Use hashicorp/serf with golang

serf.go

package main

import (
	"log"
	"os"
	"os/signal"
	"strconv"
	"syscall"

	"github.com/hashicorp/serf/serf"
	"github.com/pkg/errors"
)

// go buidl && BIND_ADDR=127.0.0.1 BIND_PORT=6666 ADVERTISE_ADDR=127.0.0.1 ADVERTISE_PORT=6666 CLUSTER_ADDR=127.0.0.1 CLUSTER_PORT=6666 NAME=a1 ./go-serf-example
// BIND_ADDR=127.0.0.1 BIND_PORT=6667 ADVERTISE_ADDR=127.0.0.1 ADVERTISE_PORT=6667 CLUSTER_ADDR=127.0.0.1 CLUSTER_PORT=6666 NAME=a2 ./go-serf-example
func main() {
	cluster, err := setupCluster(
		os.Getenv("BIND_ADDR"),
		os.Getenv("BIND_PORT"), // BIND defines where the agent listen for incomming connection
		os.Getenv("ADVERTISE_ADDR"),
		os.Getenv("ADVERTISE_PORT"), // ADVERTISE defines where the agent is reachable, often it the same as BIND
		os.Getenv("CLUSTER_ADDR"),
		os.Getenv("CLUSTER_PORT"), // CLUSTER is the address of a first agent
		os.Getenv("NAME"))         // NAME must be unique in a cluster

	if err != nil {
		log.Fatal(err)
	}

	c := make(chan os.Signal, 2)
	signal.Notify(c, os.Interrupt, syscall.SIGTERM)
	<-c
	cluster.Leave()
	os.Exit(1)
}

func setupCluster(bindAddr, bindPort, advertiseAddr, advertisePort, clusterAddr, clusterPort, name string) (*serf.Serf, error) {
	conf := serf.DefaultConfig()
	conf.Init()
	conf.MemberlistConfig.AdvertiseAddr = advertiseAddr
	conf.MemberlistConfig.AdvertisePort, _ = strconv.Atoi(advertisePort)
	conf.MemberlistConfig.BindAddr = bindAddr
	conf.MemberlistConfig.BindPort, _ = strconv.Atoi(bindPort)
	conf.MemberlistConfig.ProtocolVersion = 3 // Version 3 enable the ability to bind different port for each agent
	conf.NodeName = name

	cluster, err := serf.Create(conf)
	if err != nil {
		return nil, errors.Wrap(err, "Couldn't create cluster")
	}

	_, err = cluster.Join([]string{clusterAddr + ":" + clusterPort}, true)
	if err != nil {
		log.Printf("Couldn't join cluster, starting own: %v\n", err)
	}

	return cluster, nil
}