Implement transport stats.

plugins/elasticsearch/elasticsearch.go

@@ -22,6 +22,7 @@ type node struct {
 	ThreadPool interface{}       `json:"thread_pool"`
 	Network    interface{}       `json:"network"`
 	FS         interface{}       `json:"fs"`
+	Transport  interface{}       `json:"transport"`
 }
 
 const sampleConfig = `
@@ -123,6 +124,9 @@ func (e *Elasticsearch) gatherUrl(url string, acc plugins.Accumulator) error {
 		if err := e.parseInterface(acc, "fs", tags, n.FS); err != nil {
 			return err
 		}
+		if err := e.parseInterface(acc, "transport", tags, n.Transport); err != nil {
+			return err
+		}
 	}
 
 	return nil

plugins/elasticsearch/elasticsearch_test.go

@@ -78,4 +78,8 @@ func TestElasticsearch(t *testing.T) {
 	for key, val := range fsExpected {
 		assert.NoError(t, acc.ValidateTaggedValue(key, val, tags))
 	}
+
+	for key, val := range transportExpected {
+		assert.NoError(t, acc.ValidateTaggedValue(key, val, tags))
+	}
 }

plugins/elasticsearch/testdata_test.go

@@ -400,6 +400,13 @@ const statsResponse = `
             "available_in_bytes": 15894814720
           }
         ]
+      },
+      "transport": {
+        "server_open": 13,
+        "rx_count": 6,
+        "rx_size_in_bytes": 1380,
+        "tx_count": 6,
+        "tx_size_in_bytes": 1380
       }
     }
   }
@@ -667,3 +674,11 @@ var fsExpected = map[string]float64{
 	"fs_total_available_in_bytes": 15894814720,
 	"fs_total_total_in_bytes":     19507089408,
 }
+
+var transportExpected = map[string]float64{
+	"transport_server_open":      13,
+	"transport_rx_count":         6,
+	"transport_rx_size_in_bytes": 1380,
+	"transport_tx_count":         6,
+	"transport_tx_size_in_bytes": 1380,
+}