Add script to periodically update oper status of management interface

Why I did it
Cherry-pick of changes in sonic-net/sonic-buildimage#21245

Work item tracking
Microsoft ADO 30279044:
How I did it
Remove update of mgmt oper status from sonic-swss
Use monit script to periodically update oper status of mgmt interface.

How to verify it
Verified on Chassis platform

Author: arlakshm

files/build_templates/sonic_debian_extension.j2

@@ -393,6 +393,8 @@ sudo cp $IMAGE_CONFIGS/monit/memory_checker $FILESYSTEM_ROOT/usr/bin/
 sudo chmod 755 $FILESYSTEM_ROOT/usr/bin/memory_checker
 sudo cp $IMAGE_CONFIGS/monit/restart_service $FILESYSTEM_ROOT/usr/bin/
 sudo chmod 755 $FILESYSTEM_ROOT/usr/bin/restart_service
+sudo cp $IMAGE_CONFIGS/monit/mgmt_oper_status.py $FILESYSTEM_ROOT/usr/bin/
+sudo chmod 755 $FILESYSTEM_ROOT/usr/bin/mgmt_oper_status.py
 
 # Installed smartmontools version should match installed smartmontools in docker-platform-monitor Dockerfile
 # TODO: are mismatching versions fine for bookworm?

files/image_config/monit/conf.d/sonic-host

@@ -56,3 +56,8 @@ check program vnetRouteCheck with path "/usr/local/bin/vnet_route_check.py"
 # memory_check tool that verifies that memory usage does not cross the threshold or invokes techsupport.
 check program memory_check with path "/usr/local/bin/memory_threshold_check.py"
     if status == 2 for 10 times within 20 cycles then exec "/usr/local/bin/memory_threshold_check_handler.py"
+
+# Periodically update oper status of mgmt interface in STATE_DB 
+check program mgmtOperStatus with path "/usr/bin/mgmt_oper_status.py"
+    every 1 cycles
+    if status != 0 for 3 cycle then alert repeat every 1 cycles

files/image_config/monit/mgmt_oper_status.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python3
+
+"""
+"""
+import sys
+import subprocess
+import syslog
+
+from sonic_py_common import multi_asic, device_info
+from swsscommon.swsscommon import SonicV2Connector
+
+
+def main():
+    db = SonicV2Connector(use_unix_socket_path=True)
+    db.connect('CONFIG_DB')
+    db.connect('STATE_DB')
+    mgmt_ports_keys = db.keys(db.CONFIG_DB, 'MGMT_PORT|*' )
+    if not mgmt_ports_keys:
+        syslog.syslog(syslog.LOG_DEBUG, 'No management interface found')
+    else:
+        try:
+            mgmt_ports = [key.split('MGMT_PORT|')[-1] for key in mgmt_ports_keys]
+            for port in mgmt_ports:
+                state_db_mgmt_port = db.keys(db.STATE_DB, 'MGMT_PORT_TABLE|*' )
+                state_db_key = "MGMT_PORT_TABLE|{}".format(port)
+                prev_oper_status = 'unknown'
+                if state_db_key in state_db_mgmt_port:
+                    prev_oper_status = db.get(db.STATE_DB, state_db_key, 'oper_status')
+                port_operstate_path = '/sys/class/net/{}/operstate'.format(port)
+                oper_status = subprocess.run(['cat', port_operstate_path], capture_output=True, text=True)
+                current_oper_status = oper_status.stdout.strip()
+                if current_oper_status != prev_oper_status:
+                    db.set(db.STATE_DB, state_db_key, 'oper_status', current_oper_status)
+                    log_level = syslog.LOG_INFO if current_oper_status == 'up' else syslog.LOG_WARNING 
+                    syslog.syslog(log_level, "mgmt_oper_status: {}".format(current_oper_status))
+        except Exception as e:
+            syslog.syslog(syslog.LOG_ERR, "mgmt_oper_status exception : {}".format(str(e)))
+            db.set(db.STATE_DB, state_db_key, 'oper_status', 'unknown')
+            sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()
+    sys.exit(0)

