Allow loading images by name from imagestore

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

Makefile

@@ -114,6 +114,7 @@ binaries: clean \
 	$(HELPERS) \
 	$(GUESTAGENT)
 	cp -aL examples _output/share/lima/templates
+	cp -aL images _output/share/lima/images
 ifneq ($(GOOS),windows)
 	ln -sf templates _output/share/lima/examples
 else

cmd/limactl/edit.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/lima-vm/lima/cmd/limactl/editflags"
 	"github.com/lima-vm/lima/pkg/editutil"
+	"github.com/lima-vm/lima/pkg/imagestore"
 	"github.com/lima-vm/lima/pkg/limayaml"
 	networks "github.com/lima-vm/lima/pkg/networks/reconcile"
 	"github.com/lima-vm/lima/pkg/start"
@@ -90,6 +91,7 @@ func editAction(cmd *cobra.Command, args []string) error {
 		logrus.Info("Aborting, no changes made to the instance")
 		return nil
 	}
+	limayaml.ReadImage = imagestore.Read
 	y, err := limayaml.Load(yBytes, filePath)
 	if err != nil {
 		return err

cmd/limactl/start.go

@@ -15,6 +15,7 @@ import (
 	"github.com/lima-vm/lima/cmd/limactl/editflags"
 	"github.com/lima-vm/lima/cmd/limactl/guessarg"
 	"github.com/lima-vm/lima/pkg/editutil"
+	"github.com/lima-vm/lima/pkg/imagestore"
 	"github.com/lima-vm/lima/pkg/ioutilx"
 	"github.com/lima-vm/lima/pkg/limayaml"
 	networks "github.com/lima-vm/lima/pkg/networks/reconcile"
@@ -323,6 +324,7 @@ func createInstance(ctx context.Context, st *creatorState, saveBrokenEditorBuffe
 	}
 	// limayaml.Load() needs to pass the store file path to limayaml.FillDefault() to calculate default MAC addresses
 	filePath := filepath.Join(instDir, filenames.LimaYAML)
+	limayaml.ReadImage = imagestore.Read
 	y, err := limayaml.Load(st.yBytes, filePath)
 	if err != nil {
 		return nil, err

cmd/limactl/validate.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 
 	"github.com/lima-vm/lima/cmd/limactl/guessarg"
+	"github.com/lima-vm/lima/pkg/imagestore"
+	"github.com/lima-vm/lima/pkg/limayaml"
 	"github.com/lima-vm/lima/pkg/store"
 	"github.com/spf13/cobra"
 
@@ -28,6 +30,7 @@ func validateAction(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
+	limayaml.ReadImage = imagestore.Read
 	for _, f := range args {
 		y, err := store.LoadYAMLByFilePath(f)
 		if err != nil {

examples/default.yaml

@@ -21,21 +21,9 @@ arch: null
 
 # OpenStack-compatible disk image.
 # 🟢 Builtin default: null (must be specified)
-# 🔵 This file: Ubuntu images
+# 🔵 This file: ["default"] (see the output of `limactl info | jq .defaultImage.images`)
 images:
-# Try to use release-yyyyMMdd image if available. Note that release-yyyyMMdd will be removed after several months.
-- location: "https://cloud-images.ubuntu.com/releases/24.04/release-20240423/ubuntu-24.04-server-cloudimg-amd64.img"
-  arch: "x86_64"
-  digest: "sha256:32a9d30d18803da72f5936cf2b7b9efcb4d0bb63c67933f17e3bdfd1751de3f3"
-- location: "https://cloud-images.ubuntu.com/releases/24.04/release-20240423/ubuntu-24.04-server-cloudimg-arm64.img"
-  arch: "aarch64"
-  digest: "sha256:c841bac00925d3e6892d979798103a867931f255f28fefd9d5e07e3e22d0ef22"
-# Fallback to the latest release image.
-# Hint: run `limactl prune` to invalidate the cache
-- location: "https://cloud-images.ubuntu.com/releases/24.04/release/ubuntu-24.04-server-cloudimg-amd64.img"
-  arch: "x86_64"
-- location: "https://cloud-images.ubuntu.com/releases/24.04/release/ubuntu-24.04-server-cloudimg-arm64.img"
-  arch: "aarch64"
+- default
 
