idle.go

package main

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

func main() {
	// Create a server with low idle timeout
	server := &http.Server{
		Addr: ":8080",
		// IdleTimeout is the maximum amount of time to wait for the
		// next request when keep-alives are enabled. If IdleTimeout
		// is zero, the value of ReadTimeout is used. If both are
		// zero, there is no timeout.
		IdleTimeout: time.Nanosecond,
	}
	go func() {
		err := server.ListenAndServe()
		if err != nil {
			log.Fatalf("failed to start http server: %s", err)
		}
	}()

	client := &http.Client{}
	for i := 0; i < 2; i++ {
		req, _ := http.NewRequest("GET", "http://0.0.0.0:8080", nil)
		// The second request, which uses keep-alive by default since it's HTTP 1.1, should fail due to the tiny
		// IdleTimeout set above. But it succeeds.
		resp, err := client.Do(req)
		if err != nil {
			log.Fatalf("http request failed: %s", err)
		}
		body, _ := io.ReadAll(resp.Body)
		resp.Body.Close()
		log.Printf("got response: `%s`", body)
		time.Sleep(time.Millisecond)
	}
}