Zmq ROUTER-ROUTER via zmq3 golang

zmq-ROUTER-ROUTER.go

package main

import (
    "fmt"
	zmq "github.com/pebbe/zmq3"
	"log"
)

func main() {
	var err error
	//  Socket facing clients
	frontend, _ := zmq.NewSocket(zmq.ROUTER)
	backend, _ := zmq.NewSocket(zmq.ROUTER)
	defer frontend.Close()
	defer backend.Close()

	err = frontend.Bind("tcp://127.0.0.1:10002")
	if err != nil {
		log.Fatalln("Binding frontend:", err)
	}
	err = backend.Bind("tcp://*:10001")
	if err != nil {
		log.Fatalln("Binding backend:", err)
	}

	//  Initialize poll set
	poller := zmq.NewPoller()
	poller.Add(frontend, zmq.POLLIN)
	poller.Add(backend, zmq.POLLIN)

	fmt.Println("starting zmq broker")

	//  Switch messages between sockets
	for {
		sockets, _ := poller.Poll(-1)
		for _, socket := range sockets {
			switch s := socket.Socket; s {
			case frontend:
				request, err := s.RecvMessage(0)
				if err != nil {
					fmt.Println(err)
				}

				reqIdentity := request[0]
				repIdentity := request[2]
				msg := request[3]

				backend.Send(repIdentity, zmq.SNDMORE)
				backend.Send("", zmq.SNDMORE)
				backend.Send(reqIdentity, zmq.SNDMORE)
				backend.Send(msg, 0)

				break
			case backend:
				response, err := s.RecvMessage(0)
				if err != nil {
					fmt.Println(err)
				}

				repIdentity := response[0]
				reqIdentity := response[2]
				msg := response[3]

				frontend.Send(reqIdentity, zmq.SNDMORE)
				frontend.Send("", zmq.SNDMORE)
				frontend.Send(repIdentity, zmq.SNDMORE)
				frontend.Send(msg, 0)
			}
		}
	}
}