Add kafka output

output_kafka.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+	"github.com/Shopify/sarama"
+	"log"
+	"strings"
+	"time"
+)
+
+// KafkaConfig should contains required information to
+// build producers.
+type KafkaConfig struct {
+	zookeeper string
+	topic     string
+}
+
+// KafkaOutput should make producer client.
+type KafkaOutput struct {
+	address  string
+	config   *KafkaConfig
+	producer sarama.AsyncProducer
+}
+
+// NewKafkaOutput creates instance of kafka producer client.
+func NewKafkaOutput(address string, config *KafkaConfig) *KafkaOutput {
+	c := sarama.NewConfig()
+	c.Producer.RequiredAcks = sarama.WaitForLocal
+	c.Producer.Compression = sarama.CompressionSnappy
+	c.Producer.Flush.Frequency = 500 * time.Millisecond
+
+	brokerList := strings.Split(config.zookeeper, ",")
+
+	producer, err := sarama.NewAsyncProducer(brokerList, c)
+	if err != nil {
+		log.Fatalln("Failed to start Sarama(Kafka) producer:", err)
+	}
+
+	o := &KafkaOutput{
+		address:  address,
+		config:   config,
+		producer: producer,
+	}
+
+	// Start infinite loop for tracking errors for kafka producer.
+	go o.ErrorHandler()
+
+	return o
+}
+
+// ErrorHandler should receive errors
+func (o *KafkaOutput) ErrorHandler() {
+	for err := range o.producer.Errors() {
+		log.Println("Failed to write access log entry:", err)
+	}
+}
+
+func (o *KafkaOutput) Write(data []byte) (n int, err error) {
+	buf := make(sarama.ByteEncoder, len(data))
+	copy(buf, data)
+
+	o.producer.Input() <- &sarama.ProducerMessage{
+		Topic: o.config.topic,
+		Key:   sarama.StringEncoder(o.address),
+		Value: buf,
+	}
+
+	return len(data), nil
+}