 # CPUs
 # 🟢 Builtin default: min(4, host CPU cores)

images/ubuntu-24.04.yaml

@@ -0,0 +1,14 @@
+images:
+# Try to use release-yyyyMMdd image if available. Note that release-yyyyMMdd will be removed after several months.
+- location: "https://cloud-images.ubuntu.com/releases/24.04/release-20240423/ubuntu-24.04-server-cloudimg-amd64.img"
+  arch: "x86_64"
+  digest: "sha256:32a9d30d18803da72f5936cf2b7b9efcb4d0bb63c67933f17e3bdfd1751de3f3"
+- location: "https://cloud-images.ubuntu.com/releases/24.04/release-20240423/ubuntu-24.04-server-cloudimg-arm64.img"
+  arch: "aarch64"
+  digest: "sha256:c841bac00925d3e6892d979798103a867931f255f28fefd9d5e07e3e22d0ef22"
+# Fallback to the latest release image.
+# Hint: run `limactl prune` to invalidate the cache
+- location: "https://cloud-images.ubuntu.com/releases/24.04/release/ubuntu-24.04-server-cloudimg-amd64.img"
+  arch: "x86_64"
+- location: "https://cloud-images.ubuntu.com/releases/24.04/release/ubuntu-24.04-server-cloudimg-arm64.img"
+  arch: "aarch64"

pkg/imagestore/imagestore.go

@@ -0,0 +1,63 @@
+package imagestore
+
+import (
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strings"
+
+	securejoin "github.com/cyphar/filepath-securejoin"
+	"github.com/lima-vm/lima/pkg/usrlocalsharelima"
+)
+
+type Image struct {
+	Name     string `json:"name"`
+	Location string `json:"location"`
+}
+
+func Read(name string) ([]byte, error) {
+	dir, err := usrlocalsharelima.Dir()
+	if err != nil {
+		return nil, err
+	}
+	if name == "default" {
+		name = Default
+	}
+	yamlPath, err := securejoin.SecureJoin(filepath.Join(dir, "images"), name+".yaml")
+	if err != nil {
+		return nil, err
+	}
+	return os.ReadFile(yamlPath)
+}
+
+const Default = "ubuntu-24.04"
+
+func Images() ([]Image, error) {
+	usrlocalsharelimaDir, err := usrlocalsharelima.Dir()
+	if err != nil {
+		return nil, err
+	}
+	imagesDir := filepath.Join(usrlocalsharelimaDir, "images")
+
+	var res []Image
+	walkDirFn := func(p string, _ fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		base := filepath.Base(p)
+		if strings.HasPrefix(base, ".") || !strings.HasSuffix(base, ".yaml") {
+			return nil
+		}
+		x := Image{
+			// Name is like "ubuntu-24.04", "debian-12", ...
+			Name:     strings.TrimSuffix(strings.TrimPrefix(p, imagesDir+"/"), ".yaml"),
+			Location: p,
+		}
+		res = append(res, x)
+		return nil
+	}
+	if err = filepath.WalkDir(imagesDir, walkDirFn); err != nil {
+		return nil, err
+	}
+	return res, nil
+}

