func main() {
me, err := url.Parse(*myEndpoint)
if err != nil {
panic(err)
}
log.Printf("my address is: %s", me.String())
multicast, err := url.Parse(*multicastEndpoint)
if err != nil {
panic(err)
}
log.Printf("joining multicast group on: %s", multicast.String())
go func() {
http.HandleFunc(progol.ValidationPath, progol.ValidationHandler)
log.Printf("starting HTTP server on %s", me.Host)
log.Fatal(http.ListenAndServe(me.Host, nil))
}()
d, err := progol.NewMulticastDiscovery(*myEndpoint, multicast.Host, 3*time.Second)
if err != nil {
log.Fatalf("creating Multicast Discovery: %s", err)
}
v := progol.NewValidator(d, 1*time.Second)
c := make(chan []progol.Peer)
go func() {
for peers := range c {
log.Printf("Peers: %v", peers)
}
}()
v.Subscribe(c)
select {}
}
// newMulticastDiscovery creates a progol.MulticastDiscovery for this process,
// choosing a random port.
func newMulticastDiscovery(host, group string, ttl time.Duration) (progol.Discovery, int, error) {
for i := 0; i < 10; i++ {
port := 10000 + rand.Intn(9999)
laddr := "http://" + net.JoinHostPort(host, fmt.Sprint(port))
discovery, err := progol.NewMulticastDiscovery(laddr, group, ttl)
if err != nil {
log.Printf("%s: %s, retrying...", laddr, err)
time.Sleep(time.Duration(10+rand.Intn(40)) * time.Millisecond)
continue
}
log.Printf("Multicast Discovery on %s", laddr)
return discovery, port, nil
}
return nil, 0, fmt.Errorf("couldn't find free port")
}