Golang : Set up source IP address before making HTTP request

Problem :

There are times that you want to use certain IP address in a machine ( such as the one with permission to connect outside a firewall ) before making a HTTP request to another server. This is similar to the wget binding command :

For example : wget --bind-address= \

How to do that in Golang?

NOTE : This is not for masking or spoofing your IP address

Solution :

Build your own custom HTTP transport client and specify the local IP address that has the permission to connect outside a firewall.

For example :

 package main

 import (

 func main() {
 OKAddr := "<change here>" // local IP address to use

 OKAddress, _ := net.ResolveTCPAddr("tcp", OKAddr)

 transport := &http.Transport{
 Proxy: http.ProxyFromEnvironment,
 Dial: (&net.Dialer{
 Timeout: 30 * time.Second,
 KeepAlive: 30 * time.Second,
 OKAddr: OKAddress}).Dial, TLSHandshakeTimeout: 10 * time.Second}

 client := &http.Client{
 Transport: transport,

 resp, err := client.Get("http://example.com/filetodown.zip")

 if err != nil {

 defer resp.Body.Close()

 html, err := ioutil.ReadAll(resp.Body)

 if err != nil {

 // fmt.Println(os.Stdout, string(html))
 // or save the zip - see https://www.socketloop.com/tutorials/golang-download-file-example

References :



By Adam Ng

IF you gain some knowledge or the information here solved your programming problem. Please consider donating to the less fortunate or some charities that you like. Apart from donation, planting trees, volunteering or reducing your carbon footprint will be great too.