pkg/infoutil/infoutil.go

@@ -2,6 +2,7 @@ package infoutil
 
 import (
 	"github.com/lima-vm/lima/pkg/driverutil"
+	"github.com/lima-vm/lima/pkg/imagestore"
 	"github.com/lima-vm/lima/pkg/limayaml"
 	"github.com/lima-vm/lima/pkg/store/dirnames"
 	"github.com/lima-vm/lima/pkg/templatestore"
@@ -12,6 +13,8 @@ type Info struct {
 	Version         string                   `json:"version"`
 	Templates       []templatestore.Template `json:"templates"`
 	DefaultTemplate *limayaml.LimaYAML       `json:"defaultTemplate"`
+	Images          []imagestore.Image       `json:"images"`
+	DefaultImage    *limayaml.ImageYAML      `json:"defaultImage"`
 	LimaHome        string                   `json:"limaHome"`
 	VMTypes         []string                 `json:"vmTypes"` // since Lima v0.14.2
 }
@@ -25,15 +28,28 @@ func GetInfo() (*Info, error) {
 	if err != nil {
 		return nil, err
 	}
+	bi, err := imagestore.Read(imagestore.Default)
+	if err != nil {
+		return nil, err
+	}
+	yi, err := limayaml.LoadImage(bi, "")
+	if err != nil {
+		return nil, err
+	}
 	info := &Info{
 		Version:         version.Version,
 		DefaultTemplate: y,
+		DefaultImage:    yi,
 		VMTypes:         driverutil.Drivers(),
 	}
 	info.Templates, err = templatestore.Templates()
 	if err != nil {
 		return nil, err
 	}
+	info.Images, err = imagestore.Images()
+	if err != nil {
+		return nil, err
+	}
 	info.LimaHome, err = dirnames.LimaDir()
 	if err != nil {
 		return nil, err

pkg/limayaml/defaults.go

@@ -156,6 +156,8 @@ func defaultGuestInstallPrefix() string {
 	return "/usr/local"
 }
 
+var ReadImage func(name string) ([]byte, error)
+
 // FillDefault updates undefined fields in y with defaults from d (or built-in default), and overwrites with values from o.
 // Both d and o may be empty.
 //
@@ -195,6 +197,26 @@ func FillDefault(y, d, o *LimaYAML, filePath string) {
 	y.Arch = ptr.Of(ResolveArch(y.Arch))
 
 	y.Images = append(append(o.Images, y.Images...), d.Images...)
+	images := []Image{}
+	for i := range y.Images {
+		img := &y.Images[i]
+		if img.Name != "" && ReadImage != nil {
+			ib, err := ReadImage(img.Name)
+			if err != nil {
+				logrus.Error(err)
+				continue
+			}
+			iy, err := LoadImage(ib, img.Name)
+			if err != nil {
+				logrus.Error(err)
+				continue
+			}
+			images = append(images, iy.Images...)
+		} else {
+			images = append(images, *img)
+		}
+	}
+	y.Images = images
 	for i := range y.Images {
 		img := &y.Images[i]
 		if img.Arch == "" {

pkg/limayaml/image.yaml

@@ -0,0 +1 @@
+../../images/ubuntu-24.04.yaml

pkg/limayaml/limayaml.go

@@ -44,6 +44,10 @@ type LimaYAML struct {
 	TimeZone          *string        `yaml:"timezone,omitempty" json:"timezone,omitempty"`
 }
 
+type ImageYAML struct {
+	Images []Image `yaml:"images" json:"images"`
+}
+
 type (
 	OS        = string
 	Arch      = string
@@ -93,6 +97,7 @@ type Kernel struct {
 }
 
 type Image struct {
+	Name   string `yaml:"name,omitempty" json:"name,omitempty"`
 	File   `yaml:",inline"`
 	Kernel *Kernel `yaml:"kernel,omitempty" json:"kernel,omitempty"`
 	Initrd *File   `yaml:"initrd,omitempty" json:"initrd,omitempty"`

pkg/limayaml/load.go

@@ -22,6 +22,20 @@ func unmarshalDisk(dst *Disk, b []byte) error {
 	return yaml.Unmarshal(b, dst)
 }
 
+func unmarshalImage(dst *Image, b []byte) error {
+	var s string
+	if err := yaml.Unmarshal(b, &s); err == nil {
+		*dst = Image{Name: s}
+		return nil
+	}
+	return yaml.Unmarshal(b, dst)
+}
+
+var customMarshalers = []yaml.DecodeOption{
+	yaml.CustomUnmarshaler[Disk](unmarshalDisk),
+	yaml.CustomUnmarshaler[Image](unmarshalImage),
+}
+
 func (d *Disk) UnmarshalYAML(value *yamlv3.Node) error {
 	var v interface{}
 	if err := value.Decode(&v); err != nil {
@@ -33,23 +47,43 @@ func (d *Disk) UnmarshalYAML(value *yamlv3.Node) error {
 	return nil
 }
 
