Golang runtime.HandleError函數代碼示例

// UpgradeResponse upgrades an HTTP response to one that supports multiplexed
// streams. newStreamHandler will be called synchronously whenever the
// other end of the upgraded connection creates a new stream.
func (u responseUpgrader) UpgradeResponse(w http.ResponseWriter, req *http.Request, newStreamHandler httpstream.NewStreamHandler) httpstream.Connection {
	connectionHeader := strings.ToLower(req.Header.Get(httpstream.HeaderConnection))
	upgradeHeader := strings.ToLower(req.Header.Get(httpstream.HeaderUpgrade))
	if !strings.Contains(connectionHeader, strings.ToLower(httpstream.HeaderUpgrade)) || !strings.Contains(upgradeHeader, strings.ToLower(HeaderSpdy31)) {
		w.WriteHeader(http.StatusBadRequest)
		fmt.Fprintf(w, "unable to upgrade: missing upgrade headers in request: %#v", req.Header)
		return nil
	}

	hijacker, ok := w.(http.Hijacker)
	if !ok {
		w.WriteHeader(http.StatusInternalServerError)
		fmt.Fprintf(w, "unable to upgrade: unable to hijack response")
		return nil
	}

	w.Header().Add(httpstream.HeaderConnection, httpstream.HeaderUpgrade)
	w.Header().Add(httpstream.HeaderUpgrade, HeaderSpdy31)
	w.WriteHeader(http.StatusSwitchingProtocols)

	conn, _, err := hijacker.Hijack()
	if err != nil {
		runtime.HandleError(fmt.Errorf("unable to upgrade: error hijacking response: %v", err))
		return nil
	}

	spdyConn, err := NewServerConnection(conn, newStreamHandler)
	if err != nil {
		runtime.HandleError(fmt.Errorf("unable to upgrade: error creating SPDY server connection: %v", err))
		return nil
	}

	return spdyConn
}

// watchHandler watches w and keeps *resourceVersion up to date.
func (r *Reflector) watchHandler(w watch.Interface, resourceVersion *string, errc chan error, stopCh <-chan struct{}) error {
	start := time.Now()
	eventCount := 0

	// Stopping the watcher should be idempotent and if we return from this function there's no way
	// we're coming back in with the same watch interface.
	defer w.Stop()

loop:
	for {
		select {
		case <-stopCh:
			return errorStopRequested
		case err := <-errc:
			return err
		case event, ok := <-w.ResultChan():
			if !ok {
				break loop
			}
			if event.Type == watch.Error {
				return apierrs.FromObject(event.Object)
			}
			if e, a := r.expectedType, reflect.TypeOf(event.Object); e != nil && e != a {
				utilruntime.HandleError(fmt.Errorf("%s: expected type %v, but watch event object had type %v", r.name, e, a))
				continue
			}
			meta, err := meta.Accessor(event.Object)
			if err != nil {
				utilruntime.HandleError(fmt.Errorf("%s: unable to understand watch event %#v", r.name, event))
				continue
			}
			newResourceVersion := meta.GetResourceVersion()
			switch event.Type {
			case watch.Added:
				r.store.Add(event.Object)
			case watch.Modified:
				r.store.Update(event.Object)
			case watch.Deleted:
				// TODO: Will any consumers need access to the "last known
				// state", which is passed in event.Object? If so, may need
				// to change this.
				r.store.Delete(event.Object)
			default:
				utilruntime.HandleError(fmt.Errorf("%s: unable to understand watch event %#v", r.name, event))
			}
			*resourceVersion = newResourceVersion
			r.setLastSyncResourceVersion(newResourceVersion)
			eventCount++
		}
	}

	watchDuration := time.Now().Sub(start)
	if watchDuration < 1*time.Second && eventCount == 0 {
		glog.V(4).Infof("%s: Unexpected watch close - watch lasted less than a second and no items received", r.name)
		return errors.New("very short watch")
	}
	glog.V(4).Infof("%s: Watch close - %v total %v items received", r.name, r.expectedType, eventCount)
	return nil
}

