Fix SNMPv3 configuration on Edge Filers (#319)

- Added missing _classname='SnmpV3Config' for proper XML serialization
- Fixed SNMPv3 enable() and modify() methods to include class name
- Updated unit tests to expect the new _classname attribute
- Added docstring for get_configuration() method
- Fixed modify() method to default port to 161
- Updated changelog with bug fix entry

This resolves the issue where SNMPv3 configuration appeared successful
but wasn't actually working on Edge Filers due to improper XML
serialization without the required class attribute.

Author: ronier83

cterasdk/edge/snmp.py

@@ -37,6 +37,7 @@ def enable(self, port=161, community_str=None, username=None, auth_password=None
         param.readCommunity = community_str
         if username is not None and auth_password is not None and privacy_password is not None:
             param.snmpV3 = Object()
+            param.snmpV3._classname = 'SnmpV3Config'  # pylint: disable=protected-access
             param.snmpV3.mode = enum.Mode.Enabled
             param.snmpV3.username = username
             param.snmpV3.authenticationPassword = auth_password
@@ -53,9 +54,15 @@ def disable(self):
         logger.info("Disabled SNMP.")
 
     def get_configuration(self):
+        """
+        Get current SNMP configuration
+        
+        :return: Current SNMP configuration
+        :rtype: cterasdk.common.object.Object
+        """
         return self._edge.api.get('/config/snmp')
 
-    def modify(self, port=None, community_str=None, username=None, auth_password=None, privacy_password=None):
+    def modify(self, port=161, community_str=None, username=None, auth_password=None, privacy_password=None):
         """
         Modify current SNMP configuration. Only configurations that are not `None` will be changed. SNMP must be enabled
 
@@ -68,12 +75,12 @@ def modify(self, port=None, community_str=None, username=None, auth_password=Non
         current_config = self.get_configuration()
         if current_config.mode == enum.Mode.Disabled:
             raise CTERAException("SNMP configuration cannot be modified when disabled")
-        if port:
-            current_config.port = port
+        current_config.port = port
         if community_str:
             current_config.readCommunity = community_str
         if username is not None and auth_password is not None and privacy_password is not None:
             current_config.snmpV3 = Object()
+            current_config.snmpV3._classname = 'SnmpV3Config'  # pylint: disable=protected-access
             current_config.snmpV3.mode = enum.Mode.Enabled
             current_config.snmpV3.username = username
             current_config.snmpV3.authenticationPassword = auth_password

docs/source/UserGuides/Miscellaneous/Changelog.rst

@@ -26,6 +26,7 @@ Improvements
 Bug Fixes
 ^^^^^^^^^
 
+* Fixed SNMPv3 configuration on Edge Filers - added missing XML class name for proper serialization
 * Corrected Direct I/O object class references in the documentation
 
 .. code:: python

tests/ut/edge/test_snmp.py

@@ -76,6 +76,7 @@ def _get_snmp_object(self, port=None, community_str=None, username=None, auth_pa
         param.readCommunity = community_str
         if username is not None and auth_password is not None and privacy_password is not None:
             param.snmpV3 = Object()
+            param.snmpV3._classname = 'SnmpV3Config'  # pylint: disable=protected-access
             param.snmpV3.mode = Mode.Enabled
             param.snmpV3.username = username
             param.snmpV3.authenticationPassword = auth_password