api: add sandbox StatusContainer API

It retrieves container status from sandbox.

Signed-off-by: Peng Tao <bergwolf@gmail.com>

virtcontainers/errors.go

@@ -17,4 +17,5 @@ var (
 	errNeedFile        = errors.New("File cannot be empty")
 	errNeedState       = errors.New("State cannot be empty")
 	errInvalidResource = errors.New("Invalid sandbox resource")
+	errNoSuchContainer = errors.New("Container does not exist")
 )

virtcontainers/interfaces.go

@@ -53,6 +53,7 @@ type VCSandbox interface {
 	CreateContainer(contConfig ContainerConfig) (VCContainer, error)
 	DeleteContainer(contID string) (VCContainer, error)
 	StartContainer(containerID string) (VCContainer, error)
+	StatusContainer(containerID string) (ContainerStatus, error)
 }
 
 // VCContainer is the Container interface

virtcontainers/pkg/vcmock/sandbox.go

@@ -84,3 +84,8 @@ func (p *Sandbox) DeleteContainer(contID string) (vc.VCContainer, error) {
 func (p *Sandbox) StartContainer(contID string) (vc.VCContainer, error) {
 	return &Container{}, nil
 }
+
+// StatusContainer implements the VCSandbox function of the same name.
+func (p *Sandbox) StatusContainer(contID string) (vc.ContainerStatus, error) {
+	return vc.ContainerStatus{}, nil
+}

virtcontainers/sandbox.go

@@ -946,6 +946,29 @@ func (s *Sandbox) DeleteContainer(containerID string) (VCContainer, error) {
 	return c, nil
 }
 
+// StatusContainer gets the status of a container
+// TODO: update container status properly, see kata-containers/runtime#253
+func (s *Sandbox) StatusContainer(containerID string) (ContainerStatus, error) {
+	if containerID == "" {
+		return ContainerStatus{}, errNeedContainerID
+	}
+
+	for _, c := range s.containers {
+		if c.id == containerID {
+			return ContainerStatus{
+				ID:          c.id,
+				State:       c.state,
+				PID:         c.process.Pid,
+				StartTime:   c.process.StartTime,
+				RootFs:      c.config.RootFs,
+				Annotations: c.config.Annotations,
+			}, nil
+		}
+	}
+
+	return ContainerStatus{}, errNoSuchContainer
+}
+
 // createContainers registers all containers to the proxy, create the
 // containers in the guest and starts one shim per container.
 func (s *Sandbox) createContainers() error {

virtcontainers/sandbox_test.go

@@ -1336,3 +1336,23 @@ func TestStartContainer(t *testing.T) {
 	_, err = s.StartContainer(contID)
 	assert.Nil(t, err, "Start container failed: %v", err)
 }
+
+func TestStatusContainer(t *testing.T) {
+	s, err := testCreateSandbox(t, testSandboxID, MockHypervisor, newHypervisorConfig(nil, nil), NoopAgentType, NoopNetworkModel, NetworkConfig{}, nil, nil)
+	assert.Nil(t, err, "VirtContainers should not allow empty sandboxes")
+	defer cleanUp()
+
+	contID := "999"
+	_, err = s.StatusContainer(contID)
+	assert.NotNil(t, err, "Status non-existing container should fail")
+
+	contConfig := newTestContainerConfigNoop(contID)
+	_, err = s.CreateContainer(contConfig)
+	assert.Nil(t, err, "Failed to create container %+v in sandbox %+v: %v", contConfig, s, err)
+
+	_, err = s.StatusContainer(contID)
+	assert.Nil(t, err, "Status container failed: %v", err)
+
+	_, err = s.DeleteContainer(contID)
+	assert.Nil(t, err, "Failed to delete container %s in sandbox %s: %v", contID, s.ID(), err)
+}