net/http: should get "ok" but get no response

[anotherGoogleFan]

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

go version go1.9.2 linux/amd64
go version go1.9.2 windows/amd64
both got the same problem

Does this issue reproduce with the latest release?

yes

What operating system and processor architecture are you using (go env)?

one is windows:
$ go env
set GOARCH=amd64
set GOBIN=
set GOEXE=.exe
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOOS=windows
set GOPATH=E:\GoProject
set GORACE=
set GOROOT=C:\Go
set GOTOOLDIR=C:\Go\pkg\tool\windows_amd64
set GCCGO=gccgo
set CC=gcc
set GOGCCFLAGS=-m64 -mthreads -fmessage-length=0
set CXX=g++
set CGO_ENABLED=1
set CGO_CFLAGS=-g -O2
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-g -O2
set CGO_FFLAGS=-g -O2
set CGO_LDFLAGS=-g -O2
set PKG_CONFIG=pkg-config

one is linux:
GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/root/GoProject"
GORACE=""
GOROOT="/usr/local/go"
GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
CC="gcc"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build038803651=/tmp/go-build"
CXX="g++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"

What did you do?

code is simple enough:

package main

import (
	"context"
	"net/http"
	"os"
	"os/signal"
	"time"

	"github.com/anotherGoogleFan/log"
)

func main() {
	mux := http.NewServeMux()
	mux.Handle("/video/upload", http.HandlerFunc(UploadVideo))
	srv := &http.Server{
		Addr:    ":8848",
		Handler: mux,
	}
	// 如果接收到关闭信号(如 kill -2)则进行graceful shutdown
	go gracefulShutdown(srv)

	// service connections
	if err := srv.ListenAndServe(); err != nil {
		log.Fields{
			"port": "8848",
			"err":  err.Error(),
		}.Error("unexpected service stop")
		return
	}
}

func gracefulShutdown(srv *http.Server) {
	stopChan := make(chan os.Signal)
	signal.Notify(stopChan, os.Interrupt, os.Kill)
	<-stopChan
	log.Info("receive shutdown signal. Ready to exist")
	defer log.Info("program exists")
	ctx, _ := context.WithTimeout(context.Background(), 5*time.Second)
	srv.Shutdown(ctx)
}

func UploadVideo(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "only post allowed", http.StatusMethodNotAllowed)
		return
	}

	http.Error(w, "ok", http.StatusOK)
}

What did you expect to see?

I post a file

with chrome plugin postman. I should get the response "ok".

What did you see instead?

No response.

[mvdan]

Please see https://github.com/golang/go/wiki/Questions for a more appropriate place to ask questions. I don't see a specific bug report here - just a program that isn't doing what you wanted it to do.

If there is a bug, please clarify what it is and give a short, concise program to reproduce it.

[brenol]

This issue seems to happen in when using Postman only.

• I was able to reproduce in Windows
• I was able to reproduce in Linux (Ubuntu 17.10)
• The file being sent must be at least over 700KB from what I have tested
• If the file is over 700KB, that message is shown most times when using Postman
• I was unable to reproduce this using curl

Minimal repro: https://play.golang.org/p/UQ6AVD5Lqlj

Seems to me Postman is doing something with the connection.

Tests were made using Go1.9.2/Windows & Go1.9.2/Linux

[katakonst]

You need to read the body. From what i see it exists a limit for unread request body data.

// maxPostHandlerReadBytes is the max number of Request.Body bytes not
// consumed by a handler that the server will read from the client
// in order to keep a connection alive. If there are more bytes than
// this then the server to be paranoid instead sends a "Connection:
// close" response.
//
// This number is approximately what a typical machine's TCP buffer
// size is anyway.  (if we have the bytes on the machine, we might as
// well read them)
const maxPostHandlerReadBytes = 256 << 10

A quick solution for your code can be

func UploadVideo(w http.ResponseWriter, r *http.Request) {
	io.Copy(ioutil.Discard, r.Body)
	if r.Method != http.MethodPost {
		http.Error(w, "only post allowed", http.StatusMethodNotAllowed)
		return
	}

	http.Error(w, "ok", http.StatusOK)
}

[gopherbot]

Timed out in state WaitingForInfo. Closing.

(I am just a bot, though. Please speak up if this is a mistake or you have the requested information.)