Support Redis Unix sockets (#16227)

* Fixes #15962: support Redis Unix sockets

* Clean up language & remove obsolete note

---------

Co-authored-by: Jeremy Stretch <jstretch@netboxlabs.com>

docs/configuration/required-parameters.md

@@ -94,15 +94,25 @@ REDIS = {
 }
 ```
 
-!!! note
-    If you are upgrading from a NetBox release older than v2.7.0, please note that the Redis connection configuration
-    settings have changed. Manual modification to bring the `REDIS` section inline with the above specification is
-    necessary
-
 !!! warning
     It is highly recommended to keep the task and cache databases separate. Using the same database number on the
     same Redis instance for both may result in queued background tasks being lost during cache flushing events.
 
+### UNIX Socket Support
+
+Redis may alternatively be configured by specifying a complete URL instead of individual components. This approach supports the use of a UNIX socket connection. For example:
+
+```python
+REDIS = {
+    'tasks': {
+        'URL': 'unix:///run/redis-netbox/redis.sock?db=0'
+    },
+    'caching': {
+        'URL': 'unix:///run/redis-netbox/redis.sock?db=1'
+    },
+}
+```
+
 ### Using Redis Sentinel
 
 If you are using [Redis Sentinel](https://redis.io/topics/sentinel) for high-availability purposes, there is minimal 

netbox/netbox/settings.py

@@ -242,6 +242,7 @@ if 'tasks' not in REDIS:
 TASKS_REDIS = REDIS['tasks']
 TASKS_REDIS_HOST = TASKS_REDIS.get('HOST', 'localhost')
 TASKS_REDIS_PORT = TASKS_REDIS.get('PORT', 6379)
+TASKS_REDIS_URL = TASKS_REDIS.get('URL')
 TASKS_REDIS_SENTINELS = TASKS_REDIS.get('SENTINELS', [])
 TASKS_REDIS_USING_SENTINEL = all([
     isinstance(TASKS_REDIS_SENTINELS, (list, tuple)),
@@ -270,7 +271,7 @@ CACHING_REDIS_SENTINEL_SERVICE = REDIS['caching'].get('SENTINEL_SERVICE', 'defau
 CACHING_REDIS_PROTO = 'rediss' if REDIS['caching'].get('SSL', False) else 'redis'
 CACHING_REDIS_SKIP_TLS_VERIFY = REDIS['caching'].get('INSECURE_SKIP_TLS_VERIFY', False)
 CACHING_REDIS_CA_CERT_PATH = REDIS['caching'].get('CA_CERT_PATH', False)
-CACHING_REDIS_URL = f'{CACHING_REDIS_PROTO}://{CACHING_REDIS_USERNAME_HOST}:{CACHING_REDIS_PORT}/{CACHING_REDIS_DATABASE}'
+CACHING_REDIS_URL = REDIS['caching'].get('URL', f'{CACHING_REDIS_PROTO}://{CACHING_REDIS_USERNAME_HOST}:{CACHING_REDIS_PORT}/{CACHING_REDIS_DATABASE}')
 
 # Configure Django's default cache to use Redis
 CACHES = {
@@ -678,6 +679,12 @@ if TASKS_REDIS_USING_SENTINEL:
             'socket_connect_timeout': TASKS_REDIS_SENTINEL_TIMEOUT
         },
     }
+elif TASKS_REDIS_URL:
+    RQ_PARAMS = {
+        'URL': TASKS_REDIS_URL,
+        'SSL': TASKS_REDIS_SSL,
+        'SSL_CERT_REQS': None if TASKS_REDIS_SKIP_TLS_VERIFY else 'required',
+    }
 else:
     RQ_PARAMS = {
         'HOST': TASKS_REDIS_HOST,