Remove the ghosts and kill everything

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

container.go

@@ -55,6 +55,7 @@ type Container struct {
 	HostsPath      string
 	Name           string
 	Driver         string
+	ExecDriver     string
 
 	command   *execdriver.Command
 	stdout    *utils.WriteBroadcaster
@@ -777,15 +778,8 @@ func (container *Container) monitor(callback execdriver.StartCallback) error {
 		exitCode int
 	)
 
-	if container.command == nil {
-		// This happends when you have a GHOST container with lxc
-		populateCommand(container)
-		err = container.runtime.RestoreCommand(container)
-	} else {
-		pipes := execdriver.NewPipes(container.stdin, container.stdout, container.stderr, container.Config.OpenStdin)
-		exitCode, err = container.runtime.Run(container, pipes, callback)
-	}
-
+	pipes := execdriver.NewPipes(container.stdin, container.stdout, container.stderr, container.Config.OpenStdin)
+	exitCode, err = container.runtime.Run(container, pipes, callback)
 	if err != nil {
 		utils.Errorf("Error running container: %s", err)
 	}

execdriver/driver.go

@@ -77,7 +77,6 @@ type TtyTerminal interface {
 type Driver interface {
 	Run(c *Command, pipes *Pipes, startCallback StartCallback) (int, error) // Run executes the process and blocks until the process exits and returns the exit code
 	Kill(c *Command, sig int) error
-	Restore(c *Command) error                     // Wait and try to re-attach on an out of process command
 	Name() string                                 // Driver name
 	Info(id string) Info                          // "temporary" hack (until we move state from core to plugins)
 	GetPidsForContainer(id string) ([]int, error) // Returns a list of pids for the given container.

execdriver/lxc/driver.go

@@ -189,20 +189,7 @@ func getExitCode(c *execdriver.Command) int {
 }
 
 func (d *driver) Kill(c *execdriver.Command, sig int) error {
-	return d.kill(c, sig)
-}
-
-func (d *driver) Restore(c *execdriver.Command) error {
-	for {
-		output, err := exec.Command("lxc-info", "-n", c.ID).CombinedOutput()
-		if err != nil {
-			return err
-		}
-		if !strings.Contains(string(output), "RUNNING") {
-			return nil
-		}
-		time.Sleep(500 * time.Millisecond)
-	}
+	return KillLxc(c.ID, sig)
 }
 
 func (d *driver) version() string {
@@ -225,16 +212,16 @@ func (d *driver) version() string {
 	return version
 }
 
-func (d *driver) kill(c *execdriver.Command, sig int) error {
+func KillLxc(id string, sig int) error {
 	var (
 		err    error
 		output []byte
 	)
 	_, err = exec.LookPath("lxc-kill")
 	if err == nil {
-		output, err = exec.Command("lxc-kill", "-n", c.ID, strconv.Itoa(sig)).CombinedOutput()
+		output, err = exec.Command("lxc-kill", "-n", id, strconv.Itoa(sig)).CombinedOutput()
 	} else {
-		output, err = exec.Command("lxc-stop", "-k", "-n", c.ID, strconv.Itoa(sig)).CombinedOutput()
+		output, err = exec.Command("lxc-stop", "-k", "-n", id, strconv.Itoa(sig)).CombinedOutput()
 	}
 	if err != nil {
 		return fmt.Errorf("Err: %s Output: %s", err, output)

execdriver/native/driver.go

@@ -16,7 +16,6 @@ import (
 	"strconv"
 	"strings"
 	"syscall"
-	"time"
 )
 
 const (
@@ -109,41 +108,9 @@ func (d *driver) Run(c *execdriver.Command, pipes *execdriver.Pipes, startCallba
 }
 
