@@ -1,12 +1,32 @@

 package daemon

 import (

-	"fmt"

+	"errors"

+	"strconv"

 	"github.com/docker/engine-api/types"

 )

-// ContainerTop is not supported on Windows and returns an error.

-func (daemon *Daemon) ContainerTop(name string, psArgs string) (*types.ContainerProcessList, error) {

-	return nil, fmt.Errorf("Top is not supported on Windows")

+// ContainerTop is a minimal implementation on Windows currently.

+// TODO Windows: This needs more work, but needs platform API support.

+// All we can currently return (particularly in the case of Hyper-V containers)

+// is a PID and the command.

+func (daemon *Daemon) ContainerTop(containerID string, psArgs string) (*types.ContainerProcessList, error) {

+

+	// It's really not an equivalent to linux 'ps' on Windows

+	if psArgs != "" {

+		return nil, errors.New("Windows does not support arguments to top")

+	}

+

+	s, err := daemon.containerd.Summary(containerID)

+	if err != nil {

+		return nil, err

+	}

+

+	procList := &types.ContainerProcessList{}

+

+	for _, v := range s {

+		procList.Titles = append(procList.Titles, strconv.Itoa(int(v.Pid))+" "+v.Command)

+	}

+	return procList, nil

 }

@@ -299,6 +299,12 @@ func (clnt *client) GetPidsForContainer(containerID string) ([]int, error) {

 	return pids, nil

 }

+// Summary returns a summary of the processes running in a container.

+// This is a no-op on Linux.

+func (clnt *client) Summary(containerID string) ([]Summary, error) {

+	return nil, nil

+}

+

 func (clnt *client) getContainerdContainer(containerID string) (*containerd.Container, error) {

 	resp, err := clnt.remote.apiClient.State(context.Background(), &containerd.StateRequest{Id: containerID})

 	if err != nil {

@@ -303,6 +303,7 @@ func (clnt *client) Create(containerID string, spec Spec, options ...CreateOptio

 					client:       clnt,

 					friendlyName: InitFriendlyName,

 				},

+				commandLine: strings.Join(spec.Process.Args, " "),

 			},

 			processes: make(map[string]*process),

 		},

@@ -396,6 +397,7 @@ func (clnt *client) AddProcess(containerID, processFriendlyName string, procToAd

 				client:       clnt,

 				systemPid:    pid,

 			},

+			commandLine: createProcessParms.CommandLine,

 		}

 	// Make sure the lock is not held while calling back into the daemon

@@ -508,9 +510,53 @@ func (clnt *client) Restore(containerID string, unusedOnWindows ...CreateOption)

 	})

 }

-// GetPidsForContainers is not implemented on Windows.

+// GetPidsForContainer returns a list of process IDs running in a container.

+// Although implemented, this is not used in Windows.

 func (clnt *client) GetPidsForContainer(containerID string) ([]int, error) {

-	return nil, errors.New("GetPidsForContainer: GetPidsForContainer() not implemented")

+	var pids []int

+	clnt.lock(containerID)

+	defer clnt.unlock(containerID)

+	cont, err := clnt.getContainer(containerID)

+	if err != nil {

+		return nil, err

+	}

+

+	// Add the first process

+	pids = append(pids, int(cont.containerCommon.systemPid))

+	// And add all the exec'd processes

+	for _, p := range cont.processes {

+		pids = append(pids, int(p.processCommon.systemPid))

+	}

+	return pids, nil

+}

+

+// Summary returns a summary of the processes running in a container.

+// This is present in Windows to support docker top. In linux, the

+// engine shells out to ps to get process information. On Windows, as

+// the containers could be Hyper-V containers, they would not be

+// visible on the container host. However, libcontainerd does have

+// that information.

+func (clnt *client) Summary(containerID string) ([]Summary, error) {

+	var s []Summary

+	clnt.lock(containerID)

+	defer clnt.unlock(containerID)

+	cont, err := clnt.getContainer(containerID)

+	if err != nil {

+		return nil, err

+	}

+

+	// Add the first process

+	s = append(s, Summary{

+		Pid:     cont.containerCommon.systemPid,

+		Command: cont.ociSpec.Process.Args[0]})

+	// And add all the exec'd processes

+	for _, p := range cont.processes {

+		s = append(s, Summary{

+			Pid:     p.processCommon.systemPid,

+			Command: p.commandLine})

+	}

+	return s, nil

+

 }

 // UpdateResources updates resources for a running container.

@@ -8,7 +8,10 @@ import (

 type process struct {

 	processCommon

-	// Platform specific fields are below here. There are none presently on Windows.

+	// Platform specific fields are below here.

+

+	// commandLine is to support returning summary information for docker top

+	commandLine string

 }

 func openReaderFromPipe(p io.ReadCloser) io.Reader {

@@ -42,6 +42,7 @@ type Client interface {

 	Restore(containerID string, options ...CreateOption) error

 	Stats(containerID string) (*Stats, error)

 	GetPidsForContainer(containerID string) ([]int, error)

+	Summary(containerID string) ([]Summary, error)

 	UpdateResources(containerID string, resources Resources) error

 }

@@ -36,6 +36,9 @@ type Process struct {

 // Stats contains a stats properties from containerd.

 type Stats containerd.StatsResponse

+// Summary container a container summary from containerd

+type Summary struct{}

+

 // User specifies linux specific user and group information for the container's

 // main process.

 type User specs.User

@@ -11,6 +11,12 @@ type Process windowsoci.Process

 // User specifies user information for the containers main process.

 type User windowsoci.User

+// Summary container a container summary from containerd

+type Summary struct {

+	Pid     uint32

+	Command string

+}

+

 // Stats contains a stats properties from containerd.

 type Stats struct{}