adds a watch dog for the mqtt server

cmd/spaceDevices.go

@@ -26,7 +26,7 @@ func main() {
 		"user": config.MacDb.UserFile,
 	}).Info("SpaceDevices starting...")
 
-	//spaceDevices.EnableMqttDebugLogging()
+	//mqtt.EnableMqttDebugLogging()
 
 	userDb := db.NewUserDb(config.MacDb)
 	masterDb := db.NewMasterDb(config.MacDb)

conf/config.go

@@ -51,7 +51,8 @@ type MqttConf struct {
 	Username string
 	Password string
 	// if empty, the system certificates are used
-	CertFile     string
-	SessionTopic string
-	DevicesTopic string
+	CertFile                 string
+	SessionTopic             string
+	DevicesTopic             string
+	WatchDogTimeoutInMinutes int
 }

config.example.toml

@@ -21,6 +21,9 @@ username = "user"
 password = "pass"
 sessionTopic = "/net/wlan-sessions"
 devicesTopic = "/net/devices"
+# after this amount of minutes without any data from the sessions toptic, the program will be killed
+# a value < 1 will disable this check
+watchDogTimeoutInMinutes = 5
 
 [[location]]
 name = "Bar"

do.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 
 usage() {
-    echo "Usage $0 (build-linux|sync)"
+    echo "Usage $0 (build-linux|test-sync|sync)"
 }
 
 if [ "$1" == "" ]; then

mqtt/mqtt.go

@@ -21,7 +21,7 @@ type MqttHandler struct {
 	newDataChan  chan []byte
 	sessionTopic string
 	devicesTopic string
-
+	watchDog     *watchDog
 }
 
 //func init() {
@@ -70,7 +70,6 @@ func NewMqttHandler(conf conf.MqttConf) *MqttHandler {
 	opts.SetMaxReconnectInterval(5 * time.Minute)
 	opts.SetWill(conf.DevicesTopic, emptyPeopleAndDevices(), 0, true)
 
-
 	handler := MqttHandler{newDataChan: make(chan []byte), devicesTopic: conf.DevicesTopic, sessionTopic: conf.SessionTopic}
 	opts.SetOnConnectHandler(handler.onConnect)
 	opts.SetConnectionLostHandler(handler.onConnectionLost)
@@ -80,6 +79,11 @@ func NewMqttHandler(conf conf.MqttConf) *MqttHandler {
 		mqttLogger.WithError(tok.Error()).Fatal("Could not connect to mqtt server.")
 	}
 
+	if conf.WatchDogTimeoutInMinutes > 0 {
+		mqttLogger.Println("Enable mqtt watch dog, timeout in minutes is", conf.WatchDogTimeoutInMinutes)
+		handler.watchDog = NewWatchDog(time.Duration(conf.WatchDogTimeoutInMinutes) * time.Minute)
+	}
+
 	return &handler
 }
 
@@ -111,6 +115,10 @@ func (h *MqttHandler) onConnect(client mqtt.Client) {
 	err := subscribe(client, h.sessionTopic,
 		func(client mqtt.Client, message mqtt.Message) {
 			mqttLogger.Debug("new wifi sessions")
+			if h.watchDog != nil {
+				h.watchDog.Ping()
+			}
+
 			/*
 							mock := []byte(`{  "38134": {
 				    "last-auth": 1509211121,
@@ -151,7 +159,7 @@ func (h *MqttHandler) onConnect(client mqtt.Client) {
 
 		})
 	if err != nil {
-		mqttLogger.WithError(err).Fatal("Could not subscribe")
+		mqttLogger.WithField("topic", h.sessionTopic).WithError(err).Fatal("Could not subscribe.")
 	}
 }