| 1 | // Copyright 2013 The Go Authors. All rights reserved. |
|---|---|
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | // Package playground registers an HTTP handler at "/compile" that |
| 6 | // proxies requests to the golang.org playground service. |
| 7 | // This package may be used unaltered on App Engine Standard with Go 1.11+ runtime. |
| 8 | package playground // import "golang.org/x/tools/playground" |
| 9 | |
| 10 | import ( |
| 11 | "bytes" |
| 12 | "context" |
| 13 | "fmt" |
| 14 | "io" |
| 15 | "log" |
| 16 | "net/http" |
| 17 | "time" |
| 18 | ) |
| 19 | |
| 20 | const baseURL = "https://play.golang.org" |
| 21 | |
| 22 | func init() { |
| 23 | http.Handle("/compile", Proxy()) |
| 24 | } |
| 25 | |
| 26 | // Proxy returns a handler that can be registered on /compile to proxy requests to the Go playground. |
| 27 | // |
| 28 | // This package already contains a func init that does: |
| 29 | // |
| 30 | // func init() { |
| 31 | // http.Handle("/compile", Proxy()) |
| 32 | // } |
| 33 | // |
| 34 | // Proxy may be useful for servers that use HTTP muxes other than the default mux. |
| 35 | func Proxy() http.Handler { |
| 36 | return http.HandlerFunc(bounce) |
| 37 | } |
| 38 | |
| 39 | func bounce(w http.ResponseWriter, r *http.Request) { |
| 40 | b := new(bytes.Buffer) |
| 41 | if err := passThru(b, r); err != nil { |
| 42 | http.Error(w, "500 Internal Server Error", http.StatusInternalServerError) |
| 43 | log.Println(err) |
| 44 | return |
| 45 | } |
| 46 | io.Copy(w, b) |
| 47 | } |
| 48 | |
| 49 | func passThru(w io.Writer, req *http.Request) error { |
| 50 | defer req.Body.Close() |
| 51 | url := baseURL + req.URL.Path |
| 52 | ctx, cancel := context.WithTimeout(req.Context(), 60*time.Second) |
| 53 | defer cancel() |
| 54 | r, err := post(ctx, url, req.Header.Get("Content-Type"), req.Body) |
| 55 | if err != nil { |
| 56 | return fmt.Errorf("making POST request: %v", err) |
| 57 | } |
| 58 | defer r.Body.Close() |
| 59 | if _, err := io.Copy(w, r.Body); err != nil { |
| 60 | return fmt.Errorf("copying response Body: %v", err) |
| 61 | } |
| 62 | return nil |
| 63 | } |
| 64 | |
| 65 | func post(ctx context.Context, url, contentType string, body io.Reader) (*http.Response, error) { |
| 66 | req, err := http.NewRequest(http.MethodPost, url, body) |
| 67 | if err != nil { |
| 68 | return nil, fmt.Errorf("http.NewRequest: %v", err) |
| 69 | } |
| 70 | req.Header.Set("Content-Type", contentType) |
| 71 | return http.DefaultClient.Do(req.WithContext(ctx)) |
| 72 | } |
| 73 |
Members