Prevent using port 0 with address_mode=driver

command/agent/consul/client.go

@@ -1126,6 +1126,9 @@ func getAddress(addrMode, portLabel string, networks structs.Networks, driverNet
 		if err != nil {
 			return "", 0, fmt.Errorf("invalid port %q: %v", portLabel, err)
 		}
+		if port == 0 {
+			return "", 0, fmt.Errorf("invalid port: %q: port 0 is invalid", portLabel)
+		}
 
 		return driverNet.IP, port, nil
 

command/agent/consul/unit_test.go

@@ -1541,6 +1541,15 @@ func TestGetAddress(t *testing.T) {
 			},
 			ErrContains: "invalid port",
 		},
+		{
+			Name:      "DriverZeroPort",
+			Mode:      structs.AddressModeDriver,
+			PortLabel: "0",
+			Driver: &cstructs.DriverNetwork{
+				IP: "10.1.2.3",
+			},
+			ErrContains: "invalid port",
+		},
 		{
 			Name:        "HostBadPort",
 			Mode:        structs.AddressModeHost,