[system-health] Add fan direction check for system health (#14509)

- Why I did it
Add fan direction check to system health, all fans should be in the same direction

- How I did it
Add fan direction check to system health, all fans should be in the same direction

- How to verify it
Manual test
Unit test
Added sonic-mgmt test case to verify

src/system-health/health_checker/hardware_checker.py

@@ -71,6 +71,7 @@ def _check_fan_status(self, config):
             1. Check all fans are present
             2. Check all fans are in good state
             3. Check fan speed is in valid range
+            4. Check all fans direction are the same
         :param config: Health checker configuration
         :return:
         """
@@ -82,6 +83,7 @@ def _check_fan_status(self, config):
             self.set_object_not_ok('Fan', 'Fan', 'Failed to get fan information')
             return
 
+        expect_fan_direction = None
         for key in natsorted(keys):
             key_list = key.split('|')
             if len(key_list) != 2:  # error data in DB, log it and ignore
@@ -133,6 +135,18 @@ def _check_fan_status(self, config):
                                                    speed_tolerance))
                         continue
 
+            if not self._ignore_check(config.ignore_devices, 'fan', name, 'direction'):
+                direction = data_dict.get('direction', 'N/A')
+                # ignore fan whose direction is not available to avoid too many false alarms
+                if direction != 'N/A':
+                    if not expect_fan_direction:
+                        # initialize the expect fan direction
+                        expect_fan_direction = (name, direction)
+                    elif direction != expect_fan_direction[1]:
+                        self.set_object_not_ok('Fan', name,
+                                               f'{name} direction {direction} is not aligned with {expect_fan_direction[0]} direction {expect_fan_direction[1]}')
+                        continue
+
             status = data_dict.get('status', 'false')
             if status.lower() != 'true':
                 self.set_object_not_ok('Fan', name, '{} is broken'.format(name))

src/system-health/tests/test_system_health.py

@@ -298,7 +298,8 @@ def test_hardware_checker():
             'status': 'True',
             'speed': '60',
             'speed_target': '60',
-            'speed_tolerance': '20'
+            'speed_tolerance': '20',
+            'direction': 'intake'
         },
         'FAN_INFO|fan2': {
             'presence': 'False',
@@ -320,6 +321,14 @@ def test_hardware_checker():
             'speed': '20',
             'speed_target': '60',
             'speed_tolerance': '20'
+        },
+        'FAN_INFO|fan5': {
+            'presence': 'True',
+            'status': 'True',
+            'speed': '60',
+            'speed_target': '60',
+            'speed_tolerance': '20',
+            'direction': 'exhaust'
         }
     })
 
@@ -415,6 +424,10 @@ def test_hardware_checker():
     assert 'fan4' in checker._info
     assert checker._info['fan4'][HealthChecker.INFO_FIELD_OBJECT_STATUS] == HealthChecker.STATUS_NOT_OK
 
+    assert 'fan5' in checker._info
+    assert checker._info['fan5'][HealthChecker.INFO_FIELD_OBJECT_STATUS] == HealthChecker.STATUS_NOT_OK
+    assert checker._info['fan5'][HealthChecker.INFO_FIELD_OBJECT_MSG] == 'fan5 direction exhaust is not aligned with fan1 direction intake'
+
     assert 'PSU 1' in checker._info
     assert checker._info['PSU 1'][HealthChecker.INFO_FIELD_OBJECT_STATUS] == HealthChecker.STATUS_OK