Merge pull request #99 from crosbymichael/improve-term-handling

Remove terminal handling in libcontainer

console/console.go

@@ -90,13 +90,16 @@ func CreateMasterAndConsole() (*os.File, string, error) {
 	if err != nil {
 		return nil, "", err
 	}
+
 	console, err := Ptsname(master)
 	if err != nil {
 		return nil, "", err
 	}
+
 	if err := Unlockpt(master); err != nil {
 		return nil, "", err
 	}
+
 	return master, console, nil
 }
 

namespaces/exec.go

@@ -3,6 +3,7 @@
 package namespaces
 
 import (
+	"io"
 	"os"
 	"os/exec"
 	"syscall"
@@ -11,7 +12,6 @@ import (
 	"github.com/docker/libcontainer/cgroups"
 	"github.com/docker/libcontainer/cgroups/fs"
 	"github.com/docker/libcontainer/cgroups/systemd"
-	consolePkg "github.com/docker/libcontainer/console"
 	"github.com/docker/libcontainer/network"
 	"github.com/docker/libcontainer/syncpipe"
 	"github.com/docker/libcontainer/system"
@@ -21,11 +21,9 @@ import (
 // Move this to libcontainer package.
 // Exec performs setup outside of a namespace so that a container can be
 // executed.  Exec is a high level function for working with container namespaces.
-func Exec(container *libcontainer.Config, term Terminal, rootfs, dataPath string, args []string, createCommand CreateCommand, startCallback func()) (int, error) {
+func Exec(container *libcontainer.Config, stdin io.Reader, stdout, stderr io.Writer, console string, rootfs, dataPath string, args []string, createCommand CreateCommand, startCallback func()) (int, error) {
 	var (
-		master  *os.File
-		console string
-		err     error
+		err error
 	)
 
 	// create a pipe so that we can syncronize with the namespaced process and
@@ -36,20 +34,13 @@ func Exec(container *libcontainer.Config, term Terminal, rootfs, dataPath string
 	}
 	defer syncPipe.Close()
 
-	if container.Tty {
-		master, console, err = consolePkg.CreateMasterAndConsole()
-		if err != nil {
-			return -1, err
-		}
-		term.SetMaster(master)
-	}
-
 	command := createCommand(container, console, rootfs, dataPath, os.Args[0], syncPipe.Child(), args)
-
-	if err := term.Attach(command); err != nil {
-		return -1, err
-	}
-	defer term.Close()
+	// Note: these are only used in non-tty mode
+	// if there is a tty for the container it will be opened within the namespace and the
+	// fds will be duped to stdin, stdiout, and stderr
+	command.Stdin = stdin
+	command.Stdout = stdout
+	command.Stderr = stderr
 
 	if err := command.Start(); err != nil {
 		return -1, err

namespaces/std_term.go

@@ -1,49 +0,0 @@
-package namespaces
-
-import (
-	"io"
-	"os"
-	"os/exec"
-)
-
-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) Resize(h, w int) 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
-}

namespaces/term.go

@@ -1,29 +0,0 @@
-package namespaces
-
-import (
-	"io"
-	"os"
-	"os/exec"
-)
-
-type Terminal interface {
-	io.Closer
-	SetMaster(*os.File)
-	Attach(*exec.Cmd) error
-	Resize(h, w int) 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,
-	}
-}

namespaces/tty_term.go

@@ -1,56 +0,0 @@
-package namespaces
-
-import (
-	"io"
-	"os"
-	"os/exec"
-
-	"github.com/dotcloud/docker/pkg/term"
-)
-
-type TtyTerminal struct {
-	stdin          io.Reader
-	stdout, stderr io.Writer
-	master         *os.File
-	state          *term.State
-}
-
-func (t *TtyTerminal) Resize(h, w int) error {
-	return term.SetWinsize(t.master.Fd(), &term.Winsize{Height: uint16(h), Width: uint16(w)})
-}
-
-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 {
-		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()
-}

nsinit/exec.go

@@ -2,14 +2,18 @@ package nsinit
 
 import (
 	"fmt"
+	"io"
 	"log"
 	"os"
 	"os/exec"
 	"os/signal"
+	"syscall"
 
 	"github.com/codegangsta/cli"
 	"github.com/docker/libcontainer"
+	consolepkg "github.com/docker/libcontainer/console"
 	"github.com/docker/libcontainer/namespaces"
+	"github.com/dotcloud/docker/pkg/term"
 )
 
 var execCommand = cli.Command{
@@ -34,8 +38,7 @@ func execAction(context *cli.Context) {
 	if state != nil {
 		err = namespaces.ExecIn(container, state, []string(context.Args()))
 	} else {
-		term := namespaces.NewTerminal(os.Stdin, os.Stdout, os.Stderr, container.Tty)
-		exitCode, err = startContainer(container, term, dataPath, []string(context.Args()))
+		exitCode, err = startContainer(container, dataPath, []string(context.Args()))
 	}
 
 	if err != nil {
@@ -49,7 +52,7 @@ func execAction(context *cli.Context) {
 // error.
 //
 // Signals sent to the current process will be forwarded to container.
-func startContainer(container *libcontainer.Config, term namespaces.Terminal, dataPath string, args []string) (int, error) {
+func startContainer(container *libcontainer.Config, dataPath string, args []string) (int, error) {
 	var (
 		cmd  *exec.Cmd
 		sigc = make(chan os.Signal, 10)
@@ -65,13 +68,66 @@ func startContainer(container *libcontainer.Config, term namespaces.Terminal, da
 		return cmd
 	}
 
+	var (
+		master  *os.File
+		console string
+		err     error
+
+		stdin  = os.Stdin
+		stdout = os.Stdout
+		stderr = os.Stderr
+	)
+
+	if container.Tty {
+		stdin = nil
+		stdout = nil
+		stderr = nil
+
+		master, console, err = consolepkg.CreateMasterAndConsole()
+		if err != nil {
+			return -1, err
+		}
+
+		go io.Copy(master, os.Stdin)
+		go io.Copy(os.Stdout, master)
+
+		state, err := term.SetRawTerminal(os.Stdin.Fd())
+		if err != nil {
+			return -1, err
+		}
+
+		defer term.RestoreTerminal(os.Stdin.Fd(), state)
+	}
+
 	startCallback := func() {
 		go func() {
+			resizeTty(master)
+
 			for sig := range sigc {
-				cmd.Process.Signal(sig)
+				switch sig {
+				case syscall.SIGWINCH:
+					resizeTty(master)
+				default:
+					cmd.Process.Signal(sig)
+				}
 			}
 		}()
 	}
 
-	return namespaces.Exec(container, term, "", dataPath, args, createCommand, startCallback)
+	return namespaces.Exec(container, stdin, stdout, stderr, console, "", dataPath, args, createCommand, startCallback)
+}
+
+func resizeTty(master *os.File) {
+	if master == nil {
+		return
+	}
+
+	ws, err := term.GetWinsize(os.Stdin.Fd())
+	if err != nil {
+		return
+	}
+
+	if err := term.SetWinsize(master.Fd(), ws); err != nil {
+		return
+	}
 }