Do not checkpoint sandbox pid.

Signed-off-by: Lantao Liu <lantaol@google.com>

pkg/server/container_create.go

@@ -44,6 +44,11 @@ func (c *criContainerdService) CreateContainer(ctx context.Context, r *runtime.C
 		return nil, fmt.Errorf("failed to find sandbox id %q: %v", r.GetPodSandboxId(), err)
 	}
 	sandboxID := sandbox.ID
+	s, err := sandbox.Container.Task(ctx, nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get sandbox container task: %v", err)
+	}
+	sandboxPid := s.Pid()
 
 	// Generate unique id and name for the container and reserve the name.
 	// Reserve the container name to avoid concurrent `CreateContainer` request creating
@@ -81,7 +86,7 @@ func (c *criContainerdService) CreateContainer(ctx context.Context, r *runtime.C
 
 	// Generate container runtime spec.
 	mounts := c.generateContainerMounts(getSandboxRootDir(c.rootDir, sandboxID), config)
-	spec, err := c.generateContainerSpec(id, sandbox.Pid, config, sandboxConfig, image.Config, mounts)
+	spec, err := c.generateContainerSpec(id, sandboxPid, config, sandboxConfig, image.Config, mounts)
 	if err != nil {
 		return nil, fmt.Errorf("failed to generate container %q spec: %v", id, err)
 	}

pkg/server/sandbox_portforward.go

@@ -40,7 +40,7 @@ func (c *criContainerdService) PortForward(ctx context.Context, r *runtime.PortF
 
 	t, err := sandbox.Container.Task(ctx, nil)
 	if err != nil {
-		return nil, fmt.Errorf("failed to get sandbox container: %v", err)
+		return nil, fmt.Errorf("failed to get sandbox container task: %v", err)
 	}
 	status, err := t.Status(ctx)
 	if err != nil {
@@ -61,7 +61,11 @@ func (c *criContainerdService) portForward(id string, port int32, stream io.Read
 	if err != nil {
 		return fmt.Errorf("failed to find sandbox in store: %v", err)
 	}
-	pid := s.Pid
+	t, err := s.Container.Task(context.Background(), nil)
+	if err != nil {
+		return fmt.Errorf("failed to get sandbox container task: %v", err)
+	}
+	pid := t.Pid()
 
 	socat, err := exec.LookPath("socat")
 	if err != nil {

pkg/server/sandbox_run.go

@@ -118,11 +118,6 @@ func (c *criContainerdService) RunPodSandbox(ctx context.Context, r *runtime.Run
 	glog.V(4).Infof("Sandbox container spec: %+v", spec)
 
 	// Checkpoint metadata into container
-	// TODO(random-liu): Switch to extensions(after merge containerd #1378).
-	// Actually the Pid, NetNS and CreatedAt underlying are not included here.
-	// I'm fine with this for now. After this PR is merged, we could:
-	// 1.Get Pid from containerd, so that we don't need to checkpoint it ourselves;
-	// 2.Use permanent NetNS after #138 is merged, so that we'll have network namespace here.
 	metaBytes, err := sandbox.Metadata.Encode()
 	if err != nil {
 		return nil, fmt.Errorf("failed to convert sandbox metadata: %+v, %v", sandbox.Metadata, err)
@@ -194,7 +189,6 @@ func (c *criContainerdService) RunPodSandbox(ctx context.Context, r *runtime.Run
 		}
 	}()
 
-	sandbox.Pid = task.Pid()
 	if err = task.Start(ctx); err != nil {
 		return nil, fmt.Errorf("failed to start sandbox container task %q: %v",
 			id, err)

pkg/store/sandbox/metadata.go

@@ -46,8 +46,6 @@ type Metadata struct {
 	Name string
 	// Config is the CRI sandbox config.
 	Config *runtime.PodSandboxConfig
-	// Pid is the process id of the sandbox.
-	Pid uint32
 	// NetNSPath is the network namespace used by the sandbox.
 	NetNSPath string
 }

pkg/store/sandbox/sandbox_test.go

@@ -39,7 +39,6 @@ func TestSandboxStore(t *testing.T) {
 					Attempt:   1,
 				},
 			},
-			Pid:       1001,
 			NetNSPath: "TestNetNS-1",
 		},
 		"2": {
@@ -53,7 +52,6 @@ func TestSandboxStore(t *testing.T) {
 					Attempt:   2,
 				},
 			},
-			Pid:       1002,
 			NetNSPath: "TestNetNS-2",
 		},
 		"3": {
@@ -67,7 +65,6 @@ func TestSandboxStore(t *testing.T) {
 					Attempt:   3,
 				},
 			},
-			Pid:       1003,
 			NetNSPath: "TestNetNS-3",
 		},
 	}