remove soldier after time out

client/client.go

@@ -189,7 +189,22 @@ func (c *Client) Start() {
 	}()
 	wg.Wait()
 }
-
+func (l *Leader) Shutdown() error {
+	// delete request to /system
+	rq, err := http.NewRequest("DELETE", l.DispatcherServer+"/system", nil)
+	if err != nil {
+		return err
+	}
+	rq.Header.Set("Authorization", l.Password)
+	do, err := l.Do(rq)
+	if err != nil {
+		return err
+	}
+	if do.StatusCode == http.StatusOK {
+		return nil
+	}
+	return errors.New("error in shutting down")
+}
 func (l *Leader) ListenChangeView(changedDataChan chan CampAPI) {
 	prevCamp := l.GetCamp()
 	changedDataChan <- prevCamp
@@ -206,15 +221,17 @@ func (l *Leader) ListenChangeView(changedDataChan chan CampAPI) {
 	}
 }
 func (l *Leader) Start() {
-
 	func() {
 		defer func() {
 			if r := recover(); r != nil {
 				color.Red("Dispatcher server is not running")
 				os.Exit(0)
 			}
 		}()
-		l.GetCamp()
+		err := l.Ping()
+		if err != nil {
+			panic(err)
+		}
 	}()
 
 	var changedDataChan = make(chan CampAPI, 1)
@@ -232,19 +249,17 @@ func (l *Leader) Start() {
 	}()
 	wg.Wait()
 }
-func (l *Leader) Shutdown() error {
-	// delete request to /system
-	rq, err := http.NewRequest("DELETE", l.DispatcherServer+"/system", nil)
+func (c *Client) Ping() error {
+	rq, err := http.NewRequest("GET", c.DispatcherServer+"/ping", nil)
 	if err != nil {
 		return err
 	}
-	rq.Header.Set("Authorization", l.Password)
-	do, err := l.Do(rq)
+	do, err := c.Do(rq)
 	if err != nil {
 		return err
 	}
 	if do.StatusCode == http.StatusOK {
 		return nil
 	}
-	return errors.New("error in shutting down")
+	return errors.New("error in pinging")
 }

dispatcher/camp.go

@@ -1,13 +1,16 @@
 package dispatcher
 
+import "time"
+
 type Leader struct {
 	Name               string `json:"name"`
 	AuthenticationHash string `json:"-"`
 }
 
 type Soldier struct {
-	Name string `json:"name"`
-	Ip   string `json:"ip"`
+	Name        string    `json:"name"`
+	Ip          string    `json:"ip"`
+	LastRequest time.Time `json:"last_request"`
 }
 
 const (
@@ -43,22 +46,22 @@ func (c *Camp) RemoveSoldier(name string) {
 		}
 	}
 }
-func (c *Camp) GetSoldierByName(name string) Soldier {
-	for _, soldier := range c.Soldiers {
+func (c *Camp) GetSoldierByName(name string) *Soldier {
+	for index, soldier := range c.Soldiers {
 		if soldier.Name == name {
-			return soldier
+			return &c.Soldiers[index]
 		}
 	}
-	return Soldier{}
+	return nil
 }
 
-func (c *Camp) GetSoldierByIp(ip string) Soldier {
-	for _, soldier := range c.Soldiers {
+func (c *Camp) GetSoldierByIp(ip string) *Soldier {
+	for index, soldier := range c.Soldiers {
 		if soldier.Ip == ip {
-			return soldier
+			return &c.Soldiers[index]
 		}
 	}
-	return Soldier{}
+	return nil
 }
 func (c *Camp) SoldierExists(name string) bool {
 	for _, soldier := range c.Soldiers {

dispatcher/dispatcher.go

@@ -4,6 +4,7 @@ import (
 	"crypto/md5"
 	"encoding/hex"
 	"sync"
+	"time"
 )
 
 type Dispatcher struct {
@@ -62,3 +63,16 @@ func (c *Camp) UpdateSettings(status, victim, ddosType string) {
 		c.Settings.DDOSType = ddosType
 	}
 }
+func (d *Dispatcher) ScanAndRemoveTimeOutSoldiers() {
+	c := &d.Cmp
+	for {
+		for i, soldier := range c.Soldiers {
+			if soldier.LastRequest.IsZero() {
+				continue
+			}
+			if time.Now().Sub(soldier.LastRequest) > time.Second*4 {
+				c.Soldiers = append(c.Soldiers[:i], c.Soldiers[i+1:]...)
+			}
+		}
+	}
+}

dispatcher/server.go

@@ -6,15 +6,37 @@ import (
 	"net"
 	"net/http"
 	"os"
+	"time"
 )
 
+func HandlePing(writer http.ResponseWriter, request *http.Request) {
+	if request.Method == "GET" {
+		_, _ = writer.Write([]byte("pong"))
+	}
+}
+
 func HandleCamp(writer http.ResponseWriter, request *http.Request, d *Dispatcher) {
 	if request.Method == "GET" {
+
 		err := json.NewEncoder(writer).Encode(d.Cmp)
 		if err != nil {
 			http.Error(writer, err.Error(), http.StatusBadRequest)
 			return
 		}
+		//update soldier last request
+		ip, _, err := net.SplitHostPort(request.RemoteAddr)
+		if err != nil {
+			http.Error(writer, err.Error(), http.StatusBadRequest)
+			return
+		}
+		soldier := d.Cmp.GetSoldierByIp(ip)
+		if soldier == nil {
+			//maybe its first request or its leader
+			return
+		}
+		if soldier.Name != "" {
+			soldier.LastRequest = time.Now()
+		}
 	}
 	if request.Method == "POST" {
 		//add soldier to camp
@@ -132,12 +154,16 @@ func isAuthorized(auth string, hash string) bool {
 }
 
 func Start(d *Dispatcher) {
+	go d.ScanAndRemoveTimeOutSoldiers()
 	http.HandleFunc("/camp", func(writer http.ResponseWriter, request *http.Request) {
 		HandleCamp(writer, request, d)
 	})
 	http.HandleFunc("/system", func(writer http.ResponseWriter, request *http.Request) {
 		HandleSystem(writer, request, d)
 	})
+	http.HandleFunc("/ping", func(writer http.ResponseWriter, request *http.Request) {
+		HandlePing(writer, request)
+	})
 	color.Green("Starting dispatcher server on %s:%s", d.ListeningAddress, d.ListeningPort)
 	err := http.ListenAndServe(d.ListeningAddress+":"+d.ListeningPort, nil)
 	if err != nil {