Merge pull request #238 from buildpacks/refactor/v1image

Refactor: local images should be v1.Images

fakes/image.go

@@ -113,6 +113,14 @@ func (i *Image) Identifier() (imgutil.Identifier, error) {
  return i.identifier, nil
 }
 
+func (i *Image) Kind() string {
+ return ""
+}
+
+func (i *Image) UnderlyingImage() v1.Image {
+ return nil
+}
+
 func (i *Image) Rebase(baseTopLayer string, newBase imgutil.Image) error {
  i.base = newBase.Name()
  return nil

image.go

@@ -21,13 +21,14 @@ type Image interface {
  Env(key string) (string, error)
  // Found tells whether the image exists in the repository by `Name()`.
  Found() bool
- // Valid returns true if the image is well-formed (e.g. all manifest layers exist on the registry).
- Valid() bool
  GetAnnotateRefName() (string, error)
  // GetLayer retrieves layer by diff id. Returns a reader of the uncompressed contents of the layer.
  GetLayer(diffID string) (io.ReadCloser, error)
  History() ([]v1.History, error)
  Identifier() (Identifier, error)
+ // Kind exposes the type of image that backs the imgutil.Image implementation.
+ // It could be `local`, `locallayout`, `remote`, or `layout`.
+ Kind() string
  Label(string) (string, error)
  Labels() (map[string]string, error)
  // ManifestSize returns the size of the manifest. If a manifest doesn't exist, it returns 0.
@@ -37,6 +38,9 @@ type Image interface {
  OSVersion() (string, error)
  // TopLayer returns the diff id for the top layer
  TopLayer() (string, error)
+ UnderlyingImage() v1.Image
+ // Valid returns true if the image is well-formed (e.g. all manifest layers exist on the registry).
+ Valid() bool
  Variant() (string, error)
  WorkingDir() (string, error)
 

layout/layout.go

@@ -151,6 +151,10 @@ func (i *Image) Identifier() (imgutil.Identifier, error) {
  return newLayoutIdentifier(i.path, hash)
 }
 
+func (i *Image) Kind() string {
+ return `layout`
+}
+
 func (i *Image) Label(key string) (string, error) {
  cfg, err := i.Image.ConfigFile()
  if err != nil {
@@ -271,6 +275,10 @@ func (i *Image) TopLayer() (string, error) {
  return hex.String(), nil
 }
 
+func (i *Image) UnderlyingImage() v1.Image {
+ return i.Image
+}
+
 func (i *Image) Variant() (string, error) {
  cfg, err := i.Image.ConfigFile()
  if err != nil {

local/local.go

@@ -115,6 +115,10 @@ func (i *Image) Identifier() (imgutil.Identifier, error) {
  }, nil
 }
 
+func (i *Image) Kind() string {
+ return `local`
+}
+
 func (i *Image) Label(key string) (string, error) {
  labels := i.inspect.Config.Labels
  return labels[key], nil
@@ -155,6 +159,10 @@ func (i *Image) TopLayer() (string, error) {
  return topLayer, nil
 }
 
+func (i *Image) UnderlyingImage() v1.Image {
+ return nil
+}
+
 func (i *Image) Variant() (string, error) {
  return i.inspect.Variant, nil
 }

locallayout/image.go

@@ -0,0 +1,112 @@
+package locallayout
+
+import (
+ "errors"
+ "fmt"
+ "io"
+ "strings"
+ "sync"
+
+ v1 "github.com/google/go-containerregistry/pkg/v1"
+
+ "github.com/buildpacks/imgutil"
+)
+
+// Image wraps an imgutil.CNBImageCore and implements the methods needed to complete the imgutil.Image interface.
+type Image struct {
+ *imgutil.CNBImageCore
+ lastIdentifier string
+ daemonOS string
+ downloadOnce *sync.Once
+}
+
+var _ imgutil.Image = &Image{}
+
+func (i *Image) Found() bool {
+ return i.lastIdentifier != ""
+}
+
+func (i *Image) Identifier() (imgutil.Identifier, error) {
+ return idStringer{
+ id: strings.TrimPrefix(i.lastIdentifier, "sha256:"),
+ }, nil
+}
+
+type idStringer struct {
+ id string
+}
+
+func (i idStringer) String() string {
+ return i.id
+}
+
+// GetLayer returns an io.ReadCloser with uncompressed layer data.
+// The layer will always have data, even if that means downloading ALL the image layers from the daemon.
+func (i *Image) GetLayer(diffID string) (io.ReadCloser, error) {
+ layerHash, err := v1.NewHash(diffID)
+ if err != nil {
+ return nil, err
+ }
+ layer, err := i.LayerByDiffID(layerHash)
+ if err == nil {
+ // this avoids downloading ALL the image layers from the daemon
+ // if the layer is available locally
+ // (e.g., it was added using AddLayer).
+ if size, err := layer.Size(); err != nil && size != -1 {
+ return layer.Uncompressed()
+ }
+ }
+ if err = i.ensureLayers(); err != nil {
+ return nil, err
+ }
+ layer, err = i.LayerByDiffID(layerHash)
+ if err != nil {
+ return nil, fmt.Errorf("image %q does not contain layer with diff ID %q", i.Name(), layerHash.String())
+ }
+ return layer.Uncompressed()
+}
+
+func (i *Image) ensureLayers() error {
+ var err error
+ i.downloadOnce.Do(func() {
+ err = i.Store.DownloadLayersFor(i.lastIdentifier)
+ })
+ if err != nil {
+ return fmt.Errorf("fetching base layers: %w", err)
+ }
+ return nil
+}
+
+func (i *Image) SetOS(osVal string) error {
+ if osVal != i.daemonOS {
+ return errors.New("invalid os: must match the daemon")
+ }
+ return i.CNBImageCore.SetOS(osVal)
+}
+
+func (i *Image) Rebase(baseTopLayerDiffID string, withNewBase imgutil.Image) error {
+ if err := i.ensureLayers(); err != nil {
+ return err
+ }
+ return i.CNBImageCore.Rebase(baseTopLayerDiffID, withNewBase)
+}
+
+func (i *Image) Save(additionalNames ...string) error {
+ var err error
+ i.lastIdentifier, err = i.Store.Save(i, i.Name(), additionalNames...)
+ return err
+}
+
+func (i *Image) SaveAs(name string, additionalNames ...string) error {
+ var err error
+ i.lastIdentifier, err = i.Store.Save(i, name, additionalNames...)
+ return err
+}
+
+func (i *Image) SaveFile() (string, error) {
+ return i.Store.SaveFile(i, i.Name())
+}
+
+func (i *Image) Delete() error {
+ return i.Store.Delete(i.lastIdentifier)
+}