Introduce DATABASE_ROUTERS config parameter

docs/configuration/required-parameters.md

@@ -46,7 +46,7 @@ DATABASES = {
 }
 ```
 
-NetBox itself requires only a `default` database be defined. However, certain plugins may require the configuration of additional databases.
+NetBox itself requires only that a `default` database is defined. However, certain plugins may require the configuration of additional databases. (Consider also configuring the [`DATABASE_ROUTERS`](./system.md#database_routers) parameter when multiple databases are in use.)
 
 The following parameters must be defined for each database:
 

docs/configuration/system.md

@@ -12,6 +12,14 @@ BASE_PATH = 'netbox/'
 
 ---
 
+## DATABASE_ROUTERS
+
+Default: `[]` (empty list)
+
+An iterable of [database routers](https://docs.djangoproject.com/en/stable/topics/db/multi-db/) to use for automatically selecting the appropriate database(s) for a query. This is useful only when [multiple databases](./required-parameters.md#databases) have been configured.
+
+---
+
 ## DEFAULT_LANGUAGE
 
 Default: `en-us` (US English)

netbox/netbox/settings.py

@@ -88,6 +88,7 @@ CSRF_COOKIE_SECURE = getattr(configuration, 'CSRF_COOKIE_SECURE', False)
 CSRF_TRUSTED_ORIGINS = getattr(configuration, 'CSRF_TRUSTED_ORIGINS', [])
 DATA_UPLOAD_MAX_MEMORY_SIZE = getattr(configuration, 'DATA_UPLOAD_MAX_MEMORY_SIZE', 2621440)
 DATABASE = getattr(configuration, 'DATABASE', None)  # Legacy DB definition
+DATABASE_ROUTERS = getattr(configuration, 'DATABASE_ROUTERS', [])
 DATABASES = getattr(configuration, 'DATABASES', {'default': DATABASE})
 DEBUG = getattr(configuration, 'DEBUG', False)
 DEFAULT_DASHBOARD = getattr(configuration, 'DEFAULT_DASHBOARD', None)