Merge pull request #450 from umohnani8/dir_transport

Add manifest type conversion to skopeo copy

cmd/skopeo/copy.go

@@ -7,9 +7,11 @@ import (
 	"strings"
 
 	"github.com/containers/image/copy"
+	"github.com/containers/image/manifest"
 	"github.com/containers/image/transports"
 	"github.com/containers/image/transports/alltransports"
 	"github.com/containers/image/types"
+	imgspecv1 "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/urfave/cli"
 )
 
@@ -55,12 +57,27 @@ func copyHandler(context *cli.Context) error {
 		return err
 	}
 
+	var manifestType string
+	if context.IsSet("format") {
+		switch context.String("format") {
+		case "oci":
+			manifestType = imgspecv1.MediaTypeImageManifest
+		case "v2s1":
+			manifestType = manifest.DockerV2Schema1SignedMediaType
+		case "v2s2":
+			manifestType = manifest.DockerV2Schema2MediaType
+		default:
+			return fmt.Errorf("unknown format %q. Choose on of the supported formats: 'oci', 'v2s1', or 'v2s2'", context.String("format"))
+		}
+	}
+
 	return copy.Image(policyContext, destRef, srcRef, &copy.Options{
 		RemoveSignatures:      removeSignatures,
 		SignBy:                signBy,
 		ReportWriter:          os.Stdout,
 		SourceCtx:             sourceCtx,
 		DestinationCtx:        destinationCtx,
+		ForceManifestMIMEType: manifestType,
 	})
 }
 
@@ -131,5 +148,13 @@ var copyCmd = cli.Command{
 			Value: "",
 			Usage: "`DIRECTORY` to use to store retrieved blobs (OCI layout destinations only)",
 		},
+		cli.StringFlag{
+			Name:  "format, f",
+			Usage: "`MANIFEST TYPE` (oci, v2s1, or v2s2) to use when saving image to directory using the 'dir:' transport (default is manifest type of source)",
+		},
+		cli.BoolFlag{
+			Name:  "dest-compress",
+			Usage: "Compress tarball image layers when saving to directory using the 'dir' transport. (default is same compression type as source)",
+		},
 	},
 }

cmd/skopeo/utils.go

@@ -18,6 +18,7 @@ func contextFromGlobalOptions(c *cli.Context, flagPrefix string) (*types.SystemC
 		DockerInsecureSkipTLSVerify: !c.GlobalBoolT("tls-verify"),
 		OSTreeTmpDirPath:            c.String(flagPrefix + "ostree-tmp-dir"),
 		OCISharedBlobDirPath:        c.String(flagPrefix + "shared-blob-dir"),
+		DirForceCompress:            c.Bool(flagPrefix + "compress"),
 	}
 	if c.IsSet(flagPrefix + "tls-verify") {
 		ctx.DockerInsecureSkipTLSVerify = !c.BoolT(flagPrefix + "tls-verify")

completions/bash/skopeo

@@ -21,6 +21,7 @@ _complete_() {
 
 _skopeo_copy() {
     local options_with_args="
+    --format -f
     --sign-by
     --src-creds --screds
     --src-cert-dir
@@ -30,9 +31,12 @@ _skopeo_copy() {
     --dest-ostree-tmp-dir
     --dest-tls-verify
     "
+
     local boolean_options="
+    --dest-compress
     --remove-signatures
     "
+
     _complete_ "$options_with_args" "$boolean_options"
 }
 

docs/skopeo.1.md

@@ -60,12 +60,16 @@ Uses the system's trust policy to validate images, rejects images not trusted by
 
   _destination-image_ use the "image name" format described above
 
+  **--format, -f** _manifest-type_ Manifest type (oci, v2s1, or v2s2) to use when saving image to directory using the 'dir:' transport (default is manifest type of source)
+
   **--remove-signatures** do not copy signatures, if any, from _source-image_. Necessary when copying a signed image to a destination which does not support signatures.
 
