tools/playground/playground.go

73 строки
2.0 KiB
Go

// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package playground registers an HTTP handler at "/compile" that
// proxies requests to the golang.org playground service.
// This package may be used unaltered on App Engine Standard with Go 1.11+ runtime.
package playground // import "golang.org/x/tools/playground"
import (
"bytes"
"context"
"fmt"
"io"
"log"
"net/http"
"time"
)
const baseURL = "https://play.golang.org"
func init() {
http.Handle("/compile", Proxy())
}
// Proxy returns a handler that can be registered on /compile to proxy requests to the Go playground.
//
// This package already contains a func init that does:
//
// func init() {
// http.Handle("/compile", Proxy())
// }
//
// Proxy may be useful for servers that use HTTP muxes other than the default mux.
func Proxy() http.Handler {
return http.HandlerFunc(bounce)
}
func bounce(w http.ResponseWriter, r *http.Request) {
b := new(bytes.Buffer)
if err := passThru(b, r); err != nil {
http.Error(w, "500 Internal Server Error", http.StatusInternalServerError)
log.Println(err)
return
}
io.Copy(w, b)
}
func passThru(w io.Writer, req *http.Request) error {
defer req.Body.Close()
url := baseURL + req.URL.Path
ctx, cancel := context.WithTimeout(req.Context(), 60*time.Second)
defer cancel()
r, err := post(ctx, url, req.Header.Get("Content-Type"), req.Body)
if err != nil {
return fmt.Errorf("making POST request: %v", err)
}
defer r.Body.Close()
if _, err := io.Copy(w, r.Body); err != nil {
return fmt.Errorf("copying response Body: %v", err)
}
return nil
}
func post(ctx context.Context, url, contentType string, body io.Reader) (*http.Response, error) {
req, err := http.NewRequest(http.MethodPost, url, body)
if err != nil {
return nil, fmt.Errorf("http.NewRequest: %v", err)
}
req.Header.Set("Content-Type", contentType)
return http.DefaultClient.Do(req.WithContext(ctx))
}