Clean up reference type switches

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

api/client/build.go

@@ -522,21 +522,9 @@ func rewriteDockerfileFrom(dockerfileName string, translator func(reference.Name
 			if err != nil {
 				return nil, nil, err
 			}
-
-			digested := false
-			switch ref.(type) {
-			case reference.NamedTagged:
-			case reference.Canonical:
-				digested = true
-			default:
-				ref, err = reference.WithTag(ref, reference.DefaultTag)
-				if err != nil {
-					return nil, nil, err
-				}
-			}
-
-			if !digested && isTrusted() {
-				trustedRef, err := translator(ref.(reference.NamedTagged))
+			ref = reference.WithDefaultTag(ref)
+			if ref, ok := ref.(reference.NamedTagged); ok && isTrusted() {
+				trustedRef, err := translator(ref)
 				if err != nil {
 					return nil, nil, err
 				}
@@ -544,7 +532,7 @@ func rewriteDockerfileFrom(dockerfileName string, translator func(reference.Name
 				line = dockerfileFromLinePattern.ReplaceAllLiteralString(line, fmt.Sprintf("FROM %s", trustedRef.String()))
 				resolvedTags = append(resolvedTags, &resolvedTag{
 					digestRef: trustedRef,
-					tagRef:    ref.(reference.NamedTagged),
+					tagRef:    ref,
 				})
 			}
 		}

api/client/create.go

@@ -25,14 +25,11 @@ func (cli *DockerCli) pullImageCustomOut(image string, out io.Writer) error {
 	}
 
 	var tag string
-	switch x := ref.(type) {
+	switch x := reference.WithDefaultTag(ref).(type) {
 	case reference.Canonical:
 		tag = x.Digest().String()
 	case reference.NamedTagged:
 		tag = x.Tag()
-	default:
-		// pull only the image tagged 'latest' if no tag was specified
-		tag = reference.DefaultTag
 	}
 
 	// Resolve the Repository name from fqn to RepositoryInfo
@@ -97,24 +94,13 @@ func (cli *DockerCli) createContainer(config *runconfig.Config, hostConfig *runc
 	if err != nil {
 		return nil, err
 	}
-
-	isCanonical := false
-	switch ref.(type) {
-	case reference.NamedTagged:
-	case reference.Canonical:
-		isCanonical = true
-	default:
-		ref, err = reference.WithTag(ref, reference.DefaultTag)
-		if err != nil {
-			return nil, err
-		}
-	}
+	ref = reference.WithDefaultTag(ref)
 
 	var trustedRef reference.Canonical
 
-	if isTrusted() && !isCanonical {
+	if ref, ok := ref.(reference.NamedTagged); ok && isTrusted() {
 		var err error
-		trustedRef, err = cli.trustedReference(ref.(reference.NamedTagged))
+		trustedRef, err = cli.trustedReference(ref)
 		if err != nil {
 			return nil, err
 		}
@@ -132,8 +118,8 @@ func (cli *DockerCli) createContainer(config *runconfig.Config, hostConfig *runc
 			if err = cli.pullImageCustomOut(config.Image, cli.err); err != nil {
 				return nil, err
 			}
-			if trustedRef != nil && !isCanonical {
-				if err := cli.tagTrusted(trustedRef, ref.(reference.NamedTagged)); err != nil {
+			if ref, ok := ref.(reference.NamedTagged); ok && trustedRef != nil {
+				if err := cli.tagTrusted(trustedRef, ref); err != nil {
 					return nil, err
 				}
 			}

api/client/import.go

@@ -59,7 +59,6 @@ func (cli *DockerCli) CmdImport(args ...string) error {
 		}
 		defer file.Close()
 		in = file
-
 	}
 
 	options := types.ImageImportOptions{

api/client/pull.go

@@ -13,8 +13,6 @@ import (
 	"github.com/docker/docker/registry"
 )
 
-var errTagCantBeUsed = errors.New("tag can't be used with --all-tags/-a")
-
 // CmdPull pulls an image or a repository from the registry.
 //
 // Usage: docker pull [OPTIONS] IMAGENAME[:TAG|@DIGEST]
@@ -31,28 +29,21 @@ func (cli *DockerCli) CmdPull(args ...string) error {
 	if err != nil {
 		return err
 	}
+	if *allTags && !reference.IsNameOnly(distributionRef) {
+		return errors.New("tag can't be used with --all-tags/-a")
+	}
+
+	if !*allTags && reference.IsNameOnly(distributionRef) {
+		distributionRef = reference.WithDefaultTag(distributionRef)
+		fmt.Fprintf(cli.out, "Using default tag: %s\n", reference.DefaultTag)
+	}
 
