Enable global vlan

1. Decouple site/vlan, make site optional for vlan/vlangroup
2. Change html generation code to check site existence before
dereference
3. Create site search function, if site is None for a VLAN, view it as
global VLAN

netbox/ipam/filters.py

@@ -262,37 +262,47 @@ class IPAddressFilter(CustomFieldFilterSet, django_filters.FilterSet):
 
 
 class VLANGroupFilter(django_filters.FilterSet):
-    site_id = django_filters.ModelMultipleChoiceFilter(
+    site_id = NullableModelMultipleChoiceFilter(
         name='site',
         queryset=Site.objects.all(),
         label='Site (ID)',
+        method='site_search',
     )
-    site = django_filters.ModelMultipleChoiceFilter(
+    site = NullableModelMultipleChoiceFilter(
         name='site__slug',
         queryset=Site.objects.all(),
         to_field_name='slug',
         label='Site (slug)',
+        method='site_search',
     )
 
     class Meta:
         model = VLANGroup
 
+    def site_search(self, queryset, name, value):
+        q = Q(**{name: None})
+        for v in value:
+            q |= Q(**{name: v})
+        return queryset.filter(q)
+
 
 class VLANFilter(CustomFieldFilterSet, django_filters.FilterSet):
     q = django_filters.MethodFilter(
         action='search',
         label='Search',
     )
-    site_id = django_filters.ModelMultipleChoiceFilter(
+    site_id = NullableModelMultipleChoiceFilter(
         name='site',
         queryset=Site.objects.all(),
         label='Site (ID)',
+        method='site_search',
     )
-    site = django_filters.ModelMultipleChoiceFilter(
+    site = NullableModelMultipleChoiceFilter(
         name='site__slug',
         queryset=Site.objects.all(),
         to_field_name='slug',
         label='Site (slug)',
+        method='site_search',
     )
     group_id = NullableModelMultipleChoiceFilter(
         name='group',
@@ -349,6 +359,12 @@ class VLANFilter(CustomFieldFilterSet, django_filters.FilterSet):
             pass
         return queryset.filter(qs_filter)
 
+    def site_search(self, queryset, name, value):
+        q = Q(**{name: None})
+        for v in value:
+            q |= Q(**{name: v})
+        return queryset.filter(q)
+
 
 class ServiceFilter(django_filters.FilterSet):
     device_id = django_filters.ModelMultipleChoiceFilter(

netbox/ipam/forms.py

@@ -153,7 +153,8 @@ class RoleForm(BootstrapMixin, forms.ModelForm):
 
 class PrefixForm(BootstrapMixin, CustomFieldForm):
     site = forms.ModelChoiceField(queryset=Site.objects.all(), required=False, label='Site',
-                                  widget=forms.Select(attrs={'filter-for': 'vlan'}))
+                                  widget=forms.Select(attrs={'filter-for': 'vlan',
+                                                             'default_value': '0'}))
     vlan = forms.ModelChoiceField(queryset=VLAN.objects.all(), required=False, label='VLAN',
                                   widget=APISelect(api_url='/api/ipam/vlans/?site_id={{site}}',
                                                    display_field='display_name'))
@@ -173,7 +174,7 @@ class PrefixForm(BootstrapMixin, CustomFieldForm):
         elif self.initial.get('site'):
             self.fields['vlan'].queryset = VLAN.objects.filter(site=self.initial['site'])
         else:
-            self.fields['vlan'].choices = []
+            self.fields['vlan'].queryset = VLAN.objects.filter(site=None)
 
 
 class PrefixFromCSVForm(forms.ModelForm):
@@ -532,7 +533,7 @@ class VLANForm(BootstrapMixin, CustomFieldForm):
             'role': "The primary function of this VLAN",
         }
         widgets = {
-            'site': forms.Select(attrs={'filter-for': 'group'}),
+            'site': forms.Select(attrs={'filter-for': 'group', 'default_value': '0'}),
         }
 
     def __init__(self, *args, **kwargs):
@@ -545,7 +546,7 @@ class VLANForm(BootstrapMixin, CustomFieldForm):
         elif self.initial.get('site'):
             self.fields['group'].queryset = VLANGroup.objects.filter(site=self.initial['site'])
         else:
-            self.fields['group'].choices = []
+            self.fields['group'].queryset = VLANGroup.objects.filter(site=None)
 
 
 class VLANFromCSVForm(forms.ModelForm):

netbox/ipam/models.py

@@ -485,7 +485,7 @@ class VLANGroup(models.Model):
     """
     name = models.CharField(max_length=50)
     slug = models.SlugField()
-    site = models.ForeignKey('dcim.Site', related_name='vlan_groups')
+    site = models.ForeignKey('dcim.Site', related_name='vlan_groups', on_delete=models.SET_NULL, blank=True, null=True)
 
     class Meta:
         ordering = ['site', 'name']
@@ -497,7 +497,8 @@ class VLANGroup(models.Model):
         verbose_name_plural = 'VLAN groups'
 
     def __str__(self):
-        return u'{} - {}'.format(self.site.name, self.name)
+        site_name = self.site.name if self.site else '__global'
+        return u'{} - {}'.format(site_name, self.name)
 
     def get_absolute_url(self):
         return "{}?group_id={}".format(reverse('ipam:vlan_list'), self.pk)
@@ -513,7 +514,7 @@ class VLAN(CreatedUpdatedModel, CustomFieldModel):
     Like Prefixes, each VLAN is assigned an operational status and optionally a user-defined Role. A VLAN can have zero
     or more Prefixes assigned to it.
     """
-    site = models.ForeignKey('dcim.Site', related_name='vlans', on_delete=models.PROTECT)
+    site = models.ForeignKey('dcim.Site', related_name='vlans', on_delete=models.PROTECT, blank=True, null=True)
     group = models.ForeignKey('VLANGroup', related_name='vlans', blank=True, null=True, on_delete=models.PROTECT)
     vid = models.PositiveSmallIntegerField(verbose_name='ID', validators=[
         MinValueValidator(1),

netbox/templates/ipam/vlan.html

@@ -53,7 +53,11 @@
             <table class="table table-hover panel-body attr-table">
                 <tr>
                     <td>Site</td>
-                    <td><a href="{% url 'dcim:site' slug=vlan.site.slug %}">{{ vlan.site }}</a></td>
+                    <td>
+                        {% if vlan.site %}
+                            <a href="{% url 'dcim:site' slug=vlan.site.slug %}">{{ vlan.site }}</a>
+                        {% endif %}
+                    </td>
                 </tr>
                 <tr>
                     <td>Group</td>