oci-image-tool: address review comments

Signed-off-by: Sergiusz Urbaniak <[email protected]>

Author: s-urbaniak

Makefile

@@ -70,9 +70,6 @@ media-types.png: media-types.dot
 %.png: %.dot
 	dot -Tpng $^ > $@
 
-fs:
-	esc -o schema/fs.go -pkg="schema" -ignore=".*go" schema
-
 .PHONY: \
 	validate-examples \
 	lint

cmd/oci-image-tool/validate.go

@@ -10,12 +10,12 @@ import (
 	"os"
 	"strings"
 
-	"github.com/opencontainers/image-spec/oci"
 	"github.com/opencontainers/image-spec/schema"
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 )
 
+// supported validation types
 const (
 	typeImageLayout  = "imageLayout"
 	typeImage        = "image"
@@ -80,7 +80,7 @@ func (v *validateCmd) Run(cmd *cobra.Command, args []string) {
 		}
 
 		var errs []error
-		if verr, ok := errors.Cause(err).(oci.ValidationError); ok {
+		if verr, ok := errors.Cause(err).(schema.ValidationError); ok {
 			errs = verr.Errs
 		} else {
 			v.stderr.Printf("file %s: validation failed: %v", arg, err)
@@ -108,15 +108,21 @@ func (v *validateCmd) validatePath(name string) error {
 		}
 	}
 
+	f, err := os.Open(name)
+	if err != nil {
+		return errors.Wrap(err, "unable to open file")
+	}
+	defer f.Close()
+
 	switch typ {
 	case typeManifest:
-		if err := withFile(name, oci.ValidateManifest); err != nil {
+		if err := schema.MediaTypeManifest.Validate(f); err != nil {
 			return err
 		}
 
 		return nil
 	case typeManifestList:
-		if err := withFile(name, oci.ValidateManifestList); err != nil {
+		if err := schema.MediaTypeManifestList.Validate(f); err != nil {
 			return err
 		}
 
@@ -126,20 +132,8 @@ func (v *validateCmd) validatePath(name string) error {
 	return fmt.Errorf("type %q unimplemented", typ)
 }
 
-// withFile opens the named file for reading and executes the given function fn if no error occured.
-// If the given function returns an error it will be returned.
-func withFile(name string, fn func(f io.Reader) error) error {
-	f, err := os.Open(name)
-	if err != nil {
-		return errors.Wrap(err, "unable to open file")
-	}
-	defer f.Close()
-
-	return fn(f)
-}
-
-// autodetect returns one of the type.. constants of the content of the given path
-// or an error if the type could not be resolved.
+// autodetect detects the validation type for the given path
+// or an error if the validation type could not be resolved.
 func autodetect(path string) (string, error) {
 	fi, err := os.Stat(path)
 	if err != nil {
@@ -156,7 +150,7 @@ func autodetect(path string) (string, error) {
 	}
 	defer f.Close()
 
-	buf, err := ioutil.ReadAll(io.LimitReader(f, 512)) // read up to 512 bytes for content detection
+	buf, err := ioutil.ReadAll(io.LimitReader(f, 512)) // read some initial bytes to detect content
 	if err != nil {
 		return "", errors.Wrap(err, "unable to read")
 	}
@@ -192,10 +186,10 @@ func autodetect(path string) (string, error) {
 	}
 
 	switch {
-	case header.MediaType == schema.MediaTypeManifest:
+	case header.MediaType == string(schema.MediaTypeManifest):
 		return typeManifest, nil
 
-	case header.MediaType == schema.MediaTypeManifestList:
+	case header.MediaType == string(schema.MediaTypeManifestList):
 		return typeManifestList, nil
 
 	case header.MediaType == "" && header.SchemaVersion == 0 && header.Config != nil:

cmd/oci-validate-examples/main.go

@@ -13,6 +13,7 @@ import (
 	"path/filepath"
 	"strings"
 
+	"github.com/opencontainers/image-spec/schema"
 	"github.com/russross/blackfriday"
 	"github.com/xeipuuv/gojsonschema"
 )
@@ -93,18 +94,13 @@ func main() {
 }
 
 var (
-	specsByMediaType = map[string]string{
-		"application/vnd.oci.image.manifest.v1+json":      "image-manifest-schema.json",
-		"application/vnd.oci.image.manifest.list.v1+json": "manifest-list-schema.json",
-	}
-
 	errSchemaNotFound = errors.New("schema: not found")
 	errFormatInvalid  = errors.New("format: invalid")
 )
 
 func schemaByMediatype(root, mediatype string) (gojsonschema.JSONLoader, error) {
-	name, ok := specsByMediaType[mediatype]
-	if !ok {
+	name := schema.File(mediatype)
+	if name == "" {
 		return nil, errSchemaNotFound
 	}
 

oci/doc.go

@@ -1,2 +1,2 @@
-// Package schema defines the media types as well as the schema definitions.
+// Package schema defines the OCI image media types, schema definitions and validation functions.
 package schema