Add configurable separator graphite serializer and output (#7545)

plugins/outputs/graphite/graphite.go

@@ -17,6 +17,7 @@ import (
 
 type Graphite struct {
 	GraphiteTagSupport bool
+	GraphiteSeparator  string
 	// URL is only for backwards compatibility
 	Servers   []string
 	Prefix    string
@@ -41,6 +42,9 @@ var sampleConfig = `
   ## Enable Graphite tags support
   # graphite_tag_support = false
 
+  ## Character for separating metric name and field for Graphite tags
+  # graphite_separator = "."
+
   ## Graphite templates patterns
   ## 1. Template for cpu
   ## 2. Template for disk*
@@ -145,7 +149,7 @@ func checkEOF(conn net.Conn) {
 func (g *Graphite) Write(metrics []telegraf.Metric) error {
 	// Prepare data
 	var batch []byte
-	s, err := serializers.NewGraphiteSerializer(g.Prefix, g.Template, g.GraphiteTagSupport, g.Templates)
+	s, err := serializers.NewGraphiteSerializer(g.Prefix, g.Template, g.GraphiteTagSupport, g.GraphiteSeparator, g.Templates)
 	if err != nil {
 		return err
 	}