chore(serializers.prometheusremotewrite): Migrate to new-style framework (#13341)

plugins/serializers/all/prometheusremotewrite.go

@@ -0,0 +1,7 @@
+//go:build !custom || serializers || serializers.prometheusremotewrite
+
+package all
+
+import (
+	_ "github.com/influxdata/telegraf/plugins/serializers/prometheusremotewrite" // register plugin
+)

plugins/serializers/prometheusremotewrite/prometheusremotewrite.go

@@ -13,38 +13,15 @@ import (
 	"github.com/prometheus/prometheus/prompb"
 
 	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/plugins/serializers"
 	"github.com/influxdata/telegraf/plugins/serializers/prometheus"
 )
 
 type MetricKey uint64
 
-// MetricSortOrder controls if the output is sorted.
-type MetricSortOrder int
-
-const (
-	NoSortMetrics MetricSortOrder = iota
-	SortMetrics
-)
-
-// StringHandling defines how to process string fields.
-type StringHandling int
-
-const (
-	DiscardStrings StringHandling = iota
-	StringAsLabel
-)
-
-type FormatConfig struct {
-	MetricSortOrder MetricSortOrder
-	StringHandling  StringHandling
-}
-
 type Serializer struct {
-	config FormatConfig
+	SortMetrics   bool `toml:"prometheus_sort_metrics"`
-}
+	StringAsLabel bool `toml:"prometheus_string_as_label"`
-
-func NewSerializer(config FormatConfig) *Serializer {
-	return &Serializer{config: config}
 }
 
 func (s *Serializer) Serialize(metric telegraf.Metric) ([]byte, error) {
@@ -204,7 +181,7 @@ func (s *Serializer) SerializeBatch(metrics []telegraf.Metric) ([]byte, error) {
 		i++
 	}
 
-	if s.config.MetricSortOrder == SortMetrics {
+	if s.SortMetrics {
 		sort.Slice(promTS, func(i, j int) bool {
 			lhs := promTS[i].Labels
 			rhs := promTS[j].Labels
@@ -274,7 +251,7 @@ func (s *Serializer) appendCommonLabels(labels []prompb.Label, metric telegraf.M
 		labels = append(labels, prompb.Label{Name: name, Value: tag.Value})
 	}
 
-	if s.config.StringHandling != StringAsLabel {
+	if !s.StringAsLabel {
 		return labels
 	}
 
@@ -342,3 +319,19 @@ func (sl sortableLabels) Less(i, j int) bool {
 func (sl sortableLabels) Swap(i, j int) {
 	sl[i], sl[j] = sl[j], sl[i]
 }
+
+func init() {
+	serializers.Add("prometheusremotewrite",
+		func() serializers.Serializer {
+			return &Serializer{}
+		},
+	)
+}
+
+// InitFromConfig is a compatibility function to construct the parser the old way
+func (s *Serializer) InitFromConfig(cfg *serializers.Config) error {
+	s.SortMetrics = cfg.PrometheusSortMetrics
+	s.StringAsLabel = cfg.PrometheusStringAsLabel
+
+	return nil
+}

plugins/serializers/prometheusremotewrite/prometheusremotewrite_test.go

@@ -32,7 +32,7 @@ func BenchmarkRemoteWrite(b *testing.B) {
 			time.Unix(0, 0),
 		)
 	}
-	s := NewSerializer(FormatConfig{})
+	s := &Serializer{}
 	for n := 0; n < b.N; n++ {
 		_, _ = s.SerializeBatch(batch)
 	}
@@ -41,7 +41,6 @@ func BenchmarkRemoteWrite(b *testing.B) {
 func TestRemoteWriteSerialize(t *testing.T) {
 	tests := []struct {
 		name     string
-		config   FormatConfig
 		metric   telegraf.Metric
 		expected []byte
 	}{
@@ -186,10 +185,9 @@ http_request_duration_seconds_bucket{le="0.5"} 129389
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			s := NewSerializer(FormatConfig{
+			s := &Serializer{
-				MetricSortOrder: SortMetrics,
+				SortMetrics: true,
-				StringHandling:  tt.config.StringHandling,
+			}
-			})
 			data, err := s.Serialize(tt.metric)
 			require.NoError(t, err)
 			actual, err := prompbToText(data)
@@ -203,10 +201,10 @@ http_request_duration_seconds_bucket{le="0.5"} 129389
 