   **--sign-by=**_key-id_ add a signature using that key ID for an image name corresponding to _destination-image_
 
   **--src-creds** _username[:password]_ for accessing the source registry
 
+  **--dest-compress** _bool-value_ Compress tarball image layers when saving to directory using the 'dir' transport. (default is same compression type as source)
+
   **--dest-creds** _username[:password]_ for accessing the destination registry
 
   **--src-cert-dir** _path_ Use certificates at _path_ (*.crt, *.cert, *.key) to connect to the source registry

integration/copy_test.go

@@ -15,6 +15,7 @@ import (
 	"github.com/containers/image/signature"
 	"github.com/go-check/check"
 	"github.com/opencontainers/go-digest"
+	imgspecv1 "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/opencontainers/image-tools/image"
 )
 
@@ -591,6 +592,32 @@ func (s *CopySuite) TestCopySchemaConversion(c *check.C) {
 	s.testCopySchemaConversionRegistries(c, "docker://"+v2s1DockerRegistryURL+"/schema1", "docker://"+v2DockerRegistryURL+"/schema2")
 }
 
+func (s *CopySuite) TestCopyManifestConversion(c *check.C) {
+	topDir, err := ioutil.TempDir("", "manifest-conversion")
+	c.Assert(err, check.IsNil)
+	defer os.RemoveAll(topDir)
+	srcDir := filepath.Join(topDir, "source")
+	destDir1 := filepath.Join(topDir, "dest1")
+	destDir2 := filepath.Join(topDir, "dest2")
+
+	// oci to v2s1 and vice-versa not supported yet
+	// get v2s2 manifest type
+	assertSkopeoSucceeds(c, "", "copy", "docker://busybox", "dir:"+srcDir)
+	verifyManifestMIMEType(c, srcDir, manifest.DockerV2Schema2MediaType)
+	// convert from v2s2 to oci
+	assertSkopeoSucceeds(c, "", "copy", "--format=oci", "dir:"+srcDir, "dir:"+destDir1)
+	verifyManifestMIMEType(c, destDir1, imgspecv1.MediaTypeImageManifest)
+	// convert from oci to v2s2
+	assertSkopeoSucceeds(c, "", "copy", "--format=v2s2", "dir:"+destDir1, "dir:"+destDir2)
+	verifyManifestMIMEType(c, destDir2, manifest.DockerV2Schema2MediaType)
+	// convert from v2s2 to v2s1
+	assertSkopeoSucceeds(c, "", "copy", "--format=v2s1", "dir:"+srcDir, "dir:"+destDir1)
+	verifyManifestMIMEType(c, destDir1, manifest.DockerV2Schema1SignedMediaType)
+	// convert from v2s1 to v2s2
+	assertSkopeoSucceeds(c, "", "copy", "--format=v2s2", "dir:"+destDir1, "dir:"+destDir2)
+	verifyManifestMIMEType(c, destDir2, manifest.DockerV2Schema2MediaType)
+}
+
 func (s *CopySuite) testCopySchemaConversionRegistries(c *check.C, schema1Registry, schema2Registry string) {
 	topDir, err := ioutil.TempDir("", "schema-conversion")
 	c.Assert(err, check.IsNil)

vendor.conf

@@ -1,5 +1,5 @@
 github.com/urfave/cli v1.17.0
-github.com/containers/image master
+github.com/containers/image f950aa3529148eb0dea90888c24b6682da641b13
 github.com/opencontainers/go-digest master
 gopkg.in/cheggaaa/pb.v1 ad4efe000aa550bb54918c06ebbadc0ff17687b9 https://github.com/cheggaaa/pb
 github.com/containers/storage master

vendor/github.com/containers/image/copy/copy.go

@@ -12,8 +12,6 @@ import (
 	"strings"
 	"time"
 
-	pb "gopkg.in/cheggaaa/pb.v1"
-
 	"github.com/containers/image/image"
 	"github.com/containers/image/pkg/compression"
 	"github.com/containers/image/signature"
@@ -22,6 +20,7 @@ import (
 	"github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
+	pb "gopkg.in/cheggaaa/pb.v1"
 )
 
 type digestingReader struct {
@@ -95,6 +94,8 @@ type Options struct {
 	DestinationCtx   *types.SystemContext
 	ProgressInterval time.Duration                 // time to wait between reports to signal the progress channel
 	Progress         chan types.ProgressProperties // Reported to when ProgressInterval has arrived for a single artifact+offset.
+	// manifest MIME type of image set by user. "" is default and means use the autodetection to the the manifest MIME type
+	ForceManifestMIMEType string
 }
 
 // Image copies image from srcRef to destRef, using policyContext to validate
@@ -193,7 +194,7 @@ func Image(policyContext *signature.PolicyContext, destRef, srcRef types.ImageRe
 
