added reconnection functionality to the agent, which is used if the server is not reachable

agents/agent.go

@@ -74,28 +74,63 @@ func registerAgent(agentName string, agentId string, agentIp string) error {
 }
 
 
-func connectToWebSocket(agentName string, agentIp string) error {
+func connectToWebSocket(agentName, agentIp string) error {
 	wsURL := fmt.Sprintf("ws://%s/data?agentName=%s&IPv4Address=%s", webSocketAddr, url.QueryEscape(agentName), url.QueryEscape(agentIp))
 	var err error
-	conn, _, err = websocket.DefaultDialer.Dial(wsURL, nil)
-	if err != nil {
-		return fmt.Errorf("Failed to connect to WebSocket: %v", err)
-	}
+	for {
+		conn, _, err = websocket.DefaultDialer.Dial(wsURL, nil)
+		if err == nil {
+			log.Println("WeSocket connection established")
+			return nil
+		}
 
-	log.Println("WebSocket connection established")
-	return nil
+		log.Printf("Failed to connect to WebSocket: %v. Retrying in 5 seconds...", err)
+		time.Sleep(5 * time.Second)
+	}
 }
 
-func listenForCommands() {
+func reconnectToWebSocket(agentName, agentIp string) error {
+	backoff := 2 * time.Second
+	maxBackoff := 1 * time.Minute
+
+	for {
+		log.Println("Attempting to reconnect to WebSocket...")
+		err := connectToWebSocket(agentName, agentIp)
+		if err == nil {
+			log.Println("Reconnection succesful.")
+			return nil
+		}
+
+		log.Printf("Reconnection failed: %v", err)
+
+		time.Sleep(backoff)
+		backoff *= 2
+		if backoff > maxBackoff {
+			backoff = maxBackoff
+		}
+	}
+}
+
+func listenForCommands(agentName, agentIp string) {
 	defer conn.Close()
 
 	for {
 		_, rawMessage, err := conn.ReadMessage()
 		if err != nil {
-			log.Printf("Error reading message: %v", err)
-			break
+			log.Printf("Connection lost: %v", err)
+			if reconnectErr := reconnectToWebSocket(agentName, agentIp); reconnectErr != nil {
+				log.Printf("Critical error during reconnection: %v", reconnectErr)
+				}
+			continue
 		}
 
+	// for {
+	// 	_, rawMessage, err := conn.ReadMessage()
+	// 	if err != nil {
+	// 		log.Printf("Error reading message: %v", err)
+	// 		break
+	// 	}
+
 		var message Message
 		if err := json.Unmarshal(rawMessage, &message); err != nil {
 			log.Printf("Error unmarshalling message: %v", err)
@@ -154,5 +189,5 @@ func main() {
 		log.Fatalf("Websocket connection failed: %v", err)
 	}
 
-	listenForCommands()
+	listenForCommands(agentName, agentIp)
 }