// forward dials the remote host specific in req, upgrades the request, starts
// listeners for each port specified in ports, and forwards local connections
// to the remote host via streams.
func (pf *PortForwarder) forward() error {
	var err error

	listenSuccess := false
	for _, port := range pf.ports {
		err = pf.listenOnPort(&port)
		switch {
		case err == nil:
			listenSuccess = true
		default:
			if pf.errOut != nil {
				fmt.Fprintf(pf.errOut, "Unable to listen on port %d: %v\n", port.Local, err)
			}
		}
	}

	if !listenSuccess {
		return fmt.Errorf("Unable to listen on any of the requested ports: %v", pf.ports)
	}

	if pf.Ready != nil {
		close(pf.Ready)
	}

	// wait for interrupt or conn closure
	select {
	case <-pf.stopChan:
	case <-pf.streamConn.CloseChan():
		runtime.HandleError(errors.New("lost connection to pod"))
	}

	return nil
}

func recordToSink(sink EventSink, event *v1.Event, eventCorrelator *EventCorrelator, randGen *rand.Rand, sleepDuration time.Duration) {
	// Make a copy before modification, because there could be multiple listeners.
	// Events are safe to copy like this.
	eventCopy := *event
	event = &eventCopy
	result, err := eventCorrelator.EventCorrelate(event)
	if err != nil {
		utilruntime.HandleError(err)
	}
	if result.Skip {
		return
	}
	tries := 0
	for {
		if recordEvent(sink, result.Event, result.Patch, result.Event.Count > 1, eventCorrelator) {
			break
		}
		tries++
		if tries >= maxTriesPerEvent {
			glog.Errorf("Unable to write event '%#v' (retry limit exceeded!)", event)
			break
		}
		// Randomize the first sleep so that various clients won't all be
		// synced up if the master goes down.
		if tries == 1 {
			time.Sleep(time.Duration(float64(sleepDuration) * randGen.Float64()))
		} else {
			time.Sleep(sleepDuration)
		}
	}
}

// ServePortForward handles a port forwarding request.  A single request is
// kept alive as long as the client is still alive and the connection has not
// been timed out due to idleness. This function handles multiple forwarded
// connections; i.e., multiple `curl http://localhost:8888/` requests will be
// handled by a single invocation of ServePortForward.
func ServePortForward(w http.ResponseWriter, req *http.Request, portForwarder PortForwarder, podName string, uid types.UID, idleTimeout time.Duration, streamCreationTimeout time.Duration) {
	supportedPortForwardProtocols := []string{PortForwardProtocolV1Name}
	_, err := httpstream.Handshake(req, w, supportedPortForwardProtocols)
	// negotiated protocol isn't currently used server side, but could be in the future
	if err != nil {
		// Handshake writes the error to the client
		utilruntime.HandleError(err)
		return
	}

	streamChan := make(chan httpstream.Stream, 1)

	glog.V(5).Infof("Upgrading port forward response")
	upgrader := spdy.NewResponseUpgrader()
	conn := upgrader.UpgradeResponse(w, req, portForwardStreamReceived(streamChan))
	if conn == nil {
		return
	}
	defer conn.Close()

	glog.V(5).Infof("(conn=%p) setting port forwarding streaming connection idle timeout to %v", conn, idleTimeout)
	conn.SetIdleTimeout(idleTimeout)

	h := &portForwardStreamHandler{
		conn:                  conn,
		streamChan:            streamChan,
		streamPairs:           make(map[string]*portForwardStreamPair),
		streamCreationTimeout: streamCreationTimeout,
		pod:       podName,
		uid:       uid,
		forwarder: portForwarder,
	}
	h.run()
}

