django ModelForm without all fields - fill them automatically
class MyView(CreateView):

  def post(self, request, *args, **kwargs):
    self.form_class.client_ip = request.META.get('REMOTE_ADDR')
    super(MyView, self).post(request, *args, **kwargs)

  model = MyModel
  form_class = MyForm

class MyForm(forms.ModelForm):
  class Meta:
    model = MyModel
    exclude = ('ip',)

def get_initial(self):
    return { 'ip': ... }