Allow set custom interval

Author: MMulthaupt

cmd/exporter/flags/flags.go

@@ -2,15 +2,16 @@ package flags
 
 import "flag"
 
-func Parse(arguments []string) (namespace, binary, argName string, port int) {
+func Parse(arguments []string) (namespace, binary, argName string, port int, interval float64) {
 	flagSet := flag.NewFlagSet("flags", flag.ExitOnError)
 	namespacePtr := flagSet.String("namespace", "mine", "Prometheus metric namespace.")
 	binaryPtr := flagSet.String("binary", "", "Filter which processes to watch by binary name. This is limited to 15 bytes because of the kernel.")
 	nameFlagPtr := flagSet.String("nameflag", "name", "Set Prometheus \"name\"-label value to value of this command line argument of the monitored processes.")
 	portPtr := flagSet.Int("port", 80, "Port on which to listen to requests to /metrics.")
+	intervalPtr := flagSet.Float64("interval", 10, "Interval between refreshes of metrics, in seconds. Should not be too large to prevent CPU reading from getting noisy.")
 	err := flagSet.Parse(arguments)
 	if err != nil {
 		panic(err)
 	}
-	return *namespacePtr, *binaryPtr, *nameFlagPtr, *portPtr
+	return *namespacePtr, *binaryPtr, *nameFlagPtr, *portPtr, *intervalPtr
 }

cmd/exporter/main.go

@@ -13,24 +13,24 @@ import (
 )
 
 func main() {
-	namespace, procBinaryName, nameFlag, port := flags.Parse(os.Args[1:])
+	namespace, procBinaryName, nameFlag, port, interval := flags.Parse(os.Args[1:])
 	metricsSet := metrics.NewPrometheusProcessMetricsSet(namespace, procBinaryName, nameFlag)
 	mu := &sync.Mutex{}
 	updateMetricsSet(metricsSet, mu)
 	// ctx, cancelFunc := context.WithCancel(context.Background())
-	go keepMetricsUpToDate(metricsSet, mu)
+	go keepMetricsUpToDate(metricsSet, mu, time.Duration(float64(time.Second)*interval))
 	http.Handle("/metrics", newHttpMetricsRequestHandler(metricsSet, mu))
 	log.Fatal(http.ListenAndServe(fmt.Sprintf(":%d", port), nil))
 }
 
-func keepMetricsUpToDate(set *metrics.PrometheusProcessMetricsSet, mu *sync.Mutex) {
+func keepMetricsUpToDate(set *metrics.PrometheusProcessMetricsSet, mu *sync.Mutex, interval time.Duration) {
 	defer func() {
 		if r := recover(); r != nil {
 			defer func() { go func() { time.Sleep(time.Second); log.Exit(1) }() }()
 			log.Panicf("Panic in keepMetricsUpToDate(): %v", r)
 		}
 	}()
-	ticker := time.NewTicker(time.Second * 10)
+	ticker := time.NewTicker(interval)
 	for {
 		select {
 		case <-ticker.C: