Register DataBackend classes in application registry

netbox/core/data_backends.py

@@ -8,6 +8,8 @@ from django import forms
 from django.conf import settings
 from django.utils.translation import gettext as _
 
+from netbox.registry import registry
+from .choices import DataSourceTypeChoices
 from .exceptions import SyncError
 
 __all__ = (
@@ -18,6 +20,17 @@ __all__ = (
 logger = logging.getLogger('netbox.data_backends')
 
 
+def register_backend(name):
+    """
+    Decorator for registering a DataBackend class.
+    """
+    def _wrapper(cls):
+        registry['data_backends'][name] = cls
+        return cls
+
+    return _wrapper
+
+
 class DataBackend:
     parameters = {}
 
@@ -34,6 +47,7 @@ class DataBackend:
         raise NotImplemented()
 
 
+@register_backend(DataSourceTypeChoices.LOCAL)
 class LocalBackend(DataBackend):
 
     @contextmanager
@@ -44,6 +58,7 @@ class LocalBackend(DataBackend):
         yield local_path
 
 
+@register_backend(DataSourceTypeChoices.GIT)
 class GitBackend(DataBackend):
     parameters = {
         'username': forms.CharField(

netbox/core/forms/model_forms.py

@@ -2,7 +2,7 @@ import copy
 
 from core.models import *
 from netbox.forms import NetBoxModelForm, StaticSelect
-from ..models.data import BACKEND_CLASSES
+from netbox.registry import registry
 
 __all__ = (
     'DataSourceForm',
@@ -33,13 +33,14 @@ class DataSourceForm(NetBoxModelForm):
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
 
-        if self.is_bound and self.data.get('type') in BACKEND_CLASSES:
+        backend_classes = registry['data_backends']
-            backend_type = self.data['type']
+
-        elif self.initial and self.initial.get('type') in BACKEND_CLASSES:
+        if self.is_bound and self.data.get('type') in backend_classes:
-            backend_type = self.initial['type']
+            backend = backend_classes.get(self.data['type'])
+        elif self.initial and self.initial.get('type') in backend_classes:
+            backend = backend_classes.get(self.initial['type'])
         else:
-            backend_type = self.fields['type'].initial
+            backend = backend_classes.get(self.fields['type'].initial)
-        backend = BACKEND_CLASSES.get(backend_type)
         for name, form_field in backend.parameters.items():
             field_name = f'backend_{name}'
             self.fields[field_name] = copy.copy(form_field)

netbox/core/models/data.py

@@ -14,10 +14,10 @@ from django.utils.translation import gettext as _
 
 from extras.models import JobResult
 from netbox.models import ChangeLoggedModel
+from netbox.registry import registry
 from utilities.files import sha256_hash
 from utilities.querysets import RestrictedQuerySet
 from ..choices import *
-from ..data_backends import GitBackend, LocalBackend
 from ..exceptions import SyncError
 
 __all__ = (
@@ -27,11 +27,6 @@ __all__ = (
 
 logger = logging.getLogger('netbox.core.data')
 
-BACKEND_CLASSES = {
-    DataSourceTypeChoices.LOCAL: LocalBackend,
-    DataSourceTypeChoices.GIT: GitBackend,
-}
-
 
 class DataSource(ChangeLoggedModel):
     """
@@ -129,7 +124,7 @@ class DataSource(ChangeLoggedModel):
         return job_result
 
     def get_backend(self):
-        backend_cls = BACKEND_CLASSES.get(self.type)
+        backend_cls = registry['data_backends'].get(self.type)
         backend_params = self.parameters or {}
 
         return backend_cls(self.url, **backend_params)

netbox/netbox/registry.py

@@ -25,9 +25,10 @@ class Registry(dict):
 
 # Initialize the global registry
 registry = Registry()
+registry['data_backends'] = dict()
+registry['denormalized_fields'] = collections.defaultdict(list)
 registry['model_features'] = {
     feature: collections.defaultdict(set) for feature in EXTRAS_FEATURES
 }
-registry['denormalized_fields'] = collections.defaultdict(list)
 registry['search'] = dict()
 registry['views'] = collections.defaultdict(dict)