Add console support

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

linux/linux.go

@@ -395,9 +395,21 @@ func (r *libcontainerRuntime) Create(id, bundlePath string) (runtime.Container,
 	if err != nil {
 		return nil, nil, err
 	}
-	i, err := process.InitializeIO(int(spec.Process.User.UID))
-	if err != nil {
-		return nil, nil, err
+	var rio runtime.IO
+	if spec.Process.Terminal {
+		console, err := process.NewConsole(int(spec.Process.User.UID))
+		if err != nil {
+			return nil, nil, err
+		}
+		rio.Console = console
+	} else {
+		i, err := process.InitializeIO(int(spec.Process.User.UID))
+		if err != nil {
+			return nil, nil, err
+		}
+		rio.Stdin = i.Stdin
+		rio.Stderr = i.Stderr
+		rio.Stdout = i.Stdout
 	}
 	c := &libcontainerContainer{
 		c:                   container,
@@ -408,11 +420,7 @@ func (r *libcontainerRuntime) Create(id, bundlePath string) (runtime.Container,
 		},
 		path: bundlePath,
 	}
-	return c, &runtime.IO{
-		Stdin:  i.Stdin,
-		Stdout: i.Stdout,
-		Stderr: i.Stderr,
-	}, nil
+	return c, &rio, nil
 }
 
 func (r *libcontainerRuntime) StartProcess(ci runtime.Container, p specs.Process) (runtime.Process, *runtime.IO, error) {
@@ -450,10 +458,6 @@ func (r *libcontainerRuntime) StartProcess(ci runtime.Container, p specs.Process
 // newProcess returns a new libcontainer Process with the arguments from the
 // spec and stdio from the current process.
 func (r *libcontainerRuntime) newProcess(p specs.Process) (*libcontainer.Process, error) {
-	// TODO: support terminals
-	if p.Terminal {
-		return nil, runtime.ErrTerminalsNotSupported
-	}
 	return &libcontainer.Process{
 		Args: p.Args,
 		Env:  p.Env,

runtime/container.go

@@ -26,10 +26,16 @@ type State struct {
 	Status Status
 }
 
+type Console interface {
+	io.ReadWriter
+	io.Closer
+}
+
 type IO struct {
-	Stdin  io.WriteCloser
-	Stdout io.ReadCloser
-	Stderr io.ReadCloser
+	Stdin   io.WriteCloser
+	Stdout  io.ReadCloser
+	Stderr  io.ReadCloser
+	Console Console
 }
 
 func (i *IO) Close() error {
@@ -39,10 +45,15 @@ func (i *IO) Close() error {
 		i.Stdout,
 		i.Stderr,
 	} {
-		if err := c.Close(); oerr == nil {
-			oerr = err
+		if c != nil {
+			if err := c.Close(); oerr == nil {
+				oerr = err
+			}
 		}
 	}
+	if i.Console != nil {
+		oerr = i.Console.Close()
+	}
 	return oerr
 }