Strip permissions when extracting a release, and create the directory

Tar extraction tries to preserve all permissions by default, which is
not useful for release content. Also attempt to create the directory
so users have a convenient shortcut

Author: smarterclayton

pkg/oc/cli/admin/release/extract.go

@@ -2,6 +2,7 @@ package release
 
 import (
 	"fmt"
+	"os"
 	"time"
 
 	"github.com/spf13/cobra"
@@ -62,6 +63,9 @@ func (o *ExtractOptions) Run() error {
 	}
 
 	dir := o.Directory
+	if err := os.MkdirAll(dir, 0755); err != nil {
+		return err
+	}
 
 	src := o.From
 	ref, err := imagereference.Parse(src)
@@ -70,6 +74,7 @@ func (o *ExtractOptions) Run() error {
 	}
 	opts := extract.NewOptions(genericclioptions.IOStreams{Out: o.Out, ErrOut: o.ErrOut})
 	opts.OnlyFiles = true
+	opts.RemovePermissions = true
 	opts.Mappings = []extract.Mapping{
 		{
 			ImageRef: ref,
@@ -80,9 +85,9 @@ func (o *ExtractOptions) Run() error {
 	}
 	opts.ImageMetadataCallback = func(m *extract.Mapping, dgst digest.Digest, config *docker10.DockerImageConfig) {
 		if len(ref.ID) > 0 {
-			fmt.Fprintf(o.Out, "Extracted release payload from %s created at %s\n", ref, config.Created.Format(time.RFC3339))
+			fmt.Fprintf(o.Out, "Extracted release payload created at %s\n", config.Created.Format(time.RFC3339))
 		} else {
-			fmt.Fprintf(o.Out, "Extracted release payload from %s (digest %s) created at %s\n", ref, dgst, config.Created.Format(time.RFC3339))
+			fmt.Fprintf(o.Out, "Extracted release payload from digest %s created at %s\n", dgst, config.Created.Format(time.RFC3339))
 		}
 	}
 	if err := opts.Run(); err != nil {

pkg/oc/cli/image/extract/extract.go

@@ -92,7 +92,8 @@ type Options struct {
 
 	Paths []string
 
-	OnlyFiles bool
+	OnlyFiles         bool
+	RemovePermissions bool
 
 	FilterOptions imagemanifest.FilterOptions
 
@@ -313,6 +314,9 @@ func (o *Options) Run() error {
 						return fmt.Errorf("unable to filter layers for %s: %v", from, err)
 					}
 				}
+				if o.RemovePermissions {
+					alter = append(alter, removePermissions{})
+				}
 
 				for i := range filteredLayers {
 					layer := &filteredLayers[i]
@@ -417,6 +421,18 @@ func (a alterations) Alter(hdr *tar.Header) (bool, error) {
 	return true, nil
 }
 
+type removePermissions struct{}
+
+func (_ removePermissions) Alter(hdr *tar.Header) (bool, error) {
+	switch hdr.Typeflag {
+	case tar.TypeReg, tar.TypeRegA:
+		hdr.Mode = int64(os.FileMode(0640))
+	default:
+		hdr.Mode = int64(os.FileMode(0755))
+	}
+	return true, nil
+}
+
 type copyFromDirectory struct {
 	From string
 }