Ability to configure serial path

main.go

@@ -38,6 +38,7 @@ var (
 )
 
 type Conf struct {
+	SerialAddress  string `yaml:"serial_address"`
 	Port           int    `yaml:"port"`
 	SslCertificate string `yaml:"ssl_certificate"`
 	SslPrivatekey  string `yaml:"ssl_privatekey"`
@@ -276,6 +277,7 @@ func parseConfigFile() {
 // Write the default configuration to $HOME/.config/enervent-ctrl/configuration.yaml
 func initDefaultConfig(confpath string) {
 	config = Conf{
+		"/dev/ttyS0",
 		8888,
 		confpath + "/certificate.pem",
 		confpath + "/privatekey.pem",
@@ -311,6 +313,7 @@ func configure() {
 	passwflag := flag.String("password", config.Password, "Password for HTTP Basic Authentication")
 	promflag := flag.Bool("enable-metrics", config.EnableMetrics, "Enable the built-in Prometheus exporter")
 	logflag := flag.String("logfile", config.LogFile, "Path to log file. Default is empty string, log to stdout")
+	serialflag := flag.String("serial", config.SerialAddress, "Path to serial console for RS-485 connection. Defaults to /dev/ttyS0")
 	// TODO: log file flag
 	flag.Parse()
 	config.Debug = *debugflag
@@ -322,6 +325,7 @@ func configure() {
 	config.Password = *passwflag
 	config.EnableMetrics = *promflag
 	config.LogFile = *logflag
+	config.SerialAddress = *serialflag
 	usernamehash = sha256.Sum256([]byte(config.Username))
 	passwordhash = sha256.Sum256([]byte(config.Password))
 	if len(config.LogFile) != 0 {
@@ -354,7 +358,7 @@ func configure() {
 func main() {
 	log.Println("enervent-ctrl version", version)
 	configure()
-	device = *pingvin.New(config.Debug)
+	device = *pingvin.New(config.SerialAddress, config.Debug)
 	device.Update()
 	go device.Monitor(config.Interval)
 	serve(&config.SslCertificate, &config.SslPrivatekey)

pingvin/pingvin.go

@@ -183,7 +183,7 @@ func readCsvLines(file string) [][]string {
 
 // Create modbus.Handler, store it in p.handler,
 // connect the handler and create p.modbusclient (modbus.Client)
-func (p *Pingvin) createModbusClient() {
+func (p *Pingvin) createModbusClient(serial string) {
 	// TODO: read configuration from file, hardcoded for now
 	p.handler = modbus.NewRTUClientHandler("/dev/ttyS0")
 	p.handler.BaudRate = 19200
@@ -613,11 +613,11 @@ func (p *Pingvin) Collect(ch chan<- prometheus.Metric) {
 }
 
 // create a Pingvin struct, read coils and registers from CSVs
-func New(debug bool) *Pingvin {
+func New(serial string, debug bool) *Pingvin {
 	pingvin := Pingvin{}
 	pingvin.Debug.dbg = debug
 	pingvin.buslock = &sync.Mutex{}
-	pingvin.createModbusClient()
+	pingvin.createModbusClient(serial)
 	log.Println("Parsing coil data...")
 	coilData := readCsvLines("coils.csv")
 	for i := 0; i < len(coilData); i++ {