Add checkpoint and restore to client package

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

.travis.yml

@@ -18,6 +18,15 @@ addons:
       - btrfs-tools
       - libseccomp-dev
       - libapparmor-dev
+      - libnl-3-dev
+      - libnet-dev
+      - protobuf-c-compiler
+      - protobuf-compiler
+      - python-minimal
+      - libcap-dev
+      - libaio-dev
+      - libprotobuf-c0-dev
+      - libprotobuf-dev
 
 env:
   - TRAVIS_GOOS=windows TRAVIS_CGO_ENABLED=1
@@ -31,6 +40,10 @@ install:
   - export PATH=$PATH:/tmp/protobuf/bin/
   - go get -u github.com/vbatts/git-validation
   - sudo wget https://github.com/crosbymichael/runc/releases/download/ctd-1/runc -O /bin/runc; sudo chmod +x /bin/runc
+  - wget https://github.com/xemul/criu/archive/v3.0.tar.gz -O /tmp/criu.tar.gz
+  - tar -C /tmp/ -zxf /tmp/criu.tar.gz
+  - cd /tmp/criu-3.0 && sudo make install-criu
+  - cd $TRAVIS_BUILD_DIR
 
 script:
   - export GOOS=$TRAVIS_GOOS

checkpoint_test.go

@@ -0,0 +1,193 @@
+package containerd
+
+import (
+	"context"
+	"syscall"
+	"testing"
+)
+
+func TestCheckpointRestore(t *testing.T) {
+	if testing.Short() {
+		t.Skip()
+	}
+	client, err := New(address)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer client.Close()
+
+	var (
+		ctx = context.Background()
+		id  = "CheckpointRestore"
+	)
+	image, err := client.GetImage(ctx, testImage)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	spec, err := GenerateSpec(WithImageConfig(ctx, image), WithProcessArgs("sleep", "100"))
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	container, err := client.NewContainer(ctx, id, WithSpec(spec), WithImage(image), WithNewRootFS(id, image))
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	defer container.Delete(ctx)
+
+	task, err := container.NewTask(ctx, empty())
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	defer task.Delete(ctx)
+
+	statusC := make(chan uint32, 1)
+	go func() {
+		status, err := task.Wait(ctx)
+		if err != nil {
+			t.Error(err)
+		}
+		statusC <- status
+	}()
+
+	if err := task.Start(ctx); err != nil {
+		t.Error(err)
+		return
+	}
+
+	checkpoint, err := task.Checkpoint(ctx, WithExit)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
+	<-statusC
+
+	if _, err := task.Delete(ctx); err != nil {
+		t.Error(err)
+		return
+	}
+	if task, err = container.NewTask(ctx, empty(), WithTaskCheckpoint(checkpoint)); err != nil {
+		t.Error(err)
+		return
+	}
+	defer task.Delete(ctx)
+
+	go func() {
+		status, err := task.Wait(ctx)
+		if err != nil {
+			t.Error(err)
+		}
+		statusC <- status
+	}()
+
+	if err := task.Start(ctx); err != nil {
+		t.Error(err)
+		return
+	}
+
+	if err := task.Kill(ctx, syscall.SIGKILL); err != nil {
+		t.Error(err)
+		return
+	}
+	<-statusC
+}
+
+func TestCheckpointRestoreNewContainer(t *testing.T) {
+	if testing.Short() {
+		t.Skip()
+	}
+	client, err := New(address)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer client.Close()
+
+	const id = "CheckpointRestoreNewContainer"
+	ctx := context.Background()
+	image, err := client.GetImage(ctx, testImage)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	spec, err := GenerateSpec(WithImageConfig(ctx, image), WithProcessArgs("sleep", "100"))
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	container, err := client.NewContainer(ctx, id, WithSpec(spec), WithImage(image), WithNewRootFS(id, image))
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	defer container.Delete(ctx)
+
+	task, err := container.NewTask(ctx, empty())
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	defer task.Delete(ctx)
+
+	statusC := make(chan uint32, 1)
+	go func() {
+		status, err := task.Wait(ctx)
+		if err != nil {
+			t.Error(err)
+		}
+		statusC <- status
+	}()
+
+	if err := task.Start(ctx); err != nil {
+		t.Error(err)
+		return
+	}
+
+	checkpoint, err := task.Checkpoint(ctx, WithExit)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
+	<-statusC
+
+	if err := container.Delete(ctx); err != nil {
+		t.Error(err)
+		return
+	}
+	if _, err := task.Delete(ctx); err != nil {
+		t.Error(err)
+		return
+	}
+	if container, err = client.NewContainer(ctx, id, WithCheckpoint(checkpoint, id)); err != nil {
+		t.Error(err)
+		return
+	}
+	if task, err = container.NewTask(ctx, empty(), WithTaskCheckpoint(checkpoint)); err != nil {
+		t.Error(err)
+		return
+	}
+	defer task.Delete(ctx)
+
+	go func() {
+		status, err := task.Wait(ctx)
+		if err != nil {
+			t.Error(err)
+		}
+		statusC <- status
+	}()
+
+	if err := task.Start(ctx); err != nil {
+		t.Error(err)
+		return
+	}
+
+	if err := task.Kill(ctx, syscall.SIGKILL); err != nil {
+		t.Error(err)
+		return
+	}
+	<-statusC
+}

