Add experimental support for web-config-file

Fixes #55

cmd/mqtt2prometheus.go

@@ -15,11 +15,14 @@ import (
 	"go.uber.org/zap/zapcore"
 
 	mqtt "github.com/eclipse/paho.mqtt.golang"
+	"github.com/go-kit/kit/log"
+	kitzap "github.com/go-kit/kit/log/zap"
 	"github.com/hikhvar/mqtt2prometheus/pkg/config"
 	"github.com/hikhvar/mqtt2prometheus/pkg/metrics"
 	"github.com/hikhvar/mqtt2prometheus/pkg/mqttclient"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"github.com/prometheus/exporter-toolkit/web"
 )
 
 // These variables are set by goreleaser at linking time.
@@ -56,6 +59,11 @@ var (
 		"console",
 		"set the desired log output format. Valid values are 'console' and 'json'",
 	)
+	webConfigFlag = flag.String(
+		"web-config-file",
+		"",
+		"[EXPERIMENTAL] Path to configuration file that can enable TLS or authentication for metric scraping.",
+	)
 )
 
 func main() {
@@ -119,8 +127,12 @@ func main() {
 	prometheus.MustRegister(ingest.Collector())
 	prometheus.MustRegister(collector)
 	http.Handle("/metrics", promhttp.Handler())
+	s := &http.Server{
+		Addr:    getListenAddress(),
+		Handler: http.DefaultServeMux,
+	}
 	go func() {
-		err = http.ListenAndServe(getListenAddress(), nil)
+		err = web.ListenAndServe(s, *webConfigFlag, setupGoKitLogger(logger))
 		if err != nil {
 			logger.Fatal("Error while serving http", zap.Error(err))
 		}
@@ -183,6 +195,10 @@ func mustSetupLogger() *zap.Logger {
 	return logger
 }
 
+func setupGoKitLogger(l *zap.Logger) log.Logger {
+	return kitzap.NewZapSugarLogger(l, zap.NewAtomicLevelAt(*logLevelFlag).Level())
+}
+
 func setupExtractor(cfg config.Config) (metrics.Extractor, error) {
 	parser := metrics.NewParser(cfg.Metrics)
 	if cfg.MQTT.ObjectPerTopicConfig != nil {

go.mod

@@ -3,10 +3,13 @@ module github.com/hikhvar/mqtt2prometheus
 go 1.14
 
 require (
+	github.com/dvyukov/go-fuzz v0.0.0-20210103155950-6a8e9d1f2415 // indirect
 	github.com/eclipse/paho.mqtt.golang v1.1.1
+	github.com/go-kit/kit v0.10.0
 	github.com/patrickmn/go-cache v2.1.0+incompatible
-	github.com/prometheus/client_golang v1.6.0
+	github.com/prometheus/client_golang v1.7.1
+	github.com/prometheus/exporter-toolkit v0.5.1
 	github.com/thedevsaddam/gojsonq/v2 v2.5.2
 	go.uber.org/zap v1.16.0
-	gopkg.in/yaml.v2 v2.2.5
+	gopkg.in/yaml.v2 v2.4.0
 )