 func (d *driver) Kill(p *execdriver.Command, sig int) error {
-	return syscall.Kill(p.Process.Pid, syscall.Signal(sig))
-}
-
-func (d *driver) Restore(c *execdriver.Command) error {
-	var nspid int
-	f, err := os.Open(filepath.Join(d.root, c.ID, "pid"))
-	if err != nil {
-		return err
-	}
-	defer d.removeContainerRoot(c.ID)
-
-	if _, err := fmt.Fscanf(f, "%d", &nspid); err != nil {
-		f.Close()
-		return err
-	}
-	f.Close()
-
-	if _, err := os.FindProcess(nspid); err != nil {
-		return fmt.Errorf("finding existing pid %d %s", nspid, err)
-	}
-	c.Process = &os.Process{
-		Pid: nspid,
-	}
-	ticker := time.NewTicker(500 * time.Millisecond)
-	defer ticker.Stop()
-
-	for _ = range ticker.C {
-		if err := syscall.Kill(nspid, 0); err != nil {
-			if strings.Contains(err.Error(), "no such process") {
-				return nil
-			}
-			return fmt.Errorf("signal error %s", err)
-		}
-	}
-	return nil
+	err := syscall.Kill(p.Process.Pid, syscall.Signal(sig))
+	d.removeContainerRoot(p.ID)
+	return err
 }
 
 func (d *driver) Info(id string) execdriver.Info {

integration/runtime_test.go

@@ -589,90 +589,6 @@ func TestRestore(t *testing.T) {
 	container2.State.SetStopped(0)
 }
 
-func TestReloadContainerLinks(t *testing.T) {
-	root, err := newTestDirectory(unitTestStoreBase)
-	if err != nil {
-		t.Fatal(err)
-	}
-	// FIXME: here we don't use NewTestEngine because it calls initserver with Autorestart=false,
-	// and we want to set it to true.
-
-	eng := newTestEngine(t, true, root)
-
-	runtime1 := mkRuntimeFromEngine(eng, t)
-	defer nuke(runtime1)
-	// Create a container with one instance of docker
-	container1, _, _ := mkContainer(runtime1, []string{"-i", "_", "/bin/sh"}, t)
-	defer runtime1.Destroy(container1)
-
-	// Create a second container meant to be killed
-	container2, _, _ := mkContainer(runtime1, []string{"-i", "_", "/bin/cat"}, t)
-	defer runtime1.Destroy(container2)
-
-	// Start the container non blocking
-	if err := container2.Start(); err != nil {
-		t.Fatal(err)
-	}
-	// Add a link to container 2
-	// FIXME @shykes: setting hostConfig.Links seems redundant with calling RegisterLink().
-	// Why do we need it @crosbymichael?
-	// container1.hostConfig.Links = []string{"/" + container2.ID + ":first"}
-	if err := runtime1.RegisterLink(container1, container2, "first"); err != nil {
-		t.Fatal(err)
-	}
-	if err := container1.Start(); err != nil {
-		t.Fatal(err)
-	}
-
-	if !container2.State.IsRunning() {
-		t.Fatalf("Container %v should appear as running but isn't", container2.ID)
-	}
-
-	if !container1.State.IsRunning() {
-		t.Fatalf("Container %s should appear as running but isn't", container1.ID)
-	}
-
-	if len(runtime1.List()) != 2 {
-		t.Errorf("Expected 2 container, %v found", len(runtime1.List()))
-	}
-
-	// Here are are simulating a docker restart - that is, reloading all containers
-	// from scratch
-	eng = newTestEngine(t, false, root)
-	runtime2 := mkRuntimeFromEngine(eng, t)
-	if len(runtime2.List()) != 2 {
-		t.Errorf("Expected 2 container, %v found", len(runtime2.List()))
-	}
-	runningCount := 0
-	for _, c := range runtime2.List() {
-		if c.State.IsRunning() {
-			runningCount++
-		}
-	}
-	if runningCount != 2 {
-		t.Fatalf("Expected 2 container alive, %d found", runningCount)
-	}
-
-	// FIXME: we no longer test if containers were registered in the right order,
-	// because there is no public
-	// Make sure container 2 ( the child of container 1 ) was registered and started first
-	// with the runtime
-	//
-	containers := runtime2.List()
-	if len(containers) == 0 {
-		t.Fatalf("Runtime has no containers")
-	}
-	first := containers[0]
-	if first.ID != container2.ID {
-		t.Fatalf("Container 2 %s should be registered first in the runtime", container2.ID)
-	}
-
-	// Verify that the link is still registered in the runtime
-	if c := runtime2.Get(container1.Name); c == nil {
-		t.Fatal("Named container is no longer registered after restart")
-	}
-}
-
 func TestDefaultContainerName(t *testing.T) {
 	eng := NewTestEngine(t)
 	runtime := mkRuntimeFromEngine(eng, t)

