Reduce log spam from unauthenticated websocket connections (#151388)

Author: bdraco

homeassistant/components/websocket_api/http.py

@@ -37,6 +37,7 @@
 from .util import describe_request
 
 CLOSE_MSG_TYPES = {WSMsgType.CLOSE, WSMsgType.CLOSED, WSMsgType.CLOSING}
+AUTH_MESSAGE_TIMEOUT = 10  # seconds
 
 if TYPE_CHECKING:
     from .connection import ActiveConnection
@@ -389,9 +390,11 @@ async def _async_handle_auth_phase(
 
         # Auth Phase
         try:
-            msg = await self._wsock.receive(10)
+            msg = await self._wsock.receive(AUTH_MESSAGE_TIMEOUT)
         except TimeoutError as err:
-            raise Disconnect("Did not receive auth message within 10 seconds") from err
+            raise Disconnect(
+                f"Did not receive auth message within {AUTH_MESSAGE_TIMEOUT} seconds"
+            ) from err
 
         if msg.type in (WSMsgType.CLOSE, WSMsgType.CLOSED, WSMsgType.CLOSING):
             raise Disconnect("Received close message during auth phase")
@@ -538,6 +541,14 @@ async def _async_cleanup_writer_and_close(
             finally:
                 if disconnect_warn is None:
                     logger.debug("%s: Disconnected", self.description)
+                elif connection is None:
+                    # Auth phase disconnects (connection is None) should be logged at debug level
+                    # as they can be from random port scanners or non-legitimate connections
+                    logger.debug(
+                        "%s: Disconnected during auth phase: %s",
+                        self.description,
+                        disconnect_warn,
+                    )
                 else:
                     logger.warning(
                         "%s: Disconnected: %s", self.description, disconnect_warn

tests/components/websocket_api/test_http.py

@@ -2,6 +2,7 @@
 
 import asyncio
 from datetime import timedelta
+import logging
 from typing import Any, cast
 from unittest.mock import patch
 
@@ -20,7 +21,11 @@
 from homeassistant.util.dt import utcnow
 
 from tests.common import async_call_logger_set_level, async_fire_time_changed
-from tests.typing import MockHAClientWebSocket, WebSocketGenerator
+from tests.typing import (
+    ClientSessionGenerator,
+    MockHAClientWebSocket,
+    WebSocketGenerator,
+)
 
 
 @pytest.fixture
@@ -400,6 +405,48 @@ async def test_prepare_fail_connection_reset(
     assert "Connection reset by peer while preparing WebSocket" in caplog.text
 
 
+async def test_auth_timeout_logs_at_debug(
+    hass: HomeAssistant,
+    hass_client: ClientSessionGenerator,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Test auth timeout is logged at debug level not warning."""
+    # Setup websocket API
+    assert await async_setup_component(hass, "websocket_api", {})
+
+    client = await hass_client()
+
+    # Patch the auth timeout to be very short (0.001 seconds)
+    with (
+        caplog.at_level(logging.DEBUG, "homeassistant.components.websocket_api"),
+        patch(
+            "homeassistant.components.websocket_api.http.AUTH_MESSAGE_TIMEOUT", 0.001
+        ),
+    ):
+        # Try to connect - will timeout quickly since we don't send auth
+        ws = await client.ws_connect("/api/websocket")
+        # Wait a bit for the timeout to trigger and cleanup to complete
+        await asyncio.sleep(0.1)
+        await ws.close()
+        await asyncio.sleep(0.1)
+
+        # Check that "Did not receive auth message" is logged at debug, not warning
+        debug_messages = [
+            r.message for r in caplog.records if r.levelno == logging.DEBUG
+        ]
+        assert any(
+            "Disconnected during auth phase: Did not receive auth message" in msg
+            for msg in debug_messages
+        )
+
+        # Check it's NOT logged at warning level
+        warning_messages = [
+            r.message for r in caplog.records if r.levelno >= logging.WARNING
+        ]
+        for msg in warning_messages:
+            assert "Did not receive auth message" not in msg
+
+
 async def test_enable_coalesce(
     hass: HomeAssistant,
     hass_ws_client: WebSocketGenerator,