Abstract out diff implementations for importing

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)

libcontainer/nsinit/term.go

@@ -0,0 +1,109 @@
+package nsinit
+
+import (
+	"github.com/dotcloud/docker/pkg/term"
+	"io"
+	"os"
+	"os/exec"
+)
+
+type Terminal interface {
+	io.Closer
+	SetMaster(*os.File)
+	Attach(*exec.Cmd) error
+}
+
+func NewTerminal(stdin io.Reader, stdout, stderr io.Writer, tty bool) Terminal {
+	if tty {
+		return &TtyTerminal{
+			stdin:  stdin,
+			stdout: stdout,
+			stderr: stderr,
+		}
+	}
+	return &StdTerminal{
+		stdin:  stdin,
+		stdout: stdout,
+		stderr: stderr,
+	}
+}
+
+type TtyTerminal struct {
+	stdin          io.Reader
+	stdout, stderr io.Writer
+	master         *os.File
+	state          *term.State
+}
+
+func (t *TtyTerminal) SetMaster(master *os.File) {
+	t.master = master
+}
+
+func (t *TtyTerminal) Attach(command *exec.Cmd) error {
+	go io.Copy(t.stdout, t.master)
+	go io.Copy(t.master, t.stdin)
+
+	state, err := t.setupWindow(t.master, os.Stdin)
+	if err != nil {
+		command.Process.Kill()
+		return err
+	}
+	t.state = state
+	return err
+}
+
+// SetupWindow gets the parent window size and sets the master
+// pty to the current size and set the parents mode to RAW
+func (t *TtyTerminal) setupWindow(master, parent *os.File) (*term.State, error) {
+	ws, err := term.GetWinsize(parent.Fd())
+	if err != nil {
+		return nil, err
+	}
+	if err := term.SetWinsize(master.Fd(), ws); err != nil {
+		return nil, err
+	}
+	return term.SetRawTerminal(parent.Fd())
+}
+
+func (t *TtyTerminal) Close() error {
+	term.RestoreTerminal(os.Stdin.Fd(), t.state)
+	return t.master.Close()
+}
+
+type StdTerminal struct {
+	stdin          io.Reader
+	stdout, stderr io.Writer
+}
+
+func (s *StdTerminal) SetMaster(*os.File) {
+	// no need to set master on non tty
+}
+
+func (s *StdTerminal) Close() error {
+	return nil
+}
+
+func (s *StdTerminal) Attach(command *exec.Cmd) error {
+	inPipe, err := command.StdinPipe()
+	if err != nil {
+		return err
+	}
+	outPipe, err := command.StdoutPipe()
+	if err != nil {
+		return err
+	}
+	errPipe, err := command.StderrPipe()
+	if err != nil {
+		return err
+	}
+
+	go func() {
+		defer inPipe.Close()
+		io.Copy(inPipe, s.stdin)
+	}()
+
+	go io.Copy(s.stdout, outPipe)
+	go io.Copy(s.stderr, errPipe)
+
+	return nil
+}