fix(serializers.splunkmetric): omit event metric tag with option

fixes: influxdata#11237

config/config.go

@@ -1179,6 +1179,7 @@ func (c *Config) buildSerializer(tbl *ast.Table) (serializers.Serializer, error)
 
 	c.getFieldBool(tbl, "splunkmetric_hec_routing", &sc.HecRouting)
 	c.getFieldBool(tbl, "splunkmetric_multimetric", &sc.SplunkmetricMultiMetric)
+	c.getFieldBool(tbl, "splunkmetric_omit_event_tag", &sc.SplunkmetricOmitEventTag)
 
 	c.getFieldStringSlice(tbl, "wavefront_source_override", &sc.WavefrontSourceOverride)
 	c.getFieldBool(tbl, "wavefront_use_strict", &sc.WavefrontUseStrict)
@@ -1257,7 +1258,7 @@ func (c *Config) missingTomlField(_ reflect.Type, key string) error {
 		"json_timestamp_format", "json_timestamp_units", "json_transformation",
 		"prometheus_export_timestamp", "prometheus_sort_metrics", "prometheus_string_as_label",
 		"prometheus_compact_encoding",
-		"splunkmetric_hec_routing", "splunkmetric_multimetric",
+		"splunkmetric_hec_routing", "splunkmetric_multimetric", "splunkmetric_omit_event_tag",
 		"wavefront_disable_prefix_conversion", "wavefront_source_override", "wavefront_use_strict":
 	default:
 		c.unusedFieldsMutex.Lock()

plugins/serializers/registry.go

@@ -110,6 +110,9 @@ type Config struct {
 	// Enable Splunk MultiMetric output (Splunk 8.0+)
 	SplunkmetricMultiMetric bool `toml:"splunkmetric_multi_metric"`
 
+	// Omit the Splunk Event "metric" tag
+	SplunkmetricOmitEventTag bool `toml:"splunkmetric_omit_event_tag"`
+
 	// Point tags to use as the source name for Wavefront (if none found, host will be used).
 	WavefrontSourceOverride []string `toml:"wavefront_source_override"`
 
@@ -149,7 +152,7 @@ func NewSerializer(config *Config) (Serializer, error) {
 	case "json":
 		serializer, err = NewJSONSerializer(config.TimestampUnits, config.TimestampFormat, config.Transformation)
 	case "splunkmetric":
-		serializer, err = NewSplunkmetricSerializer(config.HecRouting, config.SplunkmetricMultiMetric)
+		serializer, err = NewSplunkmetricSerializer(config.HecRouting, config.SplunkmetricMultiMetric, config.SplunkmetricOmitEventTag)
 	case "nowmetric":
 		serializer, err = NewNowSerializer()
 	case "carbon2":
@@ -225,8 +228,8 @@ func NewCarbon2Serializer(carbon2format string, carbon2SanitizeReplaceChar strin
 	return carbon2.NewSerializer(carbon2format, carbon2SanitizeReplaceChar)
 }
 
-func NewSplunkmetricSerializer(splunkmetricHecRouting bool, splunkmetricMultimetric bool) (Serializer, error) {
-	return splunkmetric.NewSerializer(splunkmetricHecRouting, splunkmetricMultimetric)
+func NewSplunkmetricSerializer(splunkmetricHecRouting bool, splunkmetricMultimetric bool, splunkmetricOmitEventTag bool) (Serializer, error) {
+	return splunkmetric.NewSerializer(splunkmetricHecRouting, splunkmetricMultimetric, splunkmetricOmitEventTag)
 }
 
 func NewNowSerializer() (Serializer, error) {

plugins/serializers/splunkmetric/splunkmetric.go

@@ -10,6 +10,7 @@ import (
 type serializer struct {
 	HecRouting              bool
 	SplunkmetricMultiMetric bool
+	OmitEventTag            bool
 }
 
 type CommonTags struct {
@@ -22,19 +23,20 @@ type CommonTags struct {
 
 type HECTimeSeries struct {
 	Time   float64                `json:"time"`
-	Event  string                 `json:"event"`
+	Event  string                 `json:"event,omitempty"`
 	Host   string                 `json:"host,omitempty"`
 	Index  string                 `json:"index,omitempty"`
 	Source string                 `json:"source,omitempty"`
 	Fields map[string]interface{} `json:"fields"`
 }
 
 // NewSerializer Setup our new serializer
-func NewSerializer(splunkmetricHecRouting bool, splunkmetricMultimetric bool) (*serializer, error) {
+func NewSerializer(splunkmetricHecRouting bool, splunkmetricMultimetric bool, splunkmetricOmitEventTag bool) (*serializer, error) {
 	/*	Define output params */
 	s := &serializer{
 		HecRouting:              splunkmetricHecRouting,
 		SplunkmetricMultiMetric: splunkmetricMultimetric,
+		OmitEventTag:            splunkmetricOmitEventTag,
 	}
 	return s, nil
 }
@@ -66,7 +68,9 @@ func (s *serializer) createMulti(metric telegraf.Metric, dataGroup HECTimeSeries
 	var metricJSON []byte
 
 	// Set the event data from the commonTags above.
-	dataGroup.Event = "metric"
+	if !s.OmitEventTag {
+		dataGroup.Event = "metric"
+	}
 	dataGroup.Time = commonTags.Time
 	dataGroup.Host = commonTags.Host
 	dataGroup.Index = commonTags.Index
@@ -123,7 +127,9 @@ func (s *serializer) createSingle(metric telegraf.Metric, dataGroup HECTimeSerie
 		dataGroup.Time = commonTags.Time
 