client.go

@@ -27,11 +27,9 @@ import (
 	imagesservice "github.com/containerd/containerd/services/images"
 	snapshotservice "github.com/containerd/containerd/services/snapshot"
 	"github.com/containerd/containerd/snapshot"
-	protobuf "github.com/gogo/protobuf/types"
 	"github.com/opencontainers/image-spec/identity"
 	"github.com/opencontainers/image-spec/specs-go/v1"
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
-	specs "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/pkg/errors"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/grpclog"
@@ -176,18 +174,10 @@ func WithImage(i Image) NewContainerOpts {
 
 // NewContainer will create a new container in container with the provided id
 // the id must be unique within the namespace
-func (c *Client) NewContainer(ctx context.Context, id string, spec *specs.Spec, opts ...NewContainerOpts) (Container, error) {
-	data, err := json.Marshal(spec)
-	if err != nil {
-		return nil, err
-	}
+func (c *Client) NewContainer(ctx context.Context, id string, opts ...NewContainerOpts) (Container, error) {
 	container := containers.Container{
 		ID:      id,
 		Runtime: c.runtime,
-		Spec: &protobuf.Any{
-			TypeUrl: specs.Version,
-			Value:   data,
-		},
 	}
 	for _, o := range opts {
 		if err := o(ctx, c, &container); err != nil {

client_test.go

@@ -18,10 +18,14 @@ const (
 	testImage    = "docker.io/library/alpine:latest"
 )
 
-var address string
+var (
+	address  string
+	noDaemon bool
+)
 
 func init() {
 	flag.StringVar(&address, "address", "/run/containerd/containerd.sock", "The address to the containerd socket for use in the tests")
+	flag.BoolVar(&noDaemon, "no-daemon", false, "Do not start a dedicated daemon for the tests")
 	flag.Parse()
 }
 
@@ -29,17 +33,23 @@ func TestMain(m *testing.M) {
 	if testing.Short() {
 		os.Exit(m.Run())
 	}
-	// setup a new containerd daemon if !testing.Short
-	cmd := exec.Command("containerd",
-		"--root", defaultRoot,
-		"--state", defaultState,
+	var (
+		cmd *exec.Cmd
+		buf = bytes.NewBuffer(nil)
 	)
-	buf := bytes.NewBuffer(nil)
-	cmd.Stderr = buf
-	if err := cmd.Start(); err != nil {
-		fmt.Println(err)
-		os.Exit(1)
+	if !noDaemon {
+		// setup a new containerd daemon if !testing.Short
+		cmd = exec.Command("containerd",
+			"--root", defaultRoot,
+			"--state", defaultState,
+		)
+		cmd.Stderr = buf
+		if err := cmd.Start(); err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
 	}
+
 	client, err := New(address)
 	if err != nil {
 		fmt.Fprintln(os.Stderr, err)
@@ -62,20 +72,22 @@ func TestMain(m *testing.M) {
 	// run the test
 	status := m.Run()
 
