fix: Implement NaN and inf handling for elasticsearch output

plugins/outputs/elasticsearch/README.md

@@ -199,6 +199,15 @@ This plugin will format the events in the following way:
   ## If set to true a unique ID hash will be sent as sha256(concat(timestamp,measurement,series-hash)) string
   ## it will enable data resend and update metric points avoiding duplicated metrics with diferent id's
   force_document_id = false
+
+  ## Specifies the handling of NaN and Inf values.
+  ## This option can have the following values:
+  ##    none    -- do not modify field-values (default); will produce an error if NaNs or infs are encountered
+  ##    drop    -- drop fields containing NaNs or infs
+  ##    replace -- replace with the value in "float_replacement_value" (default: 0.0)
+  ##               NaNs and inf will be replaced with the given number, -inf with the negative of that number
+  # float_handling = "none"
+  # float_replacement_value = 0.0
 ```
 
 ### Permissions
@@ -236,6 +245,8 @@ Additionally, you can specify dynamic index names by using tags with the notatio
 * `template_name`: The template name used for telegraf indexes.
 * `overwrite_template`: Set to true if you want telegraf to overwrite an existing template.
 * `force_document_id`: Set to true will compute a unique hash from as sha256(concat(timestamp,measurement,series-hash)),enables resend or update data withoud ES duplicated documents.
+* `float_handling`: Specifies how to handle `NaN` and infinite field values. `"none"` (default) will do nothing, `"drop"` will drop the field and `replace` will replace the field value by the number in `float_replacement_value`
+* `float_replacement_value`: Value (defaulting to `0.0`) to replace `NaN`s and `inf`s if `float_handling` is set to `replace`. Negative `inf` will be replaced by the negative value in this number to respect the sign of the field's original value.
 
 ## Known issues
 

plugins/outputs/elasticsearch/elasticsearch.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"math"
 	"net/http"
 	"strconv"
 	"strings"
@@ -35,6 +36,8 @@ type Elasticsearch struct {
 	OverwriteTemplate   bool
 	ForceDocumentID     bool `toml:"force_document_id"`
 	MajorReleaseNumber  int
+	FloatHandling       string          `toml:"float_handling"`
+	FloatReplacement    float64         `toml:"float_replacement_value"`
 	Log                 telegraf.Logger `toml:"-"`
 	tls.ClientConfig
 
@@ -95,6 +98,15 @@ var sampleConfig = `
   ## If set to true a unique ID hash will be sent as sha256(concat(timestamp,measurement,series-hash)) string
   ## it will enable data resend and update metric points avoiding duplicated metrics with diferent id's
   force_document_id = false
+
+  ## Specifies the handling of NaN and Inf values.
+  ## This option can have the following values:
+  ##    none    -- do not modify field-values (default); will produce an error if NaNs or infs are encountered
+  ##    drop    -- drop fields containing NaNs or infs
+  ##    replace -- replace with the value in "float_replacement_value" (default: 0.0)
+  ##               NaNs and inf will be replaced with the given number, -inf with the negative of that number
+  # float_handling = "none"
+  # float_replacement_value = 0.0
 `
 
 const telegrafTemplate = `
@@ -177,6 +189,15 @@ func (a *Elasticsearch) Connect() error {
 		return fmt.Errorf("elasticsearch urls or index_name is not defined")
 	}
 
+	// Determine if we should process NaN and inf values
+	switch a.FloatHandling {
+	case "", "none":
+		a.FloatHandling = "none"
+	case "drop", "replace":
+	default:
+		return fmt.Errorf("invalid float_handling type %q", a.FloatHandling)
+	}
+
 	ctx, cancel := context.WithTimeout(context.Background(), time.Duration(a.Timeout))
 	defer cancel()
 
@@ -278,12 +299,31 @@ func (a *Elasticsearch) Write(metrics []telegraf.Metric) error {
 		// to send the metric to the correct time-based index
 		indexName := a.GetIndexName(a.IndexName, metric.Time(), a.TagKeys, metric.Tags())
 
+		// Handle NaN and inf field-values
+		fields := make(map[string]interface{})
+		for k, value := range metric.Fields() {
+			v, ok := value.(float64)
+			if !ok || a.FloatHandling == "none" || !(math.IsNaN(v) || math.IsInf(v, 0)) {
+				fields[k] = value
+				continue
+			}
+			if a.FloatHandling == "drop" {
+				continue
+			}
+
+			if math.IsNaN(v) || math.IsInf(v, 1) {
+				fields[k] = a.FloatReplacement
+			} else {
+				fields[k] = -a.FloatReplacement
+			}
+		}
+
 		m := make(map[string]interface{})
 
 		m["@timestamp"] = metric.Time()
 		m["measurement_name"] = name
 		m["tag"] = metric.Tags()
-		m[name] = metric.Fields()
+		m[name] = fields
 
 		br := elastic.NewBulkIndexRequest().Index(indexName).Doc(m)
 

plugins/outputs/elasticsearch/elasticsearch_test.go

@@ -2,12 +2,14 @@ package elasticsearch
 
 import (
 	"context"
+	"math"
 	"net/http"
 	"net/http/httptest"
 	"reflect"
 	"testing"
 	"time"
 
+	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/config"
 	"github.com/influxdata/telegraf/testutil"
