Ensure we close connections (no KeepAlives)

fetchtest.go

package main

import (
	"bufio"
	"errors"
	"flag"
	"fmt"
	"net/http"
	"os"
	"sync"
	"time"
)

var parallel = flag.Int("parallel", 5, "parallel requests")
var timeout = flag.Duration("timeout", 2*time.Second, "request timeout")

func noRedirect(req *http.Request, via []*http.Request) error {
	return errors.New("stop redirects")
}

func main() {
	flag.Parse()
	transport := &http.Transport{
		DisableKeepAlives: true,
	}
	client := http.Client{
		Transport:     transport,
		CheckRedirect: noRedirect,
		Timeout:       *timeout,
	}
	names := make(chan string)
	var wg sync.WaitGroup
	for i := 0; i < *parallel; i++ {
		wg.Add(1)
		go func() {
			for name := range names {
				resp, err := client.Get("https://" + name + "/")
				if resp != nil {
					fmt.Printf("%s: ok status code %d\n", name, resp.StatusCode)
					// we got a redirect response
					continue
				}
				if err != nil {
					fmt.Printf("%s: error %s\n", name, err)
				} else {
					fmt.Printf("%s: ok status code %d\n", name, resp.StatusCode)
				}
			}
			wg.Done()
		}()
	}
	reader := bufio.NewScanner(os.Stdin)
	for reader.Scan() {
		name := reader.Text()
		if name != "" {
			names <- name
		}
	}
	close(names)
	wg.Wait()
}