[psud] Add PSU Hardware Revision to Redis STATE_DB (sonic-net#179)

Added "hardware revision" field to list of platform fields to sync to STATE_DB for the PSU. Also updated relevant unit tests. 

Now that hardware revision exists as a platform 2.0 field for all devices, it is appropriate to synchronize this field to STATE_DB for PSUs as is done with all other fields. This will allow this field to be exposed to CLI tools through psushow in the future which reads state from STATE_DB.

sonic-psud/scripts/psud

@@ -48,6 +48,7 @@ PSU_INFO_KEY_TEMPLATE = 'PSU {}'
 PSU_INFO_PRESENCE_FIELD = 'presence'
 PSU_INFO_MODEL_FIELD = 'model'
 PSU_INFO_SERIAL_FIELD = 'serial'
+PSU_INFO_REV_FIELD = 'revision'
 PSU_INFO_STATUS_FIELD = 'status'
 PSU_INFO_TEMP_FIELD = 'temp'
 PSU_INFO_TEMP_TH_FIELD = 'temp_threshold'
@@ -510,6 +511,7 @@ class DaemonPsud(daemon_base.DaemonBase):
         fvs = swsscommon.FieldValuePairs(
             [(PSU_INFO_MODEL_FIELD, str(try_get(psu.get_model, NOT_AVAILABLE))),
              (PSU_INFO_SERIAL_FIELD, str(try_get(psu.get_serial, NOT_AVAILABLE))),
+             (PSU_INFO_REV_FIELD, str(try_get(psu.get_revision, NOT_AVAILABLE))),
              (PSU_INFO_TEMP_FIELD, str(temperature)),
              (PSU_INFO_TEMP_TH_FIELD, str(temperature_threshold)),
              (PSU_INFO_VOLTAGE_FIELD, str(voltage)),

sonic-psud/tests/mock_platform.py

@@ -273,6 +273,7 @@ def __init__(self,
                  presence=True,
                  model='Module Model',
                  serial='Module Serial',
+                 revision='Module Revision',
                  status=True,
                  voltage=12.0,
                  current=8.0,
@@ -287,6 +288,7 @@ def __init__(self,
         self._presence = presence
         self._model = model
         self._serial = serial
+        self._revision = revision
         self._status = status
         self._position_in_parent = position_in_parent
         self._replaceable = replaceable
@@ -365,6 +367,9 @@ def get_model(self):
     def get_serial(self):
         return self._serial
 
+    def get_revision(self):
+        return self._revision
+
     def get_status(self):
         return self._status
 

sonic-psud/tests/test_DaemonPsud.py

@@ -148,13 +148,14 @@ def test_update_single_psu_data(self):
         psud._wrapper_get_psu_presence.return_value = True
         psud._wrapper_get_psu_status.return_value = True
 
-        psu1 = MockPsu('PSU 1', 0, True, 'Fake Model', '12345678')
+        psu1 = MockPsu('PSU 1', 0, True, 'Fake Model', '12345678', '1234')
         psud.platform_chassis = MockChassis()
         psud.platform_chassis._psu_list.append(psu1)
 
         expected_fvp = psud.swsscommon.FieldValuePairs(
             [(psud.PSU_INFO_MODEL_FIELD, 'Fake Model'),
              (psud.PSU_INFO_SERIAL_FIELD, '12345678'),
+             (psud.PSU_INFO_REV_FIELD, '1234'),
              (psud.PSU_INFO_TEMP_FIELD, '30.0'),
              (psud.PSU_INFO_TEMP_TH_FIELD, '50.0'),
              (psud.PSU_INFO_VOLTAGE_FIELD, '12.0'),