wgengine: log node IDs when peers are added/removed (#381)

Also stop logging data sent/received from nodes we're not connected to (ie all those `x`s being logged in the `peers: ` line)
Signed-off-by: Wendi <wendi.yu@yahoo.ca>

types/logger/logger.go

@@ -15,6 +15,7 @@ import (
 	"io/ioutil"
 	"log"
 	"sync"
+	"time"
 
 	"golang.org/x/time/rate"
 )
@@ -60,10 +61,10 @@ type limitData struct {
 }
 
 // RateLimitedFn returns a rate-limiting Logf wrapping the given logf.
-// Messages are allowed through at a maximum of f messages/second, in
+// Messages are allowed through at a maximum of one message every f (where f is a time.Duration), in
 // bursts of up to burst messages at a time. Up to maxCache strings will be held at a time.
-func RateLimitedFn(logf Logf, f float64, burst int, maxCache int) Logf {
-	r := rate.Limit(f)
+func RateLimitedFn(logf Logf, f time.Duration, burst int, maxCache int) Logf {
+	r := rate.Every(f)
 	var (
 		mu       sync.Mutex
 		msgLim   = make(map[string]*limitData) // keyed by logf format
@@ -109,11 +110,31 @@ func RateLimitedFn(logf Logf, f float64, burst int, maxCache int) Logf {
 		case warn:
 			logf("Repeated messages were suppressed by rate limiting. Original message: %s",
 				fmt.Sprintf(format, args...))
-
 		}
 	}
 }
 
+// LogOnChange logs a given line only if line != lastLine, or if maxInterval has passed
+// since the last time this identical line was logged.
+func LogOnChange(logf Logf, maxInterval time.Duration, timeNow func() time.Time) Logf {
+	var (
+		sLastLogged string
+		tLastLogged = timeNow()
+	)
+
+	return func(format string, args ...interface{}) {
+		s := fmt.Sprintf(format, args...)
+		if s == sLastLogged && timeNow().Sub(tLastLogged) < maxInterval {
+			return
+		}
+
+		sLastLogged = s
+		tLastLogged = timeNow()
+		logf(s)
+	}
+
+}
+
 // ArgWriter is a fmt.Formatter that can be passed to any Logf func to
 // efficiently write to a %v argument without allocations.
 type ArgWriter func(*bufio.Writer)

types/logger/logger_test.go

@@ -10,6 +10,7 @@ import (
 	"fmt"
 	"log"
 	"testing"
+	"time"
 )
 
 func TestFuncWriter(t *testing.T) {
@@ -23,22 +24,21 @@ func TestStdLogger(t *testing.T) {
 	lg.Printf("plumbed through")
 }
 
-func TestRateLimiter(t *testing.T) {
-
-	// Testing function. args[0] should indicate what should
-	logTester := func(want []string) Logf {
-		i := 0
-		return func(format string, args ...interface{}) {
-			got := fmt.Sprintf(format, args...)
-			if i >= len(want) {
-				t.Fatalf("Logging continued past end of expected input: %s", got)
-			}
-			if got != want[i] {
-				t.Fatalf("wanted: %s \n got: %s", want[i], got)
-			}
-			i++
+func logTester(want []string, t *testing.T, i *int) Logf {
+	return func(format string, args ...interface{}) {
+		got := fmt.Sprintf(format, args...)
+		if *i >= len(want) {
+			t.Fatalf("Logging continued past end of expected input: %s", got)
 		}
+		if got != want[*i] {
+			t.Fatalf("wanted: %s \n got: %s", want[*i], got)
+		}
+		t.Log(got)
+		*i++
 	}
+}
+
+func TestRateLimiter(t *testing.T) {
 
 	want := []string{
 		"boring string with constant formatting (constant)",
@@ -51,7 +51,9 @@ func TestRateLimiter(t *testing.T) {
 		"4 shouldn't get filtered.",
 	}
 
-	lg := RateLimitedFn(logTester(want), 1, 2, 50)
+	testsRun := 0
+	lgtest := logTester(want, t, &testsRun)
+	lg := RateLimitedFn(lgtest, 1*time.Second, 2, 50)
 	var prefixed Logf
 	for i := 0; i < 10; i++ {
 		lg("boring string with constant formatting %s", "(constant)")
@@ -62,9 +64,48 @@ func TestRateLimiter(t *testing.T) {
 			prefixed(" shouldn't get filtered.")
 		}
 	}
+	if testsRun < len(want) {
+		t.Fatalf("Tests after %s weren't logged.", want[testsRun])
+	}
 
 }
 
+func testTimer(d time.Duration) func() time.Time {
+	timeNow := time.Now()
+	return func() time.Time {
+		timeNow = timeNow.Add(d)
+		return timeNow
+	}
+}
+
+func TestLogOnChange(t *testing.T) {
+	want := []string{
+		"1 2 3 4 5 6",
+		"1 2 3 4 5 6",
+		"1 2 3 4 5 7",
+		"1 2 3 4 5",
+		"1 2 3 4 5 6 7",
+	}
+
+	timeNow := testTimer(1 * time.Second)
+
+	testsRun := 0
+	lgtest := logTester(want, t, &testsRun)
+	lg := LogOnChange(lgtest, 5*time.Second, timeNow)
+
+	for i := 0; i < 10; i++ {
+		lg("%s", "1 2 3 4 5 6")
+	}
+	lg("1 2 3 4 5 7")
+	lg("1 2 3 4 5")
+	lg("1 2 3 4 5")
+	lg("1 2 3 4 5 6 7")
+
+	if testsRun < len(want) {
+		t.Fatalf("'Wanted' lines including and after [%s] weren't logged.", want[testsRun])
+	}
+}
+
 func TestArgWriter(t *testing.T) {
 	got := new(bytes.Buffer)
 	fmt.Fprintf(got, "Greeting: %v", ArgWriter(func(bw *bufio.Writer) {