add wait client command for pouch

apis/server/container_bridge.go

@@ -383,3 +383,17 @@ func (s *Server) removeContainers(ctx context.Context, rw http.ResponseWriter, r
 	rw.WriteHeader(http.StatusNoContent)
 	return nil
 }
+
+func (s *Server) waitContainer(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
+	name := mux.Vars(req)["name"]
+
+	status, err := s.ContainerMgr.Wait(ctx, name, -1*time.Second)
+
+	if err != nil {
+		return err
+	}
+
+	return EncodeResponse(rw, http.StatusOK, &types.ContainerWaitOKBody{
+		StatusCode: int64(status),
+	})
+}

apis/server/router.go

@@ -53,6 +53,7 @@ func initRoute(s *Server) http.Handler {
 	s.addRoute(r, http.MethodGet, "/containers/{name:.*}/logs", withCancelHandler(s.logsContainer))
 	s.addRoute(r, http.MethodPost, "/containers/{name:.*}/resize", s.resizeContainer)
 	s.addRoute(r, http.MethodPost, "/containers/{name:.*}/restart", s.restartContainer)
+	s.addRoute(r, http.MethodPost, "/containers/{name:.*}/wait", s.waitContainer)
 
 	// image
 	s.addRoute(r, http.MethodPost, "/images/create", s.pullImage)

apis/swagger.yml

@@ -518,6 +518,29 @@ paths:
           $ref: "#/responses/500ErrorResponse"
       tags: ["Container"]
 
+  /containers/{id}/wait:
+    post:
+      summary: "Block until a container stops, then returns the exit code."
+      operationId: "ContainerWait"
+      parameters:
+        - $ref: "#/parameters/id"
+      responses:
+        200:
+          description: "The container has exited."
+          schema:
+            type: "object"
+            required: [StatusCode]
+            properties:
+              StatusCode:
+                description: "Exit code of the container"
+                type: "integer"
+                x-nullable: false
+        404:
+          $ref: "#/responses/404ErrorResponse"
+        500:
+          $ref: "#/responses/500ErrorResponse"
+      tags: ["Container"]
+
   /containers/{id}:
     delete:
       summary: "Remove one container"
@@ -3425,3 +3448,4 @@ responses:
     description: An unexpected server error occurred.
     schema:
       $ref: "#/definitions/Error"
+

cli/main.go

@@ -42,6 +42,7 @@ func main() {
 	cli.AddCommand(base, &TopCommand{})
 	cli.AddCommand(base, &LogsCommand{})
 	cli.AddCommand(base, &RemountLxcfsCommand{})
+	cli.AddCommand(base, &WaitCommand{})
 
 	// add generate doc command
 	cli.AddCommand(base, &GenDocCommand{})

cli/wait.go

@@ -0,0 +1,70 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/spf13/cobra"
+)
+
+// waitDescription is used to describe wait command in detail and auto generate command doc.
+var waitDescription = "Block until one or more containers stop, then print their exit codes. " +
+	"If container state is already stopped, the command will return exit code immediately. " +
+	"On a successful stop, the exit code of the container is returned. "
+
+// WaitCommand is used to implement 'wait' command.
+type WaitCommand struct {
+	baseCommand
+}
+
+// Init initialize wait command.
+func (wait *WaitCommand) Init(c *Cli) {
+	wait.cli = c
+	wait.cmd = &cobra.Command{
+		Use:   "wait CONTAINER [CONTAINER...]",
+		Short: "Block until one or more containers stop, then print their exit codes",
+		Long:  waitDescription,
+		Args:  cobra.MinimumNArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return wait.runWait(args)
+		},
+		Example: waitExamples(),
+	}
+}
+
+// runWait is the entry of wait command.
+func (wait *WaitCommand) runWait(args []string) error {
+	ctx := context.Background()
+	apiClient := wait.cli.Client()
+
+	var errs []string
+	for _, name := range args {
+		status, err := apiClient.ContainerWait(ctx, name)
+		if err != nil {
+			errs = append(errs, name)
+			continue
+		}
+		fmt.Printf("%d\n", status)
+	}
+
+	if len(errs) > 0 {
+		return errors.New(strings.Join(errs, "\n"))
+	}
+
+	return nil
+}
+
+// waitExamples shows examples in wait command, and is used in auto-generated cli docs.
+func waitExamples() string {
+	return `$ pouch ps
+Name   ID       Status         Created         Image                                            Runtime
+foo    f6717e   Up 2 seconds   3 seconds ago   registry.hub.docker.com/library/busybox:latest   runc
+$ pouch stop foo
+$ pouch ps -a
+Name   ID       Status                 Created         Image                                            Runtime
+foo    f6717e   Stopped (0) 1 minute   2 minutes ago   registry.hub.docker.com/library/busybox:latest   runc
+$ pouch wait foo
+0`
+}

client/container_wait.go

@@ -0,0 +1,21 @@
+package client
+
+import (
+	"context"
+
+	"github.com/alibaba/pouch/apis/types"
+)
+
+// ContainerWait pauses execution until a container exits.
+// It returns the API status code as response of its readiness.
+func (client *APIClient) ContainerWait(ctx context.Context, name string) (int64, error) {
+	resp, err := client.post(ctx, "/containers/"+name+"/wait", nil, nil, nil)
+	if err != nil {
+		return -1, err
+	}
+
+	var response types.ContainerWaitOKBody
+	err = decodeBody(&response, resp.Body)
+	ensureCloseReader(resp)
+	return response.StatusCode, err
+}

client/interface.go

@@ -39,6 +39,7 @@ type ContainerAPIClient interface {
 	ContainerTop(ctx context.Context, name string, arguments []string) (types.ContainerProcessList, error)
 	ContainerLogs(ctx context.Context, name string, options types.ContainerLogsOptions) (io.ReadCloser, error)
 	ContainerResize(ctx context.Context, name, height, width string) error
+	ContainerWait(ctx context.Context, name string) (int64, error)
 }
 
