feat: allows to bind on localhost or specific IP address (#11)

Adds the `-metrics.listen-addr` flag

* [Add] metrics.addr config option

* [Fix] Remove .exe in documentation

* [Fix] Rename metrics.addr to metrics.listen-addr

README.md

@@ -10,6 +10,16 @@ Download from [releases](https://github.com/fffonion/tplink-plug-exporter/releas
 docker run -d -p 9233:9233 fffonion/tplink-plug-exporter
 ```
 
+### Usage
+Use the -h flag to see full usage:
+
+```
+$ tplink-plug-exporter -h
+Usage of tplink-plug-exporter:
+  -metrics.listen-addr string
+        listen address for tplink-plug exporter (default ":9233")
+```
+
 ## Grafana dashboard
 
 Search for `Kasa` inside grafana or install from https://grafana.com/grafana/dashboards/10957

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"flag"
 	"net/http"
 
 	"github.com/prometheus/common/log"
@@ -9,7 +10,10 @@ import (
 )
 
 func main() {
+	var metricsAddr = flag.String("metrics.listen-addr", ":9233", "listen address for tplink-plug exporter")
+
+	flag.Parse()
 	s := exporter.NewHttpServer()
-	log.Infoln("Accepting Prometheus Requests on :9233")
-	log.Fatal(http.ListenAndServe(":9233", s))
+	log.Infof("Accepting Prometheus Requests on %s", *metricsAddr)
+	log.Fatal(http.ListenAndServe(*metricsAddr, s))
 }