Full mesh monitoring

fmm.go

package main

import (
	"log"
	"flag"
	"net"
	"strings"
	"time"
	"os"
	"os/signal"

	serf2 "github.com/hashicorp/serf/serf"
)

func main()  {

	listen := flag.String("listen", "", "Listen address")
	advertise := flag.String("advertise", "", "Advertise address")
	bootstrap := flag.String("bootstrap","","List of bootstrap server")
	flag.Parse()

	events := make(chan serf2.Event, 0)
	serfConfig := serf2.DefaultConfig()
	serfConfig.EventCh = events
	serfConfig.MemberlistConfig.DisableTcpPings = true

	if *listen != "" {
		serfConfig.NodeName = *listen
		addr, err := net.ResolveUDPAddr("udp", *listen)
		if err != nil {
			log.Fatalf("Unable to resolve bind address : %v", err)
		}
		serfConfig.MemberlistConfig.BindAddr = addr.IP.String()
		serfConfig.MemberlistConfig.BindPort = addr.Port
	}

	if *advertise != "" {
		addr, err := net.ResolveUDPAddr("udp", *listen)
		if err != nil {
			log.Fatalf("Unable to resolve advertise address : %v", err)
		}
		serfConfig.MemberlistConfig.AdvertiseAddr = addr.IP.String()
		serfConfig.MemberlistConfig.AdvertisePort = addr.Port
	}

	serf, err := serf2.Create(serfConfig)
	if err != nil {
		log.Fatalf("Unable to start serf : %v", err)
	}

	/*
	 * Handle SIGINT
	 */
	c := make(chan os.Signal, 1)
	signal.Notify(c, os.Interrupt)
	go func() {
		for {
			<-c
			log.Println("SIGING detected")
			err = serf.Shutdown()
			if err != nil {
				log.Printf("Unable to shutdown serf : %v", err)
				os.Exit(1)
			}
			os.Exit(0)
		}
	}()


	if *bootstrap != "" {
		serf.Join(strings.Split(*bootstrap,","), false)
	}

	go func() {
		for {
			for _, member := range serf.Members() {
				rtt, err := serf.Memberlist().Ping(member.Name,net.Addr(&net.UDPAddr{IP: member.Addr, Port: int(member.Port)}))
				if err == nil {
					log.Printf("node %s rtt is %s", member.Name, rtt)
				} else {
					log.Printf("node %s rtt is %v", member.Name, err)
				}
			}
			time.Sleep(10 * time.Second)
		}
	}()

	select {}
}