// run is the main loop for the portForwardStreamHandler. It processes new
// streams, invoking portForward for each complete stream pair. The loop exits
// when the httpstream.Connection is closed.
func (h *portForwardStreamHandler) run() {
	glog.V(5).Infof("(conn=%p) waiting for port forward streams", h.conn)
Loop:
	for {
		select {
		case <-h.conn.CloseChan():
			glog.V(5).Infof("(conn=%p) upgraded connection closed", h.conn)
			break Loop
		case stream := <-h.streamChan:
			requestID := h.requestID(stream)
			streamType := stream.Headers().Get(api.StreamType)
			glog.V(5).Infof("(conn=%p, request=%s) received new stream of type %s", h.conn, requestID, streamType)

			p, created := h.getStreamPair(requestID)
			if created {
				go h.monitorStreamPair(p, time.After(h.streamCreationTimeout))
			}
			if complete, err := p.add(stream); err != nil {
				msg := fmt.Sprintf("error processing stream for request %s: %v", requestID, err)
				utilruntime.HandleError(errors.New(msg))
				p.printError(msg)
			} else if complete {
				go h.portForward(p)
			}
		}
	}
}

// RunUntil starts a watch and handles watch events. Will restart the watch if it is closed.
// RunUntil starts a goroutine and returns immediately. It will exit when stopCh is closed.
func (r *Reflector) RunUntil(stopCh <-chan struct{}) {
	glog.V(3).Infof("Starting reflector %v (%s) from %s", r.expectedType, r.resyncPeriod, r.name)
	go wait.Until(func() {
		if err := r.ListAndWatch(stopCh); err != nil {
			utilruntime.HandleError(err)
		}
	}, r.period, stopCh)
}

// Run starts a watch and handles watch events. Will restart the watch if it is closed.
// Run starts a goroutine and returns immediately.
func (r *Reflector) Run() {
	glog.V(3).Infof("Starting reflector %v (%s) from %s", r.expectedType, r.resyncPeriod, r.name)
	go wait.Until(func() {
		if err := r.ListAndWatch(wait.NeverStop); err != nil {
			utilruntime.HandleError(err)
		}
	}, r.period, wait.NeverStop)
}

func (pf *PortForwarder) Close() {
	// stop all listeners
	for _, l := range pf.listeners {
		if err := l.Close(); err != nil {
			runtime.HandleError(fmt.Errorf("error closing listener: %v", err))
		}
	}
}

// monitorStreamPair waits for the pair to receive both its error and data
// streams, or for the timeout to expire (whichever happens first), and then
// removes the pair.
func (h *portForwardStreamHandler) monitorStreamPair(p *portForwardStreamPair, timeout <-chan time.Time) {
	select {
	case <-timeout:
		err := fmt.Errorf("(conn=%v, request=%s) timed out waiting for streams", h.conn, p.requestID)
		utilruntime.HandleError(err)
		p.printError(err.Error())
	case <-p.complete:
		glog.V(5).Infof("(conn=%v, request=%s) successfully received error and data streams", h.conn, p.requestID)
	}
	h.removeStreamPair(p.requestID)
}

// waitForConnection waits for new connections to listener and handles them in
// the background.
func (pf *PortForwarder) waitForConnection(listener net.Listener, port ForwardedPort) {
	for {
		conn, err := listener.Accept()
		if err != nil {
			// TODO consider using something like https://github.com/hydrogen18/stoppableListener?
			if !strings.Contains(strings.ToLower(err.Error()), "use of closed network connection") {
				runtime.HandleError(fmt.Errorf("Error accepting connection on port %d: %v", port.Local, err))
			}
			return
		}
		go pf.handleConnection(conn, port)
	}
}

// portForward invokes the portForwardStreamHandler's forwarder.PortForward
// function for the given stream pair.
func (h *portForwardStreamHandler) portForward(p *portForwardStreamPair) {
	defer p.dataStream.Close()
	defer p.errorStream.Close()

	portString := p.dataStream.Headers().Get(api.PortHeader)
	port, _ := strconv.ParseUint(portString, 10, 16)

	glog.V(5).Infof("(conn=%p, request=%s) invoking forwarder.PortForward for port %s", h.conn, p.requestID, portString)
	err := h.forwarder.PortForward(h.pod, h.uid, uint16(port), p.dataStream)
	glog.V(5).Infof("(conn=%p, request=%s) done invoking forwarder.PortForward for port %s", h.conn, p.requestID, portString)

	if err != nil {
		msg := fmt.Errorf("error forwarding port %d to pod %s, uid %v: %v", port, h.pod, h.uid, err)
		utilruntime.HandleError(msg)
		fmt.Fprint(p.errorStream, msg.Error())
	}
}

