Unit test improved.

plugins/outputs/elasticsearch/elasticsearch.go

@@ -110,6 +110,51 @@ func (a *Elasticsearch) Write(metrics []telegraf.Metric) error {
 	return nil
 }
 
+func (a *Elasticsearch) WriteOneMessage(metric telegraf.Metric) (string, error) {
+
+	m := make(map[string]interface{})
+	m["created"] = metric.Time()
+
+	if host, ok := metric.Tags()["host"]; ok {
+		m["host"] = host
+	} 
+
+	// Elasticsearch 2.x does not support this dots-to-object transformation
+	// and so dots in field names are not allowed in versions 2.X.
+	// In this case, dots will be replaced with "_"
+
+	for key, value := range metric.Tags() {
+		if key != "host" {
+			if strings.HasPrefix(a.Version, "2.") {
+				m[strings.Replace(key, ".", "_", -1)] = value
+			} else {
+				m[key] = value
+			}
+		}
+	}
+
+	for key, value := range metric.Fields() {
+		if strings.HasPrefix(a.Version, "2.") {
+			m[strings.Replace(key, ".", "_", -1)] = value
+		} else {
+			m[key] = value
+		}
+	}
+
+	put1, errMessage := a.Client.Index().
+		Index(a.IndexName).
+		Type(metric.Name()).
+		BodyJson(m).
+		Do()
+
+	if errMessage != nil {
+		return "",fmt.Errorf("FAILED to send Elasticsearch message to index %s : %s\n", a.IndexName, errMessage)
+	}
+
+	return put1.Id,nil
+
+}
+
 func (a *Elasticsearch) SampleConfig() string {
 	return sampleConfig
 }

plugins/outputs/elasticsearch/elasticsearch_test.go

@@ -2,9 +2,14 @@ package elasticsearch
 
 import (
 	"testing"
+	"time"
+	"encoding/json"
+
+	"github.com/influxdata/telegraf"
 
 	"github.com/influxdata/telegraf/testutil"
 	"github.com/stretchr/testify/require"
+
 )
 
 func TestConnectAndWrite(t *testing.T) {
@@ -26,4 +31,35 @@ func TestConnectAndWrite(t *testing.T) {
 	// Verify that we can successfully write data to the ElasticSearch
 	err = e.Write(testutil.MockMetrics())
 	require.NoError(t, err)
+
+	// Verify if metric sent has same data on Elasticsearch
+	metrictest, _ := telegraf.NewMetric(
+		"my_measurement",
+		map[string]string{"host": "192.168.0.1"},
+		map[string]interface{}{"value": float64(3.14)},
+		time.Date(2010, time.November, 10, 23, 0, 0, 0, time.UTC),
+	)
+
+	messageid, err := e.WriteOneMessage(metrictest)
+	require.NoError(t, err)
+
+	get1, errGet := e.Client.Get().
+		Index(e.IndexName).
+ 		Type(metrictest.Name()).
+ 		Id(messageid).
+		Do()
+	require.NoError(t, errGet)
+
+	require.Equal(t,true,get1.Found,"Message not found on Elasticsearch.")
+
+	require.NotEqual(t,nil,get1.Source,"Source not found on Elasticsearch.")
+
+	var dat map[string]interface{}
+	err = json.Unmarshal(*get1.Source, &dat)
+	require.NoError(t, err)
+
+        require.Equal(t,"192.168.0.1",dat["host"],"Values of Host are not the same.")
+        require.Equal(t,"2010-11-10T23:00:00Z",dat["created"],"Values of Created are not the same.")
+        require.Equal(t,3.14,dat["value"],"Values of Value are not the same.")
+
 }