[change] Migrate signal receivers to WhoIs model

Migrated all receivers related to WhoIs to the
model class.
Includes minor refactoring as well.

Signed-off-by: DragnEmperor <[email protected]>

Author: DragnEmperor

openwisp_controller/config/apps.py

@@ -64,6 +64,7 @@ def __setmodels__(self):
         self.cert_model = load_model("django_x509", "Cert")
         self.org_model = load_model("openwisp_users", "Organization")
         self.org_config_model = load_model("config", "OrganizationConfigSettings")
+        self.who_is_model = load_model("config", "WhoIsInfo")
 
     def connect_signals(self):
         """
@@ -75,10 +76,6 @@ def connect_signals(self):
         * cache invalidation
         """
         from . import handlers  # noqa
-        from .who_is.handlers import (
-            device_who_is_info_delete_handler,
-            invalidate_org_settings_cache,
-        )
 
         m2m_changed.connect(
             self.config_model.clean_templates,
@@ -162,17 +159,17 @@ def connect_signals(self):
             dispatch_uid="organization_allowed_devices_post_save_handler",
         )
         post_delete.connect(
-            device_who_is_info_delete_handler,
+            self.who_is_model.device_who_is_info_delete_handler,
             sender=self.device_model,
             dispatch_uid="device.delete_who_is_info",
         )
         post_save.connect(
-            invalidate_org_settings_cache,
+            self.who_is_model.invalidate_org_settings_cache,
             self.org_config_model,
             dispatch_uid="invalidate_org_config_cache_on_org_config_save",
         )
         post_delete.connect(
-            invalidate_org_settings_cache,
+            self.who_is_model.invalidate_org_settings_cache,
             self.org_config_model,
             dispatch_uid="invalidate_org_config_cache_on_org_config_delete",
         )

openwisp_controller/config/base/who_is.py

@@ -1,7 +1,8 @@
 from ipaddress import ip_address
 
+from django.core.cache import cache
 from django.core.exceptions import ValidationError
-from django.db import models
+from django.db import models, transaction
 from django.utils.translation import gettext_lazy as _
 from jsonfield import JSONField
 
@@ -56,3 +57,30 @@ def clean(self):
                 _("WhoIs information cannot be created for private IP addresses.")
             )
         return super().clean()
+
+    @staticmethod
+    def device_who_is_info_delete_handler(instance, **kwargs):
+        """
+        Delete WhoIs information for a device when the last IP address is removed or
+        when device is deleted.
+        """
+        # importing here to avoid AppRegistryNotReady error
+        from openwisp_controller.config.who_is.service import WhoIsService
+
+        transaction.on_commit(
+            lambda: WhoIsService.delete_who_is_record.delay(instance.last_ip)
+        )
+
+    # this method is kept here instead of in OrganizationConfigSettings because
+    # currently the caching is used only for WhoIs feature
+    @staticmethod
+    def invalidate_org_settings_cache(instance, **kwargs):
+        """
+        Invalidate the cache for Organization settings on update/delete of
+        Organization settings instance.
+        """
+        # importing here to avoid AppRegistryNotReady error
+        from openwisp_controller.config.who_is.service import WhoIsService
+
+        org_id = instance.organization_id
+        cache.delete(WhoIsService.get_cache_key(org_id))

openwisp_controller/config/who_is/handlers.py

@@ -5,7 +5,6 @@
 from celery import shared_task
 from django.core.cache import cache
 from django.db import transaction
-from django.db.models import Subquery
 from django.utils.translation import gettext as _
 from geoip2 import errors
 from geoip2 import webservice as geoip2_webservice
@@ -59,11 +58,16 @@ class WhoIsService:
     A handler class for managing the WhoIs functionality.
     """
 
-    ORG_SETTINGS_CACHE_KEY = "organization_config_{org_pk}"
-
     def __init__(self, device):
         self.device = device
 
+    @staticmethod
+    def get_cache_key(org_id):
+        """
+        Used to get cache key for caching org settings of a device.
+        """
+        return f"organization_config_{org_id}"
+
     @staticmethod
     def _get_geoip2_client():
         """
@@ -126,22 +130,18 @@ def is_who_is_enabled(self):
         is set to the same as the checksum cache timeout for consistency
         with DeviceChecksumView.
         """
-        org_pk = self.device.organization.pk
-        org_settings = cache.get(self.ORG_SETTINGS_CACHE_KEY.format(org_pk=org_pk))
+        org_id = self.device.organization.pk
+        org_settings = cache.get(self.get_cache_key(org_id=org_id))
         if org_settings is None:
             try:
                 org_settings = OrganizationConfigSettings.objects.get(
-                    organization=Subquery(
-                        Device.objects.filter(pk=self.device.pk).values(
-                            "organization_id"
-                        )[:1]
-                    )
+                    organization=org_id
                 )
             except OrganizationConfigSettings.DoesNotExist:
                 # If organization settings do not exist, fall back to global setting
                 return app_settings.WHO_IS_ENABLED
             cache.set(
-                self.ORG_SETTINGS_CACHE_KEY.format(org_pk=org_pk),
+                self.get_cache_key(org_id=org_id),
                 org_settings,
                 timeout=Config._CHECKSUM_CACHE_TIMEOUT,
             )