How to set timeout for http.Get() requests in Golang?

If you want to do it per request, err handling ignored for brevity:

ctx, cncl := context.WithTimeout(context.Background(), time.Second*3)
defer cncl()

req, _ := http.NewRequestWithContext(ctx, http.MethodGet, "https://google.com", nil)

resp, _ := http.DefaultClient.Do(req)

Apparently in Go 1.3 http.Client has Timeout field

client := http.Client{
    Timeout: 5 * time.Second,
}
client.Get(url)

That's done the trick for me.

You need to set up your own Client with your own Transport which uses a custom Dial function which wraps around DialTimeout.

Something like (completely untested) this:

var timeout = time.Duration(2 * time.Second)

func dialTimeout(network, addr string) (net.Conn, error) {
    return net.DialTimeout(network, addr, timeout)
}

func main() {
    transport := http.Transport{
        Dial: dialTimeout,
    }

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

    resp, err := client.Get("http://some.url")
}