var DefaultConfig = Config{
	StreamIdleTimeout:               4 * time.Hour,
	StreamCreationTimeout:           remotecommandconsts.DefaultStreamCreationTimeout,
	SupportedRemoteCommandProtocols: remotecommandconsts.SupportedStreamingProtocols,
	SupportedPortForwardProtocols:   portforward.SupportedProtocols,
}

type Config struct {
	// The host:port address the server will listen on.
	Addr string
	// The optional base URL for constructing streaming URLs. If empty, the baseURL will be
	// constructed from the serve address.
	// Note that for port "0", the URL port will be set to actual port in use.
	BaseURL *url.URL

	// How long to leave idle connections open for.
	StreamIdleTimeout time.Duration
	// How long to wait for clients to create streams. Only used for SPDY streaming.
	StreamCreationTimeout time.Duration

	// The streaming protocols the server supports (understands and permits).  See
	// k8s.io/kubernetes/pkg/kubelet/server/remotecommand/constants.go for available protocols.
	// Only used for SPDY streaming.
	SupportedRemoteCommandProtocols []string

	// The streaming protocols the server supports (understands and permits).  See
	// k8s.io/kubernetes/pkg/kubelet/server/portforward/constants.go for available protocols.
	// Only used for SPDY streaming.
	SupportedPortForwardProtocols []string

	// The config for serving over TLS. If nil, TLS will not be used.
	TLSConfig *tls.Config
}

type Runtime interface {
	Exec(ctx context.Context, containerID string, cmd []string, in io.Reader, out, err io.WriteCloser, tty bool, resize <-chan remotecommand.TerminalSize) error
	Attach(ctx context.Context, containerID string, in io.Reader, out, err io.WriteCloser, tty bool, resize <-chan remotecommand.TerminalSize) error
	PortForward(ctx context.Context, podSandboxID string, port int32, stream io.ReadWriteCloser) error
}

type Server interface {
	http.Handler

	// Get the serving URL for the requests.
	// Requests must not be nil. Responses may be nil iff an error is returned.
	GetExec(*runtimeapi.ExecRequest) (*runtimeapi.ExecResponse, error)
	GetAttach(req *runtimeapi.AttachRequest) (*runtimeapi.AttachResponse, error)
	GetPortForward(*runtimeapi.PortForwardRequest) (*runtimeapi.PortForwardResponse, error)

	// Start the server.
	// addr is the address to serve on (address:port) stayUp indicates whether the server should
	// listen until Stop() is called, or automatically stop after all expected connections are
	// closed. Calling Get{Exec,Attach,PortForward} increments the expected connection count.
	// Function does not return until the server is stopped.
	Start(stayUp bool) error
	// Stop the server, and terminate any open connections.
	Stop() error
}