-	// tear down the daemon and resources created
-	if err := cmd.Process.Signal(syscall.SIGTERM); err != nil {
-		fmt.Fprintln(os.Stderr, err)
-	}
-	if _, err := cmd.Process.Wait(); err != nil {
-		fmt.Fprintln(os.Stderr, err)
-	}
-	if err := os.RemoveAll(defaultRoot); err != nil {
-		fmt.Fprintln(os.Stderr, err)
-		os.Exit(1)
-	}
-	// only print containerd logs if the test failed
-	if status != 0 {
-		fmt.Fprintln(os.Stderr, buf.String())
+	if !noDaemon {
+		// tear down the daemon and resources created
+		if err := cmd.Process.Signal(syscall.SIGTERM); err != nil {
+			fmt.Fprintln(os.Stderr, err)
+		}
+		if _, err := cmd.Process.Wait(); err != nil {
+			fmt.Fprintln(os.Stderr, err)
+		}
+		if err := os.RemoveAll(defaultRoot); err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(1)
+		}
+		// only print containerd logs if the test failed
+		if status != 0 {
+			fmt.Fprintln(os.Stderr, buf.String())
+		}
 	}
 	os.Exit(status)
 }

container.go

@@ -14,7 +14,7 @@ import (
 type Container interface {
 	ID() string
 	Delete(context.Context) error
-	NewTask(context.Context, IOCreation) (Task, error)
+	NewTask(context.Context, IOCreation, ...NewTaskOpts) (Task, error)
 	Spec() (*specs.Spec, error)
 	Task() Task
 	LoadTask(context.Context, IOAttach) (Task, error)
@@ -71,7 +71,9 @@ func (c *container) Task() Task {
 	return c.task
 }
 
-func (c *container) NewTask(ctx context.Context, ioCreate IOCreation) (Task, error) {
+type NewTaskOpts func(context.Context, *Client, *execution.CreateRequest) error
+
+func (c *container) NewTask(ctx context.Context, ioCreate IOCreation, opts ...NewTaskOpts) (Task, error) {
 	i, err := ioCreate()
 	if err != nil {
 		return nil, err
@@ -97,15 +99,28 @@ func (c *container) NewTask(ctx context.Context, ioCreate IOCreation) (Task, err
 			})
 		}
 	}
-	response, err := c.client.TaskService().Create(ctx, request)
-	if err != nil {
-		return nil, err
+	for _, o := range opts {
+		if err := o(ctx, c.client, request); err != nil {
+			return nil, err
+		}
 	}
 	t := &task{
 		client:      c.client,
 		io:          i,
-		containerID: response.ContainerID,
-		pid:         response.Pid,
+		containerID: c.ID(),
+		pidSync:     make(chan struct{}),
+	}
+
+	if request.Checkpoint != nil {
+		// we need to defer the create call to start
+		t.deferred = request
+	} else {
+		response, err := c.client.TaskService().Create(ctx, request)
+		if err != nil {
+			return nil, err
+		}
+		t.pid = response.Pid
+		close(t.pidSync)
 	}
 	c.task = t
 	return t, nil

