Implement the suspend and resume commands

For halting the emulation and putting the VM into paused run state.

Also query the status of running instances, when showing in "list".

Signed-off-by: Anders F Björklund <anders.f.bjorklund@gmail.com>

Author: afbjorklund

cmd/limactl/main.go

@@ -148,6 +148,8 @@ func newApp() *cobra.Command {
 		newDiskCommand(),
 		newUsernetCommand(),
 		newGenDocCommand(),
+		newResumeCommand(),
+		newSuspendCommand(),
 		newSnapshotCommand(),
 		newProtectCommand(),
 		newUnprotectCommand(),

cmd/limactl/resume.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/lima-vm/lima/pkg/pause"
+	"github.com/lima-vm/lima/pkg/store"
+
+	"github.com/spf13/cobra"
+)
+
+func newResumeCommand() *cobra.Command {
+	var resumeCmd = &cobra.Command{
+		Use:               "resume INSTANCE",
+		Short:             "Resume (unpause) an instance",
+		Aliases:           []string{"unpause"},
+		Args:              cobra.MaximumNArgs(1),
+		RunE:              resumeAction,
+		ValidArgsFunction: resumeBashComplete,
+	}
+
+	return resumeCmd
+}
+
+func resumeAction(cmd *cobra.Command, args []string) error {
+	instName := DefaultInstanceName
+	if len(args) > 0 {
+		instName = args[0]
+	}
+
+	inst, err := store.Inspect(instName)
+	if err != nil {
+		return err
+	}
+
+	if inst.Status != store.StatusPaused {
+		return fmt.Errorf("expected status %q, got %q", store.StatusPaused, inst.Status)
+	}
+
+	ctx := cmd.Context()
+	return pause.Resume(ctx, inst)
+}
+
+func resumeBashComplete(cmd *cobra.Command, _ []string, _ string) ([]string, cobra.ShellCompDirective) {
+	return bashCompleteInstanceNames(cmd)
+}

cmd/limactl/suspend.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/lima-vm/lima/pkg/pause"
+	"github.com/lima-vm/lima/pkg/store"
+
+	"github.com/spf13/cobra"
+)
+
+func newSuspendCommand() *cobra.Command {
+	var suspendCmd = &cobra.Command{
+		Use:               "suspend INSTANCE",
+		Short:             "Suspend (pause) an instance",
+		Aliases:           []string{"pause"},
+		Args:              cobra.MaximumNArgs(1),
+		RunE:              suspendAction,
+		ValidArgsFunction: suspendBashComplete,
+	}
+
+	return suspendCmd
+}
+
+func suspendAction(cmd *cobra.Command, args []string) error {
+	instName := DefaultInstanceName
+	if len(args) > 0 {
+		instName = args[0]
+	}
+
+	inst, err := store.Inspect(instName)
+	if err != nil {
+		return err
+	}
+
+	if inst.Status != store.StatusRunning {
+		return fmt.Errorf("expected status %q, got %q", store.StatusRunning, inst.Status)
+	}
+
+	ctx := cmd.Context()
+	return pause.Suspend(ctx, inst)
+}
+
+func suspendBashComplete(cmd *cobra.Command, _ []string, _ string) ([]string, cobra.ShellCompDirective) {
+	return bashCompleteInstanceNames(cmd)
+}

hack/test-templates.sh

@@ -26,6 +26,7 @@ declare -A CHECKS=(
 	["systemd-strict"]="1"
 	["mount-home"]="1"
 	["container-engine"]="1"
+	["pause"]="1"
 	["restart"]="1"
 	# snapshot tests are too flaky (especially with archlinux)
 	["snapshot-online"]=""
@@ -325,6 +326,28 @@ if [[ -n ${CHECKS["disk"]} ]]; then
 	set +x
 fi
 
