feature: add kill command

Signed-off-by: Lang Chi <21860405@zju.edu.cn>

apis/server/container_bridge.go

@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"strconv"
 	"strings"
+	"syscall"
 	"time"
 
 	"github.com/alibaba/pouch/apis/metrics"
@@ -186,6 +187,24 @@ func (s *Server) getContainers(ctx context.Context, rw http.ResponseWriter, req
 	return EncodeResponse(rw, http.StatusOK, containerList)
 }
 
+func (s *Server) killContainer(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
+	var sig syscall.Signal
+	name := mux.Vars(req)["name"]
+
+	// If we have a signal, look at it. Otherwise, do nothing
+	if sigStr := req.FormValue("signal"); sigStr != "" {
+		var err error
+		if sig, err = utils.ParseSignal(sigStr); err != nil {
+			return err
+		}
+	}
+
+	if err := s.ContainerMgr.Kill(ctx, name, uint64(sig)); err != nil {
+		return err
+	}
+	return nil
+}
+
 func (s *Server) startContainer(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
 	label := util_metrics.ActionStartLabel
 	defer func(start time.Time) {

apis/server/router.go

@@ -40,6 +40,7 @@ func initRoute(s *Server) *mux.Router {
 		{Method: http.MethodGet, Path: "/containers/{name:.*}/checkpoints", HandlerFunc: withCancelHandler(s.listContainerCheckpoint)},
 		{Method: http.MethodDelete, Path: "/containers/{name}/checkpoints/{id}", HandlerFunc: withCancelHandler(s.deleteContainerCheckpoint)},
 		{Method: http.MethodPost, Path: "/containers/create", HandlerFunc: s.createContainer},
+		{Method: http.MethodPost, Path: "/containers/{name:.*}/kill", HandlerFunc: s.killContainer},
 		{Method: http.MethodPost, Path: "/containers/{name:.*}/start", HandlerFunc: s.startContainer},
 		{Method: http.MethodPost, Path: "/containers/{name:.*}/stop", HandlerFunc: s.stopContainer},
 		{Method: http.MethodPost, Path: "/containers/{name:.*}/attach", HandlerFunc: s.attachContainer},

cli/kill.go

@@ -0,0 +1,79 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/spf13/cobra"
+)
+
+// killDescription is used to describe kill command in detail and auto generate command doc.
+var killDescription = "Kill one or more running container objects in Pouchd. " +
+	"You can kill a container using the container’s ID, ID-prefix, or name. " +
+	"This is useful when you wish to kill a container which is running."
+
+// KillCommand use to implement 'kill' command, it kill one or more containers.
+type KillCommand struct {
+	baseCommand
+	signal string
+}
+
+// Init initialize kill command.
+func (s *KillCommand) Init(c *Cli) {
+	s.cli = c
+	s.cmd = &cobra.Command{
+		Use:   "kill [OPTIONS] CONTAINER [CONTAINER...]",
+		Short: "kill one or more running containers",
+		Long:  killDescription,
+		Args:  cobra.MinimumNArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return s.runKill(args)
+		},
+		Example: killExample(),
+	}
+	s.addFlags()
+}
+
+// addFlags adds flags for specific command.
+func (s *KillCommand) addFlags() {
+	flagSet := s.cmd.Flags()
+	flagSet.StringVarP(&s.signal, "signal", "s", "KILL", "Signal to send to the container")
+
+}
+
+// runKill is the entry of kill command.
+func (s *KillCommand) runKill(args []string) error {
+	ctx := context.Background()
+	apiClient := s.cli.Client()
+
+	var errs []string
+	for _, name := range args {
+		if err := apiClient.ContainerKill(ctx, name, s.signal); err != nil {
+			errs = append(errs, err.Error())
+			continue
+		}
+		fmt.Printf("%s\n", name)
+	}
+
+	if len(errs) > 0 {
+		return errors.New(strings.Join(errs, "\n"))
+	}
+
+	return nil
+}
+
+// killExample shows examples in kill command, and is used in auto-generated cli docs.
+func killExample() string {
+	return `$ pouch ps -a
+Name   ID       Status    		Created         Image                                            Runtime
+foo2   5a0ede   Up 2 seconds   	3 second ago    registry.hub.docker.com/library/busybox:latest   runc
+foo1   e05637   Up 6 seconds   	7 seconds ago   registry.hub.docker.com/library/busybox:latest   runc
+$ pouch kill foo1
+foo1
+$ pouch ps
+Name   ID       Status         Created          Image                                            Runtime
+foo2   5a0ede   Up 11 seconds   12 seconds ago   registry.hub.docker.com/library/busybox:latest   runc
+`
+}

cli/main.go

@@ -18,6 +18,7 @@ func main() {
 	cli.AddCommand(base, &PullCommand{})
 	cli.AddCommand(base, &PushCommand{})
 	cli.AddCommand(base, &CreateCommand{})
+	cli.AddCommand(base, &KillCommand{})
 	cli.AddCommand(base, &StartCommand{})
 	cli.AddCommand(base, &StopCommand{})
 	cli.AddCommand(base, &PsCommand{})

