Add NatsSink to send data via the NATS messaging system

metric-collector.go

@@ -27,6 +27,7 @@ var Collectors = map[string]collectors.MetricGetter{
 var Sinks = map[string]sinks.SinkFuncs{
 	"influxdb": &sinks.InfluxSink{},
 	"stdout": &sinks.StdoutSink{},
+	"nats": &sinks.NatsSink{},
 }
 
 // Structure of the configuration file

sinks/natsSink.go

@@ -0,0 +1,60 @@
+package sinks
+
+import (
+	"bytes"
+	"fmt"
+	protocol "github.com/influxdata/line-protocol"
+	nats "github.com/nats-io/nats.go"
+	"log"
+	"time"
+)
+
+type NatsSink struct {
+	Sink
+	client  *nats.Conn
+	encoder *protocol.Encoder
+	buffer  *bytes.Buffer
+}
+
+func (s *NatsSink) Init(host string, port string, user string, password string, database string) error {
+	s.host = host
+	s.port = port
+	s.user = user
+	s.password = password
+	s.database = database
+	// Setup Influx line protocol
+	s.buffer = &bytes.Buffer{}
+	s.buffer.Grow(1025)
+	s.encoder = protocol.NewEncoder(s.buffer)
+	s.encoder.SetPrecision(time.Second)
+	s.encoder.SetMaxLineBytes(1024)
+	// Setup infos for connection
+	uinfo := nats.UserInfo(s.user, s.password)
+	uri := fmt.Sprintf("nats://%s:%s", s.host, s.port)
+	nc, err := nats.Connect(uri, uinfo)
+	if err != nil {
+		log.Fatal(err)
+		return err
+	}
+	s.client = nc
+	return nil
+}
+
+func (s *NatsSink) Write(measurement string, tags map[string]string, fields map[string]interface{}, t time.Time) error {
+	m, err := protocol.New(measurement, tags, fields, t)
+	if err != nil {
+		log.Print(err)
+		return err
+	}
+	_, err = s.encoder.Encode(m)
+	if err != nil {
+		log.Print(err)
+		return err
+	}
+	s.client.Publish(s.database, s.buffer.Bytes())
+	return nil
+}
+
+func (s *NatsSink) Close() {
+	s.client.Close()
+}