Add http path configuration for OpenTSDB output (#4347)

etc/telegraf.conf

@@ -723,6 +723,10 @@
 #   ## Not used with telnet API.
 #   httpBatchSize = 50
 #
+#   ## URI Path for Http requests to OpenTSDB.
+#   ## Used in cases where OpenTSDB is located behind a reverse proxy.
+#   httpPath = "/api/put"
+#
 #   ## Debug true - Prints OpenTSDB communication
 #   debug = false
 #

plugins/outputs/opentsdb/opentsdb.go

@@ -22,6 +22,7 @@ var (
 		`%`, "-",
 		"#", "-",
 		"$", "-")
+	defaultHttpPath  = "/api/put"
 	defaultSeperator = "_"
 )
 
@@ -32,6 +33,7 @@ type OpenTSDB struct {
 	Port int
 
 	HttpBatchSize int
+	HttpPath      string
 
 	Debug bool
 
@@ -54,6 +56,10 @@ var sampleConfig = `
   ## Not used with telnet API.
   httpBatchSize = 50
 
+  ## URI Path for Http requests to OpenTSDB.
+  ## Used in cases where OpenTSDB is located behind a reverse proxy.
+  httpPath = "/api/put"
+
   ## Debug true - Prints OpenTSDB communication
   debug = false
 
@@ -121,6 +127,7 @@ func (o *OpenTSDB) WriteHttp(metrics []telegraf.Metric, u *url.URL) error {
 		Scheme:    u.Scheme,
 		User:      u.User,
 		BatchSize: o.HttpBatchSize,
+		Path:      o.HttpPath,
 		Debug:     o.Debug,
 	}
 
@@ -260,6 +267,7 @@ func sanitize(value string) string {
 func init() {
 	outputs.Add("opentsdb", func() telegraf.Output {
 		return &OpenTSDB{
+			HttpPath:  defaultHttpPath,
 			Separator: defaultSeperator,
 		}
 	})

plugins/outputs/opentsdb/opentsdb_http.go

@@ -26,6 +26,7 @@ type openTSDBHttp struct {
 	Scheme    string
 	User      *url.Userinfo
 	BatchSize int
+	Path      string
 	Debug     bool
 
 	metricCounter int
@@ -123,7 +124,7 @@ func (o *openTSDBHttp) flush() error {
 		Scheme: o.Scheme,
 		User:   o.User,
 		Host:   fmt.Sprintf("%s:%d", o.Host, o.Port),
-		Path:   "/api/put",
+		Path:   o.Path,
 	}
 
 	if o.Debug {

plugins/outputs/opentsdb/opentsdb_test.go

@@ -156,6 +156,7 @@ func BenchmarkHttpSend(b *testing.B) {
 		Port:          port,
 		Prefix:        "",
 		HttpBatchSize: BatchSize,
+		HttpPath:      "/api/put",
 	}
 
 	b.ResetTimer()