+func (d *Image) UnmarshalYAML(value *yamlv3.Node) error {
+	var v interface{}
+	if err := value.Decode(&v); err != nil {
+		return err
+	}
+	if s, ok := v.(string); ok {
+		*d = Image{Name: s}
+	}
+	return nil
+}
+
 func unmarshalYAML(data []byte, v interface{}, comment string) error {
-	if err := yaml.UnmarshalWithOptions(data, v, yaml.DisallowDuplicateKey(), yaml.CustomUnmarshaler[Disk](unmarshalDisk)); err != nil {
+	if err := yaml.UnmarshalWithOptions(data, v, append(customMarshalers, yaml.DisallowDuplicateKey())...); err != nil {
 		return fmt.Errorf("failed to unmarshal YAML (%s): %w", comment, err)
 	}
 	// the go-yaml library doesn't catch all markup errors, unfortunately
 	// make sure to get a "second opinion", using the same library as "yq"
 	if err := yamlv3.Unmarshal(data, v); err != nil {
 		return fmt.Errorf("failed to unmarshal YAML (%s): %w", comment, err)
 	}
-	if err := yaml.UnmarshalWithOptions(data, v, yaml.Strict(), yaml.CustomUnmarshaler[Disk](unmarshalDisk)); err != nil {
+	if err := yaml.UnmarshalWithOptions(data, v, append(customMarshalers, yaml.Strict())...); err != nil {
 		logrus.WithField("comment", comment).WithError(err).Warn("Non-strict YAML is deprecated and will be unsupported in a future version of Lima")
 		// Non-strict YAML is known to be used by Rancher Desktop:
 		// https://github.com/rancher-sandbox/rancher-desktop/blob/c7ea7508a0191634adf16f4675f64c73198e8d37/src/backend/lima.ts#L114-L117
 	}
 	return nil
 }
 
+// LoadImage loads the yaml.
+func LoadImage(b []byte, filePath string) (*ImageYAML, error) {
+	var y ImageYAML
+	if err := unmarshalYAML(b, &y, filePath); err != nil {
+		return nil, err
+	}
+	return &y, nil
+}
+
 // Load loads the yaml and fulfills unspecified fields with the default values.
 //
 // Load does not validate. Use Validate for validation.

pkg/limayaml/validate.go

@@ -69,6 +69,15 @@ func Validate(y *LimaYAML, warn bool) error {
 		return errors.New("field `images` must be set")
 	}
 	for i, f := range y.Images {
+		if f.Name != "" {
+			if ReadImage == nil {
+				return fmt.Errorf("limayaml.ReadImage is not set")
+			}
+			if _, err := ReadImage(f.Name); err != nil {
+				return err
+			}
+			continue
+		}
 		if err := validateFileObject(f.File, fmt.Sprintf("images[%d]", i)); err != nil {
 			return err
 		}

pkg/limayaml/validate_test.go

@@ -1,6 +1,7 @@
 package limayaml
 
 import (
+	"fmt"
 	"os"
 	"runtime"
 	"testing"
@@ -17,6 +18,13 @@ func TestValidateEmpty(t *testing.T) {
 
 // Note: can't embed symbolic links, use "os"
 
+func readImage(name string) ([]byte, error) {
+	if name != "default" {
+		return nil, fmt.Errorf("Unexpected image: %s", name)
+	}
+	return os.ReadFile("image.yaml")
+}
+
 func TestValidateDefault(t *testing.T) {
 	if runtime.GOOS == "windows" {
 		// FIXME: `assertion failed: error is not nil: field `mounts[1].location` must be an absolute path, got "/tmp/lima"`
@@ -25,6 +33,7 @@ func TestValidateDefault(t *testing.T) {
 
 	bytes, err := os.ReadFile("default.yaml")
 	assert.NilError(t, err)
+	ReadImage = readImage
 	y, err := Load(bytes, "default.yaml")
 	assert.NilError(t, err)
 	err = Validate(y, true)