write to kafka using request handler channel

main.go

@@ -2,9 +2,10 @@ package main
 
 
 import (
+	lib "com.navi.medici.janus/lib"
 	config "com.navi.medici.janus/config"
-	producer_module "com.navi.medici.janus/producer"
 	server "com.navi.medici.janus/server"
+	producer_module "com.navi.medici.janus/producer"
 
 	"fmt"
 	"log"
@@ -48,11 +49,17 @@ func init() {
 	log.Printf(configuration.SchemaRegistry.Endpoint)
 
 	producer_module.GetSchemaVersions(configuration.SchemaRegistry.Endpoint, strings.Split(configuration.SchemaRegistry.Topics, ","))
+	producer_module.InitializeProducers(configuration.Kafka)
+
+	// TO DO: read number of goroutines from config
+	for i := 0; i < 10; i++ {
+		go lib.ProcessRequestChannel()
+	}
 
 	// sync producer using sarama
 	// sync_producer := producer_module.GetSyncProducer(configuration.Kafka)
 	// log.Println(sync_producer)
-	// producer_module.KafkaWriter(sync_producer)
+	// producer_module.KafkaWriter(sync_producer, topic, messageToSendBytes)
 	// sync_producer.Close()
 
 	// async producer using sarama

producer/get_schema.go

@@ -8,7 +8,7 @@ import (
 
 
 var (
-	schemaVersionMap         = make(map[string]int)
+	SchemaVersionMap         = make(map[string]int)
 )
 
 
@@ -22,10 +22,10 @@ func GetSchemaVersions(schemaRegistryEndpoint string, topicList []string) {
 			log.Println(err)
 		} else {
 			schemaId := schema.ID()
-			schemaVersionMap[topic] = schemaId
+			SchemaVersionMap[topic] = schemaId
 		}
 	}
 
-	log.Println(schemaVersionMap)
+	log.Println(SchemaVersionMap)
 
 }

producer/kafka_writer.go

@@ -1,49 +1,16 @@
 package producer
 
 import (
-    // "fmt"
     "log"
-    // "io/ioutil"
-    "encoding/binary"
-
-    // data "com.navi.medici.janus/data"
 
     "github.com/Shopify/sarama"
 )
 
-func KafkaWriter(producer sarama.SyncProducer, topic string, messageToSendBytes []byte) {
-
-    // to be of the format [magicByte] + [schemaID] + [messageIndex] + [value]
-    recordValue := []byte{}
-
-    // add [magicByte]
-    recordValue = append(recordValue, byte(0))
-
-    // add schemaID]
-    schemaIDBytes := make([]byte, 4)
-    binary.BigEndian.PutUint32(schemaIDBytes, uint32(schemaVersionMap[topic]))
-    recordValue = append(recordValue, schemaIDBytes...)
-
-    // add [messageIndex]
-    messageIndexBytes := []byte{byte(2), byte(0)}
-    recordValue = append(recordValue, messageIndexBytes...)
-
-    // Now write the bytes from the actual value...
-    // valueBytes, _ := proto.Marshal(&sensorReading)
-    recordValue = append(recordValue, messageToSendBytes...)
-
-	msg := &sarama.ProducerMessage{
-        Topic: topic,
-        Value: sarama.ByteEncoder(recordValue),
-    }
-
-    partition, offset, error := producer.SendMessage(msg)
-    if error != nil {
-        log.Fatalln("Failed to write to kafka:", error)
-    }
-    log.Printf("Partition: ", partition)
-    log.Printf("Offset: ", offset)
-    // log.Printf(error)
-    // log.Printf("Pixel sent: %s", messageToSend)
 
+func WriteMessageToKafkaAsync(message *sarama.ProducerMessage) {
+    select {
+        case asyncProducer.Input() <- message:
+        case err := <- asyncProducer.Errors():
+            log.Printf("FAILED TO WRITE TO KAFKA", err)
+        }
 }

producer/producer_config.go

@@ -8,6 +8,10 @@ import (
 	// "gopkg.in/confluentinc/confluent-kafka-go.v1/kafka"
 )
 
+var (
+    syncProducer    sarama.SyncProducer
+    asyncProducer   sarama.AsyncProducer
+)
 
 func GetSyncProducerConfig(kafkaConfiguration config.KafkaConfigurations) *sarama.Config {
 	config := sarama.NewConfig()
@@ -81,6 +85,12 @@ func GetAsyncProducer(kafkaConfiguration config.KafkaConfigurations) sarama.Asyn
 	return producer
 }
 
+
+func InitializeProducers(kafkaConfiguration config.KafkaConfigurations) {
+	syncProducer = GetSyncProducer(kafkaConfiguration)
+	asyncProducer = GetAsyncProducer(kafkaConfiguration)
+}
+
 // using confluent-kafka-go
 // func GetProducerConfig(kafkaConfiguration config.KafkaConfigurations) *kafka.ConfigMap {
 // 	var config = kafka.ConfigMap {

server/handlers.go

@@ -1,6 +1,8 @@
 package server
 
 import (
+	lib "com.navi.medici.janus/lib"
+
 	"io"
 	"io/ioutil"
 	"log"
@@ -17,5 +19,6 @@ func eventsHandler(w http.ResponseWriter, r *http.Request) {
 	}
 
 	w.Header().Set("Content-Type", "application/json")
+	lib.RequestChannel <- &lib.RequestObject{Body: body, Header: r.Header}
 	io.WriteString(w, "ok")
 }

server/server.go

@@ -6,6 +6,7 @@ import (
 	"sync"
 
 	"github.com/pkg/errors"
+	"github.com/gorilla/mux"
 )
 
 type Server struct {
@@ -28,16 +29,18 @@ func NewServer(port string)  (*Server, error) {
 		return nil, errors.Wrap(err, "failed to create listener")
 	}
 
-	mux := http.NewServeMux()
-
-	mux.HandleFunc("/events", eventsHandler)
+	// mux := http.NewServeMux()
+	// mux.HandleFunc("/events", eventsHandler)
 	// mux.HandleFunc("/events", eventshandler).Methods("POST")
 	// mux.HandleFunc("/health", healthHandler).Methods("GET")
 	// mux.HandleFunc("/health/toggle", healthToggleHandler).Methods("POST")
 	// mux.HandleFunc("/refresh/schema", refreshSchemaHandler).Methods("POST")
 	// mux.HandleFunc("/stop", stopHandler).Methods("POST")
 
-	httpServer := &http.Server{Addr: ":" + port, Handler: mux}
+	router := mux.NewRouter()
+	router.HandleFunc("/events", eventsHandler).Methods("POST")
+
+	httpServer := &http.Server{Addr: ":" + port, Handler: router}
 	newServer := &Server{HttpServer: httpServer, Listener: listener}
 	return newServer, nil