Limit LDAP network timeout

CHANGELOG.rst

@@ -24,6 +24,8 @@ Fixed
 * Show all years in a 200 year range around the current year in date pickers
 * Imprint is now called "Imprint" and not "Impress".
 * Logo files weren't uploaded to public namespace.
+* Limit LDAP network timeouts to not hang indefinitely on login if LDAP
+  server is unreachable
 
 Changed
 ~~~~~~~

aleksis/core/settings.py

@@ -405,6 +405,10 @@ if _settings.get("ldap.uri", None):
         PosixGroupType,
     )
 
+    AUTH_LDAP_GLOBAL_OPTIONS = {
+        ldap.OPT_NETWORK_TIMEOUT: _settings.get("ldap.network_timeout", 3),
+    }
+
     # Enable Django's integration to LDAP
     AUTHENTICATION_BACKENDS.append("aleksis.core.util.ldap.LDAPBackend")