files/image_config/monit/tests/__init__.py

@@ -0,0 +1,79 @@
+import unittest
+from unittest.mock import patch, MagicMock
+import subprocess
+import syslog
+import sys
+import mgmt_oper_status
+
+class TestMgmtOperStatusCheck(unittest.TestCase):
+
+    @patch('mgmt_oper_status.SonicV2Connector')
+    @patch('mgmt_oper_status.subprocess.run')
+    @patch('mgmt_oper_status.syslog.syslog')
+    def test_main_no_mgmt_ports(self, mock_syslog, mock_subprocess, mock_SonicV2Connector):
+        mock_db = MagicMock()
+        mock_SonicV2Connector.return_value = mock_db
+        mock_db.keys.return_value = [] 
+
+        mgmt_oper_status.main()
+
+        mock_syslog.assert_called_with(syslog.LOG_DEBUG, 'No management interface found')
+
+    @patch('mgmt_oper_status.SonicV2Connector')
+    @patch('mgmt_oper_status.subprocess.run')
+    @patch('mgmt_oper_status.syslog.syslog')
+    def test_main_with_mgmt_ports(self, mock_syslog, mock_subprocess, mock_SonicV2Connector):
+        mock_db = MagicMock()
+        mock_SonicV2Connector.return_value = mock_db
+        mgmt_ports_keys = ['MGMT_PORT|eth0', 'MGMT_PORT|eth1']
+        mock_db.keys.return_value = mgmt_ports_keys
+        mock_db.set.return_value = None
+
+        mock_subprocess.return_value = subprocess.CompletedProcess(args=['cat', '/sys/class/net/eth0/operstate'], returncode=0, stdout='up', stderr='')
+
+        mgmt_oper_status.main()
+
+        mock_syslog.assert_any_call(syslog.LOG_INFO, 'mgmt_oper_status: up')
+        mock_syslog.assert_any_call(syslog.LOG_INFO, 'mgmt_oper_status: up')
+
+        mock_db.set.assert_any_call(mock_db.STATE_DB, 'MGMT_PORT_TABLE|eth0', 'oper_status', 'up')
+        mock_db.set.assert_any_call(mock_db.STATE_DB, 'MGMT_PORT_TABLE|eth1', 'oper_status', 'up')
+
+    @patch('mgmt_oper_status.SonicV2Connector')
+    @patch('mgmt_oper_status.subprocess.run')
+    @patch('mgmt_oper_status.syslog.syslog')
+    def test_main_with_mgmt_port_down(self, mock_syslog, mock_subprocess, mock_SonicV2Connector):
+        mock_db = MagicMock()
+        mock_SonicV2Connector.return_value = mock_db
+        mgmt_ports_keys = ['MGMT_PORT|eth0']
+        mock_db.keys.return_value = mgmt_ports_keys
+        mock_db.set.return_value = None
+
+        mock_subprocess.return_value = subprocess.CompletedProcess(args=['cat', '/sys/class/net/eth0/operstate'], returncode=0, stdout='down', stderr='')
+
+        mgmt_oper_status.main()
+
+        mock_syslog.assert_any_call(syslog.LOG_WARNING, 'mgmt_oper_status: down')
+
+        mock_db.set.assert_any_call(mock_db.STATE_DB, 'MGMT_PORT_TABLE|eth0', 'oper_status', 'down')
+
+
+    @patch('mgmt_oper_status.SonicV2Connector')
+    @patch('mgmt_oper_status.subprocess.run')
+    @patch('mgmt_oper_status.syslog.syslog')
+    def test_main_exception_handling(self, mock_syslog, mock_subprocess, mock_SonicV2Connector):
+        mock_db = MagicMock()
+        mock_SonicV2Connector.return_value = mock_db
+        mgmt_ports_keys = ['MGMT_PORT|eth0']
+        mock_db.keys.return_value = mgmt_ports_keys
+        mock_db.set.return_value = None
+
+        mock_subprocess.side_effect = Exception("File not found")
+
+        mgmt_oper_status.main()
+
+        mock_syslog.assert_called_with(syslog.LOG_ERR, "mgmt_oper_status exception : File not found")
+        mock_db.set.assert_any_call(mock_db.STATE_DB, 'MGMT_PORT_TABLE|eth0', 'oper_status', 'unknown')
+
+if __name__ == '__main__':
+    unittest.main()