client/container_kill.go

@@ -0,0 +1,17 @@
+package client
+
+import (
+	"context"
+	"net/url"
+)
+
+// ContainerKill kills a container.
+func (client *APIClient) ContainerKill(ctx context.Context, name, signal string) error {
+	q := url.Values{}
+	q.Add("signal", signal)
+
+	resp, err := client.post(ctx, "/containers/"+name+"/kill", q, nil, nil)
+	ensureCloseReader(resp)
+
+	return err
+}

client/interface.go

@@ -23,6 +23,7 @@ type CommonAPIClient interface {
 type ContainerAPIClient interface {
 	ContainerCreate(ctx context.Context, config types.ContainerConfig, hostConfig *types.HostConfig, networkConfig *types.NetworkingConfig, containerName string) (*types.ContainerCreateResp, error)
 	ContainerStart(ctx context.Context, name string, options types.ContainerStartOptions) error
+	ContainerKill(ctx context.Context, name, signal string) error
 	ContainerStop(ctx context.Context, name, timeout string) error
 	ContainerRemove(ctx context.Context, name string, options *types.ContainerRemoveOptions) error
 	ContainerList(ctx context.Context, option types.ContainerListOptions) ([]*types.Container, error)

ctrd/container.go

@@ -352,6 +352,46 @@ func (c *Client) recoverContainer(ctx context.Context, id string, io *containeri
 	return nil
 }
 
+// KillContainer will kill a container by signal
+func (c *Client) KillContainer(ctx context.Context, containerID string, signal int) error {
+	err := c.killContainer(ctx, containerID, signal)
+	if err != nil {
+		return convertCtrdErr(err)
+	}
+	return nil
+}
+
+// killContainer is the real process of killing a container
+func (c *Client) killContainer(ctx context.Context, containerID string, signal int) error {
+	wrapperCli, err := c.Get(ctx)
+	if err != nil {
+		return fmt.Errorf("failed to get a containerd grpc client: %v", err)
+	}
+
+	ctx = leases.WithLease(ctx, wrapperCli.lease.ID)
+
+	if !c.lock.TrylockWithRetry(ctx, containerID) {
+		return errtypes.ErrLockfailed
+	}
+	defer c.lock.Unlock(containerID)
+
+	pack, err := c.watch.get(containerID)
+	if err != nil {
+		return err
+	}
+	// the caller need to execute the all hooks.
+	pack.l.Lock()
+	pack.skipStopHooks = true
+	pack.l.Unlock()
+	defer func() {
+		pack.l.Lock()
+		pack.skipStopHooks = false
+		pack.l.Unlock()
+	}()
+
+	return pack.task.Kill(ctx, syscall.Signal(signal), containerd.WithKillAll)
+}
+
 // DestroyContainer kill container and delete it.
 func (c *Client) DestroyContainer(ctx context.Context, id string, timeout int64) (*Message, error) {
 	msg, err := c.destroyContainer(ctx, id, timeout)

ctrd/interface.go

@@ -31,6 +31,8 @@ type APIClient interface {
 
 // ContainerAPIClient provides access to containerd container features.
 type ContainerAPIClient interface {
+	// KillContainer kill container by signal
+	KillContainer(ctx context.Context, containerID string, signal int) error
 	// CreateContainer creates a containerd container and start process.
 	CreateContainer(ctx context.Context, container *Container, checkpointDir string) error
 	// DestroyContainer kill container and delete it.

daemon/mgr/container.go

@@ -68,6 +68,9 @@ type ContainerMgr interface {
 	// List returns the list of containers.
 	List(ctx context.Context, option *ContainerListOption) ([]*Container, error)
 
+	// Kill a running container
+	Kill(ctx context.Context, name string, signal uint64) (err error)
+
 	// Start a container.
 	Start(ctx context.Context, id string, options *types.ContainerStartOptions) error
 

