resub on server ping timeout; may not work in multi server enviornment

netclient/functions/daemon.go

@@ -22,7 +22,7 @@ import (
 )
 
 // ServerKeepalive  - stores time of last server keepalive message
-var KeepaliveReceived time.Time
+var keepalive chan string = make(chan string)
 var messageCache = make(map[string]string, 20)
 
 const lastNodeUpdate = "lnu"
@@ -83,7 +83,6 @@ func MessageQueue(ctx context.Context, network string) {
 	cfg.Network = network
 	cfg.ReadConfig()
 	ncutils.Log("daemon started for network:" + network)
-	KeepaliveReceived = time.Now()
 	client := SetupMQTT(&cfg)
 	if cfg.DebugOn {
 		if token := client.Subscribe("#", 0, nil); token.Wait() && token.Error() != nil {
@@ -110,6 +109,7 @@ func MessageQueue(ctx context.Context, network string) {
 		ncutils.Log("subscribed to server keepalives")
 	}
 	defer client.Disconnect(250)
+	go MonitorKeepalive(ctx, client, &cfg)
 	go Checkin(ctx, &cfg, network)
 	<-ctx.Done()
 	ncutils.Log("shutting down daemon")
@@ -227,8 +227,11 @@ func UpdatePeers(client mqtt.Client, msg mqtt.Message) {
 		cfg.ReadConfig()
 		var shouldReSub = shouldResub(cfg.Node.NetworkSettings.DefaultServerAddrs, peerUpdate.ServerAddrs)
 		if shouldReSub {
+			if err := config.ModConfig(&cfg.Node); err == nil {
 				Resubscribe(client, &cfg)
 				cfg.Node.NetworkSettings.DefaultServerAddrs = peerUpdate.ServerAddrs
+			} else {
+				ncutils.Log("resub required but mod config failed")
 			}
 			file := ncutils.GetNetclientPathSpecific() + cfg.Node.Interface + ".conf"
 			err = wireguard.UpdateWgPeers(file, peerUpdate.Peers)
@@ -242,23 +245,35 @@ func UpdatePeers(client mqtt.Client, msg mqtt.Message) {
 				ncutils.Log("error restarting wg after peer update " + err.Error())
 				return
 			}
+		}
 	}()
 }
 
+// MonitorKeepalive - checks time last server keepalive received.  If more than 3+ minutes, notify and resubscribe
+func MonitorKeepalive(ctx context.Context, client mqtt.Client, cfg *config.ClientConfig) {
+	lastUpdate := time.Now()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-time.After(time.Second * 150):
+			if time.Since(lastUpdate) < time.Second*200 { // more than 3+ minutes
+				Resubscribe(client, cfg)
+			}
+		case <-keepalive:
+			lastUpdate = time.Now()
+		}
+	}
+}
+
 // ServerKeepAlive -- handler to react to keepalive messages published by server
 func ServerKeepAlive(client mqtt.Client, msg mqtt.Message) {
-	if time.Now().Sub(KeepaliveReceived) < time.Second*200 { // more than 3+ minutes
+	serverid := string(msg.Payload())
-
+	keepalive <- serverid
-		KeepaliveReceived = time.Now()
-		return
-	}
-	ncutils.Log("server keepalive not recieved in last 3 minutes")
-	///do other stuff
 }
 
 // Resubscribe --- handles resubscribing if needed
 func Resubscribe(client mqtt.Client, cfg *config.ClientConfig) error {
-	if err := config.ModConfig(&cfg.Node); err == nil {
 	ncutils.Log("resubbing on network " + cfg.Node.Network)
 	client.Disconnect(250)
 	client = SetupMQTT(cfg)
@@ -273,10 +288,6 @@ func Resubscribe(client mqtt.Client, cfg *config.ClientConfig) error {
 	}
 	ncutils.Log("finished re subbing")
 	return nil
-	} else {
-		ncutils.Log("could not mod config when re-subbing")
-		return err
-	}
 }
 
 // UpdateKeys -- updates private key and returns new publickey