Merge pull request #28447 from nishanttotla/use-distribution-reference-pkg

Using distribution reference pkg (pin image by digest)

daemon/cluster/cluster.go

@@ -16,6 +16,7 @@ import (
 	"time"
 
 	"github.com/Sirupsen/logrus"
+	distreference "github.com/docker/distribution/reference"
 	apierrors "github.com/docker/docker/api/errors"
 	apitypes "github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/backend"
@@ -1008,16 +1009,25 @@ func (c *Cluster) GetServices(options apitypes.ServiceListOptions) ([]types.Serv
 
 // imageWithDigestString takes an image such as name or name:tag
 // and returns the image pinned to a digest, such as name@sha256:34234...
+// Due to the difference between the docker/docker/reference, and the
+// docker/distribution/reference packages, we're parsing the image twice.
+// As the two packages converge, this function should be simplified.
+// TODO(nishanttotla): After the packages converge, the function must
+// convert distreference.Named -> distreference.Canonical, and the logic simplified.
 func (c *Cluster) imageWithDigestString(ctx context.Context, image string, authConfig *apitypes.AuthConfig) (string, error) {
-	ref, err := reference.ParseNamed(image)
+	ref, err := distreference.ParseNamed(image)
 	if err != nil {
 		return "", err
 	}
 	// only query registry if not a canonical reference (i.e. with digest)
-	if _, ok := ref.(reference.Canonical); !ok {
-		ref = reference.WithDefaultTag(ref)
-
-		namedTaggedRef, ok := ref.(reference.NamedTagged)
+	if _, ok := ref.(distreference.Canonical); !ok {
+		// create a docker/docker/reference Named object because GetRepository needs it
+		dockerRef, err := reference.ParseNamed(image)
+		if err != nil {
+			return "", err
+		}
+		dockerRef = reference.WithDefaultTag(dockerRef)
+		namedTaggedRef, ok := dockerRef.(reference.NamedTagged)
 		if !ok {
 			return "", fmt.Errorf("unable to cast image to NamedTagged reference object")
 		}
@@ -1031,15 +1041,11 @@ func (c *Cluster) imageWithDigestString(ctx context.Context, image string, authC
 			return "", err
 		}
 
-		// TODO(nishanttotla): Currently, the service would lose the tag while calling WithDigest
-		// To prevent this, we create the image string manually, which is a bad idea in general
-		// This will be fixed when https://github.com/docker/distribution/pull/2044 is vendored
-		// namedDigestedRef, err := reference.WithDigest(ref, dscrptr.Digest)
-		// if err != nil {
-		// 	return "", err
-		// }
-		// return namedDigestedRef.String(), nil
-		return image + "@" + dscrptr.Digest.String(), nil
+		namedDigestedRef, err := distreference.WithDigest(distreference.EnsureTagged(ref), dscrptr.Digest)
+		if err != nil {
+			return "", err
+		}
+		return namedDigestedRef.String(), nil
 	} else {
 		// reference already contains a digest, so just return it
 		return ref.String(), nil

vendor.conf

@@ -44,7 +44,7 @@ github.com/boltdb/bolt fff57c100f4dea1905678da7e90d92429dff2904
 github.com/miekg/dns 75e6e86cc601825c5dbcd4e0c209eab180997cd7
 
 # get graph and distribution packages
-github.com/docker/distribution 8016d2d8903e378edacac11e4d809efbc987ad61
+github.com/docker/distribution d22e09a6686c32be8c17b684b639da4b90efe320
 github.com/vbatts/tar-split v0.10.1
 
 # get go-zfs packages

vendor/github.com/docker/distribution/reference/helpers.go

@@ -0,0 +1,12 @@
+package reference
+
+// IsNameOnly returns true if reference only contains a repo name.
+func IsNameOnly(ref Named) bool {
+	if _, ok := ref.(NamedTagged); ok {
+		return false
+	}
+	if _, ok := ref.(Canonical); ok {
+		return false
+	}
+	return true
+}

vendor/github.com/docker/distribution/reference/normalize.go

@@ -0,0 +1,22 @@
+package reference
+
+var (
+	defaultTag = "latest"
+)
+
+// EnsureTagged adds the default tag "latest" to a reference if it only has
+// a repo name.
+func EnsureTagged(ref Named) NamedTagged {
+	namedTagged, ok := ref.(NamedTagged)
+	if !ok {
+		namedTagged, err := WithTag(ref, defaultTag)
+		if err != nil {
+			// Default tag must be valid, to create a NamedTagged
+			// type with non-validated input the WithTag function
+			// should be used instead
+			panic(err)
+		}
+		return namedTagged
+	}
+	return namedTagged
+}