TUN-3400: Use Go HTTP2 library as transport to connect with the edge

origin/server.go

@@ -0,0 +1,160 @@
+package origin
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"github.com/cloudflare/cloudflared/h2mux"
+	"github.com/cloudflare/cloudflared/logger"
+	"golang.org/x/net/http2"
+)
+
+type cfdServer struct {
+	httpServer      *http2.Server
+	originClient    http.RoundTripper
+	logger          logger.Service
+	originURL       *url.URL
+	connectionIndex string
+	config          *TunnelConfig
+}
+
+func (c *cfdServer) serve(ctx context.Context, conn net.Conn) {
+	go func() {
+		<-ctx.Done()
+		conn.Close()
+	}()
+	c.httpServer.ServeConn(conn, &http2.ServeConnOpts{
+		Context: ctx,
+		Handler: c,
+	})
+}
+
+func (c *cfdServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	c.config.Metrics.incrementRequests(c.connectionIndex)
+	defer c.config.Metrics.decrementConcurrentRequests(c.connectionIndex)
+
+	cfRay := findCfRayHeader(r)
+	lbProbe := isLBProbeRequest(r)
+	c.logRequest(r, cfRay, lbProbe)
+
+	r.URL = c.originURL
+	// TODO: TUN-3406 support websocket, event stream and WSGI servers.
+	var resp *http.Response
+	var err error
+	if strings.ToLower(r.Header.Get("Cf-Int-Argo-Tunnel-Upgrade")) == "websocket" {
+		resp, err = serveWebsocket(newWebsocketBody(w, r, c.logger), r, c.config.HTTPHostHeader, c.config.ClientTlsConfig)
+	} else {
+		resp, err = c.originClient.RoundTrip(r)
+	}
+	if err != nil {
+		c.writeErrorResponse(w, err)
+		return
+	}
+	defer resp.Body.Close()
+
+	w.WriteHeader(resp.StatusCode)
+	_, err = io.Copy(w, resp.Body)
+	if err != nil {
+		c.logger.Errorf("Copy response error, err: %v", err)
+		w.WriteHeader(http.StatusBadGateway)
+		return
+	}
+}
+
+func (c *cfdServer) writeErrorResponse(w http.ResponseWriter, err error) {
+	c.logger.Errorf("HTTP request error: %s", err)
+	c.config.Metrics.incrementResponses(c.connectionIndex, "502")
+	jsonResponseMetaHeader, err := json.Marshal(h2mux.ResponseMetaHeader{Source: h2mux.ResponseSourceCloudflared})
+	if err != nil {
+		panic(err)
+	}
+	w.Header().Set(h2mux.ResponseMetaHeaderField, string(jsonResponseMetaHeader))
+	w.WriteHeader(http.StatusBadGateway)
+}
+
+func (c *cfdServer) logRequest(r *http.Request, cfRay string, lbProbe bool) {
+	logger := c.logger
+	if cfRay != "" {
+		logger.Debugf("CF-RAY: %s %s %s %s", cfRay, r.Method, r.URL, r.Proto)
+	} else if lbProbe {
+		logger.Debugf("CF-RAY: %s Load Balancer health check %s %s %s", cfRay, r.Method, r.URL, r.Proto)
+	} else {
+		logger.Debugf("CF-RAY: %s All requests should have a CF-RAY header. Please open a support ticket with Cloudflare. %s %s %s ", cfRay, r.Method, r.URL, r.Proto)
+	}
+	logger.Infof("CF-RAY: %s Request Headers %+v", cfRay, r.Header)
+
+	if contentLen := r.ContentLength; contentLen == -1 {
+		logger.Debugf("CF-RAY: %s Request Content length unknown", cfRay)
+	} else {
+		logger.Debugf("CF-RAY: %s Request content length %d", cfRay, contentLen)
+	}
+}
+
+func (c *cfdServer) logResponseOk(r *http.Response, cfRay string, lbProbe bool) {
+	c.config.Metrics.incrementResponses(c.connectionIndex, "200")
+	logger := c.logger
+	if cfRay != "" {
+		logger.Debugf("CF-RAY: %s %s", cfRay, r.Status)
+	} else if lbProbe {
+		logger.Debugf("Response to Load Balancer health check %s", r.Status)
+	} else {
+		logger.Infof("%s", r.Status)
+	}
+	logger.Debugf("CF-RAY: %s Response Headers %+v", cfRay, r.Header)
+
+	if contentLen := r.ContentLength; contentLen == -1 {
+		logger.Debugf("CF-RAY: %s Response content length unknown", cfRay)
+	} else {
+		logger.Debugf("CF-RAY: %s Response content length %d", cfRay, contentLen)
+	}
+}
+
+type WebsocketResp interface {
+	WriteRespHeaders(*http.Response) error
+	io.ReadWriter
+}
+
+type http2WebsocketResp struct {
+	pr *io.PipeReader
+	w  http.ResponseWriter
+}
+
+func newWebsocketBody(w http.ResponseWriter, r *http.Request, logger logger.Service) *http2WebsocketResp {
+	pr, pw := io.Pipe()
+	go func() {
+		n, err := io.Copy(pw, r.Body)
+		logger.Errorf("websocket body copy ended, err: %v, bytes: %d", err, n)
+	}()
+	return &http2WebsocketResp{pr: pr, w: w}
+}
+
+func (wr *http2WebsocketResp) WriteRespHeaders(resp *http.Response) error {
+	dest := wr.w.Header()
+	for name, values := range resp.Header {
+		for _, v := range values {
+			dest.Add(name, v)
+		}
+	}
+	return nil
+}
+
+func (wr *http2WebsocketResp) Read(p []byte) (n int, err error) {
+	return wr.pr.Read(p)
+}
+
+func (wr *http2WebsocketResp) Write(p []byte) (n int, err error) {
+	return wr.w.Write(p)
+}
+
+type h2muxWebsocketResp struct {
+	*h2mux.MuxedStream
+}
+
+func (wr *h2muxWebsocketResp) WriteRespHeaders(resp *http.Response) error {
+	return wr.WriteHeaders(h2mux.H1ResponseToH2ResponseHeaders(resp))
+}