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")
@@ -227,56 +227,67 @@ func UpdatePeers(client mqtt.Client, msg mqtt.Message) {
 		cfg.ReadConfig()
 		var shouldReSub = shouldResub(cfg.Node.NetworkSettings.DefaultServerAddrs, peerUpdate.ServerAddrs)
 		if shouldReSub {
-			Resubscribe(client, &cfg)
-			cfg.Node.NetworkSettings.DefaultServerAddrs = peerUpdate.ServerAddrs
-		}
-		file := ncutils.GetNetclientPathSpecific() + cfg.Node.Interface + ".conf"
-		err = wireguard.UpdateWgPeers(file, peerUpdate.Peers)
-		if err != nil {
-			ncutils.Log("error updating wireguard peers" + err.Error())
-			return
+			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)
+			if err != nil {
+				ncutils.Log("error updating wireguard peers" + err.Error())
+				return
+			}
+			ncutils.Log("applyWGQuickConf to " + file)
+			err = wireguard.ApplyWGQuickConf(file)
+			if err != nil {
+				ncutils.Log("error restarting wg after peer update " + err.Error())
+				return
+			}
 		}
-		ncutils.Log("applyWGQuickConf to " + file)
-		err = wireguard.ApplyWGQuickConf(file)
-		if err != nil {
-			ncutils.Log("error restarting wg after peer update " + err.Error())
+	}()
+}
+
+// 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
-
-		KeepaliveReceived = time.Now()
-		return
-	}
-	ncutils.Log("server keepalive not recieved in last 3 minutes")
-	///do other stuff
+	serverid := string(msg.Payload())
+	keepalive <- serverid
 }
 
 // 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)
-		if token := client.Subscribe("update/"+cfg.Node.ID, 0, NodeUpdate); token.Wait() && token.Error() != nil {
-			log.Fatal(token.Error())
-		}
-		if cfg.DebugOn {
-			ncutils.Log("subscribed to node updates for node " + cfg.Node.Name + " update/" + cfg.Node.ID)
-		}
-		if token := client.Subscribe("update/peers/"+cfg.Node.ID, 0, UpdatePeers); token.Wait() && token.Error() != nil {
-			log.Fatal(token.Error())
-		}
-		ncutils.Log("finished re subbing")
-		return nil
-	} else {
-		ncutils.Log("could not mod config when re-subbing")
-		return err
+	ncutils.Log("resubbing on network " + cfg.Node.Network)
+	client.Disconnect(250)
+	client = SetupMQTT(cfg)
+	if token := client.Subscribe("update/"+cfg.Node.ID, 0, NodeUpdate); token.Wait() && token.Error() != nil {
+		log.Fatal(token.Error())
+	}
+	if cfg.DebugOn {
+		ncutils.Log("subscribed to node updates for node " + cfg.Node.Name + " update/" + cfg.Node.ID)
 	}
+	if token := client.Subscribe("update/peers/"+cfg.Node.ID, 0, UpdatePeers); token.Wait() && token.Error() != nil {
+		log.Fatal(token.Error())
+	}
+	ncutils.Log("finished re subbing")
+	return nil
 }
 
 // UpdateKeys -- updates private key and returns new publickey