Go server not hearing remote requests

Question

I've written a Go server that works perfectly as long as you send it requests from localhost (and addressed to localhost), but it doesn't work when you try to access it from a browser (from a different computer) or even just directed at the external IP address. I want to be able to access it as an external server, not just locally. Why can't it?

The (pared down) source code:

package main

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

func main() {
    // Listen for incoming connections.
    l, err := net.Listen("tcp", "localhost:2082")
    if err != nil {
        fmt.Println("Error listening:", err.Error())
        os.Exit(1)
    }
    // Close the listener when the application closes.
    defer l.Close()

    for {
        // Listen for an incoming connection.
        _, err := l.Accept()
        if err != nil {
            fmt.Println("Error accepting: ", err.Error())
            os.Exit(1)
        }
        fmt.Println("Incoming connection")
    }
}

When you curl localhost:2082, it says "Incoming connection".
When you curl mydomain.com:2082, it does nothing.

The port is forwarded. I'm sure of this because I ran a (node.js) web server from that port, and it worked fine. If it's related, I'm running on Ubuntu 12.04 on an Amazon EC2 instance.

I'd appreciate any help. Thanks!

Answer 1

One way to listen to any incoming IP (not just localhost, mapped by default to 127.0.0.1) would be:

net.Listen("tcp", ":2082")

You also have the function net/http/#ListenAndServe, which allows you to trigger listen on multiple specific ip if you want.

go http.ListenAndServe("10.0.0.1:80", nil)
http.ListenAndServe("10.0.0.2:80", nil) 

A good example can be seen in "A Recap of Request Handling in Go".