lag MTU setting fix - fix for #18695

config/main.py

@@ -2208,7 +2208,6 @@ def add_portchannel(ctx, portchannel_name, min_links, fallback, fast_rate):
 
     fvs = {
         'admin_status': 'up',
-        'mtu': '9100',
         'lacp_key': 'auto',
         'fast_rate': fast_rate.lower(),
     }
@@ -2333,16 +2332,19 @@ def add_portchannel_member(ctx, portchannel_name, port_name):
 
         # Dont allow a port to be member of port channel if its MTU does not match with portchannel
         portchannel_entry =  db.get_entry('PORTCHANNEL', portchannel_name)
-        if portchannel_entry and portchannel_entry.get(PORT_MTU) is not None :
+        if portchannel_entry:
             port_entry = db.get_entry('PORT', port_name)
-
             if port_entry and port_entry.get(PORT_MTU) is not None:
                 port_mtu = port_entry.get(PORT_MTU)
+                portchannel_mtu = portchannel_entry.get(PORT_MTU)
+                # If portchannel MTU is not set, set it to the first port MTU
+                if (str(portchannel_mtu) == 'None'):
+                    portchannel_mtu = port_mtu
+                    db.mod_entry('PORTCHANNEL', portchannel_name, {PORT_MTU: port_mtu})
 
-                portchannel_mtu = portchannel_entry.get(PORT_MTU) # TODO: MISSING CONSTRAINT IN YANG MODEL
-                if portchannel_mtu != port_mtu:
-                    ctx.fail("Port MTU of {} is different than the {} MTU size"
-                             .format(port_name, portchannel_name))
+                if (portchannel_mtu != port_mtu):  # TODO: MISSING CONSTRAINT IN YANG MODEL
+                    ctx.fail("Port MTU of {} is {} different than the {} MTU size which is {}"
+                             .format(port_name, port_mtu, portchannel_name, portchannel_mtu))
 
         # Dont allow a port to be member of port channel if its TPID is not at default 0x8100
         # If TPID is supported at LAG level, when member is added, the LAG's TPID is applied to the
@@ -2403,6 +2405,10 @@ def del_portchannel_member(ctx, portchannel_name, port_name):
 
     try:
         db.set_entry('PORTCHANNEL_MEMBER', portchannel_name + '|' + port_name, None)
+        # If this was the last port in the portchannel, set the portchannel MTU to None
+        if len([(k, v) for k, v in db.get_table('PORTCHANNEL_MEMBER') if k == portchannel_name]) == 0:
+            db.mod_entry('PORTCHANNEL', portchannel_name, {PORT_MTU: None})
+
     except JsonPatchConflict:
         ctx.fail("Invalid or nonexistent portchannel or interface. Please ensure existence of portchannel member.")
 

tests/config_int_mtu_test.py

@@ -24,3 +24,27 @@ def test_interface_invalid_mtu_check(self):
         result1 = runner.invoke(config.config.commands["interface"].commands["mtu"],
             ["Ethernet0", "9217"], obj=db)
         assert "Error: Invalid value" in result1.output
+
+    def test_portchannel_mtu_check(self):
+        runner = CliRunner()
+        db = Db()
+        obj = {'db': db.cfgdb, 'db_wrap': db, 'namespace': ''}
+        # Ethernet32 is already member of PortChannel1001, try (fail) to change mtu
+        result = runner.invoke(
+                            config.config.commands["interface"].commands["mtu"],
+                            ["Ethernet32", "1000"], obj=obj)
+        assert result.exit_code != 0
+        # remove port from portchannel
+        result = runner.invoke(
+                            config.config.commands["portchannel"].commands["member"].commands["del"],
+                            ["PortChannel1001", "Ethernet32"], obj=obj)
+        assert result.exit_code == 0
+        # Set mtu for port interface
+        result = runner.invoke(config.config.commands["interface"].commands["mtu"], ["Ethernet32", "1000"], obj=obj)
+        assert result.exit_code != 0
+        # Add port back to portchannel
+        result = runner.invoke(
+                            config.config.commands["portchannel"].commands["member"].commands["add"],
+                            ["PortChannel1001", "Ethernet32"], obj=obj)
+        print(result.output)
+        assert result.exit_code == 0

