[PSU]: Return number of PSU as zero for Chassis Linecard

Signed-off-by: Suvarna Meenakshi <sumeenak@microsoft.com>

src/sonic_ax_impl/mibs/vendor/cisco/ciscoEntityFruControlMIB.py

@@ -1,6 +1,7 @@
 from enum import Enum, unique
 from sonic_ax_impl import mibs
 from ax_interface import MIBMeta, ValueType, SubtreeMIBEntry
+from sonic_py_common.device_info import is_chassis, is_supervisor
 
 CHASSIS_INFO_KEY_TEMPLATE = 'chassis {}'
 PSU_INFO_KEY_TEMPLATE = 'PSU {}'
@@ -59,6 +60,9 @@ def _get_num_psus(self):
         Get PSU number
         :return: the number of supported PSU
         """
+        if is_chassis() and not is_supervisor():
+            return 0
+
         chassis_name = CHASSIS_INFO_KEY_TEMPLATE.format(1)
         chassis_info = self.statedb.get_all(self.statedb.STATE_DB, mibs.chassis_info_table(chassis_name))
         num_psus = get_chassis_data(chassis_info)

tests/test_psu.py

@@ -9,6 +9,11 @@
 
 from unittest import TestCase
 
+if sys.version_info.major == 3:
+    from unittest import mock
+else:
+    import mock
+
 from ax_interface import ValueType
 from ax_interface.pdu_implementations import GetPDU, GetNextPDU
 from ax_interface.encodings import ObjectIdentifier
@@ -115,3 +120,46 @@ def test_getMissedPsu(self):
         self.assertEqual(value0.type_, ValueType.END_OF_MIB_VIEW)
         self.assertEqual(str(value0.name), str(oid))
         self.assertEqual(value0.data, None)
+
+    @mock.patch('sonic_ax_impl.mibs.vendor.cisco.ciscoEntityFruControlMIB.is_chassis', mock.MagicMock(return_value=True))
+    @mock.patch('sonic_ax_impl.mibs.vendor.cisco.ciscoEntityFruControlMIB.is_supervisor', mock.MagicMock(return_value=False))
+    @mock.patch('sonic_ax_impl.mibs.vendor.cisco.ciscoEntityFruControlMIB.get_chassis_data', mock.MagicMock(return_value=(('',))))
+    def test_getNoPsuChassisLineCard(self):
+        # is_chassis is True and is_supervisor is False
+        # Expect no PSU in Linecard of Chassis
+        # Fail if Exception is caught, no exception should be caught for Linecard with no PSU
+        oid = ObjectIdentifier(2, 0, 0, 0, (1, 3, 6, 1, 4, 1, 9, 9, 117, 1, 1, 2, 1, 2, 1))
+        expected_oid = None
+        try:
+            ciscoEntityFruControlMIB.cefcFruPowerStatusTable.power_status_handler._get_num_psus()
+        except Exception as e:
+            self.fail(f"Caught unexpected exception: {type(e).__name__}: {str(e)}")
+
+
+    @mock.patch('sonic_ax_impl.mibs.vendor.cisco.ciscoEntityFruControlMIB.is_chassis', mock.MagicMock(return_value=True))
+    @mock.patch('sonic_ax_impl.mibs.vendor.cisco.ciscoEntityFruControlMIB.is_supervisor', mock.MagicMock(return_value=True))
+    @mock.patch('sonic_ax_impl.mibs.vendor.cisco.ciscoEntityFruControlMIB.get_chassis_data', mock.MagicMock(return_value=(('',))))
+    def test_getNoPsuChassisSupervisor(self):
+        # is_chassis is True and is_supervisor is True
+        # get_chassis_data() should return num_psu
+        # Exception will be caught on supervisory if num_psu is empty
+        oid = ObjectIdentifier(2, 0, 0, 0, (1, 3, 6, 1, 4, 1, 9, 9, 117, 1, 1, 2, 1, 2, 1))
+        expected_oid = None
+
+        with self.assertRaises(Exception):
+            ciscoEntityFruControlMIB.cefcFruPowerStatusTable.power_status_handler._get_num_psus()
+
+    @mock.patch('sonic_ax_impl.mibs.vendor.cisco.ciscoEntityFruControlMIB.is_chassis', mock.MagicMock(return_value=True))
+    @mock.patch('sonic_ax_impl.mibs.vendor.cisco.ciscoEntityFruControlMIB.is_supervisor', mock.MagicMock(return_value=True))
+    @mock.patch('sonic_ax_impl.mibs.vendor.cisco.ciscoEntityFruControlMIB.get_chassis_data', mock.MagicMock(return_value=(('8',))))
+    def test_getPsuPresentChassisSupervisor(self):
+        # is_chassis is True and is_supervisor is True
+        # get_chassis_data() should return num_psu
+        # no exception should be caught and number of psus should be returned
+        oid = ObjectIdentifier(2, 0, 0, 0, (1, 3, 6, 1, 4, 1, 9, 9, 117, 1, 1, 2, 1, 2, 1))
+        expected_oid = None
+        try:
+            num_psus = ciscoEntityFruControlMIB.cefcFruPowerStatusTable.power_status_handler._get_num_psus()
+            self.assertEqual(num_psus, 8)
+        except Exception as e:
+            self.fail(f"Caught unexpected exception: {type(e).__name__}: {str(e)}")