Allow configuring redis to use unix sockets

related: https://github.com/netbox-community/netbox/issues/4377

docs/configuration/required-parameters.md

@@ -105,11 +105,11 @@ REDIS = {
 
 ### Using Redis Sentinel
 
-If you are using [Redis Sentinel](https://redis.io/topics/sentinel) for high-availability purposes, there is minimal 
+If you are using [Redis Sentinel](https://redis.io/topics/sentinel) for high-availability purposes, there is minimal
-configuration necessary to convert NetBox to recognize it. It requires the removal of the `HOST` and `PORT` keys from 
+configuration necessary to convert NetBox to recognize it. It requires the removal of the `HOST` and `PORT` keys from
 above and the addition of three new keys.
 
-* `SENTINELS`: List of tuples or tuple of tuples with each inner tuple containing the name or IP address 
+* `SENTINELS`: List of tuples or tuple of tuples with each inner tuple containing the name or IP address
 of the Redis server and port for each sentinel instance to connect to
 * `SENTINEL_SERVICE`: Name of the master / service to connect to
 * `SENTINEL_TIMEOUT`: Connection timeout, in seconds
@@ -142,6 +142,36 @@ REDIS = {
 !!! note
     It is permissible to use Sentinel for only one database and not the other.
 
+
+### Using Redis with Unix Sockets
+
+If you'd like to configure NetBox to access Redis over unix sockets, set `PROTO: 'unix'`
+
+Example:
+
+```python
+REDIS = {
+    'tasks': {
+        'PROTO': 'unix',
+        'HOST': '/var/run/redis/redis.sock',
+        'PASSWORD': '',
+        'USERNAME': '',
+    }
+}
+```
+Alternatively, you may specify the location string yourself:
+```python
+REDIS = {
+    'tasks': {
+        'LOCATION': 'unix://netbox@/var/run/redis/redis.sock?db=0'
+        'PASSWORD': '',
+    }
+}
+
+!!! note
+    the `PASSWORD` option is still provided even when using `LOCATION` directly so you don't have to url-encode your password yourself.
+
+
 ---
 
 ## SECRET_KEY

netbox/netbox/settings.py

@@ -277,11 +277,14 @@ TASKS_REDIS_DATABASE = TASKS_REDIS.get('DATABASE', 0)
 TASKS_REDIS_SSL = TASKS_REDIS.get('SSL', False)
 TASKS_REDIS_SKIP_TLS_VERIFY = TASKS_REDIS.get('INSECURE_SKIP_TLS_VERIFY', False)
 TASKS_REDIS_CA_CERT_PATH = TASKS_REDIS.get('CA_CERT_PATH', False)
+TASKS_REDIS_PROTO = 'rediss' if TASKS_REDIS_SSL else TASKS_REDIS.get('PROTO', 'redis')
+TASKS_REDIS_LOCATION_FROM_KEYS = f'unix://{TASKS_REDIS_USERNAME_HOST}?db={TASKS_REDIS_DATABASE}'
+TASKS_REDIS_LOCATION = TASKS_REDIS.get('LOCATION', TASKS_REDIS_LOCATION_FROM_KEYS)
 
 # Caching
 if 'caching' not in REDIS:
     raise ImproperlyConfigured(
-        "REDIS section in configuration.py is missing caching subsection."
+        "REDIS section in configuration.py is missing 'caching' subsection."
     )
 CACHING_REDIS_HOST = REDIS['caching'].get('HOST', 'localhost')
 CACHING_REDIS_PORT = REDIS['caching'].get('PORT', 6379)
@@ -291,18 +294,30 @@ CACHING_REDIS_USERNAME_HOST = '@'.join(filter(None, [CACHING_REDIS_USERNAME, CAC
 CACHING_REDIS_PASSWORD = REDIS['caching'].get('PASSWORD', '')
 CACHING_REDIS_SENTINELS = REDIS['caching'].get('SENTINELS', [])
 CACHING_REDIS_SENTINEL_SERVICE = REDIS['caching'].get('SENTINEL_SERVICE', 'default')
-CACHING_REDIS_PROTO = 'rediss' if REDIS['caching'].get('SSL', False) else 'redis'
+CACHING_REDIS_PROTO = 'rediss' if REDIS['caching'].get('SSL', False) else REDIS['caching'].get('PROTO', '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)
 
+if CACHING_REDIS_PROTO == 'unix':
+    CACHING_REDIS_LOCATION_FROM_KEYS = f'unix://{CACHING_REDIS_USERNAME_HOST}?db={CACHING_REDIS_DATABASE}'
+elif CACHING_REDIS_PROTO == 'rediss' or CACHING_REDIS_PROTO == 'redis':
+    CACHING_REDIS_LOCATION_FROM_KEYS = f'{CACHING_REDIS_PROTO}://{CACHING_REDIS_USERNAME_HOST}:{CACHING_REDIS_PORT}/CACHING_REDIS_DATABASE}'
+else:
+    raise ImproperlyConfigured(
+        "Unknown PROTO for REDIS 'caching' subsection in configuration.py"
+    )
+
+CACHING_REDIS_LOCATION = REDIS['caching'].get('LOCATION', CACHING_REDIS_LOCATION_FROM_KEYS)
+CACHING_REDIS_OPTIONS = {
+    'CLIENT_CLASS': 'django_redis.client.DefaultClient',
+    'PASSWORD': CACHING_REDIS_PASSWORD,
+}
+
 CACHES = {
     'default': {
         'BACKEND': 'django_redis.cache.RedisCache',
-        'LOCATION': f'{CACHING_REDIS_PROTO}://{CACHING_REDIS_USERNAME_HOST}:{CACHING_REDIS_PORT}/{CACHING_REDIS_DATABASE}',
+        'LOCATION': CACHING_REDIS_LOCATION,
-        'OPTIONS': {
+        'OPTIONS': CACHING_REDIS_OPTIONS,
-            'CLIENT_CLASS': 'django_redis.client.DefaultClient',
-            'PASSWORD': CACHING_REDIS_PASSWORD,
-        }
     }
 }
 
@@ -687,6 +702,10 @@ if TASKS_REDIS_USING_SENTINEL:
             'socket_connect_timeout': TASKS_REDIS_SENTINEL_TIMEOUT
         },
     }
+elif TASKS_REDIS_LOCATION:
+    RQ_PARAMS = {
+        'URL': TASKS_REDIS_LOCATION,
+    }
 else:
     RQ_PARAMS = {
         'HOST': TASKS_REDIS_HOST,