swarm: codebase split from go-ethereum (#1405)

api/http/middleware.go

@@ -0,0 +1,162 @@
+package http
+
+import (
+	"fmt"
+	"net/http"
+	"runtime/debug"
+	"strings"
+	"time"
+
+	"github.com/ethereum/go-ethereum/metrics"
+	"github.com/ethersphere/swarm/api"
+	"github.com/ethersphere/swarm/chunk"
+	"github.com/ethersphere/swarm/log"
+	"github.com/ethersphere/swarm/sctx"
+	"github.com/ethersphere/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.<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) {
+		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)
+	})
+}
+
+// InitUploadTag creates a new tag for an upload to the local HTTP proxy
+// if a tag is not named using the SwarmTagHeaderName, a fallback name will be used
+// when the Content-Length header is set, an ETA on chunking will be available since the
+// number of chunks to be split is known in advance (not including enclosing manifest chunks)
+// the tag can later be accessed using the appropriate identifier in the request context
+func InitUploadTag(h http.Handler, tags *chunk.Tags) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		var (
+			tagName        string
+			err            error
+			estimatedTotal int64 = 0
+			contentType          = r.Header.Get("Content-Type")
+			headerTag            = r.Header.Get(SwarmTagHeaderName)
+		)
+		if headerTag != "" {
+			tagName = headerTag
+			log.Trace("got tag name from http header", "tagName", tagName)
+		} else {
+			tagName = fmt.Sprintf("unnamed_tag_%d", time.Now().Unix())
+		}
+
+		if !strings.Contains(contentType, "multipart") && r.ContentLength > 0 {
+			log.Trace("calculating tag size", "contentType", contentType, "contentLength", r.ContentLength)
+			uri := GetURI(r.Context())
+			if uri != nil {
+				log.Debug("got uri from context")
+				if uri.Addr == "encrypt" {
+					estimatedTotal = calculateNumberOfChunks(r.ContentLength, true)
+				} else {
+					estimatedTotal = calculateNumberOfChunks(r.ContentLength, false)
+				}
+			}
+		}
+
+		log.Trace("creating tag", "tagName", tagName, "estimatedTotal", estimatedTotal)
+
+		t, err := tags.New(tagName, estimatedTotal)
+		if err != nil {
+			log.Error("error creating tag", "err", err, "tagName", tagName)
+		}
+
+		log.Trace("setting tag id to context", "uid", t.Uid)
+		ctx := sctx.SetTag(r.Context(), t.Uid)
+
+		h.ServeHTTP(w, r.WithContext(ctx))
+	})
+}
+
+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)
+	})
+}