[teammgrd]: Handle LAGs cleanup gracefully on Warm/Fast reboot. (sonic-net#1934)

Fixed LAGs cleanup on Warm/Fast reboot

Author: nazariig

cfgmgr/teammgr.cpp

@@ -132,23 +132,44 @@ void TeamMgr::cleanTeamProcesses()
         std::string res;
         pid_t pid;
 
+        try
         {
             std::stringstream cmd;
             cmd << "cat " << shellquote("/var/run/teamd/" + alias + ".pid");
             EXEC_WITH_ERROR_THROW(cmd.str(), res);
+        }
+        catch (const std::exception &e)
+        {
+            // Handle Warm/Fast reboot scenario
+            SWSS_LOG_NOTICE("Skipping non-existent port channel %s pid...", alias.c_str());
+            continue;
+        }
 
+        try
+        {
             pid = static_cast<pid_t>(std::stoul(res, nullptr, 10));
             aliasPidMap[alias] = pid;
 
             SWSS_LOG_INFO("Read port channel %s pid %d", alias.c_str(), pid);
         }
+        catch (const std::exception &e)
+        {
+            SWSS_LOG_ERROR("Failed to read port channel %s pid: %s", alias.c_str(), e.what());
+            continue;
+        }
 
+        try
         {
             std::stringstream cmd;
             cmd << "kill -TERM " << pid;
             EXEC_WITH_ERROR_THROW(cmd.str(), res);
 
-            SWSS_LOG_INFO("Sent SIGTERM to port channel %s pid %d", alias.c_str(), pid);
+            SWSS_LOG_NOTICE("Sent SIGTERM to port channel %s pid %d", alias.c_str(), pid);
+        }
+        catch (const std::exception &e)
+        {
+            SWSS_LOG_ERROR("Failed to send SIGTERM to port channel %s pid %d: %s", alias.c_str(), pid, e.what());
+            aliasPidMap.erase(alias);
         }
     }