container_linux.go

@@ -0,0 +1,127 @@
+package containerd
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+
+	"github.com/containerd/containerd/api/services/containers"
+	"github.com/containerd/containerd/api/services/execution"
+	"github.com/containerd/containerd/api/types/descriptor"
+	"github.com/containerd/containerd/content"
+	"github.com/containerd/containerd/images"
+	"github.com/containerd/containerd/snapshot"
+	protobuf "github.com/gogo/protobuf/types"
+	digest "github.com/opencontainers/go-digest"
+	"github.com/opencontainers/image-spec/identity"
+	"github.com/opencontainers/image-spec/specs-go/v1"
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+func WithSpec(spec *specs.Spec) NewContainerOpts {
+	return func(ctx context.Context, client *Client, c *containers.Container) error {
+		data, err := json.Marshal(spec)
+		if err != nil {
+			return err
+		}
+		c.Spec = &protobuf.Any{
+			TypeUrl: spec.Version,
+			Value:   data,
+		}
+		return nil
+	}
+}
+
+func WithCheckpoint(desc v1.Descriptor, rootfsID string) NewContainerOpts {
+	// set image and rw, and spec
+	return func(ctx context.Context, client *Client, c *containers.Container) error {
+		id := desc.Digest
+		store := client.ContentStore()
+		index, err := decodeIndex(ctx, store, id)
+		if err != nil {
+			return err
+		}
+		var rw *v1.Descriptor
+		for _, m := range index.Manifests {
+			switch m.MediaType {
+			case v1.MediaTypeImageLayer:
+				fk := m
+				rw = &fk
+			case images.MediaTypeDockerSchema2Manifest:
+				config, err := images.Config(ctx, store, m)
+				if err != nil {
+					return err
+				}
+				diffIDs, err := images.RootFS(ctx, store, config)
+				if err != nil {
+					return err
+				}
+				if _, err := client.SnapshotService().Prepare(ctx, rootfsID, identity.ChainID(diffIDs).String()); err != nil {
+					if !snapshot.IsExist(err) {
+						return err
+					}
+				}
+				c.Image = index.Annotations["image.name"]
+			case images.MediaTypeContainerd1CheckpointConfig:
+				r, err := store.Reader(ctx, m.Digest)
+				if err != nil {
+					return err
+				}
+				data, err := ioutil.ReadAll(r)
+				r.Close()
+				if err != nil {
+					return err
+				}
+				c.Spec = &protobuf.Any{
+					TypeUrl: specs.Version,
+					Value:   data,
+				}
+			}
+		}
+		if rw != nil {
+			// apply the rw snapshot to the new rw layer
+			mounts, err := client.SnapshotService().Mounts(ctx, rootfsID)
+			if err != nil {
+				return err
+			}
+			if _, err := client.DiffService().Apply(ctx, *rw, mounts); err != nil {
+				return err
+			}
+		}
+		c.RootFS = rootfsID
+		return nil
+	}
+}
+
+func WithTaskCheckpoint(desc v1.Descriptor) NewTaskOpts {
+	return func(ctx context.Context, c *Client, r *execution.CreateRequest) error {
+		id := desc.Digest
+		index, err := decodeIndex(ctx, c.ContentStore(), id)
+		if err != nil {
+			return err
+		}
+		for _, m := range index.Manifests {
+			if m.MediaType == images.MediaTypeContainerd1Checkpoint {
+				r.Checkpoint = &descriptor.Descriptor{
+					MediaType: m.MediaType,
+					Size_:     m.Size,
+					Digest:    m.Digest,
+				}
+				return nil
+			}
+		}
+		return fmt.Errorf("checkpoint not found in index %s", id)
+	}
+}
+
+func decodeIndex(ctx context.Context, store content.Store, id digest.Digest) (*v1.Index, error) {
+	var index v1.Index
+	r, err := store.Reader(ctx, id)
+	if err != nil {
+		return nil, err
+	}
+	err = json.NewDecoder(r).Decode(&index)
+	r.Close()
+	return &index, err
+}

container_test.go

@@ -53,7 +53,7 @@ func TestNewContainer(t *testing.T) {
 		t.Error(err)
 		return
 	}
-	container, err := client.NewContainer(context.Background(), id, spec)
+	container, err := client.NewContainer(context.Background(), id, WithSpec(spec))
 	if err != nil {
 		t.Error(err)
 		return
@@ -96,7 +96,7 @@ func TestContainerStart(t *testing.T) {
 		t.Error(err)
 		return
 	}
-	container, err := client.NewContainer(ctx, id, spec, WithImage(image), WithNewRootFS(id, image))
+	container, err := client.NewContainer(ctx, id, WithSpec(spec), WithImage(image), WithNewRootFS(id, image))
 	if err != nil {
 		t.Error(err)
 		return
@@ -165,7 +165,7 @@ func TestContainerOutput(t *testing.T) {
 		t.Error(err)
 		return
 	}
-	container, err := client.NewContainer(ctx, id, spec, WithImage(image), WithNewRootFS(id, image))
+	container, err := client.NewContainer(ctx, id, WithSpec(spec), WithImage(image), WithNewRootFS(id, image))
 	if err != nil {
 		t.Error(err)
 		return
@@ -235,7 +235,7 @@ func TestContainerExec(t *testing.T) {
 		t.Error(err)
 		return
 	}
-	container, err := client.NewContainer(ctx, id, spec, WithImage(image), WithNewRootFS(id, image))
+	container, err := client.NewContainer(ctx, id, WithSpec(spec), WithImage(image), WithNewRootFS(id, image))
 	if err != nil {
 		t.Error(err)
 		return
@@ -320,7 +320,7 @@ func TestContainerProcesses(t *testing.T) {
 		t.Error(err)
 		return
 	}
-	container, err := client.NewContainer(ctx, id, spec, WithImage(image), WithNewRootFS(id, image))
+	container, err := client.NewContainer(ctx, id, WithSpec(spec), WithImage(image), WithNewRootFS(id, image))
 	if err != nil {
 		t.Error(err)
 		return
@@ -391,7 +391,7 @@ func TestContainerCloseStdin(t *testing.T) {
 		t.Error(err)
 		return
 	}
-	container, err := client.NewContainer(ctx, id, spec, WithImage(image), WithNewRootFS(id, image))
+	container, err := client.NewContainer(ctx, id, WithSpec(spec), WithImage(image), WithNewRootFS(id, image))
 	if err != nil {
 		t.Error(err)
 		return
@@ -473,7 +473,7 @@ func TestContainerAttach(t *testing.T) {
 		t.Error(err)
 		return
 	}
-	container, err := client.NewContainer(ctx, id, spec, WithImage(image), WithNewRootFS(id, image))
+	container, err := client.NewContainer(ctx, id, WithSpec(spec), WithImage(image), WithNewRootFS(id, image))
 	if err != nil {
 		t.Error(err)
 		return