 // ImageAPIClient defines methods of Image client.

ctrd/container.go

@@ -500,3 +500,27 @@ func (c *Client) ResizeContainer(ctx context.Context, id string, opts types.Resi
 
 	return pack.task.Resize(ctx, uint32(opts.Height), uint32(opts.Width))
 }
+
+// WaitContainer waits until container's status is stopped.
+func (c *Client) WaitContainer(ctx context.Context, id string, timeout time.Duration) (int64, error) {
+	wrapperCli, err := c.Get(ctx)
+	if err != nil {
+		return -1, fmt.Errorf("failed to get a containerd grpc client: %v", err)
+	}
+
+	ctx = leases.WithLease(ctx, wrapperCli.lease.ID())
+
+	waitExit := func() *Message {
+		return c.ProbeContainer(ctx, id, timeout)
+	}
+
+	var msg *Message
+	// wait for the task to exit.
+	msg = waitExit()
+
+	if err := msg.RawError(); err != nil && errtypes.IsTimeout(err) {
+		return -1, err
+	}
+
+	return int64(msg.ExitCode()), nil
+}

ctrd/interface.go

@@ -46,6 +46,8 @@ type ContainerAPIClient interface {
 	// ResizeContainer changes the size of the TTY of the init process running
 	// in the container to the given height and width.
 	ResizeContainer(ctx context.Context, id string, opts types.ResizeOptions) error
+	// WaitContainer waits until container's status is stopped.
+	WaitContainer(ctx context.Context, id string, timeout time.Duration) (int64, error)
 	// UpdateResources updates the configurations of a container.
 	UpdateResources(ctx context.Context, id string, resources types.Resources) error
 	// SetExitHooks specified the handlers of container exit.

daemon/mgr/container.go

@@ -95,6 +95,9 @@ type ContainerMgr interface {
 	// Remove removes a container, it may be running or stopped and so on.
 	Remove(ctx context.Context, name string, option *types.ContainerRemoveOptions) error
 
+	// Wait stops processing until the given container is stopped.
+	Wait(ctx context.Context, name string, timeout time.Duration) (int64, error)
+
 	// 2. The following five functions is related to containr exec.
 
 	// CreateExec creates exec process's environment.
@@ -1266,6 +1269,23 @@ func (mgr *ContainerManager) Resize(ctx context.Context, name string, opts types
 	return mgr.Client.ResizeContainer(ctx, c.ID, opts)
 }
 
+// Wait stops processing until the given container is stopped.
+func (mgr *ContainerManager) Wait(ctx context.Context, name string, timeout time.Duration) (int64, error) {
+	c, err := mgr.container(name)
+	if err != nil {
+		return -1, err
+	}
+
+	// We should notice that container's meta data shouldn't be locked in wait process, otherwise waiting for
+	// a running container to stop would make other client commands which manage this container are blocked.
+	// If a container status is exited or stopped, return exit code immediately.
+	if c.IsExited() || c.IsStopped() {
+		return int64(c.ExitCode()), nil
+	}
+
+	return mgr.Client.WaitContainer(ctx, c.ID, timeout)
+}
+
 // Connect is used to connect a container to a network.
 func (mgr *ContainerManager) Connect(ctx context.Context, name string, networkIDOrName string, epConfig *types.EndpointSettings) error {
 	c, err := mgr.container(name)

daemon/mgr/container_types.go

@@ -187,6 +187,11 @@ func (c *Container) Key() string {
 	return c.ID
 }
 
+// ExitCode returns container's ExitCode.
+func (c *Container) ExitCode() int64 {
+	return c.State.ExitCode
+}
+
 // IsRunning returns container is running or not.
 func (c *Container) IsRunning() bool {
 	return c.State.Status == types.StatusRunning

test/api_container_wait_test.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"github.com/alibaba/pouch/test/environment"
+	"github.com/alibaba/pouch/test/request"
+
+	"github.com/go-check/check"
+)
+
+// APIContainerWaitSuite is the test suite for container wait API.
+type APIContainerWaitSuite struct{}
+
+func init() {
+	check.Suite(&APIContainerWaitSuite{})
+}
+
+// SetUpTest does common setup in the beginning of each test.
+func (suite *APIContainerWaitSuite) SetUpTest(c *check.C) {
+	SkipIfFalse(c, environment.IsLinux)
+	PullImage(c, busyboxImage)
+}
+
+// TestWaitOk tests waiting a stopped container return 200.
+func (suite *APIContainerWaitSuite) TestWaitOk(c *check.C) {
+	cname := "TestWaitOk"
+
+	CreateBusyboxContainerOk(c, cname)
+	StartContainerOk(c, cname)
+	StopContainerOk(c, cname)
+
+	resp, err := request.Post("/containers/" + cname + "/wait")
+	c.Assert(err, check.IsNil)
+	CheckRespStatus(c, resp, 200)
+
+	DelContainerForceOk(c, cname)
+}
+
+// TestNonExistingContainer tests waiting a non-existing container return 404.
+func (suite *APIContainerWaitSuite) TestNonExistingContainer(c *check.C) {
+	cname := "TestNonExistingContainer"
+	resp, err := request.Post("/containers/" + cname + "/wait")
+	c.Assert(err, check.IsNil)
+	CheckRespStatus(c, resp, 404)
+}