037901Z', 'tenant': OrderedDict([('id', 1146), ('url', '/api/tenancy/tenants/1146/'), ('name', 'Race'), ('slug', 'race'), ('description', 'Race')]), 'id': 575, 'comments': ''}, <class 'circuits.models.Circuit'>, 2, '2018-11-28 15:54:33.098502') (942a9529-890e-4270-882d-6f3eca24e53e)

Expected Behavior

I expect to see a detail page for the (failed/succeeded) job

Observed Behavior

Django error page:

<class 'django.db.models.fields.related_descriptors.RelatedObjectDoesNotExist'>

Circuit has no provider.

[jeremystretch]

This is happening because the webhook is passed only the model class (rather than an instance), but trying to access provider in rendering a string representation, yielding an exception:

class Circuit(ChangeLoggedModel, CustomFieldModel):
    ...
    def __str__(self):
        return '{} {}'.format(self.provider, self.cid)

The best approach is probably to tweak the __str__() method on this model (and others) to properly render when not instantiated.

[jeremystretch]

To avoid confusion, I've opened #2627 to address the root cause of this bug. Marking this as blocked.

[lampwins]

While #2627 is a good idea, this specific issue was addressed by simply not passing the model class to the rqworker process. All we actually needed was the model_name attribute anyway, so we can just pass that as a string.

[funzoneq]

Thanks @lampwins and @jeremystretch . The help is much appreciated 👍