kubernetes/staging/src/k8s.io/client-go/tools/portforward/tunneling_dialer.go

const PingPeriod …

type tunnelingDialer …

// NewTunnelingDialer creates and returns the tunnelingDialer structure which implemements the "httpstream.Dialer"
// interface. The dialer can upgrade a websocket request, creating a websocket connection. This function
// returns an error if one occurs.
func NewSPDYOverWebsocketDialer(url *url.URL, config *restclient.Config) (httpstream.Dialer, error) { … }

// Dial upgrades to a tunneling streaming connection, returning a SPDY connection
// containing a WebSockets connection (which implements "net.Conn"). Also
// returns the protocol negotiated, or an error.
func (d *tunnelingDialer) Dial(protocols ...string) (httpstream.Connection, string, error) { … }