images/image.go

@@ -33,34 +33,7 @@ type Store interface {
 // The caller can then use the descriptor to resolve and process the
 // configuration of the image.
 func (image *Image) Config(ctx context.Context, provider content.Provider) (ocispec.Descriptor, error) {
-	var configDesc ocispec.Descriptor
-	return configDesc, Walk(ctx, HandlerFunc(func(ctx context.Context, desc ocispec.Descriptor) ([]ocispec.Descriptor, error) {
-		switch image.Target.MediaType {
-		case MediaTypeDockerSchema2Manifest, ocispec.MediaTypeImageManifest:
-			rc, err := provider.Reader(ctx, image.Target.Digest)
-			if err != nil {
-				return nil, err
-			}
-			defer rc.Close()
-
-			p, err := ioutil.ReadAll(rc)
-			if err != nil {
-				return nil, err
-			}
-
-			var manifest ocispec.Manifest
-			if err := json.Unmarshal(p, &manifest); err != nil {
-				return nil, err
-			}
-
-			configDesc = manifest.Config
-
-			return nil, nil
-		default:
-			return nil, errors.New("could not resolve config")
-		}
-
-	}), image.Target)
+	return Config(ctx, provider, image.Target)
 }
 
 // RootFS returns the unpacked diffids that make up and images rootfs.
@@ -112,12 +85,43 @@ func (image *Image) Size(ctx context.Context, provider content.Provider) (int64,
 	}), image.Target)
 }
 
+func Config(ctx context.Context, provider content.Provider, image ocispec.Descriptor) (ocispec.Descriptor, error) {
+	var configDesc ocispec.Descriptor
+	return configDesc, Walk(ctx, HandlerFunc(func(ctx context.Context, desc ocispec.Descriptor) ([]ocispec.Descriptor, error) {
+		switch image.MediaType {
+		case MediaTypeDockerSchema2Manifest, ocispec.MediaTypeImageManifest:
+			rc, err := provider.Reader(ctx, image.Digest)
+			if err != nil {
+				return nil, err
+			}
+			defer rc.Close()
+
+			p, err := ioutil.ReadAll(rc)
+			if err != nil {
+				return nil, err
+			}
+
+			var manifest ocispec.Manifest
+			if err := json.Unmarshal(p, &manifest); err != nil {
+				return nil, err
+			}
+
+			configDesc = manifest.Config
+
+			return nil, nil
+		default:
+			return nil, errors.New("could not resolve config")
+		}
+
+	}), image)
+}
+
 // RootFS returns the unpacked diffids that make up and images rootfs.
 //
 // These are used to verify that a set of layers unpacked to the expected
 // values.
-func RootFS(ctx context.Context, provider content.Provider, desc ocispec.Descriptor) ([]digest.Digest, error) {
-	p, err := content.ReadBlob(ctx, provider, desc.Digest)
+func RootFS(ctx context.Context, provider content.Provider, configDesc ocispec.Descriptor) ([]digest.Digest, error) {
+	p, err := content.ReadBlob(ctx, provider, configDesc.Digest)
 	if err != nil {
 		return nil, err
 	}

