Add option to Core settings to enable duplicated logs

Introduce new option `duplicate_log_file` to HA Core configuration that will
set an environment variable `HA_DUPLICATE_LOG_FILE=1` for the Core container if
enabled. This will serve as a flag for Core to enable the legacy log file,
along the standard logging which is handled by Systemd Journal.

Author: sairon

supervisor/api/homeassistant.py

@@ -18,6 +18,7 @@
     ATTR_BLK_WRITE,
     ATTR_BOOT,
     ATTR_CPU_PERCENT,
+    ATTR_DUPLICATE_LOG_FILE,
     ATTR_IMAGE,
     ATTR_IP_ADDRESS,
     ATTR_JOB_ID,
@@ -55,6 +56,7 @@
         vol.Optional(ATTR_AUDIO_OUTPUT): vol.Maybe(str),
         vol.Optional(ATTR_AUDIO_INPUT): vol.Maybe(str),
         vol.Optional(ATTR_BACKUPS_EXCLUDE_DATABASE): vol.Boolean(),
+        vol.Optional(ATTR_DUPLICATE_LOG_FILE): vol.Boolean(),
     }
 )
 
@@ -112,6 +114,7 @@ async def info(self, request: web.Request) -> dict[str, Any]:
             ATTR_AUDIO_INPUT: self.sys_homeassistant.audio_input,
             ATTR_AUDIO_OUTPUT: self.sys_homeassistant.audio_output,
             ATTR_BACKUPS_EXCLUDE_DATABASE: self.sys_homeassistant.backups_exclude_database,
+            ATTR_DUPLICATE_LOG_FILE: self.sys_homeassistant.duplicate_log_file,
         }
 
     @api_process
@@ -151,6 +154,9 @@ async def options(self, request: web.Request) -> None:
                 ATTR_BACKUPS_EXCLUDE_DATABASE
             ]
 
+        if ATTR_DUPLICATE_LOG_FILE in body:
+            self.sys_homeassistant.duplicate_log_file = body[ATTR_DUPLICATE_LOG_FILE]
+
         await self.sys_homeassistant.save_data()
 
     @api_process

supervisor/const.py

@@ -179,6 +179,7 @@
 ATTR_DOCKER_API = "docker_api"
 ATTR_DOCUMENTATION = "documentation"
 ATTR_DOMAINS = "domains"
+ATTR_DUPLICATE_LOG_FILE = "duplicate_log_file"
 ATTR_ENABLE = "enable"
 ATTR_ENABLE_IPV6 = "enable_ipv6"
 ATTR_ENABLED = "enabled"

supervisor/docker/const.py

@@ -133,6 +133,7 @@ def from_status(cls, status: str) -> PullImageLayerStage | None:
         return None
 
 
+ENV_DUPLICATE_LOG_FILE = "HA_DUPLICATE_LOG_FILE"
 ENV_TIME = "TZ"
 ENV_TOKEN = "SUPERVISOR_TOKEN"
 ENV_TOKEN_OLD = "HASSIO_TOKEN"

supervisor/docker/homeassistant.py

@@ -14,6 +14,7 @@
 from ..jobs.const import JobConcurrency
 from ..jobs.decorator import Job
 from .const import (
+    ENV_DUPLICATE_LOG_FILE,
     ENV_TIME,
     ENV_TOKEN,
     ENV_TOKEN_OLD,
@@ -174,6 +175,8 @@ async def run(self, *, restore_job_id: str | None = None) -> None:
         }
         if restore_job_id:
             environment[ENV_RESTORE_JOB_ID] = restore_job_id
+        if self.sys_homeassistant.duplicate_log_file:
+            environment[ENV_DUPLICATE_LOG_FILE] = "1"
         await self._run(
             tag=(self.sys_homeassistant.version),
             name=self.name,

supervisor/homeassistant/module.py

@@ -23,6 +23,7 @@
     ATTR_AUDIO_OUTPUT,
     ATTR_BACKUPS_EXCLUDE_DATABASE,
     ATTR_BOOT,
+    ATTR_DUPLICATE_LOG_FILE,
     ATTR_IMAGE,
     ATTR_MESSAGE,
     ATTR_PORT,
@@ -299,6 +300,16 @@ def backups_exclude_database(self, value: bool) -> None:
         """Set whether backups should exclude database by default."""
         self._data[ATTR_BACKUPS_EXCLUDE_DATABASE] = value
 
