x/net/http2: connecting to non-compliant HTTP2 server returns Client.Timeout exceeded; fallback to HTTP/1? #20979
Description
What version of Go are you using (go version)?
go version go1.8.3 darwin/amd64
What operating system and processor architecture are you using (go env)?
GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/tkng"
GORACE=""
GOROOT="/usr/local/Cellar/go/1.8.3/libexec"
GOTOOLDIR="/usr/local/Cellar/go/1.8.3/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/z1/nc5xfnrs71g2zxr_chmshx3h0000gp/T/go-build993898931=/tmp/go-build -gno-record-gcc-switches -fno-common"
CXX="clang++"
CGO_ENABLED="1"
PKG_CONFIG="pkg-config"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
What did you do?
Following snippet code should be enough to reproduce the problem.
https://play.golang.org/p/PmZWp6NJlq
If I disabled HTTP2 by the environment variable GODEBUG=http2client=0, then I see no error. Hence I guess this issue is related to HTTP2. This is might be the same as #13959, but I'm not sure.
Also, I'm not sure this is the problem of golang's HTTP2 client library, or the problem of server side. (In most case, HTTP2 client works nicely.)
What did you expect to see?
I can connect to the server (by http2, or falling back to http1.1). At least, I want to see a more suggestive error message.
What did you see instead?
I saw an error message like following:
2017/07/11 15:22:01 http.Get failed, error: Get https://precious.jp: net/http: request canceled (Client.Timeout exceeded while awaiting headers)