api: implement fetching the container status

Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>

linux/container.go

@@ -3,6 +3,7 @@ package linux
 import (
 	"github.com/docker/containerd"
 	"github.com/docker/containerd/api/services/shim"
+	"github.com/docker/containerd/api/types/container"
 	"golang.org/x/net/context"
 )
 
@@ -42,7 +43,20 @@ func (c *Container) State(ctx context.Context) (containerd.State, error) {
 	if err != nil {
 		return nil, err
 	}
+	var status containerd.ContainerStatus
+	switch response.Status {
+	case container.Status_CREATED:
+		status = containerd.CreatedStatus
+	case container.Status_RUNNING:
+		status = containerd.RunningStatus
+	case container.Status_STOPPED:
+		status = containerd.StoppedStatus
+	case container.Status_PAUSED:
+		status = containerd.PausedStatus
+		// TODO: containerd.DeletedStatus
+	}
 	return &State{
-		pid: response.Pid,
+		pid:    response.Pid,
+		status: status,
 	}, nil
 }

linux/shim/init.go

@@ -106,6 +106,15 @@ func (p *initProcess) Status() int {
 	return p.status
 }
 
+// ContainerStatus return the state of the container (created, running, paused, stopped)
+func (p *initProcess) ContainerStatus(ctx context.Context) (string, error) {
+	c, err := p.runc.State(ctx, p.id)
+	if err != nil {
+		return "", err
+	}
+	return c.Status, nil
+}
+
 func (p *initProcess) Start(context context.Context) error {
 	return p.runc.Start(context, p.id)
 }

linux/shim/service.go

@@ -136,10 +136,26 @@ func (s *Service) Events(r *shimapi.EventsRequest, stream shimapi.Shim_EventsSer
 }
 
 func (s *Service) State(ctx context.Context, r *shimapi.StateRequest) (*shimapi.StateResponse, error) {
+	st, err := s.initProcess.ContainerStatus(ctx)
+	if err != nil {
+		return nil, err
+	}
+	status := container.Status_UNKNOWN
+	switch st {
+	case "created":
+		status = container.Status_CREATED
+	case "running":
+		status = container.Status_RUNNING
+	case "stopped":
+		status = container.Status_STOPPED
+	case "paused":
+		status = container.Status_PAUSED
+	}
 	o := &shimapi.StateResponse{
 		ID:        s.id,
 		Bundle:    s.bundle,
 		Pid:       uint32(s.initProcess.Pid()),
+		Status:    status,
 		Processes: []*container.Process{},
 	}
 	s.mu.Lock()