 	var tag string
 	switch x := distributionRef.(type) {
 	case reference.Canonical:
-		if *allTags {
-			return errTagCantBeUsed
-		}
 		tag = x.Digest().String()
 	case reference.NamedTagged:
-		if *allTags {
-			return errTagCantBeUsed
-		}
 		tag = x.Tag()
-	default:
-		if !*allTags {
-			tag = reference.DefaultTag
-			distributionRef, err = reference.WithTag(distributionRef, tag)
-			if err != nil {
-				return err
-			}
-			fmt.Fprintf(cli.out, "Using default tag: %s\n", tag)
-		}
 	}
 
 	ref := registry.ParseReference(tag)

api/client/tag.go

@@ -28,9 +28,8 @@ func (cli *DockerCli) CmdTag(args ...string) error {
 		return errors.New("refusing to create a tag with a digest reference")
 	}
 
-	tag := ""
-	tagged, isTagged := ref.(reference.NamedTagged)
-	if isTagged {
+	var tag string
+	if tagged, isTagged := ref.(reference.NamedTagged); isTagged {
 		tag = tagged.Tag()
 	}
 

api/client/trust.go

@@ -334,9 +334,11 @@ func (cli *DockerCli) trustedPull(repoInfo *registry.RepositoryInfo, ref registr
 				return err
 			}
 			trustedRef, err := reference.WithDigest(repoInfo, r.digest)
+			if err != nil {
+				return err
+			}
 			if err := cli.tagTrusted(trustedRef, tagged); err != nil {
 				return err
-
 			}
 		}
 	}

api/server/router/local/image.go

@@ -154,8 +154,7 @@ func (s *router) postImagesCreate(ctx context.Context, w http.ResponseWriter, r
 				return err
 			}
 
-			switch newRef.(type) {
-			case reference.Canonical:
+			if _, isCanonical := newRef.(reference.Canonical); isCanonical {
 				return errors.New("cannot import digest reference")
 			}
 
@@ -496,15 +495,12 @@ func sanitizeRepoAndTags(names []string) ([]reference.Named, error) {
 		if err != nil {
 			return nil, err
 		}
+		ref = reference.WithDefaultTag(ref)
 
 		if _, isCanonical := ref.(reference.Canonical); isCanonical {
 			return nil, errors.New("build tag cannot contain a digest")
 		}
 
-		if _, isTagged := ref.(reference.NamedTagged); !isTagged {
-			ref, err = reference.WithTag(ref, reference.DefaultTag)
-		}
-
 		nameWithTag := ref.String()
 
 		if _, exists := uniqNames[nameWithTag]; !exists {

daemon/daemonbuilder/builder.go

@@ -41,15 +41,7 @@ func (d Docker) Pull(name string) (*image.Image, error) {
 	if err != nil {
 		return nil, err
 	}
-	switch ref.(type) {
-	case reference.NamedTagged:
-	case reference.Canonical:
-	default:
-		ref, err = reference.WithTag(ref, "latest")
-		if err != nil {
-			return nil, err
-		}
-	}
+	ref = reference.WithDefaultTag(ref)
 
 	pullRegistryAuth := &types.AuthConfig{}
 	if len(d.AuthConfigs) > 0 {

daemon/image_delete.go

@@ -149,17 +149,7 @@ func (daemon *Daemon) getContainerUsingImage(imageID image.ID) *container.Contai
 // optional tag or digest reference. If tag or digest is omitted, the default
 // tag is used. Returns the resolved image reference and an error.
 func (daemon *Daemon) removeImageRef(ref reference.Named) (reference.Named, error) {
-	switch ref.(type) {
-	case reference.NamedTagged:
-	case reference.Canonical:
-	default:
-		var err error
-		ref, err = reference.WithTag(ref, reference.DefaultTag)
-		if err != nil {
-			return nil, err
-		}
-	}
-
+	ref = reference.WithDefaultTag(ref)
 	// Ignore the boolean value returned, as far as we're concerned, this
 	// is an idempotent operation and it's okay if the reference didn't
 	// exist in the first place.