daemon/mgr/container_kill.go

@@ -0,0 +1,94 @@
+package mgr
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"syscall"
+
+	"github.com/pkg/errors"
+
+	"github.com/alibaba/pouch/pkg/errtypes"
+	"github.com/sirupsen/logrus"
+)
+
+// Kill kills a container.
+func (mgr *ContainerManager) Kill(ctx context.Context, name string, signal uint64) (err error) {
+	c, err := mgr.container(name)
+	if err != nil {
+		return err
+	}
+
+	if syscall.Signal(signal) == syscall.SIGKILL {
+		return mgr.kill(ctx, c)
+	}
+	return mgr.killWithSignal(ctx, c, int(signal))
+}
+
+func (mgr *ContainerManager) kill(ctx context.Context, c *Container) error {
+	if !c.IsRunning() {
+		return fmt.Errorf("Container %s is not running", c.ID)
+	}
+
+	if err := mgr.killDeadProcess(ctx, c, int(syscall.SIGKILL)); err != nil {
+		if errtypes.IsNoSuchProcess(err) {
+			return nil
+		}
+
+		if c.IsRunning() {
+			return err
+		}
+	}
+
+	if pid := c.State.Pid; pid != 0 {
+		if err := syscall.Kill(int(pid), 9); err != nil {
+			if err != syscall.ESRCH {
+				return err
+			}
+
+			e := errors.Wrapf(errtypes.ErrNoSuchProcess, "Cannot kill process (pid=%d) with signal %d", c.State.Pid, 9)
+			logrus.Debug(e)
+			return nil
+		}
+	}
+	return nil
+}
+
+func (mgr *ContainerManager) killDeadProcess(ctx context.Context, c *Container, signal int) error {
+	err := mgr.killWithSignal(ctx, c, signal)
+	if err == syscall.ESRCH {
+		e := errors.Wrapf(errtypes.ErrNoSuchProcess, "Cannot kill process (pid=%d) with signal %d", c.State.Pid, signal)
+		logrus.Debug(e)
+		return e
+	}
+	return err
+}
+
+func (mgr *ContainerManager) killWithSignal(ctx context.Context, c *Container, signal int) error {
+	logrus.Debugf("Sending %d to %s", signal, c.ID)
+	c.Lock()
+	defer c.Unlock()
+
+	if c.State.Paused {
+		return fmt.Errorf("Container %s is paused. Unpause the container before stopping", c.ID)
+	}
+
+	if !c.State.Running {
+		return fmt.Errorf("Container %s is not running", c.ID)
+	}
+
+	if err := mgr.Client.KillContainer(ctx, c.ID, signal); err != nil {
+		// if container or process not exists, ignore the error
+		if strings.Contains(err.Error(), "container not found") ||
+			strings.Contains(err.Error(), "no such process") {
+			logrus.Warnf("container kill failed because of 'container not found' or 'no such process': %s", err.Error())
+		} else {
+			return fmt.Errorf("Cannot kill container %s: %s", c.ID, err)
+		}
+	}
+	attributes := map[string]string{
+		"signal": fmt.Sprintf("%d", signal),
+	}
+	mgr.LogContainerEventWithAttributes(ctx, c, "kill", attributes)
+	return nil
+}

docs/commandline/pouch_kill.md

@@ -0,0 +1,49 @@
+## pouch kill
+
+Kill one or more running containers
+
+### Synopsis
+
+Kill one or more running containers in Pouchd. You can kill a container using the container’s ID, ID-prefix, or name. This is useful when you wish to kill a container which is running. 
+
+```
+pouch kill [OPTIONS] CONTAINER [CONTAINER...]
+```
+
+### Examples
+
+```
+$ pouch ps -a
+Name   ID       Status    		Created         Image                                            Runtime
+foo2   5a0ede   Up 2 seconds   	3 second ago    registry.hub.docker.com/library/busybox:latest   runc
+foo1   e05637   Up 6 seconds   	7 seconds ago   registry.hub.docker.com/library/busybox:latest   runc
+$ pouch kill foo1
+foo1
+$ pouch ps
+Name   ID       Status         Created          Image                                            Runtime
+foo2   5a0ede   Up 11 seconds   12 seconds ago   registry.hub.docker.com/library/busybox:latest   runc
+```
+
+### Options
+
+```
+  -h, --help       help for kill
+  -s, --signal string   Signal to send to the container (default "KILL")
+```
+
+### Options inherited from parent commands
+
+```
+  -D, --debug              Switch client log level to DEBUG mode
+  -H, --host string        Specify connecting address of Pouch CLI (default "unix:///var/run/pouchd.sock")
+      --tlscacert string   Specify CA file of TLS
+      --tlscert string     Specify cert file of TLS
+      --tlskey string      Specify key file of TLS
+      --tlsverify          Use TLS and verify remote
+```
+
+### SEE ALSO
+
+* [pouch](pouch.md)	 - An efficient container engine
+
+

pkg/errtypes/errors.go

@@ -37,6 +37,9 @@ var (
 
 	// ErrPreCheckFailed represents that failed to pre check.
 	ErrPreCheckFailed = errorType{codePreCheckFailed, "pre check failed"}
+
+	// ErrNoSuchProcess represents there is no such process
+	ErrNoSuchProcess = errorType{codeNoSuchProcess, "no such process"}
 )
 
 const (
@@ -51,6 +54,7 @@ const (
 	codeInUse
 	codeNotModified
 	codePreCheckFailed
+	codeNoSuchProcess
 
 	// volume error code
 	codeVolumeExisted
@@ -97,6 +101,11 @@ func IsNotModified(err error) bool {
 	return checkError(err, codeNotModified)
 }
 
+// IsNoSuchProcess checks the error is no such process error or not.
+func IsNoSuchProcess(err error) bool {
+	return checkError(err, codeNoSuchProcess)
+}
+
 // IsPreCheckFailed checks the error is failed to pre check or not.
 func IsPreCheckFailed(err error) bool {
 	return checkError(err, codePreCheckFailed)