Abstract out diff implementations for importing

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

libcontainer/nsinit/command.go

@@ -0,0 +1,34 @@
+package nsinit
+
+import (
+	"fmt"
+	"github.com/dotcloud/docker/pkg/libcontainer"
+	"os"
+	"os/exec"
+	"syscall"
+)
+
+type CommandFactory interface {
+	Create(container *libcontainer.Container, console, logFile string, syncFd uintptr, args []string) *exec.Cmd
+}
+
+type DefaultCommandFactory struct{}
+
+// Create will return an exec.Cmd with the Cloneflags set to the proper namespaces
+// defined on the container's configuration and use the current binary as the init with the
+// args provided
+func (c *DefaultCommandFactory) Create(container *libcontainer.Container, console, logFile string, pipe uintptr, args []string) *exec.Cmd {
+	// get our binary name so we can always reexec ourself
+	name := os.Args[0]
+	command := exec.Command(name, append([]string{
+		"-console", console,
+		"-pipe", fmt.Sprint(pipe),
+		"-log", logFile,
+		"init"}, args...)...)
+
+	command.SysProcAttr = &syscall.SysProcAttr{
+		Cloneflags: uintptr(GetNamespaceFlags(container.Namespaces)),
+	}
+	command.Env = container.Env
+	return command
+}

libcontainer/nsinit/exec.go

@@ -3,13 +3,9 @@
 package nsinit
 
 import (
-	"fmt"
 	"github.com/dotcloud/docker/pkg/libcontainer"
 	"github.com/dotcloud/docker/pkg/libcontainer/network"
 	"github.com/dotcloud/docker/pkg/system"
-	"github.com/dotcloud/docker/pkg/term"
-	"io"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -18,9 +14,11 @@ import (
 
 // Exec performes 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.Container, stdin io.Reader, stdout, stderr io.Writer,
-	master *os.File, logFile string, args []string) (int, error) {
+func Exec(container *libcontainer.Container,
+	factory CommandFactory, state StateWriter, term Terminal,
+	logFile string, args []string) (int, error) {
 	var (
+		master  *os.File
 		console string
 		err     error
 	)
@@ -38,37 +36,28 @@ func Exec(container *libcontainer.Container, stdin io.Reader, stdout, stderr io.
 		if err != nil {
 			return -1, err
 		}
+		term.SetMaster(master)
 	}
 
-	command := CreateCommand(container, console, logFile, syncPipe.child.Fd(), args)
-	if container.Tty {
-		log.Printf("starting copy for tty")
-		go io.Copy(stdout, master)
-		go io.Copy(master, stdin)
-
-		state, err := SetupWindow(master, os.Stdin)
-		if err != nil {
-			command.Process.Kill()
-			return -1, err
-		}
-		defer term.RestoreTerminal(os.Stdin.Fd(), state)
-	} else {
-		if err := startStdCopy(command, stdin, stdout, stderr); err != nil {
-			command.Process.Kill()
-			return -1, err
-		}
+	command := factory.Create(container, console, logFile, syncPipe.child.Fd(), args)
+	if err := term.Attach(command); err != nil {
+		return -1, err
 	}
+	defer term.Close()
 
 	log.Printf("staring init")
 	if err := command.Start(); err != nil {
 		return -1, err
 	}
 	log.Printf("writing state file")
-	if err := writePidFile(command); err != nil {
+	if err := state.WritePid(command.Process.Pid); err != nil {
 		command.Process.Kill()
 		return -1, err
 	}
-	defer deletePidFile()
+	defer func() {
+		log.Printf("removing state file")
+		state.DeletePid()
+	}()
 
 	// Do this before syncing with child so that no children
 	// can escape the cgroup
@@ -124,19 +113,6 @@ func InitializeNetworking(container *libcontainer.Container, nspid int, pipe *Sy
 	return nil
 }
 
-// SetupWindow gets the parent window size and sets the master
-// pty to the current size and set the parents mode to RAW
-func 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())
-}
-
 // CreateMasterAndConsole will open /dev/ptmx on the host and retreive the
 // pts name for use as the pty slave inside the container
 func CreateMasterAndConsole() (*os.File, string, error) {
@@ -153,58 +129,3 @@ func CreateMasterAndConsole() (*os.File, string, error) {
 	}
 	return master, console, nil
 }
-
-// writePidFile writes the namespaced processes pid to .nspid in the rootfs for the container
-func writePidFile(command *exec.Cmd) error {
-	return ioutil.WriteFile(".nspid", []byte(fmt.Sprint(command.Process.Pid)), 0655)
-}
-
-func deletePidFile() error {
-	log.Printf("removing .nspid file")
-	return os.Remove(".nspid")
-}
-
-// createCommand will return an exec.Cmd with the Cloneflags set to the proper namespaces
-// defined on the container's configuration and use the current binary as the init with the
-// args provided
-func CreateCommand(container *libcontainer.Container, console, logFile string, pipe uintptr, args []string) *exec.Cmd {
-	// get our binary name so we can always reexec ourself
-	name := os.Args[0]
-	command := exec.Command(name, append([]string{
-		"-console", console,
-		"-pipe", fmt.Sprint(pipe),
-		"-log", logFile,
-		"init"}, args...)...)
-
-	command.SysProcAttr = &syscall.SysProcAttr{
-		Cloneflags: uintptr(GetNamespaceFlags(container.Namespaces)),
-	}
-	command.Env = container.Env
-	return command
-}
-
-func startStdCopy(command *exec.Cmd, stdin io.Reader, stdout, stderr io.Writer) error {
-	log.Printf("opening std pipes")
-	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
-	}
-
-	log.Printf("starting copy for std pipes")
-	go func() {
-		defer inPipe.Close()
-		io.Copy(inPipe, stdin)
-	}()
-	go io.Copy(stdout, outPipe)
-	go io.Copy(stderr, errPipe)
-
-	return nil
-}

libcontainer/nsinit/nsinit/main.go

@@ -57,8 +57,10 @@ func main() {
 		if nspid > 0 {
 			exitCode, err = nsinit.ExecIn(container, nspid, flag.Args()[1:])
 		} else {
+			term := nsinit.NewTerminal(os.Stdin, os.Stdout, os.Stderr, container.Tty)
 			exitCode, err = nsinit.Exec(container,
-				os.Stdin, os.Stdout, os.Stderr, nil,
+				&nsinit.DefaultCommandFactory{}, &nsinit.DefaultStateWriter{},
+				term,
 				logFile, flag.Args()[1:])
 		}
 		if err != nil {

libcontainer/nsinit/state.go

@@ -0,0 +1,24 @@
+package nsinit
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+)
+
+type StateWriter interface {
+	WritePid(pid int) error
+	DeletePid() error
+}
+
+type DefaultStateWriter struct {
+}
+
+// writePidFile writes the namespaced processes pid to .nspid in the rootfs for the container
+func (*DefaultStateWriter) WritePid(pid int) error {
+	return ioutil.WriteFile(".nspid", []byte(fmt.Sprint(pid)), 0655)
+}
+
+func (*DefaultStateWriter) DeletePid() error {
+	return os.Remove(".nspid")
+}

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
+}