package libpod import ( "fmt" "io" "net" "os" gosignal "os/signal" "path/filepath" "github.com/docker/docker/pkg/signal" "github.com/docker/docker/pkg/term" "github.com/pkg/errors" "github.com/projectatomic/libpod/pkg/kubeutils" "github.com/projectatomic/libpod/utils" "github.com/sirupsen/logrus" "golang.org/x/crypto/ssh/terminal" "golang.org/x/sys/unix" "k8s.io/client-go/tools/remotecommand" ) /* Sync with stdpipe_t in conmon.c */ const ( AttachPipeStdin = 1 AttachPipeStdout = 2 AttachPipeStderr = 3 ) // resizeTty handles TTY resizing for Attach() func resizeTty(resize chan remotecommand.TerminalSize) { sigchan := make(chan os.Signal, 1) gosignal.Notify(sigchan, signal.SIGWINCH) sendUpdate := func() { winsize, err := term.GetWinsize(os.Stdin.Fd()) if err != nil { logrus.Warnf("Could not get terminal size %v", err) return } resize <- remotecommand.TerminalSize{ Width: winsize.Width, Height: winsize.Height, } } go func() { defer close(resize) // Update the terminal size immediately without waiting // for a SIGWINCH to get the correct initial size. sendUpdate() for range sigchan { sendUpdate() } }() } func (c *Container) attach(noStdin bool, keys string) error { // Check the validity of the provided keys first var err error detachKeys := []byte{} if len(keys) > 0 { detachKeys, err = term.ToBytes(keys) if err != nil { return errors.Wrapf(err, "invalid detach keys") } } // TODO: allow resize channel to be passed in for CRI-O use resize := make(chan remotecommand.TerminalSize) if terminal.IsTerminal(int(os.Stdin.Fd())) { resizeTty(resize) } else { defer close(resize) } logrus.Debugf("Attaching to container %s", c.ID()) return c.attachContainerSocket(resize, noStdin, detachKeys) } // attachContainerSocket connects to the container's attach socket and deals with the IO // TODO add a channel to allow interruptiong func (c *Container) attachContainerSocket(resize <-chan remotecommand.TerminalSize, noStdIn bool, detachKeys []byte) error { inputStream := os.Stdin outputStream := os.Stdout errorStream := os.Stderr defer inputStream.Close() if terminal.IsTerminal(int(inputStream.Fd())) { oldTermState, err := term.SaveState(inputStream.Fd()) if err != nil { return errors.Wrapf(err, "unable to save terminal state") } defer term.RestoreTerminal(inputStream.Fd(), oldTermState) } // Put both input and output into raw when we have a terminal if !noStdIn && c.config.Spec.Process.Terminal { term.SetRawTerminal(inputStream.Fd()) } kubeutils.HandleResizing(resize, func(size remotecommand.TerminalSize) { controlPath := filepath.Join(c.bundlePath(), "ctl") controlFile, err := os.OpenFile(controlPath, unix.O_WRONLY, 0) if err != nil { logrus.Debugf("Could not open ctl file: %v", err) return } defer controlFile.Close() logrus.Debugf("Received a resize event: %+v", size) if _, err = fmt.Fprintf(controlFile, "%d %d %d\n", 1, size.Height, size.Width); err != nil { logrus.Warnf("Failed to write to control file to resize terminal: %v", err) } }) logrus.Debug("connecting to socket ", c.attachSocketPath()) conn, err := net.DialUnix("unixpacket", nil, &net.UnixAddr{Name: c.attachSocketPath(), Net: "unixpacket"}) if err != nil { return errors.Wrapf(err, "failed to connect to container's attach socket: %v") } defer conn.Close() receiveStdoutError := make(chan error) if outputStream != nil || errorStream != nil { go func() { receiveStdoutError <- redirectResponseToOutputStreams(outputStream, errorStream, conn) }() } stdinDone := make(chan error) go func() { var err error if inputStream != nil && !noStdIn { _, err = utils.CopyDetachable(conn, inputStream, detachKeys) conn.CloseWrite() } stdinDone <- err }() select { case err := <-receiveStdoutError: return err case err := <-stdinDone: if _, ok := err.(utils.DetachError); ok { return nil } if outputStream != nil || errorStream != nil { return <-receiveStdoutError } } return nil } func redirectResponseToOutputStreams(outputStream, errorStream io.Writer, conn io.Reader) error { var err error buf := make([]byte, 8192+1) /* Sync with conmon STDIO_BUF_SIZE */ for { nr, er := conn.Read(buf) if nr > 0 { var dst io.Writer switch buf[0] { case AttachPipeStdout: dst = outputStream case AttachPipeStderr: dst = errorStream default: logrus.Infof("Received unexpected attach type %+d", buf[0]) } if dst != nil { nw, ew := dst.Write(buf[1:nr]) if ew != nil { err = ew break } if nr != nw+1 { err = io.ErrShortWrite break } } } if er == io.EOF { break } if er != nil { err = er break } } return err }