Skip lines with missing refid in ntpq input (#5782)

plugins/inputs/ntpq/ntpq.go

@@ -75,6 +75,7 @@ func (n *NTPQ) Gather(acc telegraf.Accumulator) error {
 	}
 
 	lineCounter := 0
+	numColumns := 0
 	scanner := bufio.NewScanner(bytes.NewReader(out))
 	for scanner.Scan() {
 		line := scanner.Text()
@@ -96,6 +97,7 @@ func (n *NTPQ) Gather(acc telegraf.Accumulator) error {
 
 		// If lineCounter == 0, then this is the header line
 		if lineCounter == 0 {
+			numColumns = len(fields)
 			for i, field := range fields {
 				// Check if field is a tag:
 				if tagKey, ok := tagHeaders[field]; ok {
@@ -116,6 +118,10 @@ func (n *NTPQ) Gather(acc telegraf.Accumulator) error {
 				}
 			}
 		} else {
+			if len(fields) != numColumns {
+				continue
+			}
+
 			mFields := make(map[string]interface{})
 
 			// Get tags from output

plugins/inputs/ntpq/ntpq_test.go

@@ -3,10 +3,12 @@ package ntpq
 import (
 	"fmt"
 	"testing"
+	"time"
 
+	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/testutil"
-
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestSingleNTPQ(t *testing.T) {
@@ -39,35 +41,6 @@ func TestSingleNTPQ(t *testing.T) {
 	acc.AssertContainsTaggedFields(t, "ntpq", fields, tags)
 }
 
-func TestMissingJitterField(t *testing.T) {
-	tt := tester{
-		ret: []byte(missingJitterField),
-		err: nil,
-	}
-	n := &NTPQ{
-		runQ: tt.runqTest,
-	}
-
-	acc := testutil.Accumulator{}
-	assert.NoError(t, acc.GatherError(n.Gather))
-
-	fields := map[string]interface{}{
-		"when":   int64(101),
-		"poll":   int64(256),
-		"reach":  int64(37),
-		"delay":  float64(51.016),
-		"offset": float64(233.010),
-	}
-	tags := map[string]string{
-		"remote":       "uschi5-ntp-002.",
-		"state_prefix": "*",
-		"refid":        "10.177.80.46",
-		"stratum":      "2",
-		"type":         "u",
-	}
-	acc.AssertContainsTaggedFields(t, "ntpq", fields, tags)
-}
-
 func TestBadIntNTPQ(t *testing.T) {
 	tt := tester{
 		ret: []byte(badIntParseNTPQ),
@@ -428,6 +401,62 @@ func TestFailedNTPQ(t *testing.T) {
 	assert.Error(t, acc.GatherError(n.Gather))
 }
 
+// It is possible for the output of ntqp to be missing the refid column.  This
+// is believed to be http://bugs.ntp.org/show_bug.cgi?id=3484 which is fixed
+// in ntp-4.2.8p12 (included first in Debian Buster).
+func TestNoRefID(t *testing.T) {
+	now := time.Now()
+	expected := []telegraf.Metric{
+		testutil.MustMetric("ntpq",
+			map[string]string{
+				"refid":   "10.177.80.37",
+				"remote":  "83.137.98.96",
+				"stratum": "2",
+				"type":    "u",
+			},
+			map[string]interface{}{
+				"delay":  float64(54.033),
+				"jitter": float64(449514),
+				"offset": float64(243.426),
+				"poll":   int64(1024),
+				"reach":  int64(377),
+				"when":   int64(740),
+			},
+			now),
+		testutil.MustMetric("ntpq",
+			map[string]string{
+				"refid":   "10.177.80.37",
+				"remote":  "131.188.3.221",
+				"stratum": "2",
+				"type":    "u",
+			},
+			map[string]interface{}{
+				"delay":  float64(111.820),
+				"jitter": float64(449528),
+				"offset": float64(261.921),
+				"poll":   int64(1024),
+				"reach":  int64(377),
+				"when":   int64(783),
+			},
+			now),
+	}
+
+	tt := tester{
+		ret: []byte(noRefID),
+		err: nil,
+	}
+	n := &NTPQ{
+		runQ: tt.runqTest,
+	}
+
+	acc := testutil.Accumulator{
+		TimeFunc: func() time.Time { return now },
+	}
+
+	require.NoError(t, acc.GatherError(n.Gather))
+	testutil.RequireMetricsEqual(t, expected, acc.GetTelegrafMetrics())
+}
+
 type tester struct {
 	ret []byte
 	err error
@@ -474,11 +503,6 @@ var singleNTPQ = `     remote           refid      st t when poll reach   delay
 *uschi5-ntp-002. 10.177.80.46     2 u  101  256   37   51.016  233.010  17.462
 `
 
-var missingJitterField = `     remote           refid      st t when poll reach   delay   offset  jitter
-==============================================================================
-*uschi5-ntp-002. 10.177.80.46     2 u  101  256   37   51.016  233.010
-`
-
 var badHeaderNTPQ = `remote      refid   foobar t when poll reach   delay   offset  jitter
 ==============================================================================
 *uschi5-ntp-002. 10.177.80.46     2 u  101  256   37   51.016  233.010  17.462
@@ -527,6 +551,7 @@ var multiNTPQ = `     remote           refid      st t when poll reach   delay
  5.9.29.107      10.177.80.37     2 u  703 1024  377  205.704  160.406 449602.
  91.189.94.4     10.177.80.37     2 u  673 1024  377  143.047  274.726 449445.
 `
+
 var multiParserNTPQ = `     remote           refid      st t when poll reach   delay   offset  jitter
 ==============================================================================
 *SHM(0)          .PPS.                          1 u   60  64   377    0.000    0.045   1.012
@@ -535,3 +560,10 @@ var multiParserNTPQ = `     remote           refid      st t when poll reach   d
 +37.58.57.238 ( 192.53.103.103			2 u   10 1024  377    1.748    0.373   0.101
 -SHM(1)          .GPS.                          1 u   121 128  377    0.000   10.105   2.012
 `
+
+var noRefID = `     remote           refid      st t when poll reach   delay   offset  jitter
+==============================================================================
+ 83.137.98.96    10.177.80.37     2 u  740 1024  377   54.033  243.426 449514.
+ 91.189.94.4                      2 u  673 1024  377  143.047  274.726 449445.
+ 131.188.3.221   10.177.80.37     2 u  783 1024  377  111.820  261.921 449528.
+`