feat(inputs.dns_query): Allow ignoring errors of specific types (#14992)

plugins/inputs/dns_query/dns_query.go

@@ -6,6 +6,7 @@ import (
 	"errors"
 	"fmt"
 	"net"
+	"slices"
 	"strconv"
 	"sync"
 	"time"
@@ -20,6 +21,10 @@ import (
 //go:embed sample.conf
 var sampleConfig string
 
+var ignoredErrors = []string{
+	"NXDOMAIN",
+}
+
 type ResultType uint64
 
 const (
@@ -87,7 +92,7 @@ func (d *DNSQuery) Gather(acc telegraf.Accumulator) error {
 				defer wg.Done()
 
 				fields, tags, err := d.query(domain, server)
-				if err != nil {
+				if err != nil && !slices.Contains(ignoredErrors, tags["rcode"]) {
 					var opErr *net.OpError
 					if !errors.As(err, &opErr) || !opErr.Timeout() {
 						acc.AddError(err)

plugins/inputs/dns_query/dns_query_test.go

@@ -37,6 +37,23 @@ func TestGathering(t *testing.T) {
 	require.NotEqual(t, float64(0), queryTime)
 }
 
+func TestGatherInvalid(t *testing.T) {
+	if testing.Short() {
+		t.Skip("Skipping network-dependent test in short mode.")
+	}
+
+	dnsConfig := DNSQuery{
+		Servers: servers,
+		Domains: []string{"qwerty123.example.com"},
+		Timeout: config.Duration(1 * time.Second),
+	}
+
+	var acc testutil.Accumulator
+	require.NoError(t, dnsConfig.Init())
+	require.NoError(t, dnsConfig.Gather(&acc))
+	require.Empty(t, acc.Errors)
+}
+
 func TestGatheringMxRecord(t *testing.T) {
 	if testing.Short() {
 		t.Skip("Skipping network-dependent test in short mode.")