// getListener creates a listener on the interface targeted by the given hostname on the given port with
// the given protocol. protocol is in net.Listen style which basically admits values like tcp, tcp4, tcp6
func (pf *PortForwarder) getListener(protocol string, hostname string, port *ForwardedPort) (net.Listener, error) {
	listener, err := net.Listen(protocol, fmt.Sprintf("%s:%d", hostname, port.Local))
	if err != nil {
		runtime.HandleError(fmt.Errorf("Unable to create listener: Error %s", err))
		return nil, err
	}
	listenerAddress := listener.Addr().String()
	host, localPort, _ := net.SplitHostPort(listenerAddress)
	localPortUInt, err := strconv.ParseUint(localPort, 10, 16)

	if err != nil {
		return nil, fmt.Errorf("Error parsing local port: %s from %s (%s)", err, listenerAddress, host)
	}
	port.Local = uint16(localPortUInt)
	if pf.out != nil {
		fmt.Fprintf(pf.out, "Forwarding from %s:%d -> %d\n", hostname, localPortUInt, port.Remote)
	}

	return listener, nil
}

// ListAndWatch first lists all items and get the resource version at the moment of call,
// and then use the resource version to watch.
// It returns error if ListAndWatch didn't even try to initialize watch.
func (r *Reflector) ListAndWatch(stopCh <-chan struct{}) error {
	glog.V(3).Infof("Listing and watching %v from %s", r.expectedType, r.name)
	var resourceVersion string
	resyncCh, cleanup := r.resyncChan()
	defer cleanup()

	// Explicitly set "0" as resource version - it's fine for the List()
	// to be served from cache and potentially be delayed relative to
	// etcd contents. Reflector framework will catch up via Watch() eventually.
	options := api.ListOptions{ResourceVersion: "0"}
	list, err := r.listerWatcher.List(options)
	if err != nil {
		return fmt.Errorf("%s: Failed to list %v: %v", r.name, r.expectedType, err)
	}
	listMetaInterface, err := meta.ListAccessor(list)
	if err != nil {
		return fmt.Errorf("%s: Unable to understand list result %#v: %v", r.name, list, err)
	}
	resourceVersion = listMetaInterface.GetResourceVersion()
	items, err := meta.ExtractList(list)
	if err != nil {
		return fmt.Errorf("%s: Unable to understand list result %#v (%v)", r.name, list, err)
	}
	if err := r.syncWith(items, resourceVersion); err != nil {
		return fmt.Errorf("%s: Unable to sync list result: %v", r.name, err)
	}
	r.setLastSyncResourceVersion(resourceVersion)

	resyncerrc := make(chan error, 1)
	go func() {
		for {
			select {
			case <-resyncCh:
			case <-stopCh:
				return
			}
			glog.V(4).Infof("%s: forcing resync", r.name)
			if err := r.store.Resync(); err != nil {
				resyncerrc <- err
				return
			}
			cleanup()
			resyncCh, cleanup = r.resyncChan()
		}
	}()

	for {
		timemoutseconds := int64(minWatchTimeout.Seconds() * (rand.Float64() + 1.0))
		options = api.ListOptions{
			ResourceVersion: resourceVersion,
			// We want to avoid situations of hanging watchers. Stop any wachers that do not
			// receive any events within the timeout window.
			TimeoutSeconds: &timemoutseconds,
		}