distribution/pull_v2.go

@@ -54,10 +54,7 @@ func (p *v2Puller) Pull(ctx context.Context, ref reference.Named) (fallback bool
 
 func (p *v2Puller) pullV2Repository(ctx context.Context, ref reference.Named) (err error) {
 	var refs []reference.Named
-	taggedName := ref
-	if _, isTagged := ref.(reference.NamedTagged); isTagged {
-		refs = []reference.Named{ref}
-	} else if _, isCanonical := ref.(reference.Canonical); isCanonical {
+	if !reference.IsNameOnly(ref) {
 		refs = []reference.Named{ref}
 	} else {
 		manSvc, err := p.repo.Manifests(ctx)
@@ -92,7 +89,7 @@ func (p *v2Puller) pullV2Repository(ctx context.Context, ref reference.Named) (e
 		layersDownloaded = layersDownloaded || pulledNew
 	}
 
-	writeStatus(taggedName.String(), p.config.ProgressOutput, layersDownloaded)
+	writeStatus(ref.String(), p.config.ProgressOutput, layersDownloaded)
 
 	return nil
 }

image/tarexport/save.go

@@ -81,21 +81,19 @@ func (l *tarexporter) parseNames(names []string) (map[image.ID]*imageDescriptor,
 			addAssoc(imgID, nil)
 			continue
 		}
-		if _, ok := ref.(reference.Canonical); !ok {
-			if _, ok := ref.(reference.NamedTagged); !ok {
-				assocs := l.rs.ReferencesByName(ref)
-				for _, assoc := range assocs {
-					addAssoc(assoc.ImageID, assoc.Ref)
-				}
-				if len(assocs) == 0 {
-					imgID, err := l.is.Search(name)
-					if err != nil {
-						return nil, err
-					}
-					addAssoc(imgID, nil)
+		if reference.IsNameOnly(ref) {
+			assocs := l.rs.ReferencesByName(ref)
+			for _, assoc := range assocs {
+				addAssoc(assoc.ImageID, assoc.Ref)
+			}
+			if len(assocs) == 0 {
+				imgID, err := l.is.Search(name)
+				if err != nil {
+					return nil, err
 				}
-				continue
+				addAssoc(imgID, nil)
 			}
+			continue
 		}
 		var imgID image.ID
 		if imgID, err = l.rs.Get(ref); err != nil {

reference/reference.go

@@ -132,6 +132,25 @@ func (r *canonicalRef) Digest() digest.Digest {
 	return r.namedRef.Named.(distreference.Canonical).Digest()
 }
 
+// WithDefaultTag adds a default tag to a reference if it only has a repo name.
+func WithDefaultTag(ref Named) Named {
+	if IsNameOnly(ref) {
+		ref, _ = WithTag(ref, DefaultTag)
+	}
+	return ref
+}
+
+// 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
+}
+
 // splitHostname splits a repository name to hostname and remotename string.
 // If no valid hostname is found, the default hostname is used. Repository name
 // needs to be already validated before.

reference/store.go

@@ -64,19 +64,6 @@ func (a lexicalAssociations) Len() int           { return len(a) }
 func (a lexicalAssociations) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
 func (a lexicalAssociations) Less(i, j int) bool { return a[i].Ref.String() < a[j].Ref.String() }
 
-func defaultTagIfNameOnly(ref Named) Named {
-	switch ref.(type) {
-	case NamedTagged:
-		return ref
-	case Canonical:
-		return ref
-	default:
-		// Should never fail
-		ref, _ = WithTag(ref, DefaultTag)
-		return ref
-	}
-}
-
 // NewReferenceStore creates a new reference store, tied to a file path where
 // the set of references are serialized in JSON format.
 func NewReferenceStore(jsonPath string) (Store, error) {
@@ -107,7 +94,7 @@ func (store *store) AddTag(ref Named, id image.ID, force bool) error {
 	if _, isCanonical := ref.(Canonical); isCanonical {
 		return errors.New("refusing to create a tag with a digest reference")
 	}
-	return store.addReference(defaultTagIfNameOnly(ref), id, force)
+	return store.addReference(WithDefaultTag(ref), id, force)
 }
 
 // AddDigest adds a digest reference to the store.
@@ -162,7 +149,7 @@ func (store *store) addReference(ref Named, id image.ID, force bool) error {
 // Delete deletes a reference from the store. It returns true if a deletion
 // happened, or false otherwise.
 func (store *store) Delete(ref Named) (bool, error) {
-	ref = defaultTagIfNameOnly(ref)
+	ref = WithDefaultTag(ref)
 
 	store.mu.Lock()
 	defer store.mu.Unlock()
@@ -194,7 +181,7 @@ func (store *store) Delete(ref Named) (bool, error) {
 
 // Get retrieves an item from the store by
 func (store *store) Get(ref Named) (image.ID, error) {
-	ref = defaultTagIfNameOnly(ref)
+	ref = WithDefaultTag(ref)
 
 	store.mu.RLock()
 	defer store.mu.RUnlock()