Load exisiting base pnd uuid

controller.go

@@ -92,7 +92,20 @@ func createSouthboundInterfaces() error {
 
 // createPrincipalNetworkDomain initializes the controller with an initial PND
 func createPrincipalNetworkDomain(s southbound.SouthboundInterface) error {
-	pnd, err := nucleus.NewPND("base", "gosdn base pnd", uuid.New(), s)
+	var pndUUID uuid.UUID
+
+	// Check if there is already an PND.
+	pndUUIDAsString := viper.GetString("pnd")
+	if pndUUIDAsString == "" {
+		pndUUID = uuid.New()
+	}
+
+	pndUUID, err := uuid.Parse(pndUUIDAsString)
+	if err != nil {
+		return err
+	}
+
+	pnd, err := nucleus.NewPND("base", "gosdn base pnd", pndUUID, s)
 	if err != nil {
 		return err
 	}