 	"github.com/stretchr/testify/require"
@@ -41,6 +43,149 @@ func TestConnectAndWriteIntegration(t *testing.T) {
 	require.NoError(t, err)
 }
 
+func TestConnectAndWriteMetricWithNaNValueEmpty(t *testing.T) {
+	if testing.Short() {
+		t.Skip("Skipping integration test in short mode")
+	}
+
+	urls := []string{"http://" + testutil.GetLocalHost() + ":9200"}
+
+	e := &Elasticsearch{
+		URLs:                urls,
+		IndexName:           "test-%Y.%m.%d",
+		Timeout:             config.Duration(time.Second * 5),
+		ManageTemplate:      true,
+		TemplateName:        "telegraf",
+		OverwriteTemplate:   false,
+		HealthCheckInterval: config.Duration(time.Second * 10),
+		Log:                 testutil.Logger{},
+	}
+
+	metrics := []telegraf.Metric{
+		testutil.TestMetric(math.NaN()),
+		testutil.TestMetric(math.Inf(1)),
+		testutil.TestMetric(math.Inf(-1)),
+	}
+
+	// Verify that we can connect to Elasticsearch
+	err := e.Connect()
+	require.NoError(t, err)
+
+	// Verify that we can fail for metric with unhandled NaN/inf/-inf values
+	for _, m := range metrics {
+		err = e.Write([]telegraf.Metric{m})
+		require.Error(t, err, "error sending bulk request to Elasticsearch: json: unsupported value: NaN")
+	}
+}
+
+func TestConnectAndWriteMetricWithNaNValueNone(t *testing.T) {
+	if testing.Short() {
+		t.Skip("Skipping integration test in short mode")
+	}
+
+	urls := []string{"http://" + testutil.GetLocalHost() + ":9200"}
+
+	e := &Elasticsearch{
+		URLs:                urls,
+		IndexName:           "test-%Y.%m.%d",
+		Timeout:             config.Duration(time.Second * 5),
+		ManageTemplate:      true,
+		TemplateName:        "telegraf",
+		OverwriteTemplate:   false,
+		HealthCheckInterval: config.Duration(time.Second * 10),
+		FloatHandling:       "none",
+		Log:                 testutil.Logger{},
+	}
+
+	metrics := []telegraf.Metric{
+		testutil.TestMetric(math.NaN()),
+		testutil.TestMetric(math.Inf(1)),
+		testutil.TestMetric(math.Inf(-1)),
+	}
+
+	// Verify that we can connect to Elasticsearch
+	err := e.Connect()
+	require.NoError(t, err)
+
+	// Verify that we can fail for metric with unhandled NaN/inf/-inf values
+	for _, m := range metrics {
+		err = e.Write([]telegraf.Metric{m})
+		require.Error(t, err, "error sending bulk request to Elasticsearch: json: unsupported value: NaN")
+	}
+}
+
+func TestConnectAndWriteMetricWithNaNValueDrop(t *testing.T) {
+	if testing.Short() {
+		t.Skip("Skipping integration test in short mode")
+	}
+
+	urls := []string{"http://" + testutil.GetLocalHost() + ":9200"}
+
+	e := &Elasticsearch{
+		URLs:                urls,
+		IndexName:           "test-%Y.%m.%d",
+		Timeout:             config.Duration(time.Second * 5),
+		ManageTemplate:      true,
+		TemplateName:        "telegraf",
+		OverwriteTemplate:   false,
+		HealthCheckInterval: config.Duration(time.Second * 10),
+		FloatHandling:       "drop",
+		Log:                 testutil.Logger{},
+	}
+
+	metrics := []telegraf.Metric{
+		testutil.TestMetric(math.NaN()),
+		testutil.TestMetric(math.Inf(1)),
+		testutil.TestMetric(math.Inf(-1)),
+	}
+
+	// Verify that we can connect to Elasticsearch
+	err := e.Connect()
+	require.NoError(t, err)
+
+	// Verify that we can fail for metric with unhandled NaN/inf/-inf values
+	for _, m := range metrics {
+		err = e.Write([]telegraf.Metric{m})
+		require.NoError(t, err)
+	}
+}
+
+func TestConnectAndWriteMetricWithNaNValueReplacement(t *testing.T) {
+	if testing.Short() {
+		t.Skip("Skipping integration test in short mode")
+	}
+
+	urls := []string{"http://" + testutil.GetLocalHost() + ":9200"}
+
+	e := &Elasticsearch{
+		URLs:                urls,
+		IndexName:           "test-%Y.%m.%d",
+		Timeout:             config.Duration(time.Second * 5),
+		ManageTemplate:      true,
+		TemplateName:        "telegraf",
+		OverwriteTemplate:   false,
+		HealthCheckInterval: config.Duration(time.Second * 10),
+		FloatHandling:       "3.1415",
+		Log:                 testutil.Logger{},
+	}
+
+	metrics := []telegraf.Metric{
+		testutil.TestMetric(math.NaN()),
+		testutil.TestMetric(math.Inf(1)),
+		testutil.TestMetric(math.Inf(-1)),
+	}
+
+	// Verify that we can connect to Elasticsearch
+	err := e.Connect()
+	require.NoError(t, err)
+
+	// Verify that we can fail for metric with unhandled NaN/inf/-inf values
+	for _, m := range metrics {
+		err = e.Write([]telegraf.Metric{m})
+		require.NoError(t, err)
+	}
+}
+
 func TestTemplateManagementEmptyTemplateIntegration(t *testing.T) {
 	if testing.Short() {
 		t.Skip("Skipping integration test in short mode")
@@ -121,7 +266,7 @@ func TestGetTagKeys(t *testing.T) {
 		Log:             testutil.Logger{},
 	}
 
-	var tests = []struct {
+	tests := []struct {
 		IndexName         string
 		ExpectedIndexName string
 		ExpectedTagKeys   []string
@@ -181,7 +326,7 @@ func TestGetIndexName(t *testing.T) {
 		Log:             testutil.Logger{},
 	}
 
-	var tests = []struct {
+	tests := []struct {
 		EventTime time.Time
 		Tags      map[string]string
 		TagKeys   []string