Fix parsing of remote tcp address in statsd input (#6031)

plugins/inputs/statsd/datadog.go

@@ -76,7 +76,9 @@ func (s *Statsd) parseEventMessage(now time.Time, message string, defaultHostnam
 	fields := make(map[string]interface{}, 9)
 	fields["alert_type"] = eventInfo // default event type
 	fields["text"] = uncommenter.Replace(string(rawText))
-	tags["source"] = defaultHostname // Use source tag because host is reserved tag key in Telegraf.
+	if defaultHostname != "" {
+		tags["source"] = defaultHostname
+	}
 	fields["priority"] = priorityNormal
 	ts := now
 	if len(message) < 2 {

plugins/inputs/statsd/statsd.go

@@ -7,7 +7,6 @@ import (
 	"fmt"
 	"log"
 	"net"
-	"net/url"
 	"sort"
 	"strconv"
 	"strings"
@@ -817,14 +816,12 @@ func (s *Statsd) handler(conn *net.TCPConn, id string) {
 		s.forget(id)
 		s.CurrentConnections.Incr(-1)
 	}()
-	addr := conn.RemoteAddr()
+
-	parsedURL, err := url.Parse(addr.String())
+	var remoteIP string
-	if err != nil {
+	if addr, ok := conn.RemoteAddr().(*net.TCPAddr); ok {
-		// this should never happen because the conn handler should give us parsable addresses,
+		remoteIP = addr.IP.String()
-		// but if it does we will know
-		log.Printf("E! [inputs.statsd] failed to parse %s\n", addr)
-		return // close the connetion and return
 	}
+
 	var n int
 	scanner := bufio.NewScanner(conn)
 	for {
@@ -848,7 +845,7 @@ func (s *Statsd) handler(conn *net.TCPConn, id string) {
 			b.WriteByte('\n')
 
 			select {
-			case s.in <- input{Buffer: b, Time: time.Now(), Addr: parsedURL.Host}:
+			case s.in <- input{Buffer: b, Time: time.Now(), Addr: remoteIP}:
 			default:
 				s.drops++
 				if s.drops == 1 || s.drops%s.AllowedPendingMessages == 0 {

plugins/inputs/statsd/statsd_test.go

@@ -6,6 +6,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/testutil"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -15,19 +16,6 @@ const (
 	testMsg = "test.tcp.msg:100|c"
 )
 
-func newTestTCPListener() (*Statsd, chan input) {
-	in := make(chan input, 1500)
-	listener := &Statsd{
-		Protocol:               "tcp",
-		ServiceAddress:         "localhost:8125",
-		AllowedPendingMessages: 10000,
-		MaxTCPConnections:      250,
-		in:                     in,
-		done:                   make(chan struct{}),
-	}
-	return listener, in
-}
-
 func NewTestStatsd() *Statsd {
 	s := Statsd{}
 
@@ -1596,3 +1584,49 @@ func testValidateGauge(
 	}
 	return nil
 }
+
+func TestTCP(t *testing.T) {
+	statsd := Statsd{
+		Protocol:               "tcp",
+		ServiceAddress:         "localhost:0",
+		AllowedPendingMessages: 10000,
+		MaxTCPConnections:      2,
+	}
+	var acc testutil.Accumulator
+	require.NoError(t, statsd.Start(&acc))
+	defer statsd.Stop()
+
+	addr := statsd.TCPlistener.Addr().String()
+
+	conn, err := net.Dial("tcp", addr)
+	_, err = conn.Write([]byte("cpu.time_idle:42|c\n"))
+	require.NoError(t, err)
+	err = conn.Close()
+	require.NoError(t, err)
+
+	for {
+		err = statsd.Gather(&acc)
+		require.NoError(t, err)
+
+		if len(acc.Metrics) > 0 {
+			break
+		}
+	}
+
+	testutil.RequireMetricsEqual(t,
+		[]telegraf.Metric{
+			testutil.MustMetric(
+				"cpu_time_idle",
+				map[string]string{
+					"metric_type": "counter",
+				},
+				map[string]interface{}{
+					"value": 42,
+				},
+				time.Now(),
+			),
+		},
+		acc.GetTelegrafMetrics(),
+		testutil.IgnoreTime(),
+	)
+}

testutil/metric.go

@@ -143,7 +143,7 @@ func MetricEqual(expected, actual telegraf.Metric) bool {
 
 // RequireMetricEqual halts the test with an error if the metrics are not
 // equal.
-func RequireMetricEqual(t *testing.T, expected, actual telegraf.Metric) {
+func RequireMetricEqual(t *testing.T, expected, actual telegraf.Metric, opts ...cmp.Option) {
 	t.Helper()
 
 	var lhs, rhs *metricDiff
@@ -154,7 +154,7 @@ func RequireMetricEqual(t *testing.T, expected, actual telegraf.Metric) {
 		rhs = newMetricDiff(actual)
 	}
 
-	if diff := cmp.Diff(lhs, rhs); diff != "" {
+	if diff := cmp.Diff(lhs, rhs, opts...); diff != "" {
 		t.Fatalf("telegraf.Metric\n--- expected\n+++ actual\n%s", diff)
 	}
 }