Add verbosity switch to suppress diagnostic output

proxy/lib/pt_event_logger.go

@@ -2,14 +2,16 @@ package snowflake_proxy
 
 import (
 	"git.torproject.org/pluggable-transports/snowflake.git/v2/common/task"
+	"io"
 	"log"
 	"time"
 
 	"git.torproject.org/pluggable-transports/snowflake.git/v2/common/event"
 )
 
-func NewProxyEventLogger(logPeriod time.Duration) event.SnowflakeEventReceiver {
-	el := &logEventLogger{logPeriod: logPeriod}
+func NewProxyEventLogger(logPeriod time.Duration, output io.Writer) event.SnowflakeEventReceiver {
+	logger := log.New(output, "", log.LstdFlags|log.LUTC)
+	el := &logEventLogger{logPeriod: logPeriod, logger: logger}
 	el.task = &task.Periodic{Interval: logPeriod, Execute: el.logTick}
 	el.task.Start()
 	return el
@@ -21,6 +23,7 @@ type logEventLogger struct {
 	connectionCount int
 	logPeriod       time.Duration
 	task            *task.Periodic
+	logger          *log.Logger
 }
 
 func (p *logEventLogger) OnNewSnowflakeEvent(e event.SnowflakeEvent) {
@@ -36,7 +39,7 @@ func (p *logEventLogger) OnNewSnowflakeEvent(e event.SnowflakeEvent) {
 func (p *logEventLogger) logTick() error {
 	inbound, inboundUnit := formatTraffic(p.inboundSum)
 	outbound, outboundUnit := formatTraffic(p.inboundSum)
-	log.Printf("In the last %v, there are %v connections. Traffic Relayed ↑ %v %v, ↓ %v %v.\n",
+	p.logger.Printf("In the last %v, there are %v connections. Traffic Relayed ↑ %v %v, ↓ %v %v.\n",
 		p.logPeriod.String(), p.connectionCount, inbound, inboundUnit, outbound, outboundUnit)
 	p.outboundSum = 0
 	p.inboundSum = 0

proxy/main.go

@@ -4,6 +4,7 @@ import (
 	"flag"
 	"git.torproject.org/pluggable-transports/snowflake.git/v2/common/event"
 	"io"
+	"io/ioutil"
 	"log"
 	"os"
 	"time"
@@ -24,15 +25,12 @@ func main() {
 		"the time interval in second before NAT type is retested, 0s disables retest. Valid time units are \"s\", \"m\", \"h\". ")
 	SummaryInterval := flag.Duration("summary-interval", time.Hour,
 		"the time interval to output summary, 0s disables retest. Valid time units are \"s\", \"m\", \"h\". ")
+	verboseLogging := flag.Bool("verbose", false, "increase log verbosity")
 
 	flag.Parse()
 
-	periodicEventLogger := sf.NewProxyEventLogger(*SummaryInterval)
-
 	eventLogger := event.NewSnowflakeEventDispatcher()
 
-	eventLogger.AddSnowflakeEventListener(periodicEventLogger)
-
 	proxy := sf.SnowflakeProxy{
 		Capacity:           uint(*capacity),
 		STUNURL:            *stunURL,
@@ -45,16 +43,21 @@ func main() {
 	}
 
 	var logOutput io.Writer = os.Stderr
+	var eventlogOutput io.Writer = os.Stderr
 	log.SetFlags(log.LstdFlags | log.LUTC)
 
-	log.SetFlags(log.LstdFlags | log.LUTC)
+	if !*verboseLogging {
+		logOutput = ioutil.Discard
+	}
+
 	if *logFilename != "" {
 		f, err := os.OpenFile(*logFilename, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0600)
 		if err != nil {
 			log.Fatal(err)
 		}
 		defer f.Close()
-		logOutput = io.MultiWriter(os.Stderr, f)
+		logOutput = io.MultiWriter(logOutput, f)
+		eventlogOutput = io.MultiWriter(eventlogOutput, f)
 	}
 	if *unsafeLogging {
 		log.SetOutput(logOutput)
@@ -62,6 +65,9 @@ func main() {
 		log.SetOutput(&safelog.LogScrubber{Output: logOutput})
 	}
 
+	periodicEventLogger := sf.NewProxyEventLogger(*SummaryInterval, eventlogOutput)
+	eventLogger.AddSnowflakeEventListener(periodicEventLogger)
+
 	err := proxy.Start()
 	if err != nil {
 		log.Fatal(err)