Check config before restarting (#5609)

* Check config before restarting.

* Make check_config on restart async

* don't check if notification service exists

* Use .communicate()

* Reduce the number of notifications. Add tests.

homeassistant/core.py

@@ -330,11 +330,40 @@ class HomeAssistant(object):
         self.exit_code = 0
         self.loop.create_task(self.async_stop())
 
+    @asyncio.coroutine
+    def _async_check_config_and_restart(self):
+        """Restart Home Assistant if config is valid.
+
+        This method is a coroutine.
+        """
+        proc = yield from asyncio.create_subprocess_exec(
+            sys.argv[0],
+            '--script',
+            'check_config',
+            stdout=asyncio.subprocess.PIPE)
+        # Wait for the subprocess exit
+        (stdout_data, dummy) = yield from proc.communicate()
+        result = yield from proc.wait()
+        if result:
+            _LOGGER.error("check_config failed. Not restarting.")
+            content = re.sub(r'\033\[[^m]*m', '', str(stdout_data, 'utf-8'))
+            # Put error cleaned from color codes in the error log so it
+            # will be visible at the UI.
+            _LOGGER.error(content)
+            yield from self.services.async_call(
+                'persistent_notification', 'create', {
+                    'message': 'Config error. See dev-info panel for details.',
+                    'title': 'Restarting',
+                    'notification_id': '{}.restart'.format(DOMAIN)})
+            return
+
+        self.exit_code = RESTART_EXIT_CODE
+        yield from self.async_stop()
+
     @callback
     def _async_restart_handler(self, *args):
         """Restart Home Assistant."""
-        self.exit_code = RESTART_EXIT_CODE
-        self.loop.create_task(self.async_stop())
+        self.loop.create_task(self._async_check_config_and_restart())
 
 
 class EventOrigin(enum.Enum):

homeassistant/scripts/check_config.py

@@ -96,7 +96,6 @@ def run(script_args: List) -> int:
         domain_info = args.info.split(',')
 
     res = check(config_path)
-
     if args.files:
         print(color(C_HEAD, 'yaml files'), '(used /',
               color('red', 'not used') + ')')
@@ -247,6 +246,7 @@ def check(config_path):
         res['secret_cache'] = dict(yaml.__SECRET_CACHE)
     except Exception as err:  # pylint: disable=broad-except
         print(color('red', 'Fatal error while loading config:'), str(err))
+        res['except'].setdefault(ERROR_STR, []).append(err)
     finally:
         # Stop all patches
         for pat in PATCHES.values():

tests/common.py

@@ -388,6 +388,11 @@ def mock_coro(return_value=None):
     return coro
 
 
+def mock_generator(return_value=None):
+    """Helper method to return a coro generator that returns a value."""
+    return mock_coro(return_value)()
+
+
 @contextmanager
 def assert_setup_component(count, domain=None):
     """Collect valid configuration from setup_component.

tests/test_core.py

@@ -14,9 +14,10 @@ from homeassistant.util.async import run_coroutine_threadsafe
 import homeassistant.util.dt as dt_util
 from homeassistant.util.unit_system import (METRIC_SYSTEM)
 from homeassistant.const import (
-    __version__, EVENT_STATE_CHANGED, ATTR_FRIENDLY_NAME, CONF_UNIT_SYSTEM)
+    __version__, EVENT_STATE_CHANGED, ATTR_FRIENDLY_NAME, CONF_UNIT_SYSTEM,
+    SERVICE_HOMEASSISTANT_RESTART, RESTART_EXIT_CODE)
 
-from tests.common import get_test_home_assistant
+from tests.common import get_test_home_assistant, mock_generator
 
 PST = pytz.timezone('America/Los_Angeles')
 
@@ -220,6 +221,39 @@ class TestHomeAssistant(unittest.TestCase):
         with pytest.raises(ValueError):
             self.hass.add_job(None, 'test_arg')
 
+    @patch('asyncio.create_subprocess_exec')
+    def test_restart(self, mock_create):
+        """Check that restart propagates to stop."""
+        process_mock = MagicMock()
+        attrs = {
+            'communicate.return_value': mock_generator(('output', 'error')),
+            'wait.return_value': mock_generator(0)}
+        process_mock.configure_mock(**attrs)
+        mock_create.return_value = mock_generator(process_mock)
+
+        self.hass.start()
+        with patch.object(self.hass, 'async_stop') as mock_stop:
+            self.hass.services.call(ha.DOMAIN, SERVICE_HOMEASSISTANT_RESTART)
+            mock_stop.assert_called_once_with()
+        self.assertEqual(RESTART_EXIT_CODE, self.hass.exit_code)
+
+    @patch('asyncio.create_subprocess_exec')
+    def test_restart_bad_config(self, mock_create):
+        """Check that restart with a bad config doesn't propagate to stop."""
+        process_mock = MagicMock()
+        attrs = {
+            'communicate.return_value':
+                mock_generator((r'\033[hellom'.encode('utf-8'), 'error')),
+            'wait.return_value': mock_generator(1)}
+        process_mock.configure_mock(**attrs)
+        mock_create.return_value = mock_generator(process_mock)
+
+        self.hass.start()
+        with patch.object(self.hass, 'async_stop') as mock_stop:
+            self.hass.services.call(ha.DOMAIN, SERVICE_HOMEASSISTANT_RESTART)
+            mock_stop.assert_not_called()
+        self.assertEqual(None, self.hass.exit_code)
+
 
 class TestEvent(unittest.TestCase):
     """A Test Event class."""