gh-3 config file entry and cli flag to enable the Prometheus exporter. Disabled by default.

enervent-ctrl-go/main.go

@@ -44,6 +44,7 @@ type Conf struct {
 	Username       string `yaml:"username"`
 	Password       string `yaml:"password"`
 	Interval       int    `yaml:"interval"`
+	EnableMetrics  bool   `yaml:"enable_metrics"`
 	LogAccess      bool   `yaml:"log_access"`
 	Debug          bool   `yaml:"debug"`
 }
@@ -198,7 +199,9 @@ func serve(cert, key *string) {
 	http.HandleFunc("/api/v1/status", authHandlerFunc(status))
 	http.HandleFunc("/api/v1/registers/", authHandlerFunc(registers))
 	http.HandleFunc("/api/v1/temperature/", authHandlerFunc(temperature))
+	if config.EnableMetrics {
 		http.Handle("/metrics", promhttp.Handler())
+	}
 	html, err := fs.Sub(static, "static/html")
 	if err != nil {
 		log.Fatal(err)
@@ -280,6 +283,7 @@ func initDefaultConfig(confpath string) {
 		4,
 		false,
 		false,
+		false,
 	}
 	conffile := confpath + "/configuration.yaml"
 	confbytes, err := yaml.Marshal(&config)
@@ -303,6 +307,7 @@ func configure() {
 	keyflag := flag.String("key", config.SslPrivatekey, "Path to SSL private key to use for HTTPS")
 	usernflag := flag.String("username", config.Username, "Username for HTTP Basic Authentication")
 	passwflag := flag.String("password", config.Password, "Password for HTTP Basic Authentication")
+	promflag := flag.Bool("enable-metrics", config.EnableMetrics, "Enable the built-in Prometheus exporter")
 	// TODO: log file flag
 	flag.Parse()
 	config.Debug = *debugflag
@@ -312,6 +317,7 @@ func configure() {
 	config.SslPrivatekey = *keyflag
 	config.Username = *usernflag
 	config.Password = *passwflag
+	config.EnableMetrics = *promflag
 	usernamehash = sha256.Sum256([]byte(config.Username))
 	passwordhash = sha256.Sum256([]byte(config.Password))
 	// Check that certificate file exists, generate if needed
@@ -327,8 +333,10 @@ func configure() {
 		log.Println("HTTP Access logging enabled")
 	}
 	log.Println("Update interval set to", config.Interval, "seconds")
+	if config.EnableMetrics {
 		prometheus.MustRegister(&pingvin)
 	}
+}
 
 func main() {
 	log.Println("enervent-ctrl version", version)

enervent-ctrl-go/pingvinKL/pingvinKL.go

@@ -573,27 +573,7 @@ func (p *PingvinKL) Monitor(interval int) {
 	}
 }
 
-// func (p *PingvinKL) Describe(ch chan<- *prometheus.Desc) {
-
-// }
-
-func (p *PingvinKL) prometheusRegister() {
-	for _, hreg := range p.Registers {
-		hreg.PromDesc = prometheus.NewDesc(
-			prometheus.BuildFQName("", "pingvin", strings.ToLower(hreg.Symbol)),
-			hreg.Description,
-			nil,
-			nil,
-		)
-
-	}
-	// prometheus.MustRegister(
-	// 	// collectors.NewGoCollector(),
-	// 	// collectors.NewProcessCollector(collectors.ProcessCollectorOpts{}),
-	// 	p,
-	// )
-}
-
+// Implements prometheus.Describe()
 func (p *PingvinKL) Describe(ch chan<- *prometheus.Desc) {
 	for _, hreg := range p.Registers {
 		if !hreg.Reserved {
@@ -607,6 +587,7 @@ func (p *PingvinKL) Describe(ch chan<- *prometheus.Desc) {
 	}
 }
 
+// Implements prometheus.Collect()
 func (p *PingvinKL) Collect(ch chan<- prometheus.Metric) {
 	for _, hreg := range p.Registers {
 		if !hreg.Reserved {
@@ -632,22 +613,6 @@ func (p *PingvinKL) Collect(ch chan<- prometheus.Metric) {
 	}
 }
 
-// 	for _, coil := range p.Coils {
-// 		if coil.Reserved {
-// 			continue
-// 		}
-// 		if err := p.Promreg.Register(prometheus.NewGauge(
-// 			prometheus.GaugeOpts{
-// 				Subsystem: "pingvin",
-// 				Name:      strings.ToLower(coil.Symbol),
-// 				Help:      coil.Description,
-// 			},
-// 		)); err == nil {
-// 			p.Debug.Println("GaugeFunc pingvin_"+coil.Symbol, "registered.")
-// 		}
-// 	}
-// }
-
 // create a PingvinKL struct, read coils and registers from CSVs
 func New(debug bool) PingvinKL {
 	pingvin := PingvinKL{}
@@ -667,6 +632,5 @@ func New(debug bool) PingvinKL {
 			newRegister(registerData[i][0], registerData[i][1], registerData[i][2], registerData[i][3], registerData[i][6]))
 	}
 	log.Println("Parsed", len(pingvin.Registers), "registers")
-	// pingvin.prometheusRegister()
 	return pingvin
 }