Replace getPullRefPair with getPullRefName

... and use pullRefPairsFromRefNames to convert to the
desired data structure later.

This will make both getPullRefName, and later the bulk of
getPullListFromRef, independent of the storage, and thus much easier to test.

Then add tests for getPullRefName.  (Ideally they should be shorter,
e.g. hopefully the .image member can be eliminated.)

Should not change behavior, except that error messages on invalid
dstName will now include the value.

Signed-off-by: Miloslav Trmač <mitr@redhat.com>

Closes: #1176
Approved by: rhatdan

libpod/image/pull.go

@@ -64,7 +64,7 @@ type pullRefName struct {
 	dstName string
 }
 
-func (ir *Runtime) getPullRefPair(srcRef types.ImageReference, destName string) (*pullRefPair, error) {
+func getPullRefName(srcRef types.ImageReference, destName string) (*pullRefName, error) {
 	imgPart, err := decompose(destName)
 	if err == nil && !imgPart.hasRegistry {
 		// If the image doesn't have a registry, set it as the default repo
@@ -77,20 +77,16 @@ func (ir *Runtime) getPullRefPair(srcRef types.ImageReference, destName string)
 	if srcRef.DockerReference() != nil {
 		reference = srcRef.DockerReference().String()
 	}
-	destRef, err := is.Transport.ParseStoreReference(ir.store, reference)
-	if err != nil {
-		return nil, errors.Wrapf(err, "error parsing dest reference name")
-	}
-	return &pullRefPair{
-		image:  destName,
-		srcRef: srcRef,
-		dstRef: destRef,
+	return &pullRefName{
+		image:   destName,
+		srcRef:  srcRef,
+		dstName: reference,
 	}, nil
 }
 
 // returns a list of pullRefPair with the srcRef and DstRef based on the transport being used
 func (ir *Runtime) getPullListFromRef(ctx context.Context, srcRef types.ImageReference, imgName string, sc *types.SystemContext) ([]*pullRefPair, error) {
-	var pullRefPairs []*pullRefPair
+	var pullNames []*pullRefName
 	splitArr := strings.Split(imgName, ":")
 	archFile := splitArr[len(splitArr)-1]
 
@@ -112,11 +108,11 @@ func (ir *Runtime) getPullListFromRef(ctx context.Context, srcRef types.ImageRef
 			if err != nil {
 				return nil, err
 			}
-			pullInfo, err := ir.getPullRefPair(srcRef, reference)
+			pullInfo, err := getPullRefName(srcRef, reference)
 			if err != nil {
 				return nil, err
 			}
-			pullRefPairs = append(pullRefPairs, pullInfo)
+			pullNames = append(pullNames, pullInfo)
 		} else {
 			var dest []string
 			if len(manifest[0].RepoTags) > 0 {
@@ -131,11 +127,11 @@ func (ir *Runtime) getPullListFromRef(ctx context.Context, srcRef types.ImageRef
 			}
 			// Need to load in all the repo tags from the manifest
 			for _, dst := range dest {
-				pullInfo, err := ir.getPullRefPair(srcRef, dst)
+				pullInfo, err := getPullRefName(srcRef, dst)
 				if err != nil {
 					return nil, err
 				}
-				pullRefPairs = append(pullRefPairs, pullInfo)
+				pullNames = append(pullNames, pullInfo)
 			}
 		}
 	} else if srcRef.Transport().Name() == OCIArchive {
@@ -156,11 +152,11 @@ func (ir *Runtime) getPullListFromRef(ctx context.Context, srcRef types.ImageRef
 		} else {
 			dest = manifest.Annotations["org.opencontainers.image.ref.name"]
 		}
-		pullInfo, err := ir.getPullRefPair(srcRef, dest)
+		pullInfo, err := getPullRefName(srcRef, dest)
 		if err != nil {
 			return nil, err
 		}
-		pullRefPairs = append(pullRefPairs, pullInfo)
+		pullNames = append(pullNames, pullInfo)
 	} else if srcRef.Transport().Name() == DirTransport {
 		// supports pull from a directory
 		image := splitArr[1]
@@ -170,19 +166,20 @@ func (ir *Runtime) getPullListFromRef(ctx context.Context, srcRef types.ImageRef
 			// so docker.io isn't prepended, and the path becomes the repository
 			image = DefaultLocalRepo + image
 		}
-		pullInfo, err := ir.getPullRefPair(srcRef, image)
+		pullInfo, err := getPullRefName(srcRef, image)
 		if err != nil {
 			return nil, err
 		}
-		pullRefPairs = append(pullRefPairs, pullInfo)
+		pullNames = append(pullNames, pullInfo)
 	} else {
-		pullInfo, err := ir.getPullRefPair(srcRef, imgName)
+		pullInfo, err := getPullRefName(srcRef, imgName)
 		if err != nil {
 			return nil, err
 		}
-		pullRefPairs = append(pullRefPairs, pullInfo)
+		pullNames = append(pullNames, pullInfo)
 	}
-	return pullRefPairs, nil
+
+	return ir.pullRefPairsFromRefNames(pullNames)
 }
 