tests/mock_tables/config_db.json

@@ -516,13 +516,13 @@
     },
     "ACL_TABLE|BMC_ACL_NORTHBOUND": {
         "policy_desc": "BMC_ACL_NORTHBOUND",
-        "ports@": "Ethernet8,Ethernet0,Ethernet17,Ethernet16,Ethernet37,Ethernet4,Ethernet13,Ethernet45,Ethernet19,Ethernet24,Ethernet31,Ethernet30,Ethernet39,Ethernet40,Ethernet27,Ethernet43,Ethernet7,Ethernet3,Ethernet20,Ethernet6,Ethernet12,Ethernet34,Ethernet26,Ethernet11,Ethernet42,Ethernet5,Ethernet32,Ethernet36,Ethernet15,Ethernet33,Ethernet35,Ethernet9,Ethernet29,Ethernet21,Ethernet18,Ethernet38,Ethernet23,Ethernet41,Ethernet14,Ethernet2,Ethernet28,Ethernet22,Ethernet10,Ethernet25,Ethernet44,Ethernet1",
+        "ports@": "Ethernet8,Ethernet0,Ethernet17,Ethernet16,Ethernet37,Ethernet4,Ethernet13,Ethernet45,Ethernet19,Ethernet24,Ethernet31,Ethernet30,Ethernet39,Ethernet40,Ethernet27,Ethernet43,Ethernet7,Ethernet3,Ethernet20,Ethernet6,Ethernet12,Ethernet34,Ethernet26,Ethernet11,Ethernet42,Ethernet5,Ethernet36,Ethernet15,Ethernet33,Ethernet35,Ethernet9,Ethernet29,Ethernet21,Ethernet18,Ethernet38,Ethernet23,Ethernet41,Ethernet14,Ethernet2,Ethernet28,Ethernet22,Ethernet10,Ethernet25,Ethernet44,Ethernet1",
         "stage": "ingress",
         "type": "BMCDATA"
     },
     "ACL_TABLE|BMC_ACL_NORTHBOUND_V6": {
         "policy_desc": "BMC_ACL_NORTHBOUND_V6",
-        "ports@": "Ethernet13,Ethernet3,Ethernet32,Ethernet33,Ethernet34,Ethernet8,Ethernet6,Ethernet44,Ethernet39,Ethernet18,Ethernet15,Ethernet1,Ethernet19,Ethernet7,Ethernet14,Ethernet43,Ethernet40,Ethernet27,Ethernet4,Ethernet36,Ethernet41,Ethernet10,Ethernet31,Ethernet5,Ethernet9,Ethernet12,Ethernet16,Ethernet25,Ethernet24,Ethernet17,Ethernet35,Ethernet11,Ethernet38,Ethernet42,Ethernet29,Ethernet20,Ethernet45,Ethernet26,Ethernet21,Ethernet37,Ethernet0,Ethernet28,Ethernet23,Ethernet22,Ethernet2,Ethernet30",
+        "ports@": "Ethernet13,Ethernet3,Ethernet33,Ethernet34,Ethernet8,Ethernet6,Ethernet44,Ethernet39,Ethernet18,Ethernet15,Ethernet1,Ethernet19,Ethernet7,Ethernet14,Ethernet43,Ethernet40,Ethernet27,Ethernet4,Ethernet36,Ethernet41,Ethernet10,Ethernet31,Ethernet5,Ethernet9,Ethernet12,Ethernet16,Ethernet25,Ethernet24,Ethernet17,Ethernet35,Ethernet11,Ethernet38,Ethernet42,Ethernet29,Ethernet20,Ethernet45,Ethernet26,Ethernet21,Ethernet37,Ethernet0,Ethernet28,Ethernet23,Ethernet22,Ethernet2,Ethernet30",
         "stage": "ingress",
         "type": "BMCDATAV6"
     },
@@ -577,7 +577,7 @@
     },
     "ACL_TABLE|EVERFLOWV6": {
         "policy_desc": "EVERFLOWV6",
-        "ports@": "Ethernet0,Ethernet1,Ethernet2,Ethernet3,Ethernet4,Ethernet5,Ethernet6,Ethernet7,Ethernet8,Ethernet9,Ethernet10,Ethernet11,Ethernet12,Ethernet13,Ethernet14,Ethernet15,Ethernet16,Ethernet17,Ethernet18,Ethernet19,Ethernet20,Ethernet21,Ethernet22,Ethernet23,Ethernet24,Ethernet25,Ethernet26,Ethernet27,Ethernet28,Ethernet29,Ethernet30,Ethernet31,Ethernet32,Ethernet33,Ethernet34,Ethernet35,Ethernet36,Ethernet37,Ethernet38,Ethernet39,Ethernet40,Ethernet41,Ethernet42,Ethernet43,Ethernet44,Ethernet45,Ethernet46,Ethernet47",
+        "ports@": "Ethernet0,Ethernet1,Ethernet2,Ethernet3,Ethernet4,Ethernet5,Ethernet6,Ethernet7,Ethernet8,Ethernet9,Ethernet10,Ethernet11,Ethernet12,Ethernet13,Ethernet14,Ethernet15,Ethernet16,Ethernet17,Ethernet18,Ethernet19,Ethernet20,Ethernet21,Ethernet22,Ethernet23,Ethernet24,Ethernet25,Ethernet26,Ethernet27,Ethernet28,Ethernet29,Ethernet30,Ethernet31,Ethernet33,Ethernet34,Ethernet35,Ethernet36,Ethernet37,Ethernet38,Ethernet39,Ethernet40,Ethernet41,Ethernet42,Ethernet43,Ethernet44,Ethernet45,Ethernet46,Ethernet47",
         "type": "MIRRORV6",
         "stage": "ingress"
     },