Implement the snapshot commands

README.md

@@ -244,6 +244,15 @@ $ limactl ls --format='{{.SSHConfigFile}}' default
 $ ssh -F /Users/example/.lima/default/ssh.config lima-default
 ```
 
+#### `limactl snapshot`
+`limactl snapshot <COMMAND> <INSTANCE>`: manage instance snapshots
+
+Commands:
+`limactl snapshot create --tag TAG INSTANCE` : create (save) a snapshot
+`limactl snapshot apply --tag TAG INSTANCE` : apply (load) a snapshot
+`limactl snapshot delete --tag TAG INSTANCE` : delete (del) a snapshot
+`limactl snapshot list INSTANCE` : list existing snapshots in instance
+
 #### `limactl completion`
 - To enable bash completion, add `source <(limactl completion bash)` to `~/.bash_profile`.
 

cmd/limactl/main.go

@@ -112,6 +112,7 @@ func newApp() *cobra.Command {
 		newDiskCommand(),
 		newUsernetCommand(),
 		newGenManCommand(),
+		newSnapshotCommand(),
 	)
 	return rootCmd
 }

cmd/limactl/snapshot.go

@@ -0,0 +1,185 @@
+package main
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/lima-vm/lima/pkg/snapshot"
+	"github.com/lima-vm/lima/pkg/store"
+
+	"github.com/spf13/cobra"
+)
+
+func newSnapshotCommand() *cobra.Command {
+	var snapshotCmd = &cobra.Command{
+		Use:   "snapshot",
+		Short: "Manage instance snapshots",
+	}
+	snapshotCmd.AddCommand(newSnapshotApplyCommand())
+	snapshotCmd.AddCommand(newSnapshotCreateCommand())
+	snapshotCmd.AddCommand(newSnapshotDeleteCommand())
+	snapshotCmd.AddCommand(newSnapshotListCommand())
+
+	return snapshotCmd
+}
+
+func newSnapshotCreateCommand() *cobra.Command {
+	var createCmd = &cobra.Command{
+		Use:               "create INSTANCE",
+		Aliases:           []string{"save"},
+		Short:             "Create (save) a snapshot",
+		Args:              cobra.MinimumNArgs(1),
+		RunE:              snapshotCreateAction,
+		ValidArgsFunction: snapshotBashComplete,
+	}
+	createCmd.Flags().String("tag", "", "name of the snapshot")
+
+	return createCmd
+}
+
+func snapshotCreateAction(cmd *cobra.Command, args []string) error {
+	instName := args[0]
+
+	inst, err := store.Inspect(instName)
+	if err != nil {
+		return err
+	}
+
+	tag, err := cmd.Flags().GetString("tag")
+	if err != nil {
+		return err
+	}
+
+	if tag == "" {
+		return fmt.Errorf("expected tag")
+	}
+
+	ctx := cmd.Context()
+	return snapshot.Save(ctx, inst, tag)
+}
+
+func newSnapshotDeleteCommand() *cobra.Command {
+	var deleteCmd = &cobra.Command{
+		Use:               "delete INSTANCE",
+		Aliases:           []string{"del"},
+		Short:             "Delete (del) a snapshot",
+		Args:              cobra.MinimumNArgs(1),
+		RunE:              snapshotDeleteAction,
+		ValidArgsFunction: snapshotBashComplete,
+	}
+	deleteCmd.Flags().String("tag", "", "name of the snapshot")
+
+	return deleteCmd
+}
+
+func snapshotDeleteAction(cmd *cobra.Command, args []string) error {
+	instName := args[0]
+
+	inst, err := store.Inspect(instName)
+	if err != nil {
+		return err
+	}
+
+	tag, err := cmd.Flags().GetString("tag")
+	if err != nil {
+		return err
+	}
+
+	if tag == "" {
+		return fmt.Errorf("expected tag")
+	}
+
+	ctx := cmd.Context()
+	return snapshot.Del(ctx, inst, tag)
+}
+
+func newSnapshotApplyCommand() *cobra.Command {
+	var applyCmd = &cobra.Command{
+		Use:               "apply INSTANCE",
+		Aliases:           []string{"load"},
+		Short:             "Apply (load) a snapshot",
+		Args:              cobra.MinimumNArgs(1),
+		RunE:              snapshotApplyAction,
+		ValidArgsFunction: snapshotBashComplete,
+	}
+	applyCmd.Flags().String("tag", "", "name of the snapshot")
+
+	return applyCmd
+}
+
+func snapshotApplyAction(cmd *cobra.Command, args []string) error {
+	instName := args[0]
+
+	inst, err := store.Inspect(instName)
+	if err != nil {
+		return err
+	}
+
+	tag, err := cmd.Flags().GetString("tag")
+	if err != nil {
+		return err
+	}
+
+	if tag == "" {
+		return fmt.Errorf("expected tag")
+	}
+
+	ctx := cmd.Context()
+	return snapshot.Load(ctx, inst, tag)
+}
+
+func newSnapshotListCommand() *cobra.Command {
+	var listCmd = &cobra.Command{
+		Use:               "list INSTANCE",
+		Aliases:           []string{"ls"},
+		Short:             "List existing snapshots",
+		Args:              cobra.MinimumNArgs(1),
+		RunE:              snapshotListAction,
+		ValidArgsFunction: snapshotBashComplete,
+	}
+	listCmd.Flags().BoolP("quiet", "q", false, "Only show tags")
+
+	return listCmd
+}
+
+func snapshotListAction(cmd *cobra.Command, args []string) error {