 // pullImage pulls an image from configured registries

libpod/image/pull_test.go

@@ -1,15 +1,83 @@
 package image
 
 import (
+	"fmt"
 	"io/ioutil"
 	"os"
 	"testing"
 
 	"github.com/containers/image/transports"
+	"github.com/containers/image/transports/alltransports"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
+func TestGetPullRefName(t *testing.T) {
+	const imageID = "@0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+	const digestSuffix = "@sha256:0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+
+	for _, c := range []struct{ srcName, destName, expectedImage, expectedDstName string }{
+		// == Source does not have a Docker reference (as is the case for docker-archive:, oci-archive, dir:); destination formats:
+		{ // registry/name, no tag:
+			"dir:/dev/this-does-not-exist", "example.com/from-directory",
+			// The destName value will be interpreted as "example.com/from-directory:latest" by storageTransport.
+			"example.com/from-directory", "example.com/from-directory",
+		},
+		{ // name, no registry, no tag:
+			"dir:/dev/this-does-not-exist", "from-directory",
+			// FIXME(?) Adding a registry also adds a :latest tag.  OTOH that actually matches the used destination.
+			// Either way it is surprising that the localhost/ addition changes this.  (mitr hoping to remove the "image" member).
+			"localhost/from-directory:latest", "localhost/from-directory:latest",
+		},
+		{ // registry/name:tag :
+			"dir:/dev/this-does-not-exist", "example.com/from-directory:notlatest",
+			"example.com/from-directory:notlatest", "example.com/from-directory:notlatest",
+		},
+		{ // name:tag, no registry:
+			"dir:/dev/this-does-not-exist", "from-directory:notlatest",
+			"localhost/from-directory:notlatest", "localhost/from-directory:notlatest",
+		},
+		{ // name@digest, no registry:
+			"dir:/dev/this-does-not-exist", "from-directory" + digestSuffix,
+			// FIXME?! Why is this dropping the digest, and adding :none?!
+			"localhost/from-directory:none", "localhost/from-directory:none",
+		},
+		{ // registry/name@digest:
+			"dir:/dev/this-does-not-exist", "example.com/from-directory" + digestSuffix,
+			"example.com/from-directory" + digestSuffix, "example.com/from-directory" + digestSuffix,
+		},
+		{ // ns/name:tag, no registry:
+			// FIXME: This is interpreted as "registry == ns"
+			"dir:/dev/this-does-not-exist", "ns/from-directory:notlatest",
+			"ns/from-directory:notlatest", "ns/from-directory:notlatest",
+		},
+		{ // containers-storage image ID
+			"dir:/dev/this-does-not-exist", imageID,
+			imageID, imageID,
+		},
+		// == Source does have a Docker reference.
+		// In that case getPullListFromRef uses the full transport:name input as a destName,
+		// which would be invalid in the returned dstName - but dstName is derived from the source, so it does not really matter _so_ much.
+		// Note that unlike real-world use we use different :source and :destination to verify the data flow in more detail.
+		{ // registry/name:tag
+			"docker://example.com/busybox:source", "docker://example.com/busybox:destination",
+			"docker://example.com/busybox:destination", "example.com/busybox:source",
+		},
+		{ // Implied docker.io/library and :latest
+			"docker://busybox", "docker://busybox:destination",
+			"docker://busybox:destination", "docker.io/library/busybox:latest",
+		},
+	} {
+		srcRef, err := alltransports.ParseImageName(c.srcName)
+		require.NoError(t, err, c.srcName)
+
+		testName := fmt.Sprintf("%#v %#v", c.srcName, c.destName)
+		res, err := getPullRefName(srcRef, c.destName)
+		require.NoError(t, err, testName)
+		assert.Equal(t, &pullRefName{image: c.expectedImage, srcRef: srcRef, dstName: c.expectedDstName}, res, testName)
+	}
+}
+
 const registriesConfWithSearch = `[registries.search]
 registries = ['example.com', 'docker.io']
 `