Add Serializer plugins, and 'file' output plugin

plugins/serializers/registry.go

@@ -0,0 +1,55 @@
+package serializers
+
+import (
+	"github.com/influxdata/telegraf"
+
+	"github.com/influxdata/telegraf/plugins/serializers/graphite"
+	"github.com/influxdata/telegraf/plugins/serializers/influx"
+)
+
+// SerializerOutput is an interface for output plugins that are able to
+// serialize telegraf metrics into arbitrary data formats.
+type SerializerOutput interface {
+	// SetSerializer sets the serializer function for the interface.
+	SetSerializer(serializer Serializer)
+}
+
+// Serializer is an interface defining functions that a serializer plugin must
+// satisfy.
+type Serializer interface {
+	// Serialize takes a single telegraf metric and turns it into a string.
+	Serialize(metric telegraf.Metric) ([]string, error)
+}
+
+// Config is a struct that covers the data types needed for all serializer types,
+// and can be used to instantiate _any_ of the serializers.
+type Config struct {
+	// Dataformat can be one of: influx, graphite
+	DataFormat string
+
+	// Prefix to add to all measurements, only supports Graphite
+	Prefix string
+}
+
+// NewSerializer a Serializer interface based on the given config.
+func NewSerializer(config *Config) (Serializer, error) {
+	var err error
+	var serializer Serializer
+	switch config.DataFormat {
+	case "influx":
+		serializer, err = NewInfluxSerializer()
+	case "graphite":
+		serializer, err = NewGraphiteSerializer(config.Prefix)
+	}
+	return serializer, err
+}
+
+func NewInfluxSerializer() (Serializer, error) {
+	return &influx.InfluxSerializer{}, nil
+}
+
+func NewGraphiteSerializer(prefix string) (Serializer, error) {
+	return &graphite.GraphiteSerializer{
+		Prefix: prefix,
+	}, nil
+}