+	instName := args[0]
+
+	inst, err := store.Inspect(instName)
+	if err != nil {
+		return err
+	}
+
+	quiet, err := cmd.Flags().GetBool("quiet")
+	if err != nil {
+		return err
+	}
+	ctx := cmd.Context()
+	out, err := snapshot.List(ctx, inst)
+	if err != nil {
+		return err
+	}
+	if quiet {
+		for i, line := range strings.Split(out, "\n") {
+			// "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK", "ICOUNT"
+			fields := strings.Fields(line)
+			if i == 0 && len(fields) > 1 && fields[1] != "TAG" {
+				// make sure that output matches the expected
+				return fmt.Errorf("unknown header: %s", line)
+			}
+			if i == 0 || line == "" {
+				// skip header and empty line after using split
+				continue
+			}
+			tag := fields[1]
+			fmt.Printf("%s\n", tag)
+		}
+		return nil
+	}
+	fmt.Print(out)
+	return nil
+}
+
+func snapshotBashComplete(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+	return bashCompleteInstanceNames(cmd)
+}

hack/test-example.sh

@@ -22,6 +22,8 @@ declare -A CHECKS=(
 	["mount-home"]="1"
 	["containerd-user"]="1"
 	["restart"]="1"
+	["snapshot-online"]="1"
+	["snapshot-offline"]="1"
 	["port-forwards"]="1"
 	["vmnet"]=""
 	["disk"]=""
@@ -44,6 +46,9 @@ case "$NAME" in
 	# ● run-r2b459797f5b04262bfa79984077a65c7.service                                       loaded failed failed    /usr/bin/systemctl start man-db-cache-update
 	CHECKS["systemd-strict"]=
 	;;
+"9p")
+	CHECKS["snapshot-online"]=""
+	;;
 "vmnet")
 	CHECKS["vmnet"]=1
 	;;
@@ -52,6 +57,7 @@ case "$NAME" in
 	;;
 "net-user-v2")
 	CHECKS["port-forwards"]=""
+	CHECKS["snapshot-online"]=""
 	CHECKS["user-v2"]=1
 	;;
 esac
@@ -329,6 +335,45 @@ if [[ -n ${CHECKS["user-v2"]} ]]; then
 	limactl delete "$secondvm"
 	set +x
 fi
+if [[ -n ${CHECKS["snapshot-online"]} ]]; then
+	INFO "Testing online snapshots"
+	limactl shell "$NAME" sh -c 'echo foo > /tmp/test'
+	limactl snapshot create "$NAME" --tag snap1
+	got=$(limactl snapshot list "$NAME" --quiet)
+	expected="snap1"
+	INFO "snapshot list: expected=${expected} got=${got}"
+	if [ "$got" != "$expected" ]; then
+		ERROR "snapshot list did not return expected value"
+		exit 1
+	fi
+	limactl shell "$NAME" sh -c 'echo bar > /tmp/test'
+	limactl snapshot apply "$NAME" --tag snap1
+	got=$(limactl shell "$NAME" cat /tmp/test)
+	expected="foo"
+	INFO "snapshot apply: expected=${expected} got=${got}"
+	if [ "$got" != "$expected" ]; then
+		ERROR "snapshot apply did not restore snapshot"
+		exit 1
+	fi
+	limactl snapshot delete "$NAME" --tag snap1
+	limactl shell "$NAME" rm /tmp/test
+fi
+if [[ -n ${CHECKS["snapshot-offline"]} ]]; then
+	INFO "Testing offline snapshots"
+	limactl stop "$NAME"
+	sleep 3
+	limactl snapshot create "$NAME" --tag snap2
+	got=$(limactl snapshot list "$NAME" --quiet)
+	expected="snap2"
+	INFO "snapshot list: expected=${expected} got=${got}"
+	if [ "$got" != "$expected" ]; then
+		ERROR "snapshot list did not return expected value"
+		exit 1
+	fi
+	limactl snapshot apply "$NAME" --tag snap2
+	limactl snapshot delete "$NAME" --tag snap2
+	limactl start "$NAME"
+fi
 
 INFO "Stopping \"$NAME\""
 limactl stop "$NAME"

pkg/driver/driver.go

@@ -2,6 +2,7 @@ package driver
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/lima-vm/lima/pkg/limayaml"
 	"github.com/lima-vm/lima/pkg/store"
@@ -19,6 +20,14 @@ type Driver interface {
 	ChangeDisplayPassword(_ context.Context, password string) error
 
 	GetDisplayConnection(_ context.Context) (string, error)
+
+	CreateSnapshot(_ context.Context, tag string) error
+
+	ApplySnapshot(_ context.Context, tag string) error
+
+	DeleteSnapshot(_ context.Context, tag string) error
+
+	ListSnapshots(_ context.Context) (string, error)
 }
 
 type BaseDriver struct {
@@ -51,3 +60,19 @@ func (d *BaseDriver) ChangeDisplayPassword(_ context.Context, password string) e
 func (d *BaseDriver) GetDisplayConnection(_ context.Context) (string, error) {
 	return "", nil
 }
+
+func (d *BaseDriver) CreateSnapshot(_ context.Context, _ string) error {
+	return fmt.Errorf("unimplemented")
+}
+
+func (d *BaseDriver) ApplySnapshot(_ context.Context, _ string) error {
+	return fmt.Errorf("unimplemented")
+}
+
+func (d *BaseDriver) DeleteSnapshot(_ context.Context, _ string) error {
+	return fmt.Errorf("unimplemented")
+}
+
+func (d *BaseDriver) ListSnapshots(_ context.Context) (string, error) {
+	return "", fmt.Errorf("unimplemented")
+}