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=192.168.10.1 \
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 (
"fmt"
"io/ioutil"
"net"
"net/http"
"os"
"time"
)
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 {
panic(err)
}
defer resp.Body.Close()
html, err := ioutil.ReadAll(resp.Body)
if err != nil {
panic(err)
}
// fmt.Println(os.Stdout, string(html))
// or save the zip - see https://www.socketloop.com/tutorials/golang-download-file-example
}
References :
https://www.socketloop.com/tutorials/golang-convert-http-response-body-to-string
https://www.socketloop.com/tutorials/golang-download-file-example
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.
Advertisement
Tutorials
+14.2k Javascript : Prompt confirmation before exit
+7.5k Golang : Get YouTube playlist
+31.8k Golang : How to convert(cast) string to IP address?
+10.2k Golang : Use regular expression to get all upper case or lower case characters example
+23.6k Golang : minus time with Time.Add() or Time.AddDate() functions to calculate past date
+4.6k Javascript : Detect when console is activated and do something about it
+19.4k Golang : How to count the number of repeated characters in a string?
+10.6k Fix ERROR 1045 (28000): Access denied for user 'root'@'ip-address' (using password: YES)
+31.2k Golang : Calculate percentage change of two values
+11.6k Golang : Fuzzy string search or approximate string matching example
+11k Golang : Replace a parameter's value inside a configuration file example
+9.5k Golang : Accessing content anonymously with Tor