Add support for RebootMethod_HALT for Reboot API (#286)

Why I did it
Add support for HALT reboot method for Reboot gNOI API

How I did it
Implement changes for HaltSystem() function to be called when HALT reboot method is invoked.

How to verify it
Unit tests

common_utils/context.go

@@ -54,6 +54,7 @@ const (
 	DBUS_STOP_SERVICE
 	DBUS_RESTART_SERVICE
 	DBUS_FILE_STAT
+	DBUS_HALT_SYSTEM
 	COUNTER_SIZE
 )
 
@@ -91,6 +92,8 @@ func (c CounterType) String() string {
 		return "DBUS restart service"
 	case DBUS_FILE_STAT:
 		return "DBUS file stat"
+	case DBUS_HALT_SYSTEM:
+		return "DBUS halt system"
 	default:
 		return ""
 	}

gnmi_server/gnoi.go

@@ -139,6 +139,20 @@ func (srv *SystemServer) KillProcess(ctx context.Context, req *gnoi_system_pb.Ki
 	return &resp, nil
 }
 
+func HaltSystem() error {
+	sc,err := ssc.NewDbusClient()
+	if err != nil {
+		return err
+	}
+
+	log.V(2).Infof("Halting the system..")
+	err = sc.HaltSystem()
+	if err != nil {
+		log.V(2).Infof("Failed to Halt the system %v", err);
+	}
+	return err
+}
+
 func RebootSystem(fileName string) error {
 	log.V(2).Infof("Rebooting with %s...", fileName)
 	sc, err := ssc.NewDbusClient()
@@ -158,18 +172,30 @@ func (srv *SystemServer) Reboot(ctx context.Context, req *gnoi_system_pb.RebootR
 	}
 	log.V(1).Info("gNOI: Reboot")
 	log.V(1).Info("Request:", req)
-	log.V(1).Info("Reboot system now, delay is ignored...")
-	// TODO: Support GNOI reboot delay
-	// Delay in nanoseconds before issuing reboot.
-	// https://github.com/openconfig/gnoi/blob/master/system/system.proto#L102-L115
-	config_db_json, err := io.ReadFile(fileName)
-	if errors.Is(err, os.ErrNotExist) {
-		fileName = ""
-	}
-	err = RebootSystem(string(config_db_json))
-	if err != nil {
-		return nil, err
+
+	// Check the reboot type
+	switch req.GetMethod() {
+	case gnoi_system_pb.RebootMethod_HALT:
+		log.V(1).Info("Reboot method is HALT. Halting the system...")
+		err = HaltSystem()
+		if err != nil {
+			return nil, err
+		}
+	default:
+		log.V(1).Info("Reboot system now, delay is ignored...")
+		// TODO: Support GNOI reboot delay
+		// Delay in nanoseconds before issuing reboot.
+		// https://github.com/openconfig/gnoi/blob/master/system/system.proto#L102-L115
+		config_db_json, err := io.ReadFile(fileName)
+		if errors.Is(err, os.ErrNotExist) {
+			fileName = ""
+		}
+		err = RebootSystem(string(config_db_json))
+		if err != nil {
+			return nil, err
+		}
 	}
+
 	var resp gnoi_system_pb.RebootResponse
 	return &resp, nil
 }

sonic_service_client/dbus_client.go

@@ -19,6 +19,7 @@ type Service interface {
 	StopService(service string) error
 	RestartService(service string) error
 	GetFileStat(path string) (map[string]string, error)
+	HaltSystem() error
 }
 
 type DbusClient struct {
@@ -191,3 +192,21 @@ func (c *DbusClient) GetFileStat(path string) (map[string]string, error) {
 	data, _ := result.(map[string]string)
 	return data, nil
 }
+
+func (c *DbusClient) HaltSystem() error {
+    // Increment the counter for the DBUS_HALT_SYSTEM event
+    common_utils.IncCounter(common_utils.DBUS_HALT_SYSTEM)
+
+    // Set the module name and update the D-Bus properties
+    modName := "systemd"
+    busName := c.busNamePrefix + modName
+    busPath := c.busPathPrefix + modName
+    intName := c.intNamePrefix + modName + ".execute_reboot"
+
+    //Set the method to HALT(3) the system
+    const RebootMethod_HALT = 3
+
+    // Invoke the D-Bus API to execute the halt command
+    _, err := DbusApi(busName, busPath, intName, 10, RebootMethod_HALT)
+    return err
+}

test/test_gnoi.py

@@ -21,6 +21,17 @@ def test_gnoi_reboot(self):
         assert ret == 0, 'Fail to read counter'
         assert new_cnt == old_cnt+1, 'DBUS API is not invoked'
 
+    def test_gnoi_reboot_halt(self):
+        ret, old_cnt = gnmi_dump('DBUS halt system')
+        assert ret == 0, 'Fail to read counter'
+
+        ret, msg = gnoi_reboot(3, 0, 'Test halt system')
+        assert ret == 0, msg
+
+        ret, new_cnt = gnmi_dump('DBUS halt system')
+        assert ret == 0, 'Fail to read counter'
+        assert new_cnt == old_cnt+1, 'DBUS API is not invoked'
+
     def test_gnoi_rebootstatus(self):
         ret, msg = gnoi_rebootstatus()
         assert ret != 0, 'RebootStatus should fail' + msg
@@ -74,4 +85,4 @@ def test_gnoi_restartprocess_invalid(self):
 
         ret, new_cnt = gnmi_dump('DBUS restart service')
         assert ret == 0, 'Fail to read counter'
-        assert new_cnt == old_cnt, 'DBUS API invoked unexpectedly'
+        assert new_cnt == old_cnt, 'DBUS API invoked unexpectedly'