pkg/libcontainer/nsinit/init.go

@@ -48,17 +48,14 @@ func (ns *linuxNs) Init(container *libcontainer.Container, uncleanRootfs, consol
 			return fmt.Errorf("setctty %s", err)
 		}
 	}
-
-	/* this is commented out so that we get the current Ghost functionality
-	if err := system.ParentDeathSignal(); err != nil {
-		return fmt.Errorf("parent death signal %s", err)
-	}
+	/*
+		if err := system.ParentDeathSignal(); err != nil {
+			return fmt.Errorf("parent death signal %s", err)
+		}
 	*/
-
 	if err := setupNewMountNamespace(rootfs, console, container.ReadonlyFs); err != nil {
 		return fmt.Errorf("setup mount namespace %s", err)
 	}
-
 	if err := setupNetwork(container, context); err != nil {
 		return fmt.Errorf("setup networking %s", err)
 	}

runtime.go

@@ -154,12 +154,39 @@ func (runtime *Runtime) Register(container *Container) error {
 	//        if so, then we need to restart monitor and init a new lock
 	// If the container is supposed to be running, make sure of it
 	if container.State.IsRunning() {
-		info := runtime.execDriver.Info(container.ID)
+		if container.State.IsGhost() {
+			utils.Debugf("killing ghost %s", container.ID)
+
+			existingPid := container.State.Pid
+			container.State.SetGhost(false)
+			container.State.SetStopped(0)
 
+			if container.ExecDriver == "" || strings.Contains(container.ExecDriver, "lxc") {
+				lxc.KillLxc(container.ID, 9)
+			} else {
+				command := &execdriver.Command{
+					ID: container.ID,
+				}
+				command.Process = &os.Process{Pid: existingPid}
+				runtime.execDriver.Kill(command, 9)
+			}
+			// ensure that the filesystem is also unmounted
+			unmountVolumesForContainer(container)
+			if err := container.Unmount(); err != nil {
+				utils.Debugf("ghost unmount error %s", err)
+			}
+		}
+
+		info := runtime.execDriver.Info(container.ID)
 		if !info.IsRunning() {
 			utils.Debugf("Container %s was supposed to be running but is not.", container.ID)
 			if runtime.config.AutoRestart {
 				utils.Debugf("Restarting")
+				unmountVolumesForContainer(container)
+				if err := container.Unmount(); err != nil {
+					utils.Debugf("restart unmount error %s", err)
+				}
+
 				container.State.SetGhost(false)
 				container.State.SetStopped(0)
 				if err := container.Start(); err != nil {
@@ -172,15 +199,6 @@ func (runtime *Runtime) Register(container *Container) error {
 					return err
 				}
 			}
-		} else {
-			utils.Debugf("Reconnecting to container %v", container.ID)
-
-			if err := container.allocateNetwork(); err != nil {
-				return err
-			}
-
-			container.waitLock = make(chan struct{})
-			go container.monitor(nil)
 		}
 	} else {
 		// When the container is not running, we still initialize the waitLock
@@ -447,6 +465,7 @@ func (runtime *Runtime) Create(config *runconfig.Config, name string) (*Containe
 		NetworkSettings: &NetworkSettings{},
 		Name:            name,
 		Driver:          runtime.driver.String(),
+		ExecDriver:      runtime.execDriver.Name(),
 	}
 	container.root = runtime.containerRoot(container.ID)
 	// Step 1: create the container directory.
@@ -834,10 +853,6 @@ func (runtime *Runtime) Kill(c *Container, sig int) error {
 	return runtime.execDriver.Kill(c.command, sig)
 }
 
-func (runtime *Runtime) RestoreCommand(c *Container) error {
-	return runtime.execDriver.Restore(c.command)
-}
-
 // Nuke kills all containers then removes all content
 // from the content root, including images, volumes and
 // container filesystems.