Combine psu presence/status update with data update (sonic-net#424)

When sysfs is simultaneously changing while psud updating, some data could be outdated immediately once read, so delay the psu presence and status updating to the final step, insure we get the latest info.

Description
PSU Model Serial HW Rev Voltage (V) Current (A) Power (W) Status LED
PSU 1 N/A N/A N/A 12.00 N/A N/A OK green
PSU 2 XXXXXXX XXXXXXXX A3 12.01 16.25 194.75 OK green

The status should be NOTOK as the psu had been turned off and other fields had became N/A as expected.

Motivation and Context
The failure flow are showing below:

    psu_db_update(self.psu_tbl, self.num_psus) // here we read and update the old data of psu status. 
    self.update_psu_data() // now psu status had been changed to NOTOK, but we won’t read it until next psu update cycle , other filed becomes N/A as expected.
How Has This Been Tested?
platform_tests/api/test_psu.py

Signed-off-by: Yuanzhe, Liu <[email protected]>

sonic-psud/scripts/psud

@@ -125,15 +125,6 @@ def get_psu_key(psu_index):
     return PSU_INFO_KEY_TEMPLATE.format(psu_index)
 
 
-def psu_db_update(psu_tbl, psu_num):
-    for psu_index in range(1, psu_num + 1):
-        fvs = swsscommon.FieldValuePairs([(PSU_INFO_PRESENCE_FIELD,
-                                           'true' if _wrapper_get_psu_presence(psu_index) else 'false'),
-                                          (PSU_INFO_STATUS_FIELD,
-                                           'true' if _wrapper_get_psu_status(psu_index) else 'false')])
-        psu_tbl.set(get_psu_key(psu_index), fvs)
-
-
 # try get information from platform API and return a default value if we catch NotImplementedError
 def try_get(callback, default=None):
     """
@@ -443,7 +434,6 @@ class DaemonPsud(daemon_base.DaemonBase):
             return False
 
         self._update_psu_entity_info()
-        psu_db_update(self.psu_tbl, self.num_psus)
         self.update_psu_data()
         self._update_led_color()
 
@@ -606,6 +596,8 @@ class DaemonPsud(daemon_base.DaemonBase):
              (PSU_INFO_IN_CURRENT_FIELD, str(in_current)),
              (PSU_INFO_IN_VOLTAGE_FIELD, str(in_voltage)),
              (PSU_INFO_POWER_MAX_FIELD, str(max_power)),
+             (PSU_INFO_PRESENCE_FIELD, 'true' if _wrapper_get_psu_presence(index) else 'false'),
+             (PSU_INFO_STATUS_FIELD, 'true' if _wrapper_get_psu_status(index) else 'false'),
              ])
         self.psu_tbl.set(name, fvs)
 

sonic-psud/tests/test_DaemonPsud.py

@@ -162,6 +162,8 @@ def _construct_expected_fvp(self, power=100.0, power_warning_suppress_threshold=
              (psud.PSU_INFO_IN_VOLTAGE_FIELD, '220.25'),
              (psud.PSU_INFO_IN_CURRENT_FIELD, '0.72'),
              (psud.PSU_INFO_POWER_MAX_FIELD, 'N/A'),
+             (psud.PSU_INFO_PRESENCE_FIELD, 'true'),
+             (psud.PSU_INFO_STATUS_FIELD, 'true'),
              ])
         return expected_fvp
 

sonic-psud/tests/test_psud.py

@@ -96,70 +96,6 @@ def test_wrapper_get_psu_status():
     psud.platform_psuutil.get_psu_status.assert_called_with(1)
 
 
-@mock.patch('psud._wrapper_get_psu_presence', mock.MagicMock())
-@mock.patch('psud._wrapper_get_psu_status', mock.MagicMock())
-def test_psu_db_update():
-    psu_tbl = mock.MagicMock()
-
-    psud._wrapper_get_psu_presence.return_value = True
-    psud._wrapper_get_psu_status.return_value = True
-    expected_fvp = psud.swsscommon.FieldValuePairs(
-        [(psud.PSU_INFO_PRESENCE_FIELD, 'true'),
-         (psud.PSU_INFO_STATUS_FIELD, 'true'),
-         ])
-    psud.psu_db_update(psu_tbl, 1)
-    assert psu_tbl.set.call_count == 1
-    psu_tbl.set.assert_called_with(psud.PSU_INFO_KEY_TEMPLATE.format(1), expected_fvp)
-
-    psu_tbl.set.reset_mock()
-
-    psud._wrapper_get_psu_presence.return_value = False
-    psud._wrapper_get_psu_status.return_value = True
-    expected_fvp = psud.swsscommon.FieldValuePairs(
-        [(psud.PSU_INFO_PRESENCE_FIELD, 'false'),
-         (psud.PSU_INFO_STATUS_FIELD, 'true'),
-         ])
-    psud.psu_db_update(psu_tbl, 1)
-    assert psu_tbl.set.call_count == 1
-    psu_tbl.set.assert_called_with(psud.PSU_INFO_KEY_TEMPLATE.format(1), expected_fvp)
-
-    psu_tbl.set.reset_mock()
-
-    psud._wrapper_get_psu_presence.return_value = True
-    psud._wrapper_get_psu_status.return_value = False
-    expected_fvp = psud.swsscommon.FieldValuePairs(
-        [(psud.PSU_INFO_PRESENCE_FIELD, 'true'),
-         (psud.PSU_INFO_STATUS_FIELD, 'false'),
-         ])
-    psud.psu_db_update(psu_tbl, 1)
-    assert psu_tbl.set.call_count == 1
-    psu_tbl.set.assert_called_with(psud.PSU_INFO_KEY_TEMPLATE.format(1), expected_fvp)
-
-    psu_tbl.set.reset_mock()
-
-    psud._wrapper_get_psu_presence.return_value = False
-    psud._wrapper_get_psu_status.return_value = False
-    expected_fvp = psud.swsscommon.FieldValuePairs(
-        [(psud.PSU_INFO_PRESENCE_FIELD, 'false'),
-         (psud.PSU_INFO_STATUS_FIELD, 'false'),
-         ])
-    psud.psu_db_update(psu_tbl, 1)
-    assert psu_tbl.set.call_count == 1
-    psu_tbl.set.assert_called_with(psud.PSU_INFO_KEY_TEMPLATE.format(1), expected_fvp)
-
-    psu_tbl.set.reset_mock()
-
-    psud._wrapper_get_psu_presence.return_value = True
-    psud._wrapper_get_psu_status.return_value = True
-    expected_fvp = psud.swsscommon.FieldValuePairs(
-        [(psud.PSU_INFO_PRESENCE_FIELD, 'true'),
-         (psud.PSU_INFO_STATUS_FIELD, 'true'),
-         ])
-    psud.psu_db_update(psu_tbl, 32)
-    assert psu_tbl.set.call_count == 32
-    psu_tbl.set.assert_called_with(psud.PSU_INFO_KEY_TEMPLATE.format(32), expected_fvp)
-
-
 def test_log_on_status_changed():
     normal_log = "Normal log message"
     abnormal_log = "Abnormal log message"