net: LookupHost Protocol not available on nodejs/wasm

[tdegris]

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

$ go version
go version devel go1.21-fe10464358 Fri May 5 13:20:58 2023 +0000 linux/amd64

Does this issue reproduce with the latest release?

No. After doing a git bisect, I have:

4c5d97990e4a39bd3e903f8e318b7234db3ba91f is the first bad commit
commit 4c5d97990e4a39bd3e903f8e318b7234db3ba91f
Author: Johan Brandhorst-Satzkorn <johan.brandhorst@gmail.com>
Date:   Fri Jan 27 22:50:54 2023 -0800

    net/http: disable fetch on NodeJS

which is the first commit breaking http requests in WASM.

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

go env Output

$ go env
GO111MODULE=""

GOARCH="amd64"

GOBIN=""

GOCACHE="..."

GOENV="..."

GOEXE=""

GOEXPERIMENT=""

GOFLAGS=""

GOHOSTARCH="amd64"

GOHOSTOS="linux"

GOINSECURE=""

GOMODCACHE="..."

GONOPROXY=""

GONOSUMDB=""

GOOS="linux"

GOPATH="..."

GOPRIVATE=""

GOPROXY="https://proxy.golang.org,direct"

GOROOT="..."

GOSUMDB="sum.golang.org"

GOTMPDIR=""

GOTOOLDIR="/.../go/pkg/tool/linux_amd64"

GOVCS=""

GOVERSION="devel go1.21-fe10464358 Fri May 5 13:20:58 2023 +0000"

GCCGO="gccgo"

GOAMD64="v1"

AR="ar"

CC="gcc"

CXX="g++"

CGO_ENABLED="1"

GOMOD="/dev/null"

GOWORK=""

CGO_CFLAGS="-O2 -g"

CGO_CPPFLAGS=""

CGO_CXXFLAGS="-O2 -g"

CGO_FFLAGS="-O2 -g"

CGO_LDFLAGS="-O2 -g"

PKG_CONFIG="pkg-config"

GOGCCFLAGS="-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build3099992878=/tmp/go-build -gno-record-gcc-switches"

What did you do?

Compile a WASM binary using:

GOOS=js GOARCH=wasm $GOROOT/bin/go build -o main.wasm main.go

then call from the WASM binary http.Client.Do which returns the following error:

http request error: Post "https://some.host/httpgrpc": dial tcp: lookup some.host: Protocol not available

What did you expect to see?

The http query to be executed.

What did you see instead?

An error saying that tcp is not available.

[seankhliao]

cc @golang/wasm

[sza-1]

Just faced with same issue on go1.22-2eca0b1 and node v20.4.0. Some details are below.

gotip version
go version devel go1.22-2eca0b1 Fri Jul 21 21:37:46 2023 +0000 linux/amd64

node --version
v20.4.0

Go code (GOARCH=wasm and GOOS=js):

resp, err := http.Get("https://www.example.com")
log.Println(resp, err)

JavaScript/Node.js code:

import './wasm_exec.js';

const go = new Go();

go.run((await WebAssembly.instantiate(fs.readFileSync(process.argv[2]), go.importObject)).instance);

Output:

17:16:42.906000 h2_bundle.go:10048: http2: Transport failed to get client conn for www.example.com:443: http2: no cached connection was available
17:16:42.916000 main_js.go:144: <nil> Get "https://www.example.com": dial tcp: lookup www.example.com: Protocol not available

Current latest go1.20.6 in the same configuration works properly.