Add support for config file, issue #10

README.md

@@ -12,18 +12,21 @@ Supports FreeRADIUS 3.0.x.
 
 Name               | Description
 -------------------|------------
-radius.addr        | Address of [FreeRADIUS status server](https://wiki.freeradius.org/config/Status), defaults to `127.0.0.1:18121`.
-radius.secret      | FreeRADIUS client secret.
+radius.address     | Address of [FreeRADIUS status server](https://wiki.freeradius.org/config/Status), defaults to `127.0.0.1:18121`.
+radius.secret      | FreeRADIUS client secret, defaults to `adminsecret`.
 radius.timeout     | Timeout, in milliseconds, defaults to `5000`.
+radius.homeservers | Addresses of home servers separated by comma, e.g. "172.28.1.2:1812,172.28.1.3:1812"
 web.listen-address | Address to listen on for web interface and telemetry, defaults to `:9812`.
 web.telemetry-path | Path under which to expose metrics, defaults to `/metrics`.
 version            | Display version information
+config             | Config file (optional)
 
 
 ### Environment Variables
 
 Name               | Description
 -------------------|------------
-RADIUS_ADDR        | Address of [FreeRADIUS status server](https://wiki.freeradius.org/config/Status).
+RADIUS_ADDRESS     | Address of [FreeRADIUS status server](https://wiki.freeradius.org/config/Status).
 RADIUS_SECRET      | FreeRADIUS client secret.
+RADIUS_TIMEOUT     | Timeout, in milliseconds.
 RADIUS_HOMESERVERS | Addresses of home servers separated by comma, e.g. "172.28.1.2:1812,172.28.1.3:1812"

config.example

@@ -0,0 +1,6 @@
+{
+    "radius.address": "127.0.0.1:18121",
+    "radius.secret": "secret",
+    "radius.timeout": 10000,
+    "radius.homeservers": ""
+}

go.mod

@@ -3,6 +3,7 @@ module github.com/bvantagelimited/freeradius_exporter
 go 1.14
 
 require (
+	github.com/peterbourgon/ff/v3 v3.1.2
 	github.com/prometheus/client_golang v1.12.1
 	github.com/prometheus/common v0.33.0 // indirect
 	golang.org/x/sys v0.0.0-20220412211240-33da011f77ad // indirect

go.sum

@@ -151,6 +151,9 @@ github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3Rllmb
 github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk=
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
+github.com/pelletier/go-toml v1.6.0/go.mod h1:5N711Q9dKgbdkxHL+MEfF31hpT7l0S0s/t2kKREewys=
+github.com/peterbourgon/ff/v3 v3.1.2 h1:0GNhbRhO9yHA4CC27ymskOsuRpmX0YQxwxM9UPiP6JM=
+github.com/peterbourgon/ff/v3 v3.1.2/go.mod h1:XNJLY8EIl6MjMVjBS4F0+G0LYoAqs0DTa4rmHHukKDE=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=

main.go

@@ -9,6 +9,7 @@ import (
 	"path/filepath"
 	"strings"
 
+	"github.com/peterbourgon/ff/v3"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 
@@ -19,15 +20,28 @@ import (
 var version, commit, date string
 
 func main() {
-	listenAddr := flag.String("web.listen-address", ":9812", "Address to listen on for web interface and telemetry.")
-	metricsPath := flag.String("web.telemetry-path", "/metrics", "A path under which to expose metrics.")
-	radiusTimeout := flag.Int("radius.timeout", 5000, "Timeout, in milliseconds.")
-	radiusAddr := flag.String("radius.address", getEnv("RADIUS_ADDR", "127.0.0.1:18121"), "Address of FreeRADIUS status server.")
-	homeServers := flag.String("radius.homeservers", getEnv("RADIUS_HOMESERVERS", ""), "List of FreeRADIUS home servers to check, e.g. '172.28.1.2:1812,172.28.1.3:1812'.")
-	radiusSecret := flag.String("radius.secret", getEnv("RADIUS_SECRET", "adminsecret"), "FreeRADIUS client secret.")
-	appVersion := flag.Bool("version", false, "Display version information")
+	fs := flag.NewFlagSet("freeradius_exporter", flag.ContinueOnError)
+	appHelp := fs.Bool("help", false, "Display help")
+	appVersion := fs.Bool("version", false, "Display version information")
+	_ = fs.String("config", "", "Config file (optional)")
 
-	flag.Parse()
+	listenAddr := fs.String("web.listen-address", ":9812", "Address to listen on for web interface and telemetry.")
+	metricsPath := fs.String("web.telemetry-path", "/metrics", "A path under which to expose metrics.")
+	radiusTimeout := fs.Int("radius.timeout", 5000, "Timeout, in milliseconds [RADIUS_TIMEOUT].")
+	radiusAddr := fs.String("radius.address", "127.0.0.1:18121", "Address of FreeRADIUS status server [RADIUS_ADDRESS].")
+	homeServers := fs.String("radius.homeservers", "", "List of FreeRADIUS home servers to check, e.g. '172.28.1.2:1812,172.28.1.3:1812' [RADIUS_HOMESERVERS].")
+	radiusSecret := fs.String("radius.secret", "adminsecret", "FreeRADIUS client secret [RADIUS_SECRET].")
+
+	err := ff.Parse(fs, os.Args[1:], ff.WithEnvVarNoPrefix(), ff.WithConfigFileFlag("config"), ff.WithConfigFileParser(ff.JSONParser))
+	if err != nil {
+		println(err.Error())
+		os.Exit(1)
+	}
+
+	if *appHelp {
+		fs.PrintDefaults()
+		os.Exit(0)
+	}
 
 	if *appVersion {
 		println(filepath.Base(os.Args[0]), version, commit, date)
@@ -65,10 +79,3 @@ func main() {
 	log.Printf("Providing metrics at %s%s", *listenAddr, *metricsPath)
 	log.Fatal(srv.Serve(listener))
 }
-
-func getEnv(key string, defaultVal string) string {
-	if envVal, ok := os.LookupEnv(key); ok {
-		return envVal
-	}
-	return defaultVal
-}