Ensure dt_utc in /os/info always returns current time (#6602)

The /os/info API endpoint has been using D-Bus property TimeUSec which got
cached between requests, so the time returned was not always the same as
current time on the host system at the time of the request. Since there's no
reason to use D-Bus API for the time, as Supervisor runs on the same machine
and time is global, simply format current datetime object with Python and
return it in the response.

Fixes #6581

supervisor/dbus/timedate.py

@@ -8,12 +8,11 @@ from typing import Any
 from dbus_fast.aio.message_bus import MessageBus
 
 from ..exceptions import DBusError, DBusInterfaceError, DBusServiceUnkownError
-from ..utils.dt import get_time_zone, utc_from_timestamp
+from ..utils.dt import get_time_zone
 from .const import (
     DBUS_ATTR_LOCAL_RTC,
     DBUS_ATTR_NTP,
     DBUS_ATTR_NTPSYNCHRONIZED,
-    DBUS_ATTR_TIMEUSEC,
     DBUS_ATTR_TIMEZONE,
     DBUS_IFACE_TIMEDATE,
     DBUS_NAME_TIMEDATE,
@@ -65,12 +64,6 @@ class TimeDate(DBusInterfaceProxy):
         """Return if NTP is synchronized."""
         return self.properties[DBUS_ATTR_NTPSYNCHRONIZED]
 
-    @property
-    @dbus_property
-    def dt_utc(self) -> datetime:
-        """Return the system UTC time."""
-        return utc_from_timestamp(self.properties[DBUS_ATTR_TIMEUSEC] / 1000000)
-
     @property
     def timezone_tzinfo(self) -> tzinfo | None:
         """Return timezone as tzinfo object."""

supervisor/host/info.py

@@ -1,7 +1,7 @@
 """Info control for host."""
 
 import asyncio
-from datetime import datetime, tzinfo
+from datetime import UTC, datetime, tzinfo
 import logging
 
 from ..coresys import CoreSysAttributes
@@ -78,9 +78,9 @@ class InfoCenter(CoreSysAttributes):
         return self.sys_dbus.timedate.timezone_tzinfo
 
     @property
-    def dt_utc(self) -> datetime | None:
+    def dt_utc(self) -> datetime:
         """Return host UTC time."""
-        return self.sys_dbus.timedate.dt_utc
+        return datetime.now(UTC)
 
     @property
     def use_rtc(self) -> bool | None:

tests/api/test_host.py

@@ -1,10 +1,12 @@
 """Test Host API."""
 
 from collections.abc import AsyncGenerator
+from datetime import UTC, datetime
 from unittest.mock import ANY, MagicMock, patch
 
 from aiohttp.test_utils import TestClient
 import pytest
+import time_machine
 
 from supervisor.coresys import CoreSys
 from supervisor.dbus.resolved import Resolved
@@ -39,14 +41,17 @@ async def fixture_coresys_disk_info(coresys: CoreSys) -> AsyncGenerator[CoreSys]
 async def test_api_host_info(api_client: TestClient, coresys_disk_info: CoreSys):
     """Test host info api."""
     coresys = coresys_disk_info
+    dt_utc = datetime(2026, 2, 17, 1, 23, 45, 678901, tzinfo=UTC)
 
     await coresys.dbus.agent.connect(coresys.dbus.bus)
     await coresys.dbus.agent.update()
 
-    resp = await api_client.get("/host/info")
-    result = await resp.json()
+    with time_machine.travel(dt_utc, tick=False):
+        resp = await api_client.get("/host/info")
+        result = await resp.json()
 
     assert result["data"]["apparmor_version"] == "2.13.2"
+    assert result["data"]["dt_utc"] == "2026-02-17T01:23:45.678901+00:00"
 
 
 async def test_api_host_features(

tests/dbus/test_timedate.py

@@ -25,16 +25,12 @@ async def test_timedate_info(
     """Test timedate properties."""
     timedate = TimeDate()
 
-    assert timedate.dt_utc is None
     assert timedate.ntp is None
 
     await timedate.connect(dbus_session_bus)
 
-    assert timedate.dt_utc == datetime(2021, 5, 19, 8, 36, 54, 405718, tzinfo=UTC)
     assert timedate.ntp is True
 
-    assert timedate.dt_utc.isoformat() == "2021-05-19T08:36:54.405718+00:00"
-
     timedate_service.emit_properties_changed({"NTP": False})
     await timedate_service.ping()
     assert timedate.ntp is False