Cannot assign None: "Card.customer" does not allow null values.

[ukch]

I got this through from the webhook:

ValueError: Cannot assign None: "Card.customer" does not allow null values.
  File "django/core/handlers/base.py", line 132, in get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "django/views/generic/base.py", line 71, in view
    return self.dispatch(request, *args, **kwargs)
  File "django/utils/decorators.py", line 34, in _wrapper
    return bound_func(*args, **kwargs)
  File "django/views/decorators/csrf.py", line 58, in wrapped_view
    return view_func(*args, **kwargs)
  File "django/utils/decorators.py", line 30, in bound_func
    return func.__get__(self, type(self))(*args2, **kwargs2)
  File "pinax/stripe/views.py", line 177, in dispatch
    return super(Webhook, self).dispatch(*args, **kwargs)
  File "django/views/generic/base.py", line 89, in dispatch
    return handler(request, *args, **kwargs)
  File "pinax/stripe/views.py", line 192, in post
    message=data
  File "pinax/stripe/actions/events.py", line 30, in add_event
    webhook.process()
  File "pinax/stripe/webhooks.py", line 91, in process
    self.process_webhook()
  File "pinax/stripe/webhooks.py", line 281, in process_webhook
    self.event.validated_message["data"]["object"]
  File "pinax/stripe/actions/sources.py", line 118, in sync_payment_source_from_stripe_data
    sync_card(customer, source)
  File "pinax/stripe/actions/sources.py", line 71, in sync_card
    defaults=defaults
  File "django/db/models/manager.py", line 127, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "django/db/models/query.py", line 407, in get_or_create
    return self._create_object_from_params(lookup, params)
  File "django/db/models/query.py", line 439, in _create_object_from_params
    obj = self.create(**params)
  File "django/db/models/query.py", line 346, in create
    obj = self.model(**kwargs)
  File "django/db/models/base.py", line 468, in __init__
    setattr(self, field.name, rel_obj)
  File "django/db/models/fields/related.py", line 621, in __set__
    (instance._meta.object_name, self.field.name)

This was the request body sent from Stripe:

{api_version: 2015-10-16, created: 1452130000, data: {object: {address_city: None, address_country: None, address_line1: None, address_line1_check: None, address_line2: None, address_state: None, address_zip: None, address_zip_check: None, brand: Visa, country: US, customer: cus_7foAIapD8EHGaE, cvc_check: pass, dynamic_last4: None, exp_month: 1, exp_year: 2020, fingerprint: Aj881ZHXRU2aVj5K, funding: credit, id: card_17QSXvEpqJ8aOjuY0CVtUfIJ, last4: 4242, metadata: {}, name: REDACTED, object: card, tokenization_method: None}}, id: evt_17QSY0EpqJ8aOjuYVmgj11yn, livemode: False, object: event, pending_webhooks: 1, request: req_7foAc39djNtYDB, type: customer.source.created}

[paltman]

As I follow the code path, it appears that what is happening is that you don't have the customer object in your database.

I think pinax-stripe should in fact do something different than blow up like this but I am not sure what yet.

In the meantime, I'm pretty sure you can avoid this by making sure you have customer records in your project.

1. Is this a new project? In other words do you have users in your site that don't have customer records in Stripe?
2. Is this a pre-existing Stripe account and you don't have users in your new site for?
3. I suspect this might be a new project AND a new Stripe account and you just don't have a receiver setup to create customer records as each new user is created. If this is the case you can solve this by hooking up a signal on user creation or account signup (if using DUA) similar to have we've done in the Pinax Stripe starter project:

from django.dispatch import receiver
from account.signals import user_signed_up

from pinax.eventlog.models import log
from pinax.stripe.actions import customers


@receiver(user_signed_up)
def handle_user_signed_up(sender, **kwargs):
    log(
        user=kwargs.get("user"),
        action="USER_SIGNED_UP",
        extra={}
    )
    customers.create(kwargs.get("user"))

[ukch]

Yes, that is correct. Was I wrong in thinking the webhook does this automatically then?

[paltman]

@ukch does what automatically?

[lukeburden]

I'm seeing this issue too when running customer.create() and providing the card parameter.

I think it's because there is a race condition in customer.create():

1. stripe.Customer.create is called, passing in the source. This will result in customer.created and customer.source.created webhooks, arriving in indeterminate order.
2. a Customer instance is created customer.source.created
3. the stripe customer is sync'd

In some cases, it appears when the customer.source.created webhook arrives, the customer record in the database does not yet exist. This results in the none FK error.

It'd be preferable not to have to create customer records for all users ahead of time.

One option would be to change customers.create to use multiple API calls to Stripe rather than potentially creating a source and subscription in the one stripe.Customer.create call.

[blueyed]

arriving in indeterminate order

I would assume that the order is correct, i.e. customer.created first, but that is just a feeling.

Related: #410

In case of the customer not existing already, it could also just get fetched an created then?!