linux/runtime.go

@@ -86,7 +86,7 @@ type Runtime struct {
 	monitor       plugin.TaskMonitor
 }
 
-func (r *Runtime) Create(ctx context.Context, id string, opts plugin.CreateOpts) (plugin.Task, error) {
+func (r *Runtime) Create(ctx context.Context, id string, opts plugin.CreateOpts) (t plugin.Task, err error) {
 	path, err := r.newBundle(id, opts.Spec)
 	if err != nil {
 		return nil, err

linux/shim/init.go

@@ -145,6 +145,7 @@ func newInitProcess(context context.Context, path string, r *shimapi.CreateReque
 			return nil, err
 		}
 	}
+
 	copyWaitGroup.Wait()
 	pid, err := runc.ReadPidFile(pidFile)
 	if err != nil {

reaper/reaper.go

@@ -70,13 +70,13 @@ func (m *Monitor) Start(c *exec.Cmd) error {
 		c:      c,
 		ExitCh: make(chan int, 1),
 	}
-	m.Lock()
-	defer m.Unlock()
 	// start the process
 	if err := rc.c.Start(); err != nil {
 		return err
 	}
+	m.Lock()
 	m.cmds[rc.c.Process.Pid] = rc
+	m.Unlock()
 	return nil
 }
 

services/execution/service.go

@@ -156,11 +156,7 @@ func (s *Service) Create(ctx context.Context, r *api.CreateRequest) (*api.Create
 	s.mu.Unlock()
 	state, err := c.State(ctx)
 	if err != nil {
-		s.mu.Lock()
-		delete(s.tasks, r.ContainerID)
-		runtime.Delete(ctx, c)
-		s.mu.Unlock()
-		return nil, err
+		log.G(ctx).Error(err)
 	}
 	return &api.CreateResponse{
 		ContainerID: r.ContainerID,

task.go

@@ -1,11 +1,20 @@
 package containerd
 
 import (
+	"bytes"
 	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"runtime"
 	"syscall"
 
+	"github.com/containerd/containerd/api/services/containers"
 	"github.com/containerd/containerd/api/services/execution"
 	taskapi "github.com/containerd/containerd/api/types/task"
+	"github.com/containerd/containerd/content"
+	"github.com/containerd/containerd/rootfs"
+	"github.com/opencontainers/image-spec/specs-go/v1"
 	specs "github.com/opencontainers/runtime-spec/specs-go"
 )
 
@@ -21,6 +30,8 @@ const (
 	Pausing TaskStatus = "pausing"
 )
 
+type CheckpointOpts func(*execution.CheckpointRequest) error
+
 type Task interface {
 	Pid() uint32
 	Delete(context.Context) (uint32, error)
@@ -35,6 +46,7 @@ type Task interface {
 	CloseStdin(context.Context) error
 	Resize(ctx context.Context, w, h uint32) error
 	IO() *IO
+	Checkpoint(context.Context, ...CheckpointOpts) (v1.Descriptor, error)
 }
 
 type Process interface {
@@ -55,6 +67,9 @@ type task struct {
 	io          *IO
 	containerID string
 	pid         uint32
+
+	deferred *execution.CreateRequest
+	pidSync  chan struct{}
 }
 
 // Pid returns the pid or process id for the task
@@ -63,6 +78,16 @@ func (t *task) Pid() uint32 {
 }
 