 	// We compute preferredManifestMIMEType only to show it in error messages.
 	// Without having to add this context in an error message, we would be happy enough to know only that no conversion is needed.
-	preferredManifestMIMEType, otherManifestMIMETypeCandidates, err := determineManifestConversion(&manifestUpdates, src, dest.SupportedManifestMIMETypes(), canModifyManifest)
+	preferredManifestMIMEType, otherManifestMIMETypeCandidates, err := determineManifestConversion(&manifestUpdates, src, dest.SupportedManifestMIMETypes(), canModifyManifest, options.ForceManifestMIMEType)
 	if err != nil {
 		return err
 	}

vendor/github.com/containers/image/copy/manifest.go

@@ -41,12 +41,16 @@ func (os *orderedSet) append(s string) {
 // Note that the conversion will only happen later, through src.UpdatedImage
 // Returns the preferred manifest MIME type (whether we are converting to it or using it unmodified),
 // and a list of other possible alternatives, in order.
-func determineManifestConversion(manifestUpdates *types.ManifestUpdateOptions, src types.Image, destSupportedManifestMIMETypes []string, canModifyManifest bool) (string, []string, error) {
+func determineManifestConversion(manifestUpdates *types.ManifestUpdateOptions, src types.Image, destSupportedManifestMIMETypes []string, canModifyManifest bool, forceManifestMIMEType string) (string, []string, error) {
 	_, srcType, err := src.Manifest()
 	if err != nil { // This should have been cached?!
 		return "", nil, errors.Wrap(err, "Error reading manifest")
 	}
 
+	if forceManifestMIMEType != "" {
+		destSupportedManifestMIMETypes = []string{forceManifestMIMEType}
+	}
+
 	if len(destSupportedManifestMIMETypes) == 0 {
 		return srcType, []string{}, nil // Anything goes; just use the original as is, do not try any conversions.
 	}

vendor/github.com/containers/image/directory/directory_dest.go

@@ -4,19 +4,77 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
+	"path/filepath"
 
 	"github.com/containers/image/types"
 	"github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
 )
 
+const version = "Directory Transport Version: 1.0\n"
+
+// ErrNotContainerImageDir indicates that the directory doesn't match the expected contents of a directory created
+// using the 'dir' transport
+var ErrNotContainerImageDir = errors.New("not a containers image directory, don't want to overwrite important data")
+
 type dirImageDestination struct {
 	ref      dirReference
+	compress bool
 }
 
-// newImageDestination returns an ImageDestination for writing to an existing directory.
-func newImageDestination(ref dirReference) types.ImageDestination {
-	return &dirImageDestination{ref}
+// newImageDestination returns an ImageDestination for writing to a directory.
+func newImageDestination(ref dirReference, compress bool) (types.ImageDestination, error) {
+	d := &dirImageDestination{ref: ref, compress: compress}
+
+	// If directory exists check if it is empty
+	// if not empty, check whether the contents match that of a container image directory and overwrite the contents
+	// if the contents don't match throw an error
+	dirExists, err := pathExists(d.ref.resolvedPath)
+	if err != nil {
+		return nil, errors.Wrapf(err, "error checking for path %q", d.ref.resolvedPath)
+	}
+	if dirExists {
+		isEmpty, err := isDirEmpty(d.ref.resolvedPath)
+		if err != nil {
+			return nil, err
+		}
+
+		if !isEmpty {
+			versionExists, err := pathExists(d.ref.versionPath())
+			if err != nil {
+				return nil, errors.Wrapf(err, "error checking if path exists %q", d.ref.versionPath())
+			}
+			if versionExists {
+				contents, err := ioutil.ReadFile(d.ref.versionPath())
+				if err != nil {
+					return nil, err
+				}
+				// check if contents of version file is what we expect it to be
+				if string(contents) != version {
+					return nil, ErrNotContainerImageDir
+				}
+			} else {
+				return nil, ErrNotContainerImageDir
+			}
+			// delete directory contents so that only one image is in the directory at a time
+			if err = removeDirContents(d.ref.resolvedPath); err != nil {
+				return nil, errors.Wrapf(err, "error erasing contents in %q", d.ref.resolvedPath)
+			}
+			logrus.Debugf("overwriting existing container image directory %q", d.ref.resolvedPath)
+		}
+	} else {
+		// create directory if it doesn't exist
+		if err := os.MkdirAll(d.ref.resolvedPath, 0755); err != nil {
+			return nil, errors.Wrapf(err, "unable to create directory %q", d.ref.resolvedPath)
+		}
+	}
+	// create version file
+	err = ioutil.WriteFile(d.ref.versionPath(), []byte(version), 0755)
+	if err != nil {
+		return nil, errors.Wrapf(err, "error creating version file %q", d.ref.versionPath())
+	}
+	return d, nil
 }
 
