// Forwarder forwards all incoming HTTP requests to configured transport.
type Forwarder struct {
	RoundTripper http.RoundTripper
	PassHost     bool
	Logger       func(error)
	ErrorHandler func(http.ResponseWriter, *http.Request, error)

	// internal variables
	rewriter *headerRewriter
}

// NewForwarder creates an instance of Forwarder based on the provided list of configuration options

- Added a path `/header?key=` to `agnhost netexec` allowing one to view what the header value is of the incoming request.

  Ex:
  ```
  $ curl -H "X-Forwarded-For: something" 172.17.0.2:8080/header?key=X-Forwarded-For
  something
  ```
   ([#107796](https://github.com/kubernetes/kubernetes/pull/107796), [@alexanderConstantinescu](https://github.com/alexanderConstantinescu))

([#55479](https://github.com/kubernetes/kubernetes/pull/55479), [@ijc](https://github.com/ijc))

			if err != nil {
				return fmt.Errorf("could not build port forwarder for ControlZ %s: %v", podName, err)
			}
			defer portForwarder.Close()
			err = portForwarder.Start()
			if err != nil {
				return fmt.Errorf("could not start port forwarder for ControlZ %s: %v", podName, err)
			}

			ctrlzClient := &ControlzClient{
				baseURL: &url.URL{

	if err != nil {
		return fmt.Errorf("could not build port forwarder for prometheus: %v", err)
	}

	if err = fw.Start(); err != nil {
		return fmt.Errorf("failure running port forward process: %v", err)
	}

	// Close the forwarder either when we exit or when an this processes is interrupted.
	defer fw.Close()
	dashboard.ClosePortForwarderOnInterrupt(fw)

- Allowed `Label` section in vSphere e2e cloud provider configuration. ([#112427](https://github.com/kubernetes/kubernetes/pull/112427), [@gnufied](https://github.com/gnufied))

	globalInternodeTransport http.RoundTripper

	globalRemoteTargetTransport http.RoundTripper

	globalDNSCache = &dnscache.Resolver{
		Timeout: 5 * time.Second,
	}

	globalForwarder *handlers.Forwarder

	globalTierConfigMgr *TierConfigMgr

	globalConsoleSrv *consoleapi.Server

	// handles service freeze or un-freeze S3 API calls.
	globalServiceFreeze atomic.Value

	// Only needed for tracking

		if err != nil {
			return fmt.Errorf("could not build port forwarder for %s: %v", flavor, err)
		}

		if err = fw.Start(); err != nil {
			fw.Close()
			// Try the next port
			continue
		}

		// Close the port forwarder when the command is terminated.
		ClosePortForwarderOnInterrupt(fw)

	success = true

	// Make sure we remove any existing headers before
	// proxying the request to another node.
	for k := range w.Header() {
		w.Header().Del(k)
	}

	f := handlers.NewForwarder(&handlers.Forwarder{
		PassHost:     true,
		RoundTripper: ep.Transport,
		ErrorHandler: func(w http.ResponseWriter, r *http.Request, err error) {
			success = false
			if err != nil && !errors.Is(err, context.Canceled) {

	defer xioutil.SafeClose(out)
	top := make([]*metaCacheEntry, len(in))
	nDone := 0
	ctxDone := ctx.Done()

	// Use simpler forwarder.
	if len(in) == 1 {
		for {
			select {
			case <-ctxDone:
				return ctx.Err()
			case v, ok := <-in[0]:
				if !ok {
					return nil
				}
				select {
				case <-ctxDone: