Fix segfault in processors/parser (#9283)

(cherry picked from commit 6cc942f)

plugins/processors/parser/parser.go

@@ -1,19 +1,19 @@
 package parser
 
 import (
-	"log"
-
 	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/models"
 	"github.com/influxdata/telegraf/plugins/parsers"
 	"github.com/influxdata/telegraf/plugins/processors"
 )
 
 type Parser struct {
 	parsers.Config
-	DropOriginal bool     `toml:"drop_original"`
-	Merge        string   `toml:"merge"`
-	ParseFields  []string `toml:"parse_fields"`
-	Parser       parsers.Parser
+	DropOriginal bool            `toml:"drop_original"`
+	Merge        string          `toml:"merge"`
+	ParseFields  []string        `toml:"parse_fields"`
+	Log          telegraf.Logger `toml:"-"`
+	parser       parsers.Parser
 }
 
 var SampleConfig = `
@@ -43,13 +43,14 @@ func (p *Parser) Description() string {
 }
 
 func (p *Parser) Apply(metrics ...telegraf.Metric) []telegraf.Metric {
-	if p.Parser == nil {
+	if p.parser == nil {
 		var err error
-		p.Parser, err = parsers.NewParser(&p.Config)
+		p.parser, err = parsers.NewParser(&p.Config)
 		if err != nil {
-			log.Printf("E! [processors.parser] could not create parser: %v", err)
+			p.Log.Errorf("could not create parser: %v", err)
 			return metrics
 		}
+		models.SetLoggerOnPlugin(p.parser, p.Log)
 	}
 
 	results := []telegraf.Metric{}
@@ -67,7 +68,7 @@ func (p *Parser) Apply(metrics ...telegraf.Metric) []telegraf.Metric {
 					case string:
 						fromFieldMetric, err := p.parseField(value)
 						if err != nil {
-							log.Printf("E! [processors.parser] could not parse field %s: %v", key, err)
+							p.Log.Errorf("could not parse field %s: %v", key, err)
 						}
 
 						for _, m := range fromFieldMetric {
@@ -81,7 +82,7 @@ func (p *Parser) Apply(metrics ...telegraf.Metric) []telegraf.Metric {
 						// prior to returning.
 						newMetrics = append(newMetrics, fromFieldMetric...)
 					default:
-						log.Printf("E! [processors.parser] field '%s' not a string, skipping", key)
+						p.Log.Errorf("field '%s' not a string, skipping", key)
 					}
 				}
 			}
@@ -114,7 +115,7 @@ func merge(base telegraf.Metric, metrics []telegraf.Metric) telegraf.Metric {
 }
 
 func (p *Parser) parseField(value string) ([]telegraf.Metric, error) {
-	return p.Parser.Parse([]byte(value))
+	return p.parser.Parse([]byte(value))
 }
 
 func init() {

plugins/processors/parser/parser_test.go

@@ -7,17 +7,19 @@ import (
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/metric"
 	"github.com/influxdata/telegraf/plugins/parsers"
-	"github.com/stretchr/testify/assert"
+
+	"github.com/influxdata/telegraf/testutil"
+
 	"github.com/stretchr/testify/require"
 )
 
 //compares metrics without comparing time
 func compareMetrics(t *testing.T, expected, actual []telegraf.Metric) {
-	assert.Equal(t, len(expected), len(actual))
-	for i, metric := range actual {
-		require.Equal(t, expected[i].Name(), metric.Name())
-		require.Equal(t, expected[i].Fields(), metric.Fields())
-		require.Equal(t, expected[i].Tags(), metric.Tags())
+	require.Equal(t, len(expected), len(actual))
+	for i, m := range actual {
+		require.Equal(t, expected[i].Name(), m.Name())
+		require.Equal(t, expected[i].Fields(), m.Fields())
+		require.Equal(t, expected[i].Tags(), m.Tags())
 	}
 }
 
@@ -503,6 +505,7 @@ func TestApply(t *testing.T) {
 				ParseFields:  tt.parseFields,
 				DropOriginal: tt.dropOriginal,
 				Merge:        tt.merge,
+				Log:          testutil.Logger{Name: "processor.parser"},
 			}
 
 			output := parser.Apply(tt.input)
@@ -573,6 +576,7 @@ func TestBadApply(t *testing.T) {
 			parser := Parser{
 				Config:      tt.config,
 				ParseFields: tt.parseFields,
+				Log:         testutil.Logger{Name: "processor.parser"},
 			}
 
 			output := parser.Apply(tt.input)
@@ -584,17 +588,17 @@ func TestBadApply(t *testing.T) {
 
 // Benchmarks
 
-func getMetricFields(metric telegraf.Metric) interface{} {
+func getMetricFields(m telegraf.Metric) interface{} {
 	key := "field3"
-	if value, ok := metric.Fields()[key]; ok {
+	if value, ok := m.Fields()[key]; ok {
 		return value
 	}
 	return nil
 }
 
-func getMetricFieldList(metric telegraf.Metric) interface{} {
+func getMetricFieldList(m telegraf.Metric) interface{} {
 	key := "field3"
-	fields := metric.FieldList()
+	fields := m.FieldList()
 	for _, field := range fields {
 		if field.Key == key {
 			return field.Value