package http import ( "fmt" "net/http" "runtime/debug" "strings" "time" "github.com/dexon-foundation/dexon/metrics" "github.com/dexon-foundation/dexon/swarm/api" "github.com/dexon-foundation/dexon/swarm/log" "github.com/dexon-foundation/dexon/swarm/sctx" "github.com/dexon-foundation/dexon/swarm/spancontext" "github.com/pborman/uuid" ) // Adapt chains h (main request handler) main handler to adapters (middleware handlers) // Please note that the order of execution for `adapters` is FIFO (adapters[0] will be executed first) func Adapt(h http.Handler, adapters ...Adapter) http.Handler { for i := range adapters { adapter := adapters[len(adapters)-1-i] h = adapter(h) } return h } type Adapter func(http.Handler) http.Handler func SetRequestID(h http.Handler) http.Handler { return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { r = r.WithContext(SetRUID(r.Context(), uuid.New()[:8])) metrics.GetOrRegisterCounter(fmt.Sprintf("http.request.%s", r.Method), nil).Inc(1) log.Info("created ruid for request", "ruid", GetRUID(r.Context()), "method", r.Method, "url", r.RequestURI) h.ServeHTTP(w, r) }) } func SetRequestHost(h http.Handler) http.Handler { return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { r = r.WithContext(sctx.SetHost(r.Context(), r.Host)) log.Info("setting request host", "ruid", GetRUID(r.Context()), "host", sctx.GetHost(r.Context())) h.ServeHTTP(w, r) }) } func ParseURI(h http.Handler) http.Handler { return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { uri, err := api.Parse(strings.TrimLeft(r.URL.Path, "/")) if err != nil { w.WriteHeader(http.StatusBadRequest) respondError(w, r, fmt.Sprintf("invalid URI %q", r.URL.Path), http.StatusBadRequest) return } if uri.Addr != "" && strings.HasPrefix(uri.Addr, "0x") { uri.Addr = strings.TrimPrefix(uri.Addr, "0x") msg := fmt.Sprintf(`The requested hash seems to be prefixed with '0x'. You will be redirected to the correct URL within 5 seconds.
Please click here if your browser does not redirect you within 5 seconds.`, "/"+uri.String()) w.WriteHeader(http.StatusNotFound) w.Write([]byte(msg)) return } ctx := r.Context() r = r.WithContext(SetURI(ctx, uri)) log.Debug("parsed request path", "ruid", GetRUID(r.Context()), "method", r.Method, "uri.Addr", uri.Addr, "uri.Path", uri.Path, "uri.Scheme", uri.Scheme) h.ServeHTTP(w, r) }) } func InitLoggingResponseWriter(h http.Handler) http.Handler { return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { tn := time.Now() writer := newLoggingResponseWriter(w) h.ServeHTTP(writer, r) ts := time.Since(tn) log.Info("request served", "ruid", GetRUID(r.Context()), "code", writer.statusCode, "time", ts) metrics.GetOrRegisterResettingTimer(fmt.Sprintf("http.request.%s.time", r.Method), nil).Update(ts) metrics.GetOrRegisterResettingTimer(fmt.Sprintf("http.request.%s.%d.time", r.Method, writer.statusCode), nil).Update(ts) }) } func InstrumentOpenTracing(h http.Handler) http.Handler { return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { uri := GetURI(r.Context()) if uri == nil || r.Method == "" || (uri != nil && uri.Scheme == "") { h.ServeHTTP(w, r) // soft fail return } spanName := fmt.Sprintf("http.%s.%s", r.Method, uri.Scheme) ctx, sp := spancontext.StartSpan(r.Context(), spanName) defer sp.Finish() h.ServeHTTP(w, r.WithContext(ctx)) }) } func RecoverPanic(h http.Handler) http.Handler { return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { defer func() { if err := recover(); err != nil { log.Error("panic recovery!", "stack trace", string(debug.Stack()), "url", r.URL.String(), "headers", r.Header) } }() h.ServeHTTP(w, r) }) }