Add option to specify config file

config/config.go

@@ -1,6 +1,8 @@
 package config
 
 import (
+	"os"
+
 	log "github.com/sirupsen/logrus"
 	"github.com/spf13/viper"
 )
@@ -53,7 +55,7 @@ func Load() Config {
 		if _, ok := err.(viper.ConfigFileNotFoundError); ok {
 			log.Warnf("No config file found in search paths, using default values")
 		} else {
-			log.Fatalf("Error reading config: %+v", err)
+			log.Fatalf("Error reading config: %s", err)
 		}
 	}
 
@@ -66,6 +68,30 @@ func Load() Config {
 	return conf
 }
 
+func LoadFile(configFile string) Config {
+	var conf Config
+
+	f, err := os.OpenFile(configFile, os.O_RDONLY, 0444)
+
+	if err != nil {
+		log.Fatalf("Failed to open config file: %s", err)
+	}
+
+	defer f.Close()
+
+	if err := viper.ReadConfig(f); err != nil {
+		log.Fatalf("Error reading config: %s", err)
+	}
+
+	if err := viper.Unmarshal(&conf); err != nil {
+		log.Fatalf("Error parsing config: %s", err)
+	}
+
+	loadedConfig = &conf
+
+	return conf
+}
+
 func LoadedConfig() *Config {
 	if loadedConfig == nil {
 		Load()

main.go

@@ -1,6 +1,8 @@
 package main
 
 import (
+	"flag"
+
 	"github.com/librespeed/speedtest/config"
 	"github.com/librespeed/speedtest/database"
 	"github.com/librespeed/speedtest/results"
@@ -9,9 +11,21 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
+var (
+	optConfig = flag.String("c", "", "config file to be used, defaults to settings.toml in the same directory")
+)
+
 func main() {
-	conf := config.Load()
+	flag.Parse()
+
+	var conf config.Config
+	if *optConfig != "" {
+		conf = config.LoadFile(*optConfig)
+	} else {
+		conf = config.Load()
+	}
 
+	web.SetServerLocation(&conf)
 	results.Initialize(&conf)
 	database.SetDBInfo(&conf)
 	log.Fatal(web.ListenAndServe(&conf))

web/helpers.go

@@ -17,11 +17,7 @@ import (
 )
 
 var (
-	// get server location from ipinfo.io from start to minimize API access
-	serverLat, serverLng = getServerLocation()
-	// for testing
-	// serverLat, serverLng = 22.7702, 112.9578
-	// serverLat, serverLng = 23.018, 113.7487
+	serverLat, serverLng float64
 )
 
 func getRandomData(length int) []byte {
@@ -71,9 +67,7 @@ func getIPInfo(addr string) results.IPInfoResponse {
 	return ret
 }
 
-func getServerLocation() (float64, float64) {
-	conf := config.LoadedConfig()
-
+func SetServerLocation(conf *config.Config) (float64, float64) {
 	if conf.ServerLat > 0 && conf.ServerLng > 0 {
 		log.Infof("Configured server coordinates: %.6f, %.6f", conf.ServerLat, conf.ServerLng)
 		return conf.ServerLat, conf.ServerLng