portmgrd: prevent runtime failure in setting MTU on portchannel member

Do not attempt to set the MTU directly on PortChannel members as it will
likely fail.  The MTU gets inherited as part of the PortChannel.

Signed-off-by: Brad House (@bradh352)

cfgmgr/portmgr.cpp

@@ -22,6 +22,28 @@ PortMgr::PortMgr(DBConnector *cfgDb, DBConnector *appDb, DBConnector *stateDb, c
 {
 }
 
+bool PortMgr::isLag(const std::string &port)
+{
+    SWSS_LOG_ENTER();
+
+    vector<string> keys;
+    m_cfgLagMemberTable.getKeys(keys);
+
+    for (auto key: keys)
+    {
+        auto tokens = tokenize(key, config_db_key_delimiter);
+        auto lag = tokens[0];
+        auto member = tokens[1];
+
+        if (port == member)
+        {
+            return true;
+        }
+    }
+
+    return false;
+}
+
 bool PortMgr::setPortMtu(const string &alias, const string &mtu)
 {
     stringstream cmd;
@@ -128,6 +150,7 @@ void PortMgr::doSendToIngressPortTask(Consumer &consumer)
 
 }
 
+
 void PortMgr::doTask(Consumer &consumer)
 {
     SWSS_LOG_ENTER();
@@ -221,14 +244,18 @@ void PortMgr::doTask(Consumer &consumer)
 
             if (!mtu.empty())
             {
-                setPortMtu(alias, mtu);
-                SWSS_LOG_NOTICE("Configure %s MTU to %s", alias.c_str(), mtu.c_str());
+                if (isLag(alias)) {
+                    SWSS_LOG_NOTICE("Skipping Configure %s MTU to %s as interface is part of a PortChannel", alias.c_str(), mtu.c_str());
+                } else {
+                    SWSS_LOG_NOTICE("Configure %s MTU to %s", alias.c_str(), mtu.c_str());
+                    setPortMtu(alias, mtu);
+                }
             }
 
             if (!admin_status.empty())
             {
-                setPortAdminStatus(alias, admin_status == "up");
                 SWSS_LOG_NOTICE("Configure %s admin status to %s", alias.c_str(), admin_status.c_str());
+                setPortAdminStatus(alias, admin_status == "up");
             }
         }
         else if (op == DEL_COMMAND)

cfgmgr/portmgr.h

@@ -37,6 +37,7 @@ class PortMgr : public Orch
     bool setPortMtu(const std::string &alias, const std::string &mtu);
     bool setPortAdminStatus(const std::string &alias, const bool up);
     bool isPortStateOk(const std::string &alias);
+    bool isLag(const std::string &port);
 };
 
 }