Implement reading password from file

README.md

@@ -10,6 +10,8 @@ Usage of ./vodafone-station-exporter:
     	Print version and exit
   -vodafone.station-password string
     	Password for logging into the Vodafone station (default "How is the default password calculated? mhmm")
+  -vodafone.station-password-file string
+    	File that contains the password for logging into the Vodafone station
   -vodafone.station-url string
     	Vodafone station URL. For bridge mode this is 192.168.100.1 (note: Configure a route if using bridge mode) (default "http://192.168.0.1")
   -web.listen-address string

main.go

@@ -12,6 +12,7 @@ import (
 	"net/http"
 	"os"
 	"reflect"
+	"strings"
 )
 
 const version = "0.0.1"
@@ -32,6 +33,7 @@ var (
 	metricsPath                 = flag.String("web.telemetry-path", "/metrics", "Path under which to expose metrics")
 	vodafoneStationUrl          = flag.String("vodafone.station-url", "http://192.168.0.1", "Vodafone station URL. For bridge mode this is 192.168.100.1 (note: Configure a route if using bridge mode)")
 	vodafoneStationPassword     = flag.String("vodafone.station-password", "How is the default password calculated? mhmm", "Password for logging into the Vodafone station")
+	vodafoneStationPasswordFile = flag.String("vodafone.station-password-file", "", "Path to a file containing the Vodafone station password (overrides -vodafone.station-password)")
 )
 
 func main() {
@@ -40,6 +42,18 @@ func main() {
 	cfg := &promslog.Config{}
 	logger = promslog.New(cfg)
 
+	// Handle password from file if provided
+	if *vodafoneStationPasswordFile != "" {
+		data, err := os.ReadFile(*vodafoneStationPasswordFile)
+		if err != nil {
+			logger.Error("Failed to read password file", slog.String("err", err.Error()))
+			os.Exit(2)
+		}
+		pw := string(data)
+		pw = strings.TrimSpace(pw)
+		vodafoneStationPassword = &pw
+	}
+
 	if *showMetrics {
 		describeMetrics()
 		os.Exit(0)