| 1 | package server |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "io" |
| 6 | "log" |
| 7 | "net/http" |
| 8 | "strings" |
| 9 | ) |
| 10 | |
| 11 | // SumdbHandler returns a handler that serves local sumdb for our modules |
| 12 | // and proxies to upstream sumdb for everything else. |
| 13 | func (s *Server) SumdbHandler(local http.Handler, upstream, prefix string) http.Handler { |
| 14 | return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { |
| 15 | path := strings.TrimPrefix(r.URL.Path, prefix) |
| 16 | |
| 17 | // /lookup/<module>@<version> — route based on module host. |
| 18 | if strings.HasPrefix(path, "/lookup/") { |
| 19 | lookupPath := strings.TrimPrefix(path, "/lookup/") |
| 20 | if atIdx := strings.LastIndex(lookupPath, "@"); atIdx > 0 { |
| 21 | modPath := lookupPath[:atIdx] |
| 22 | if strings.HasPrefix(modPath, s.Cfg.Host+"/") { |
| 23 | local.ServeHTTP(w, r) |
| 24 | return |
| 25 | } |
| 26 | } |
| 27 | |
| 28 | if upstream != "" { |
| 29 | s.proxySumdb(w, r, upstream, path) |
| 30 | return |
| 31 | } |
| 32 | } |
| 33 | |
| 34 | // /latest and /tile/ — always serve from our local tree. |
| 35 | local.ServeHTTP(w, r) |
| 36 | }) |
| 37 | } |
| 38 | |
| 39 | func (s *Server) proxySumdb(w http.ResponseWriter, r *http.Request, upstream, path string) { |
| 40 | // Check storage cache. |
| 41 | cacheKey := "sumdb/proxy" + path |
| 42 | if s.Store != nil { |
| 43 | data, ct, err := s.Store.Get(r.Context(), cacheKey) |
| 44 | if err == nil { |
| 45 | w.Header().Set("Content-Type", ct) |
| 46 | w.Write(data) |
| 47 | return |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | url := strings.TrimRight(upstream, "/") + path |
| 52 | req, err := http.NewRequestWithContext(r.Context(), http.MethodGet, url, nil) |
| 53 | if err != nil { |
| 54 | http.Error(w, "internal error", http.StatusInternalServerError) |
| 55 | return |
| 56 | } |
| 57 | |
| 58 | resp, err := s.HTTPClient.Do(req) |
| 59 | if err != nil { |
| 60 | log.Printf("sumdb proxy %s: %v", url, err) |
| 61 | http.Error(w, "upstream sumdb error", http.StatusBadGateway) |
| 62 | return |
| 63 | } |
| 64 | defer resp.Body.Close() |
| 65 | |
| 66 | body, err := io.ReadAll(resp.Body) |
| 67 | if err != nil { |
| 68 | http.Error(w, "upstream sumdb error", http.StatusBadGateway) |
| 69 | return |
| 70 | } |
| 71 | |
| 72 | ct := resp.Header.Get("Content-Type") |
| 73 | |
| 74 | // Cache successful responses. |
| 75 | if resp.StatusCode == http.StatusOK && s.Store != nil { |
| 76 | go func() { |
| 77 | if err := s.Store.Put(context.Background(), cacheKey, body, ct); err != nil { |
| 78 | log.Printf("sumdb cache put %s: %v", cacheKey, err) |
| 79 | } |
| 80 | }() |
| 81 | } |
| 82 | |
| 83 | if ct != "" { |
| 84 | w.Header().Set("Content-Type", ct) |
| 85 | } |
| 86 | w.WriteHeader(resp.StatusCode) |
| 87 | w.Write(body) |
| 88 | } |
| 89 | |