Adding a callback function for `Set`

.gitignore

 # tooling
 build-tools/
+artifacts/
 
 # non vimmers
+.devcontainer/
 .vscode/
 .idea/
 

gnmitarget/target.go

@@ -27,7 +27,7 @@ var GnmiTargetYgot ygot.ValidatedGoStruct
 
 func scheduler(server *gnmiserver.Server, osclient os_clients.Osclient) {
 	for {
-		<-time.After(5 * time.Second)
+		<-time.After(30 * time.Second)
 		log.Info("Update config...")
 		go server.InternalUpdate(currentosclient.UpdateConfig)
 	}
@@ -66,7 +66,7 @@ func StartGNMITarget(bindAddress string, configFile string, osclient string) err
 		}
 	}
 
-	gnmiServer, err := gnmiserver.NewServer(model, GnmiTargetYgot, nil)
+	gnmiServer, err := gnmiserver.NewServer(model, GnmiTargetYgot, currentosclient.GetCallbackFunc())
 	if err != nil {
 		log.Fatalf("error in creating GNMI target: %v", err)
 	}

os_clients/ubuntu/ubuntu.go

 package ubuntu
 
 import (
-	"fmt"
 	"net"
 	"os"
 	"os/exec"
 	"strings"
+	"syscall"
 	"time"
 
 	"code.fbi.h-da.de/danet/gnmi-target/modeldata/gnmitargetygot"
 
+	gnmiv "github.com/openconfig/gnmi/value"
 	"github.com/openconfig/ygot/ygot"
 	log "github.com/sirupsen/logrus"
 	"github.com/vishvananda/netlink"
@@ -32,19 +33,19 @@ func (ou OsclientUbuntu) UpdateConfig(config *ygot.ValidatedGoStruct) error {
 func (ou *OsclientUbuntu) GetConfig() *gnmitargetygot.Gnmitarget {
 	ou.gt = &gnmitargetygot.Gnmitarget{}
 
-	// Create Interfaces
-	h, err := netlink.NewHandle()
-	if err != nil {
-		log.WithFields(log.Fields{}).Error(err)
-	}
-	// defer h.Delete()
-	localIfaces, err := h.LinkList()
-	if err != nil {
-		log.WithFields(log.Fields{}).Error(err)
-	}
-	for _, localIface := range localIfaces {
-		ou.createInterfaces(localIface, ou.gt)
-	}
+	//	// Create Interfaces
+	//	h, err := netlink.NewHandle()
+	//	if err != nil {
+	//		log.WithFields(log.Fields{}).Error(err)
+	//	}
+	//	// defer h.Delete()
+	//	localIfaces, err := h.LinkList()
+	//	if err != nil {
+	//		log.WithFields(log.Fields{}).Error(err)
+	//	}
+	//	for _, localIface := range localIfaces {
+	//		ou.createInterfaces(localIface, ou.gt)
+	//	}
 
 	ou.getSystem(ou.gt)
 
@@ -52,11 +53,35 @@ func (ou *OsclientUbuntu) GetConfig() *gnmitargetygot.Gnmitarget {
 }
 
 func (ou *OsclientUbuntu) GetCallbackFunc() func(ygot.ValidatedGoStruct) error {
-	return callbackFunc
+	return ou.callbackFunc
 }
 
-func callbackFunc(config ygot.ValidatedGoStruct) error {
-	fmt.Printf("config: %v\n", config)
+func (ou *OsclientUbuntu) callbackFunc(config ygot.ValidatedGoStruct) error {
+	diffs, err := ygot.Diff(ou.GetConfig(), config)
+	if err != nil {
+		return err
+	}
+	for _, diff := range diffs.GetUpdate() {
+		path, err := ygot.PathToString(diff.GetPath())
+		if err != nil {
+			return err
+		}
+		log.Info(path)
+		switch path {
+		case "/system/config/hostname":
+			value, err := gnmiv.ToScalar(diff.GetVal())
+			if err != nil {
+				return err
+			}
+			err = syscall.Sethostname([]byte(value.(string)))
+			if err != nil {
+				return err
+			}
+		default:
+			//INFO: currently this case is ignored
+		}
+	}
+
 	return nil
 }