+if [[ -n ${CHECKS["pause"]} ]]; then
+	INFO "Suspending \"$NAME\""
+	limactl suspend "$NAME"
+
+	got=$(limactl ls --format '{{.Status}}' "$NAME")
+	expected="Paused"
+	if [ "$got" != "$expected" ]; then
+		ERROR "suspend status: expected=${expected} got=${got}"
+		exit 1
+	fi
+
+	INFO "Resuming \"$NAME\""
+	limactl resume "$NAME"
+
+	got=$(limactl ls --format '{{.Status}}' "$NAME")
+	expected="Running"
+	if [ "$got" != "$expected" ]; then
+		ERROR "resume status: expected=${expected} got=${got}"
+		exit 1
+	fi
+fi
+
 if [[ -n ${CHECKS["restart"]} ]]; then
 	INFO "Create file in the guest home directory and verify that it still exists after a restart"
 	# shellcheck disable=SC2016

pkg/driver/driver.go

@@ -9,6 +9,11 @@ import (
 	"github.com/lima-vm/lima/pkg/store"
 )
 
+type BaseStatus struct {
+	Paused  bool
+	Running bool
+}
+
 // Driver interface is used by hostagent for managing vm.
 //
 // This interface is extended by BaseDriver which provides default implementation.
@@ -56,6 +61,13 @@ type Driver interface {
 
 	GetDisplayConnection(_ context.Context) (string, error)
 
+	Suspend(_ context.Context) error
+
+	Resume(_ context.Context) error
+
+	// Status returns the current status of the vm instance.
+	Status(_ context.Context) (*BaseStatus, error)
+
 	CreateSnapshot(_ context.Context, tag string) error
 
 	ApplySnapshot(_ context.Context, tag string) error
@@ -126,6 +138,18 @@ func (d *BaseDriver) GetDisplayConnection(_ context.Context) (string, error) {
 	return "", nil
 }
 
+func (d *BaseDriver) Suspend(_ context.Context) error {
+	return fmt.Errorf("unimplemented")
+}
+
+func (d *BaseDriver) Resume(_ context.Context) error {
+	return fmt.Errorf("unimplemented")
+}
+
+func (d *BaseDriver) Status(_ context.Context) (*BaseStatus, error) {
+	return &BaseStatus{Running: true, Paused: false}, nil
+}
+
 func (d *BaseDriver) CreateSnapshot(_ context.Context, _ string) error {
 	return fmt.Errorf("unimplemented")
 }

pkg/hostagent/api/api.go

@@ -3,3 +3,8 @@ package api
 type Info struct {
 	SSHLocalPort int `json:"sshLocalPort,omitempty"`
 }
+
+type Status struct {
+	Running bool `json:"running"`
+	Paused  bool `json:"paused"`
+}

pkg/hostagent/api/client/client.go

@@ -16,6 +16,7 @@ import (
 type HostAgentClient interface {
 	HTTPClient() *http.Client
 	Info(context.Context) (*api.Info, error)
+	Status(context.Context) (*api.Status, error)
 }
 
 // NewHostAgentClient creates a client.
@@ -62,3 +63,18 @@ func (c *client) Info(ctx context.Context) (*api.Info, error) {
 	}
 	return &info, nil
 }
+
+func (c *client) Status(ctx context.Context) (*api.Status, error) {
+	u := fmt.Sprintf("http://%s/%s/status", c.dummyHost, c.version)
+	resp, err := httpclientutil.Get(ctx, c.HTTPClient(), u)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	var status api.Status
+	dec := json.NewDecoder(resp.Body)
+	if err := dec.Decode(&status); err != nil {
+		return nil, err
+	}
+	return &status, nil
+}

pkg/hostagent/api/server/server.go

@@ -50,6 +50,28 @@ func (b *Backend) GetInfo(w http.ResponseWriter, r *http.Request) {
 	_, _ = w.Write(m)
 }
 
+// GetStatus is the handler for GET /v{N}/status
+func (b *Backend) GetStatus(w http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	status, err := b.Agent.Status(ctx)
+	if err != nil {
+		b.onError(w, err, http.StatusInternalServerError)
+		return
+	}
+	m, err := json.Marshal(status)
+	if err != nil {
+		b.onError(w, err, http.StatusInternalServerError)
+		return
+	}
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	_, _ = w.Write(m)
+}
+
 func AddRoutes(r *http.ServeMux, b *Backend) {
 	r.Handle("/v1/info", http.HandlerFunc(b.GetInfo))
+	r.Handle("/v1/status", http.HandlerFunc(b.GetStatus))
 }

pkg/hostagent/hostagent.go

@@ -466,6 +466,18 @@ func (a *HostAgent) Info(_ context.Context) (*hostagentapi.Info, error) {
 	return info, nil
 }
 