 func (t *task) Start(ctx context.Context) error {
+	if t.deferred != nil {
+		response, err := t.client.TaskService().Create(ctx, t.deferred)
+		t.deferred = nil
+		if err != nil {
+			return err
+		}
+		t.pid = response.Pid
+		close(t.pidSync)
+		return nil
+	}
 	_, err := t.client.TaskService().Start(ctx, &execution.StartRequest{
 		ContainerID: t.containerID,
 	})
@@ -110,6 +135,7 @@ func (t *task) Wait(ctx context.Context) (uint32, error) {
 	if err != nil {
 		return UnknownExitStatus, err
 	}
+	<-t.pidSync
 	for {
 		e, err := events.Recv()
 		if err != nil {
@@ -186,3 +212,119 @@ func (t *task) Resize(ctx context.Context, w, h uint32) error {
 	})
 	return err
 }
+
+func WithExit(r *execution.CheckpointRequest) error {
+	r.Exit = true
+	return nil
+}
+
+func (t *task) Checkpoint(ctx context.Context, opts ...CheckpointOpts) (d v1.Descriptor, err error) {
+	request := &execution.CheckpointRequest{
+		ContainerID: t.containerID,
+	}
+	for _, o := range opts {
+		if err := o(request); err != nil {
+			return d, err
+		}
+	}
+	// if we are not exiting the container after the checkpoint, make sure we pause it and resume after
+	// all other filesystem operations are completed
+	if !request.Exit {
+		if err := t.Pause(ctx); err != nil {
+			return d, err
+		}
+		defer t.Resume(ctx)
+	}
+	cr, err := t.client.ContainerService().Get(ctx, &containers.GetContainerRequest{
+		ID: t.containerID,
+	})
+	if err != nil {
+		return d, err
+	}
+	var index v1.Index
+	if err := t.checkpointTask(ctx, &index, request); err != nil {
+		return d, err
+	}
+	if err := t.checkpointImage(ctx, &index, cr.Container.Image); err != nil {
+		return d, err
+	}
+	if err := t.checkpointRWSnapshot(ctx, &index, cr.Container.RootFS); err != nil {
+		return d, err
+	}
+	index.Annotations = make(map[string]string)
+	index.Annotations["image.name"] = cr.Container.Image
+	return t.writeIndex(ctx, &index)
+}
+
+func (t *task) checkpointTask(ctx context.Context, index *v1.Index, request *execution.CheckpointRequest) error {
+	response, err := t.client.TaskService().Checkpoint(ctx, request)
+	if err != nil {
+		return err
+	}
+	// add the checkpoint descriptors to the index
+	for _, d := range response.Descriptors {
+		index.Manifests = append(index.Manifests, v1.Descriptor{
+			MediaType: d.MediaType,
+			Size:      d.Size_,
+			Digest:    d.Digest,
+			Platform: &v1.Platform{
+				OS:           runtime.GOOS,
+				Architecture: runtime.GOARCH,
+			},
+		})
+	}
+	return nil
+}
+
+func (t *task) checkpointRWSnapshot(ctx context.Context, index *v1.Index, id string) error {
+	rw, err := rootfs.Diff(ctx, id, fmt.Sprintf("checkpoint-rw-%s", id), t.client.SnapshotService(), t.client.DiffService())
+	if err != nil {
+		return err
+	}
+	rw.Platform = &v1.Platform{
+		OS:           runtime.GOOS,
+		Architecture: runtime.GOARCH,
+	}
+	index.Manifests = append(index.Manifests, rw)
+	return nil
+}
+
+func (t *task) checkpointImage(ctx context.Context, index *v1.Index, image string) error {
+	if image == "" {
+		return fmt.Errorf("cannot checkpoint image with empty name")
+	}
+	ir, err := t.client.ImageService().Get(ctx, image)
+	if err != nil {
+		return err
+	}
+	index.Manifests = append(index.Manifests, ir.Target)
+	return nil
+}
+
+func (t *task) writeIndex(ctx context.Context, index *v1.Index) (v1.Descriptor, error) {
+	buf := bytes.NewBuffer(nil)
+	if err := json.NewEncoder(buf).Encode(index); err != nil {
+		return v1.Descriptor{}, err
+	}
+	return writeContent(ctx, t.client.ContentStore(), v1.MediaTypeImageIndex, t.containerID, buf)
+}
+
+func writeContent(ctx context.Context, store content.Store, mediaType, ref string, r io.Reader) (d v1.Descriptor, err error) {
+	writer, err := store.Writer(ctx, ref, 0, "")
+	if err != nil {
+		return d, err
+	}
+	defer writer.Close()
+	size, err := io.Copy(writer, r)
+	if err != nil {
+		return d, err
+	}
+	if err := writer.Commit(0, ""); err != nil {
+		return d, err
+	}
+	return v1.Descriptor{
+		MediaType: mediaType,
+		Digest:    writer.Digest(),
+		Size:      size,
+	}, nil
+}