1 files changed, 95 insertions, 0 deletions
diff --git a/swarm/api/http/middleware.go b/swarm/api/http/middleware.go
new file mode 100644
index 000000000..d338a782c
--- /dev/null
+++ b/swarm/api/http/middleware.go
@@ -0,0 +1,95 @@
+package http
+
+import (
+	"fmt"
+	"net/http"
+	"runtime/debug"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/metrics"
+	"github.com/ethereum/go-ethereum/swarm/api"
+	"github.com/ethereum/go-ethereum/swarm/log"
+	"github.com/ethereum/go-ethereum/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 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.<br/>
+			Please click <a href='%[1]s'>here</a> if your browser does not redirect you within 5 seconds.<script>setTimeout("location.href='%[1]s';",5000);</script>`, "/"+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) {
+		writer := newLoggingResponseWriter(w)
+
+		h.ServeHTTP(writer, r)
+	})
+}
+
+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", debug.Stack(), "url", r.URL.String(), "headers", r.Header)
+			}
+		}()
+		h.ServeHTTP(w, r)
+	})
+}