+    @property
+    def duplicate_log_file(self) -> bool:
+        """Return True if Home Assistant should duplicate logs to file."""
+        return self._data[ATTR_DUPLICATE_LOG_FILE]
+
+    @duplicate_log_file.setter
+    def duplicate_log_file(self, value: bool) -> None:
+        """Set whether Home Assistant should duplicate logs to file."""
+        self._data[ATTR_DUPLICATE_LOG_FILE] = value
+
     async def load(self) -> None:
         """Prepare Home Assistant object."""
         await asyncio.wait(

supervisor/homeassistant/validate.py

@@ -10,6 +10,7 @@
     ATTR_AUDIO_OUTPUT,
     ATTR_BACKUPS_EXCLUDE_DATABASE,
     ATTR_BOOT,
+    ATTR_DUPLICATE_LOG_FILE,
     ATTR_IMAGE,
     ATTR_PORT,
     ATTR_REFRESH_TOKEN,
@@ -36,6 +37,7 @@
         vol.Optional(ATTR_AUDIO_OUTPUT, default=None): vol.Maybe(str),
         vol.Optional(ATTR_AUDIO_INPUT, default=None): vol.Maybe(str),
         vol.Optional(ATTR_BACKUPS_EXCLUDE_DATABASE, default=False): vol.Boolean(),
+        vol.Optional(ATTR_DUPLICATE_LOG_FILE, default=False): vol.Boolean(),
         vol.Optional(ATTR_OVERRIDE_IMAGE, default=False): vol.Boolean(),
     },
     extra=vol.REMOVE_EXTRA,

tests/docker/test_homeassistant.py

@@ -46,6 +46,7 @@ async def test_homeassistant_start(
             "TZ": ANY,
             "SUPERVISOR_TOKEN": ANY,
             "HASSIO_TOKEN": ANY,
+            # no "HA_DUPLICATE_LOG_FILE"
         }
         assert run.call_args.kwargs["mounts"] == [
             DEV_MOUNT,
@@ -105,6 +106,28 @@ async def test_homeassistant_start(
         assert "volumes" not in run.call_args.kwargs
 
 
+async def test_homeassistant_start_with_duplicate_log_file(
+    coresys: CoreSys, tmp_supervisor_data: Path, path_extern
+):
+    """Test starting homeassistant with duplicate_log_file enabled."""
+    coresys.homeassistant.version = AwesomeVersion("2025.12.0")
+    coresys.homeassistant.duplicate_log_file = True
+
+    with (
+        patch.object(DockerAPI, "run") as run,
+        patch.object(
+            DockerHomeAssistant, "is_running", side_effect=[False, False, True]
+        ),
+        patch("supervisor.homeassistant.core.asyncio.sleep"),
+    ):
+        await coresys.homeassistant.core.start()
+
+        run.assert_called_once()
+        env = run.call_args.kwargs["environment"]
+        assert "HA_DUPLICATE_LOG_FILE" in env
+        assert env["HA_DUPLICATE_LOG_FILE"] == "1"
+
+
 async def test_landingpage_start(
     coresys: CoreSys, tmp_supervisor_data: Path, path_extern
 ):
@@ -133,6 +156,7 @@ async def test_landingpage_start(
             "TZ": ANY,
             "SUPERVISOR_TOKEN": ANY,
             "HASSIO_TOKEN": ANY,
+            # no "HA_DUPLICATE_LOG_FILE"
         }
         assert run.call_args.kwargs["mounts"] == [
             DEV_MOUNT,