cmd/oci-image-tool: support multiple --ref

cmd/oci-image-tool/validate.go

@@ -39,7 +39,7 @@ type validateCmd struct {
 	stdout *log.Logger
 	stderr *log.Logger
 	typ    string // the type to validate, can be empty string
-	ref    string
+	refs   []string
 }
 
 func newValidateCmd(stdout, stderr *log.Logger) *cobra.Command {
@@ -62,9 +62,9 @@ func newValidateCmd(stdout, stderr *log.Logger) *cobra.Command {
 		),
 	)
 
-	cmd.Flags().StringVar(
-		&v.ref, "ref", "v1.0",
-		`The ref pointing to the manifest to be validated. This must be present in the "refs" subdirectory of the image. Only applicable if type is image or imageLayout.`,
+	cmd.Flags().StringSliceVar(
+		&v.refs, "ref", []string{"v1.0"},
+		`A set of refs pointing to the manifests to be validated. Each reference must be present in the "refs" subdirectory of the image. Only applicable if type is image or imageLayout.`,
 	)
 
 	return cmd
@@ -112,8 +112,10 @@ func (v *validateCmd) Run(cmd *cobra.Command, args []string) {
 }
 
 func (v *validateCmd) validatePath(name string) error {
-	var err error
-	typ := v.typ
+	var (
+		err error
+		typ = v.typ
+	)
 
 	if typ == "" {
 		if typ, err = autodetect(name); err != nil {
@@ -123,9 +125,9 @@ func (v *validateCmd) validatePath(name string) error {
 
 	switch typ {
 	case typeImageLayout:
-		return image.ValidateLayout(name, v.ref)
+		return image.ValidateLayout(name, v.refs, v.stdout)
 	case typeImage:
-		return image.Validate(name, v.ref)
+		return image.Validate(name, v.refs, v.stdout)
 	}
 
 	f, err := os.Open(name)
@@ -137,10 +139,8 @@ func (v *validateCmd) validatePath(name string) error {
 	switch typ {
 	case typeManifest:
 		return schema.MediaTypeManifest.Validate(f)
-
 	case typeManifestList:
 		return schema.MediaTypeManifestList.Validate(f)
-
 	case typeConfig:
 		return schema.MediaTypeImageConfig.Validate(f)
 	}

image/image.go

@@ -16,48 +16,57 @@ package image
 
 import (
 	"encoding/json"
+	"log"
 	"os"
 	"path/filepath"
 
 	"github.com/pkg/errors"
 )
 
 // ValidateLayout walks through the file tree given by src and
-// validates the manifest pointed to by the given ref
+// validates the manifest pointed to by the given refs
 // or returns an error if the validation failed.
-func ValidateLayout(src, ref string) error {
-	return validate(newPathWalker(src), ref)
+func ValidateLayout(src string, refs []string, out *log.Logger) error {
+	return validate(newPathWalker(src), refs, out)
 }
 
 // Validate walks through the given .tar file and
-// validates the manifest pointed to by the given ref
+// validates the manifest pointed to by the given refs
 // or returns an error if the validation failed.
-func Validate(tarFile, ref string) error {
+func Validate(tarFile string, refs []string, out *log.Logger) error {
 	f, err := os.Open(tarFile)
 	if err != nil {
 		return errors.Wrap(err, "unable to open file")
 	}
 	defer f.Close()
 
-	return validate(newTarWalker(f), ref)
+	return validate(newTarWalker(f), refs, out)
 }
 
-func validate(w walker, refName string) error {
-	ref, err := findDescriptor(w, refName)
-	if err != nil {
-		return err
-	}
-
-	if err = ref.validate(w); err != nil {
-		return err
-	}
-
-	m, err := findManifest(w, ref)
-	if err != nil {
-		return err
-	}
-
-	return m.validate(w)
+func validate(w walker, refs []string, out *log.Logger) error {
+	for _, r := range refs {
+		ref, err := findDescriptor(w, r)
+		if err != nil {
+			return err
+		}
+
+		if err = ref.validate(w); err != nil {
+			return err
+		}
+
+		m, err := findManifest(w, ref)
+		if err != nil {
+			return err
+		}
+
+		if err := m.validate(w); err != nil {
+			return err
+		}
+		if out != nil {
+			out.Printf("reference %q: OK", r)
+		}
+	}
+	return nil
 }
 
 // UnpackLayout walks through the file tree given by src and