 // Reference returns the reference used to set up this destination.  Note that this should directly correspond to user's intent,
@@ -42,7 +100,7 @@ func (d *dirImageDestination) SupportsSignatures() error {
 
 // ShouldCompressLayers returns true iff it is desirable to compress layer blobs written to this destination.
 func (d *dirImageDestination) ShouldCompressLayers() bool {
-	return false
+	return d.compress
 }
 
 // AcceptsForeignLayerURLs returns false iff foreign layers in manifest should be actually
@@ -147,3 +205,39 @@ func (d *dirImageDestination) PutSignatures(signatures [][]byte) error {
 func (d *dirImageDestination) Commit() error {
 	return nil
 }
+
+// returns true if path exists
+func pathExists(path string) (bool, error) {
+	_, err := os.Stat(path)
+	if err == nil {
+		return true, nil
+	}
+	if err != nil && os.IsNotExist(err) {
+		return false, nil
+	}
+	return false, err
+}
+
+// returns true if directory is empty
+func isDirEmpty(path string) (bool, error) {
+	files, err := ioutil.ReadDir(path)
+	if err != nil {
+		return false, err
+	}
+	return len(files) == 0, nil
+}
+
+// deletes the contents of a directory
+func removeDirContents(path string) error {
+	files, err := ioutil.ReadDir(path)
+	if err != nil {
+		return err
+	}
+
+	for _, file := range files {
+		if err := os.RemoveAll(filepath.Join(path, file.Name())); err != nil {
+			return err
+		}
+	}
+	return nil
+}

vendor/github.com/containers/image/directory/directory_transport.go

@@ -152,7 +152,11 @@ func (ref dirReference) NewImageSource(ctx *types.SystemContext) (types.ImageSou
 // NewImageDestination returns a types.ImageDestination for this reference.
 // The caller must call .Close() on the returned ImageDestination.
 func (ref dirReference) NewImageDestination(ctx *types.SystemContext) (types.ImageDestination, error) {
-	return newImageDestination(ref), nil
+	compress := false
+	if ctx != nil {
+		compress = ctx.DirForceCompress
+	}
+	return newImageDestination(ref, compress)
 }
 
 // DeleteImage deletes the named image from the registry, if supported.
@@ -175,3 +179,8 @@ func (ref dirReference) layerPath(digest digest.Digest) string {
 func (ref dirReference) signaturePath(index int) string {
 	return filepath.Join(ref.path, fmt.Sprintf("signature-%d", index+1))
 }
+
+// versionPath returns a path for the version file within a directory using our conventions.
+func (ref dirReference) versionPath() string {
+	return filepath.Join(ref.path, "version")
+}

vendor/github.com/containers/image/docker/docker_image_dest.go

@@ -236,7 +236,7 @@ func (d *dockerImageDestination) PutManifest(m []byte) error {
 		return err
 	}
 	defer res.Body.Close()
-	if res.StatusCode != http.StatusCreated {
+	if !successStatus(res.StatusCode) {
 		err = errors.Wrapf(client.HandleErrorResponse(res), "Error uploading manifest to %s", path)
 		if isManifestInvalidError(errors.Cause(err)) {
 			err = types.ManifestTypeRejectedError{Err: err}
@@ -246,6 +246,12 @@ func (d *dockerImageDestination) PutManifest(m []byte) error {
 	return nil
 }
 
+// successStatus returns true if the argument is a successful HTTP response
+// code (in the range 200 - 399 inclusive).
+func successStatus(status int) bool {
+	return status >= 200 && status <= 399
+}
+
 // isManifestInvalidError returns true iff err from client.HandleErrorReponse is a “manifest invalid” error.
 func isManifestInvalidError(err error) bool {
 	errors, ok := err.(errcode.Errors)

vendor/github.com/containers/image/types/types.go

@@ -349,6 +349,10 @@ type SystemContext struct {
 	DockerDaemonHost string
 	// Used to skip TLS verification, off by default. To take effect DockerDaemonCertPath needs to be specified as well.
 	DockerDaemonInsecureSkipTLSVerify bool
+
+	// === dir.Transport overrides ===
+	// DirForceCompress compresses the image layers if set to true
+	DirForceCompress bool
 }
 
 // ProgressProperties is used to pass information from the copy code to a monitor which