Set UserAgent in http request

Question

I'm trying to make my Go application specify itself as a specific UserAgent, but can't find anything on how to go about doing this with net/http. I'm creating an http.Client, and using it to make Get requests, via client.Get().

Is there a way to set the UserAgent in the Client, or at all?

Answer 1

When creating your request use request.Header.Set("key", "value"):

package main

import (
        "io/ioutil"
        "log"
        "net/http"
)

func main() {
        client := &http.Client{}

        req, err := http.NewRequest("GET", "http://httpbin.org/user-agent", nil)
        if err != nil {
                log.Fatalln(err)
        }

        req.Header.Set("User-Agent", "Golang_Spider_Bot/3.0")

        resp, err := client.Do(req)
        if err != nil {
                log.Fatalln(err)
        }

        defer resp.Body.Close()
        body, err := ioutil.ReadAll(resp.Body)
        if err != nil {
                log.Fatalln(err)
        }

        log.Println(string(body))

}

Result:

2012/11/07 15:05:47 {
  "user-agent": "Golang_Spider_Bot/3.0"
}

P.S. http://httpbin.org is amazing for testing this kind of thing!