		w, err := r.listerWatcher.Watch(options)
		if err != nil {
			switch err {
			case io.EOF:
				// watch closed normally
			case io.ErrUnexpectedEOF:
				glog.V(1).Infof("%s: Watch for %v closed with unexpected EOF: %v", r.name, r.expectedType, err)
			default:
				utilruntime.HandleError(fmt.Errorf("%s: Failed to watch %v: %v", r.name, r.expectedType, err))
			}
			// If this is "connection refused" error, it means that most likely apiserver is not responsive.
			// It doesn't make sense to re-list all objects because most likely we will be able to restart
			// watch where we ended.
			// If that's the case wait and resend watch request.
			if urlError, ok := err.(*url.Error); ok {
				if opError, ok := urlError.Err.(*net.OpError); ok {
					if errno, ok := opError.Err.(syscall.Errno); ok && errno == syscall.ECONNREFUSED {
						time.Sleep(time.Second)
						continue
					}
				}
			}
			return nil
		}

		if err := r.watchHandler(w, &resourceVersion, resyncerrc, stopCh); err != nil {
			if err != errorStopRequested {
				glog.Warningf("%s: watch of %v ended with: %v", r.name, r.expectedType, err)
			}
			return nil
		}
	}
}

// handleConnection copies data between the local connection and the stream to
// the remote server.
func (pf *PortForwarder) handleConnection(conn net.Conn, port ForwardedPort) {
	defer conn.Close()

	if pf.out != nil {
		fmt.Fprintf(pf.out, "Handling connection for %d\n", port.Local)
	}

	requestID := pf.nextRequestID()

	// create error stream
	headers := http.Header{}
	headers.Set(api.StreamType, api.StreamTypeError)
	headers.Set(api.PortHeader, fmt.Sprintf("%d", port.Remote))
	headers.Set(api.PortForwardRequestIDHeader, strconv.Itoa(requestID))
	errorStream, err := pf.streamConn.CreateStream(headers)
	if err != nil {
		runtime.HandleError(fmt.Errorf("error creating error stream for port %d -> %d: %v", port.Local, port.Remote, err))
		return
	}
	// we're not writing to this stream
	errorStream.Close()

	errorChan := make(chan error)
	go func() {
		message, err := ioutil.ReadAll(errorStream)
		switch {
		case err != nil:
			errorChan <- fmt.Errorf("error reading from error stream for port %d -> %d: %v", port.Local, port.Remote, err)
		case len(message) > 0:
			errorChan <- fmt.Errorf("an error occurred forwarding %d -> %d: %v", port.Local, port.Remote, string(message))
		}
		close(errorChan)
	}()

	// create data stream
	headers.Set(api.StreamType, api.StreamTypeData)
	dataStream, err := pf.streamConn.CreateStream(headers)
	if err != nil {
		runtime.HandleError(fmt.Errorf("error creating forwarding stream for port %d -> %d: %v", port.Local, port.Remote, err))
		return
	}

	localError := make(chan struct{})
	remoteDone := make(chan struct{})

	go func() {
		// Copy from the remote side to the local port.
		if _, err := io.Copy(conn, dataStream); err != nil && !strings.Contains(err.Error(), "use of closed network connection") {
			runtime.HandleError(fmt.Errorf("error copying from remote stream to local connection: %v", err))
		}

		// inform the select below that the remote copy is done
		close(remoteDone)
	}()

	go func() {
		// inform server we're not sending any more data after copy unblocks
		defer dataStream.Close()

		// Copy from the local port to the remote side.
		if _, err := io.Copy(dataStream, conn); err != nil && !strings.Contains(err.Error(), "use of closed network connection") {
			runtime.HandleError(fmt.Errorf("error copying from local connection to remote stream: %v", err))
			// break out of the select below without waiting for the other copy to finish
			close(localError)
		}
	}()

	// wait for either a local->remote error or for copying from remote->local to finish
	select {
	case <-remoteDone:
	case <-localError:
	}

	// always expect something on errorChan (it may be nil)
	err = <-errorChan
	if err != nil {
		runtime.HandleError(err)
	}
}