Log failed login attempts

src/paperless/signals.py

@@ -0,0 +1,32 @@
+import logging
+
+from django.conf import settings
+from ipware import get_client_ip
+
+logger = logging.getLogger("paperless.auth")
+
+
+# https://docs.djangoproject.com/en/4.1/ref/contrib/auth/#django.contrib.auth.signals.user_login_failed
+def handle_failed_login(sender, credentials, request, **kwargs):
+    client_ip, is_routable = get_client_ip(
+        request,
+        proxy_trusted_ips=settings.TRUSTED_PROXIES,
+    )
+    if client_ip is None:
+        logger.info(
+            f"Login failed for user `{credentials['username']}`."
+            + " Unable to determine IP address.",
+        )
+    else:
+        if is_routable:
+            # We got the client's IP address
+            logger.info(
+                f"Login failed for user `{credentials['username']}`"
+                + f" from IP `{client_ip}.`",
+            )
+        else:
+            # The client's IP address is private
+            logger.info(
+                f"Login failed for user `{credentials['username']}`"
+                + f" from private IP `{client_ip}.`",
+            )