fix pull image that includes a sha

when pulling an image that includes a sha such as:

centos/nginx-112-centos7@sha256:42330f7f29ba1ad67819f4ff3ae2472f62de13a827a74736a5098728462212e7

the final image name in libpod should not contain portions of the sha itself nor the sha
identifier.  and like docker, we provide a 'none' tag as well.

this should fix #877

Signed-off-by: baude <bbaude@redhat.com>

Closes: #1085
Approved by: mheon

libpod/image/image.go

@@ -1055,3 +1055,9 @@ func (i *Image) Comment(ctx context.Context, manifestType string) (string, error
 	}
 	return ociv1Img.History[0].Comment, nil
 }
+
+// HasShaInInputName returns a bool as to whether the user provide an image name that includes
+// a reference to a specific sha
+func (i *Image) HasShaInInputName() bool {
+	return strings.Contains(i.InputName, "@sha256:")
+}

libpod/image/parts.go

@@ -2,6 +2,7 @@ package image
 
 import (
 	"fmt"
+	"strings"
 
 	"github.com/containers/image/docker/reference"
 )
@@ -33,6 +34,9 @@ func decompose(input string) (imageParts, error) {
 	}
 	if !isTagged {
 		tag = "latest"
+		if strings.Contains(input, "@sha256:") {
+			tag = "none"
+		}
 	} else {
 		tag = ntag.Tag()
 	}

libpod/image/pull.go

@@ -49,9 +49,10 @@ var (
 )
 
 type pullStruct struct {
-	image  string
-	srcRef types.ImageReference
-	dstRef types.ImageReference
+	image       string
+	srcRef      types.ImageReference
+	dstRef      types.ImageReference
+	shaPullName string
 }
 
 func (ir *Runtime) getPullStruct(srcRef types.ImageReference, destName string) (*pullStruct, error) {
@@ -247,13 +248,22 @@ func (i *Image) pullImage(ctx context.Context, writer io.Writer, authfile, signa
 // createNamesToPull looks at a decomposed image and determines the possible
 // images names to try pulling in combination with the registries.conf file as well
 func (i *Image) createNamesToPull() ([]*pullStruct, error) {
-	var pullNames []*pullStruct
+	var (
+		pullNames []*pullStruct
+		imageName string
+	)
+
 	decomposedImage, err := decompose(i.InputName)
 	if err != nil {
 		return nil, err
 	}
 	if decomposedImage.hasRegistry {
-		srcRef, err := alltransports.ParseImageName(decomposedImage.assembleWithTransport())
+		if i.HasShaInInputName() {
+			imageName = fmt.Sprintf("%s%s", decomposedImage.transport, i.InputName)
+		} else {
+			imageName = decomposedImage.assembleWithTransport()
+		}
+		srcRef, err := alltransports.ParseImageName(imageName)
 		if err != nil {
 			return nil, errors.Wrapf(err, "unable to parse '%s'", i.InputName)
 		}
@@ -261,6 +271,9 @@ func (i *Image) createNamesToPull() ([]*pullStruct, error) {
 			image:  i.InputName,
 			srcRef: srcRef,
 		}
+		if i.HasShaInInputName() {
+			ps.shaPullName = decomposedImage.assemble()
+		}
 		pullNames = append(pullNames, &ps)
 
 	} else {
@@ -275,7 +288,11 @@ func (i *Image) createNamesToPull() ([]*pullStruct, error) {
 		}
 		for _, registry := range searchRegistries {
 			decomposedImage.registry = registry
-			srcRef, err := alltransports.ParseImageName(decomposedImage.assembleWithTransport())
+			imageName := decomposedImage.assembleWithTransport()
+			if i.HasShaInInputName() {
+				imageName = fmt.Sprintf("%s%s/%s", decomposedImage.transport, registry, i.InputName)
+			}
+			srcRef, err := alltransports.ParseImageName(imageName)
 			if err != nil {
 				return nil, errors.Wrapf(err, "unable to parse '%s'", i.InputName)
 			}
@@ -287,8 +304,13 @@ func (i *Image) createNamesToPull() ([]*pullStruct, error) {
 		}
 	}
 
+	// Here we construct the destination reference
 	for _, pStruct := range pullNames {
-		destRef, err := is.Transport.ParseStoreReference(i.imageruntime.store, pStruct.image)
+		dstName := pStruct.image
+		if pStruct.shaPullName != "" {
+			dstName = pStruct.shaPullName
+		}
+		destRef, err := is.Transport.ParseStoreReference(i.imageruntime.store, dstName)
 		if err != nil {
 			return nil, errors.Wrapf(err, "error parsing dest reference name")
 		}

test/e2e/pull_test.go

@@ -74,7 +74,7 @@ var _ = Describe("Podman pull", func() {
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 
-		session = podmanTest.Podman([]string{"rmi", "alpine:latest"})
+		session = podmanTest.Podman([]string{"rmi", "alpine:none"})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 	})