TCP server with HTTP protocol using Golang

tcp_server.go

package main

import (
    "fmt"
    "net"
    "os"
)

const (
    CONN_HOST = "localhost"
    CONN_PORT = "3333"
    CONN_TYPE = "tcp"
)

func main() {
    // Listen for incoming connections
    l, err := net.Listen(CONN_TYPE, CONN_HOST+":"+CONN_PORT)
    if err != nil {
        fmt.Println("Error listening:", err.Error())
        os.Exit(1)
    }

    // Close the listener when the application closes.
    defer l.Close()

    fmt.Println("Listening on " + CONN_HOST + ":" + CONN_PORT)
    for {
        // Listen for an incoming connection.
        conn, err := l.Accept()
        if err != nil {
            fmt.Println("Error accepting: ", err.Error())
            os.Exit(1)
        }
        // Handle connections
        go handleRequest(conn)
    }
}

func handleRequest(conn net.Conn) {
    // Make a buffer to hold incoming data.
    buf := make([]byte, 1024)
    // Read the incoming connection into the buffer.
    l, err := conn.Read(buf)
    if err != nil {
        fmt.Println("Error reading:", err.Error())
    }
    fmt.Println(l)
    // Send a response back to person contacting us.
    r := []byte("HTTP/1.1 200 OK\r\nConnection: close\r\nContent-Type: text/html\r\nContent-Length: 19\r\n\r\n<h1>Hola Mundo</h1>")
    conn.Write(r)
    // Close the connection when you're done with it.
    conn.Close()
}