Add Serializer plugins, and 'file' output plugin

plugins/serializers/graphite/graphite.go

@@ -0,0 +1,79 @@
+package graphite
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+
+	"github.com/influxdata/telegraf"
+)
+
+type GraphiteSerializer struct {
+	Prefix string
+}
+
+func (s *GraphiteSerializer) Serialize(metric telegraf.Metric) ([]string, error) {
+	out := []string{}
+	// Get name
+	name := metric.Name()
+	// Convert UnixNano to Unix timestamps
+	timestamp := metric.UnixNano() / 1000000000
+	tag_str := buildTags(metric)
+
+	for field_name, value := range metric.Fields() {
+		// Convert value
+		value_str := fmt.Sprintf("%#v", value)
+		// Write graphite metric
+		var graphitePoint string
+		if name == field_name {
+			graphitePoint = fmt.Sprintf("%s.%s %s %d",
+				tag_str,
+				strings.Replace(name, ".", "_", -1),
+				value_str,
+				timestamp)
+		} else {
+			graphitePoint = fmt.Sprintf("%s.%s.%s %s %d",
+				tag_str,
+				strings.Replace(name, ".", "_", -1),
+				strings.Replace(field_name, ".", "_", -1),
+				value_str,
+				timestamp)
+		}
+		if s.Prefix != "" {
+			graphitePoint = fmt.Sprintf("%s.%s", s.Prefix, graphitePoint)
+		}
+		out = append(out, graphitePoint)
+	}
+	return out, nil
+}
+
+func buildTags(metric telegraf.Metric) string {
+	var keys []string
+	tags := metric.Tags()
+	for k := range tags {
+		if k == "host" {
+			continue
+		}
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
+	var tag_str string
+	if host, ok := tags["host"]; ok {
+		if len(keys) > 0 {
+			tag_str = strings.Replace(host, ".", "_", -1) + "."
+		} else {
+			tag_str = strings.Replace(host, ".", "_", -1)
+		}
+	}
+
+	for i, k := range keys {
+		tag_value := strings.Replace(tags[k], ".", "_", -1)
+		if i == 0 {
+			tag_str += tag_value
+		} else {
+			tag_str += "." + tag_value
+		}
+	}
+	return tag_str
+}