Beispiel #1
0
// watchHandler watches w and keeps *resourceVersion up to date.
func (r *Reflector) watchHandler(w watch.Interface, resourceVersion *string, resyncCh <-chan time.Time, 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 <-resyncCh:
			return errorResyncRequested
		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 {
				util.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 {
				util.HandleError(fmt.Errorf("%s: unable to understand watch event %#v", r.name, event))
				continue
			}
			newResourceVersion := meta.ResourceVersion()
			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:
				util.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
}
Beispiel #2
0
// 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:
			glog.Warningf("Unable to listen on port %d: %v", port.Local, err)
		}
	}

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

	close(pf.Ready)

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

	return nil
}
Beispiel #3
0
func (pf *PortForwarder) Close() {
	// stop all listeners
	for _, l := range pf.listeners {
		if err := l.Close(); err != nil {
			util.HandleError(fmt.Errorf("error closing listener: %v", err))
		}
	}
}
Beispiel #4
0
// Returns error if ListAndWatch didn't even tried to initialize watch.
func (r *Reflector) ListAndWatch(stopCh <-chan struct{}) error {
	var resourceVersion string
	resyncCh, cleanup := r.resyncChan()
	defer cleanup()

	list, err := r.listerWatcher.List()
	if err != nil {
		return fmt.Errorf("%s: Failed to list %v: %v", r.name, r.expectedType, err)
	}
	meta, err := meta.Accessor(list)
	if err != nil {
		return fmt.Errorf("%s: Unable to understand list result %#v", r.name, list)
	}
	resourceVersion = meta.ResourceVersion()
	items, err := runtime.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)

	for {
		w, err := r.listerWatcher.Watch(resourceVersion)
		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:
				util.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, resyncCh, stopCh); err != nil {
			if err != errorResyncRequested && err != errorStopRequested {
				glog.Warningf("%s: watch of %v ended with: %v", r.name, r.expectedType, err)
			}
			return nil
		}
	}
}
Beispiel #5
0
// 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") {
				util.HandleError(fmt.Errorf("Error accepting connection on port %d: %v", port.Local, err))
			}
			return
		}
		go pf.handleConnection(conn, port)
	}
}
Beispiel #6
0
// 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 {
		util.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)
	glog.Infof("Forwarding from %s:%d -> %d", hostname, localPortUInt, port.Remote)

	return listener, nil
}
Beispiel #7
0
// 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()

	glog.Infof("Handling connection for %d", 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 {
		util.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 {
		util.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") {
			util.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") {
			util.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 {
		util.HandleError(err)
	}
}
Beispiel #8
0
func (e *Streamer) doStream() error {
	if e.upgrader == nil {
		e.upgrader = &defaultUpgrader{}
	}
	conn, err := e.upgrader.upgrade(e.req, e.config)
	if err != nil {
		return err
	}
	defer conn.Close()

	headers := http.Header{}

	// set up error stream
	errorChan := make(chan error)
	headers.Set(api.StreamType, api.StreamTypeError)
	errorStream, err := conn.CreateStream(headers)
	if err != nil {
		return err
	}

	go func() {
		message, err := ioutil.ReadAll(errorStream)
		switch {
		case err != nil && err != io.EOF:
			errorChan <- fmt.Errorf("error reading from error stream: %s", err)
		case len(message) > 0:
			errorChan <- fmt.Errorf("error executing remote command: %s", message)
		default:
			errorChan <- nil
		}
		close(errorChan)
	}()

	var wg sync.WaitGroup
	var once sync.Once

	// set up stdin stream
	if e.stdin != nil {
		headers.Set(api.StreamType, api.StreamTypeStdin)
		remoteStdin, err := conn.CreateStream(headers)
		if err != nil {
			return err
		}

		// copy from client's stdin to container's stdin
		go func() {
			// if e.stdin is noninteractive, e.g. `echo abc | kubectl exec -i <pod> -- cat`, make sure
			// we close remoteStdin as soon as the copy from e.stdin to remoteStdin finishes. Otherwise
			// the executed command will remain running.
			defer once.Do(func() { remoteStdin.Close() })

			if _, err := io.Copy(remoteStdin, e.stdin); err != nil {
				util.HandleError(err)
			}
		}()

		// read from remoteStdin until the stream is closed. this is essential to
		// be able to exit interactive sessions cleanly and not leak goroutines or
		// hang the client's terminal.
		//
		// go-dockerclient's current hijack implementation
		// (https://github.com/fsouza/go-dockerclient/blob/89f3d56d93788dfe85f864a44f85d9738fca0670/client.go#L564)
		// waits for all three streams (stdin/stdout/stderr) to finish copying
		// before returning. When hijack finishes copying stdout/stderr, it calls
		// Close() on its side of remoteStdin, which allows this copy to complete.
		// When that happens, we must Close() on our side of remoteStdin, to
		// allow the copy in hijack to complete, and hijack to return.
		go func() {
			defer once.Do(func() { remoteStdin.Close() })
			// this "copy" doesn't actually read anything - it's just here to wait for
			// the server to close remoteStdin.
			if _, err := io.Copy(ioutil.Discard, remoteStdin); err != nil {
				util.HandleError(err)
			}
		}()
	}

	// set up stdout stream
	if e.stdout != nil {
		headers.Set(api.StreamType, api.StreamTypeStdout)
		remoteStdout, err := conn.CreateStream(headers)
		if err != nil {
			return err
		}

		wg.Add(1)
		go func() {
			defer wg.Done()
			if _, err := io.Copy(e.stdout, remoteStdout); err != nil {
				util.HandleError(err)
			}
		}()
	}

	// set up stderr stream
	if e.stderr != nil && !e.tty {
		headers.Set(api.StreamType, api.StreamTypeStderr)
		remoteStderr, err := conn.CreateStream(headers)
		if err != nil {
			return err
		}

		wg.Add(1)
		go func() {
			defer wg.Done()
			if _, err := io.Copy(e.stderr, remoteStderr); err != nil {
				util.HandleError(err)
			}
		}()
	}

	// we're waiting for stdout/stderr to finish copying
	wg.Wait()

	// waits for errorStream to finish reading with an error or nil
	return <-errorChan
}