+func (a *HostAgent) Status(ctx context.Context) (*hostagentapi.Status, error) {
+	driverStatus, err := a.driver.Status(ctx)
+	if err != nil {
+		return nil, err
+	}
+	status := &hostagentapi.Status{
+		Running: driverStatus.Running,
+		Paused:  driverStatus.Paused,
+	}
+	return status, nil
+}
+
 func (a *HostAgent) startHostAgentRoutines(ctx context.Context) error {
 	if *a.instConfig.Plain {
 		logrus.Info("Running in plain mode. Mounts, port forwarding, containerd, etc. will be ignored. Guest agent will not be running.")

pkg/pause/pause.go

@@ -0,0 +1,47 @@
+package pause
+
+import (
+	"context"
+
+	"github.com/lima-vm/lima/pkg/driver"
+	"github.com/lima-vm/lima/pkg/driverutil"
+	"github.com/lima-vm/lima/pkg/store"
+)
+
+func Suspend(ctx context.Context, inst *store.Instance) error {
+	y, err := inst.LoadYAML()
+	if err != nil {
+		return err
+	}
+
+	limaDriver := driverutil.CreateTargetDriverInstance(&driver.BaseDriver{
+		Instance:   inst,
+		InstConfig: y,
+	})
+
+	if err := limaDriver.Suspend(ctx); err != nil {
+		return err
+	}
+
+	inst.Status = store.StatusPaused
+	return nil
+}
+
+func Resume(ctx context.Context, inst *store.Instance) error {
+	y, err := inst.LoadYAML()
+	if err != nil {
+		return err
+	}
+
+	limaDriver := driverutil.CreateTargetDriverInstance(&driver.BaseDriver{
+		Instance:   inst,
+		InstConfig: y,
+	})
+
+	if err := limaDriver.Resume(ctx); err != nil {
+		return err
+	}
+
+	inst.Status = store.StatusRunning
+	return nil
+}

pkg/qemu/qemu.go

@@ -185,6 +185,64 @@ func execImgCommand(cfg Config, args ...string) (string, error) {
 	return string(b), err
 }
 
+func Stop(cfg Config) error {
+	qmpClient, err := newQmpClient(cfg)
+	if err != nil {
+		return err
+	}
+	if err := qmpClient.Connect(); err != nil {
+		return err
+	}
+	defer func() { _ = qmpClient.Disconnect() }()
+	rawClient := raw.NewMonitor(qmpClient)
+	logrus.Info("Sending QMP stop command")
+	return rawClient.Stop()
+}
+
+func Cont(cfg Config) error {
+	qmpClient, err := newQmpClient(cfg)
+	if err != nil {
+		return err
+	}
+	if err := qmpClient.Connect(); err != nil {
+		return err
+	}
+	defer func() { _ = qmpClient.Disconnect() }()
+	rawClient := raw.NewMonitor(qmpClient)
+	logrus.Info("Sending QMP cont command")
+	return rawClient.Cont()
+}
+
+type StatusInfo struct {
+	raw.StatusInfo
+}
+
+func QueryStatus(cfg Config) (*StatusInfo, error) {
+	qmpClient, err := newQmpClient(cfg)
+	if err != nil {
+		return nil, err
+	}
+	if err := qmpClient.Connect(); err != nil {
+		return nil, err
+	}
+	defer func() { _ = qmpClient.Disconnect() }()
+	rawClient := raw.NewMonitor(qmpClient)
+	logrus.Debug("Sending QMP query-status command")
+	status, err := rawClient.QueryStatus()
+	if err != nil {
+		return nil, err
+	}
+	return &StatusInfo{status}, nil
+}
+
+func IsPaused(info *StatusInfo) bool {
+	return info.Status == raw.RunStatePaused
+}
+
+func IsRunning(info *StatusInfo) bool {
+	return info.Status == raw.RunStateRunning
+}
+
 func Del(cfg Config, run bool, tag string) error {
 	if run {
 		out, err := sendHmpCommand(cfg, "delvm", tag)