added oci support

Signed-off-by: Suleiman Dibirov <idsulik@gmail.com>

pkg/downloader/chart_downloader.go

@@ -149,12 +149,7 @@ func (c *ChartDownloader) DownloadTo(ref, version, dest string) (string, *proven
 		}
 	}
 
-	name := filepath.Base(u.Path)
-	if u.Scheme == registry.OCIScheme {
-		idx := strings.LastIndexByte(name, ':')
-		name = fmt.Sprintf("%s-%s.tgz", name[:idx], name[idx+1:])
-	}
-
+	name := c.getChartName(u.String())
 	destfile := filepath.Join(dest, name)
 	if err := fileutil.AtomicWriteFile(destfile, data, 0644); err != nil {
 		return destfile, nil, err
@@ -353,11 +348,12 @@ func (c *ChartDownloader) DownloadToCache(ref, version string) (string, *provena
 //
 // TODO: support OCI hash
 func (c *ChartDownloader) ResolveChartVersion(ref, version string) (string, *url.URL, error) {
-	u, err := url.Parse(ref)
+	u, err := c.parseChartURL(ref, version)
 	if err != nil {
-		return "", nil, fmt.Errorf("invalid chart URL format: %s", ref)
+		return "", u, err
 	}
 
+
 	if registry.IsOCI(u.String()) {
 		if c.RegistryClient == nil {
 			return "", nil, fmt.Errorf("unable to lookup ref %s at version '%s', missing registry client", ref, version)
@@ -574,6 +570,65 @@ func (c *ChartDownloader) scanReposForURL(u string, rf *repo.File) (*repo.Entry,
 	return nil, ErrNoOwnerRepo
 }
 
+func (c *ChartDownloader) getChartName(url string) string {
+	name := filepath.Base(url)
+	if registry.IsOCI(url) {
+		idx := strings.LastIndexByte(name, ':')
+		name = fmt.Sprintf("%s-%s.tgz", name[:idx], name[idx+1:])
+	}
+
+	return name
+}
+
+func (c *ChartDownloader) parseChartURL(ref string, version string) (*url.URL, error) {
+	u, err := url.Parse(ref)
+	if err != nil {
+		return nil, errors.Errorf("invalid chart URL format: %s", ref)
+	}
+
+	if registry.IsOCI(u.String()) {
+		tag, err := c.getOciTag(ref, version)
+
+		if err != nil {
+			return nil, err
+		}
+
+		u.Path = fmt.Sprintf("%s:%s", u.Path, tag)
+	}
+
+	return u, nil
+}
+
+func (c *ChartDownloader) getOciTag(ref, version string) (string, error) {
+	var tag string
+
+	// Evaluate whether an explicit version has been provided. Otherwise, determine version to use
+	_, errSemVer := semver.NewVersion(version)
+	if errSemVer == nil {
+		tag = version
+	} else {
+		// Retrieve list of repository tags
+		tags, err := c.RegistryClient.Tags(strings.TrimPrefix(ref, fmt.Sprintf("%s://", registry.OCIScheme)))
+		if err != nil {
+			return "", err
+		}
+		if len(tags) == 0 {
+			return "", errors.Errorf("Unable to locate any tags in provided repository: %s", ref)
+		}
+
+		// Determine if version provided
+		// If empty, try to get the highest available tag
+		// If exact version, try to find it
+		// If semver constraint string, try to find a match
+		tag, err = registry.GetTagMatchingVersionOrConstraint(tags, version)
+		if err != nil {
+			return "", err
+		}
+	}
+
+	return tag, nil
+}
+
 func loadRepoConfig(file string) (*repo.File, error) {
 	r, err := repo.LoadFile(file)
 	if err != nil && !errors.Is(err, fs.ErrNotExist) {

pkg/downloader/manager.go

@@ -328,16 +328,14 @@ func (m *Manager) downloadAll(deps []*chart.Dependency) error {
 			continue
 		}
 
-		if m.SkipDownloadIfExists {
-			name := filepath.Base(churl)
-			if _, err = os.Stat(filepath.Join(destPath, name)); err == nil {
-				fmt.Fprintf(m.Out, "Already exists locally %s from repo %s\n", dep.Name, dep.Repository)
-				continue
+		version := ""
+		if registry.IsOCI(churl) {
+			churl, version, err = parseOCIRef(churl)
+			if err != nil {
+				return errors.Wrapf(err, "could not parse OCI reference")
 			}
 		}
 
-		fmt.Fprintf(m.Out, "Downloading %s from repo %s\n", dep.Name, dep.Repository)
-
 		dl := ChartDownloader{
 			Out:              m.Out,
 			Verify:           m.Verify,
@@ -355,7 +353,6 @@ func (m *Manager) downloadAll(deps []*chart.Dependency) error {
 			},
 		}
 
-		version := ""
 		if registry.IsOCI(churl) {
 			churl, version, err = parseOCIRef(churl)
 			if err != nil {
@@ -366,6 +363,21 @@ func (m *Manager) downloadAll(deps []*chart.Dependency) error {
 				getter.WithTagName(version))
 		}
 
+		if m.SkipDownloadIfExists {
+			u, err := dl.parseChartURL(churl, version)
+
+			if err != nil {
+				return err
+			}
+
+			name := dl.getChartName(u.String())
+			if _, err = os.Stat(filepath.Join(destPath, name)); err == nil {
+				fmt.Fprintf(m.Out, "Already exists locally %s from repo %s\n", dep.Name, dep.Repository)
+				continue
+			}
+		}
+
+		fmt.Fprintf(m.Out, "Downloading %s from repo %s\n", dep.Name, dep.Repository)
 		if _, _, err = dl.DownloadTo(churl, version, tmpPath); err != nil {
 			saveError = fmt.Errorf("could not download %s: %w", churl, err)
 			break