This code changes http.DefaultClient to use a SOCKS5 proxy

useproxy.go

		// create a socks5 dialer
		dialer, err := proxy.SOCKS5("tcp", PROXY_ADDR, nil, proxy.Direct)
		if err != nil {
			fmt.Fprintln(os.Stderr, "can't connect to the proxy:", err)
			os.Exit(1)
		}
		// setup a http client
		httpTransport := &http.Transport{}
		// set our socks5 as the dialer
		httpTransport.Dial = dialer.Dial
		http.DefaultClient = &http.Client{Transport: httpTransport}