Migrate logfmt parser to the new-style.

plugins/parsers/all/all.go

@@ -5,5 +5,6 @@ import (
 	_ "github.com/influxdata/telegraf/plugins/parsers/csv"
 	_ "github.com/influxdata/telegraf/plugins/parsers/json"
 	_ "github.com/influxdata/telegraf/plugins/parsers/json_v2"
+	_ "github.com/influxdata/telegraf/plugins/parsers/logfmt"
 	_ "github.com/influxdata/telegraf/plugins/parsers/xpath"
 )

plugins/parsers/logfmt/parser.go

@@ -11,6 +11,7 @@ import (
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/filter"
 	"github.com/influxdata/telegraf/metric"
+	"github.com/influxdata/telegraf/plugins/parsers"
 )
 
 var ErrNoMetric = errors.New("no metric in line")
@@ -24,15 +25,6 @@ type Parser struct {
 	tagFilter  filter.Filter
 }
 
-// NewParser creates a parser.
-func NewParser(metricName string, defaultTags map[string]string, tagKeys []string) *Parser {
-	return &Parser{
-		metricName:  metricName,
-		DefaultTags: defaultTags,
-		TagKeys:     tagKeys,
-	}
-}
-
 // Parse converts a slice of bytes in logfmt format to metrics.
 func (p *Parser) Parse(b []byte) ([]telegraf.Metric, error) {
 	reader := bytes.NewReader(b)
@@ -122,3 +114,21 @@ func (p *Parser) Init() error {
 
 	return nil
 }
+
+func init() {
+	// Register parser
+	parsers.Add("logfmt",
+		func(defaultMetricName string) telegraf.Parser {
+			return &Parser{metricName: defaultMetricName}
+		},
+	)
+}
+
+// InitFromConfig is a compatibility function to construct the parser the old way
+func (p *Parser) InitFromConfig(config *parsers.Config) error {
+	p.metricName = config.MetricName
+	p.DefaultTags = config.DefaultTags
+	p.TagKeys = append(p.TagKeys, config.LogFmtTagKeys...)
+
+	return p.Init()
+}

plugins/parsers/logfmt/parser_test.go

@@ -6,7 +6,7 @@ import (
 
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/testutil"
-	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestParse(t *testing.T) {
@@ -261,15 +261,18 @@ func TestTags(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			l := NewParser(tt.measurement, map[string]string{}, tt.tagKeys)
-			assert.NoError(t, l.Init())
+			l := &Parser{
+				metricName:  tt.measurement,
+				DefaultTags: map[string]string{},
+				TagKeys:     tt.tagKeys,
+			}
+			require.NoError(t, l.Init())
 
 			got, err := l.ParseLine(tt.s)
-
 			if tt.wantErr {
-				assert.Error(t, err)
+				require.Error(t, err)
 			} else {
-				assert.NoError(t, err)
+				require.NoError(t, err)
 			}
 			testutil.RequireMetricEqual(t, tt.want, got, testutil.IgnoreTime())
 		})

plugins/parsers/registry.go

@@ -11,7 +11,6 @@ import (
 	"github.com/influxdata/telegraf/plugins/parsers/grok"
 	"github.com/influxdata/telegraf/plugins/parsers/influx"
 	"github.com/influxdata/telegraf/plugins/parsers/influx/influx_upstream"
-	"github.com/influxdata/telegraf/plugins/parsers/logfmt"
 	"github.com/influxdata/telegraf/plugins/parsers/nagios"
 	"github.com/influxdata/telegraf/plugins/parsers/prometheus"
 	"github.com/influxdata/telegraf/plugins/parsers/prometheusremotewrite"
@@ -243,8 +242,6 @@ func NewParser(config *Config) (Parser, error) {
 			config.GrokCustomPatternFiles,
 			config.GrokTimezone,
 			config.GrokUniqueTimestamp)
-	case "logfmt":
-		parser, err = NewLogFmtParser(config.MetricName, config.DefaultTags, config.LogFmtTagKeys)
 	case "form_urlencoded":
 		parser, err = NewFormUrlencodedParser(
 			config.MetricName,
@@ -358,13 +355,6 @@ func NewDropwizardParser(
 	return parser, err
 }
 
-// NewLogFmtParser returns a logfmt parser with the default options.
-func NewLogFmtParser(metricName string, defaultTags map[string]string, tagKeys []string) (Parser, error) {
-	parser := logfmt.NewParser(metricName, defaultTags, tagKeys)
-	err := parser.Init()
-	return parser, err
-}
-
 func NewWavefrontParser(defaultTags map[string]string) (Parser, error) {
 	return wavefront.NewWavefrontParser(defaultTags), nil
 }