 		// Apply the common tags from above to every record.
-		dataGroup.Event = "metric"
+		if !s.OmitEventTag {
+			dataGroup.Event = "metric"
+		}
 		dataGroup.Host = commonTags.Host
 		dataGroup.Index = commonTags.Index
 		dataGroup.Source = commonTags.Source

plugins/serializers/splunkmetric/splunkmetric_test.go

@@ -21,7 +21,7 @@ func TestSerializeMetricFloat(t *testing.T) {
 	}
 	m := metric.New("cpu", tags, fields, now)
 
-	s, _ := NewSerializer(false, false)
+	s, _ := NewSerializer(false, false, false)
 	var buf []byte
 	buf, err := s.Serialize(m)
 	require.NoError(t, err)
@@ -40,7 +40,7 @@ func TestSerializeMetricFloatHec(t *testing.T) {
 	}
 	m := metric.New("cpu", tags, fields, now)
 
-	s, _ := NewSerializer(true, false)
+	s, _ := NewSerializer(true, false, false)
 	var buf []byte
 	buf, err := s.Serialize(m)
 	require.NoError(t, err)
@@ -58,7 +58,7 @@ func TestSerializeMetricInt(t *testing.T) {
 	}
 	m := metric.New("cpu", tags, fields, now)
 
-	s, _ := NewSerializer(false, false)
+	s, _ := NewSerializer(false, false, false)
 	var buf []byte
 	buf, err := s.Serialize(m)
 	require.NoError(t, err)
@@ -77,7 +77,7 @@ func TestSerializeMetricIntHec(t *testing.T) {
 	}
 	m := metric.New("cpu", tags, fields, now)
 
-	s, _ := NewSerializer(true, false)
+	s, _ := NewSerializer(true, false, false)
 	var buf []byte
 	buf, err := s.Serialize(m)
 	require.NoError(t, err)
@@ -96,7 +96,7 @@ func TestSerializeMetricBool(t *testing.T) {
 	}
 	m := metric.New("docker", tags, fields, now)
 
-	s, _ := NewSerializer(false, false)
+	s, _ := NewSerializer(false, false, false)
 	var buf []byte
 	buf, err := s.Serialize(m)
 	require.NoError(t, err)
@@ -115,7 +115,7 @@ func TestSerializeMetricBoolHec(t *testing.T) {
 	}
 	m := metric.New("docker", tags, fields, now)
 
-	s, _ := NewSerializer(true, false)
+	s, _ := NewSerializer(true, false, false)
 	var buf []byte
 	buf, err := s.Serialize(m)
 	require.NoError(t, err)
@@ -135,7 +135,7 @@ func TestSerializeMetricString(t *testing.T) {
 	}
 	m := metric.New("cpu", tags, fields, now)
 
-	s, _ := NewSerializer(false, false)
+	s, _ := NewSerializer(false, false, false)
 	var buf []byte
 	buf, err := s.Serialize(m)
 	require.NoError(t, err)
@@ -165,7 +165,7 @@ func TestSerializeBatch(t *testing.T) {
 	)
 
 	metrics := []telegraf.Metric{m, n}
-	s, _ := NewSerializer(false, false)
+	s, _ := NewSerializer(false, false, false)
 	buf, err := s.SerializeBatch(metrics)
 	require.NoError(t, err)
 
@@ -185,7 +185,7 @@ func TestSerializeMulti(t *testing.T) {
 	)
 
 	metrics := []telegraf.Metric{m}
-	s, _ := NewSerializer(false, true)
+	s, _ := NewSerializer(false, true, false)
 	buf, err := s.SerializeBatch(metrics)
 	require.NoError(t, err)
 
@@ -211,7 +211,7 @@ func TestSerializeBatchHec(t *testing.T) {
 		time.Unix(0, 0),
 	)
 	metrics := []telegraf.Metric{m, n}
-	s, _ := NewSerializer(true, false)
+	s, _ := NewSerializer(true, false, false)
 	buf, err := s.SerializeBatch(metrics)
 	require.NoError(t, err)
 
@@ -231,10 +231,30 @@ func TestSerializeMultiHec(t *testing.T) {
 	)
 
 	metrics := []telegraf.Metric{m}
-	s, _ := NewSerializer(true, true)
+	s, _ := NewSerializer(true, true, false)
 	buf, err := s.SerializeBatch(metrics)
 	require.NoError(t, err)
 
 	expS := `{"time":0,"event":"metric","fields":{"metric_name:cpu.system":8,"metric_name:cpu.usage":42}}`
 	require.Equal(t, expS, string(buf))
 }
+
+func TestSerializeOmitEvent(t *testing.T) {
+	m := metric.New(
+		"cpu",
+		map[string]string{},
+		map[string]interface{}{
+			"usage":  42.0,
+			"system": 8.0,
+		},
+		time.Unix(0, 0),
+	)
+
+	metrics := []telegraf.Metric{m}
+	s, _ := NewSerializer(true, true, true)
+	buf, err := s.SerializeBatch(metrics)
+	require.NoError(t, err)
+
+	expS := `{"time":0,"fields":{"metric_name:cpu.system":8,"metric_name:cpu.usage":42}}`
+	require.Equal(t, expS, string(buf))
+}