Simple PUB-SUB using multicast, written in Go. The publisher sends the string 'hello' every 2 seconds to IPv4 multicast 224.0.0.1 on UDP port 5000

mcast_pub.go

package main

import (
    "bufio"
    "fmt"
    "net"
    "time"
)

func main() {

    mcastAddr, err := net.ResolveUDPAddr("udp", "224.0.0.1:5000")
    if err != nil {
        fmt.Printf("Unable to resolve multicast string, error: %s", err)
        return
    }

    conn, err := net.DialUDP("udp", nil, mcastAddr)
    if err != nil {
        fmt.Printf("Unable to connect to multicast addr, error: %s", err)
        return
    }

    wconn := bufio.NewWriter(conn)
    for {
        i, err := wconn.WriteString("hello\n")
        if err != nil {
            fmt.Printf("Write to socket %d bytes, error %s\n", i, err)
            return
        }
        err = wconn.Flush()
        if err != nil {
            fmt.Printf("Flush socket error %s\n", err)
            return
        }
        fmt.Println("hello")
        time.Sleep(2 * time.Second)
    }
}

mcast_sub.go

package main

import (
    "bufio"
    "fmt"
    "net"
    "strings"
)

func main() {

    mcastAddr, err := net.ResolveUDPAddr("udp", "224.0.0.1:5000")
    if err != nil {
        fmt.Printf("Unable to resolve multicast string, error: %s", err)
        return
    }

    conn, err := net.ListenMulticastUDP("udp", nil, mcastAddr)
    if err != nil {
        fmt.Printf("Unable to bind to multicast addr, error: %s", err)
        return
    }

    rconn := bufio.NewReader(conn)
    for {
        line, err := rconn.ReadString('\n')
        if err != nil {
            fmt.Printf("Read error: %s\n", err)
            return
        }

        line = strings.TrimSpace(line)
        fmt.Printf("Received: %s\n", line)
    }
}