 func TestRemoteWriteSerializeBatch(t *testing.T) {
 	tests := []struct {
-		name     string
+		name          string
-		config   FormatConfig
+		metrics       []telegraf.Metric
-		metrics  []telegraf.Metric
+		stringAsLabel bool
-		expected []byte
+		expected      []byte
 	}{
 		{
 			name: "simple",
@@ -515,11 +513,8 @@ cpu_time_idle 42
 `),
 		},
 		{
-			name: "string as label",
+			name:          "string as label",
-			config: FormatConfig{
+			stringAsLabel: true,
-				MetricSortOrder: SortMetrics,
-				StringHandling:  StringAsLabel,
-			},
 			metrics: []telegraf.Metric{
 				testutil.MustMetric(
 					"cpu",
@@ -536,11 +531,8 @@ cpu_time_idle{cpu="cpu0"} 42
 `),
 		},
 		{
-			name: "string as label duplicate tag",
+			name:          "string as label duplicate tag",
-			config: FormatConfig{
+			stringAsLabel: true,
-				MetricSortOrder: SortMetrics,
-				StringHandling:  StringAsLabel,
-			},
 			metrics: []telegraf.Metric{
 				testutil.MustMetric(
 					"cpu",
@@ -559,11 +551,8 @@ cpu_time_idle{cpu="cpu0"} 42
 `),
 		},
 		{
-			name: "replace characters when using string as label",
+			name:          "replace characters when using string as label",
-			config: FormatConfig{
+			stringAsLabel: true,
-				MetricSortOrder: SortMetrics,
-				StringHandling:  StringAsLabel,
-			},
 			metrics: []telegraf.Metric{
 				testutil.MustMetric(
 					"cpu",
@@ -666,11 +655,8 @@ rpc_duration_seconds_sum 17560473
 `),
 		},
 		{
-			name: "empty label string value",
+			name:          "empty label string value",
-			config: FormatConfig{
+			stringAsLabel: true,
-				MetricSortOrder: SortMetrics,
-				StringHandling:  StringAsLabel,
-			},
 			metrics: []telegraf.Metric{
 				testutil.MustMetric(
 					"prometheus",
@@ -690,10 +676,10 @@ rpc_duration_seconds_sum 17560473
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			s := NewSerializer(FormatConfig{
+			s := &Serializer{
-				MetricSortOrder: SortMetrics,
+				SortMetrics:   true,
-				StringHandling:  tt.config.StringHandling,
+				StringAsLabel: tt.stringAsLabel,
-			})
+			}
 			data, err := s.SerializeBatch(tt.metrics)
 			require.NoError(t, err)
 			actual, err := prompbToText(data)

plugins/serializers/registry.go

@@ -6,7 +6,6 @@ import (
 
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/serializers/prometheus"
-	"github.com/influxdata/telegraf/plugins/serializers/prometheusremotewrite"
 	"github.com/influxdata/telegraf/plugins/serializers/splunkmetric"
 	"github.com/influxdata/telegraf/plugins/serializers/wavefront"
 )
@@ -171,8 +170,6 @@ func NewSerializer(config *Config) (Serializer, error) {
 		), nil
 	case "prometheus":
 		serializer, err = NewPrometheusSerializer(config), nil
-	case "prometheusremotewrite":
-		serializer, err = NewPrometheusRemoteWriteSerializer(config), nil
 	default:
 		creator, found := Serializers[config.DataFormat]
 		if !found {
@@ -192,23 +189,6 @@ func NewSerializer(config *Config) (Serializer, error) {
 	return serializer, err
 }
 
-func NewPrometheusRemoteWriteSerializer(config *Config) Serializer {
-	sortMetrics := prometheusremotewrite.NoSortMetrics
-	if config.PrometheusExportTimestamp {
-		sortMetrics = prometheusremotewrite.SortMetrics
-	}
-
-	stringAsLabels := prometheusremotewrite.DiscardStrings
-	if config.PrometheusStringAsLabel {
-		stringAsLabels = prometheusremotewrite.StringAsLabel
-	}
-
-	return prometheusremotewrite.NewSerializer(prometheusremotewrite.FormatConfig{
-		MetricSortOrder: sortMetrics,
-		StringHandling:  stringAsLabels,
-	})
-}
-
 func NewPrometheusSerializer(config *Config) Serializer {
 	exportTimestamp := prometheus.NoExportTimestamp
 	if config.PrometheusExportTimestamp {