handle unsupported schema correctly

Signed-off-by: Đặng Minh Dũng <dungdm93@live.com>

pkg/apk/implementation.go

@@ -371,22 +371,14 @@ func (a *APK) InitKeyring(ctx context.Context, keyFiles, extraKeyFiles []string)
 		eg.Go(func() error {
 			log.Debugf("installing key %v", element)
 
-			var asURL *url.URL
-			var err error
-			if strings.HasPrefix(element, "https://") {
-				asURL, err = url.Parse(element)
-			} else {
-				// Attempt to parse non-https elements into URI's so they are translated into
-				// file:// URLs allowing them to parse into a url.URL{}
-				asURL, err = url.Parse(string(uri.New(element)))
-			}
+			asURL, err := url.Parse(element)
 			if err != nil {
 				return fmt.Errorf("failed to parse key as URI: %w", err)
 			}
 
 			var data []byte
 			switch asURL.Scheme {
-			case "file": //nolint:goconst
+			case "", "file": //nolint:goconst
 				data, err = os.ReadFile(element)
 				if err != nil {
 					return fmt.Errorf("failed to read apk key: %w", err)

pkg/apk/index.go

@@ -66,7 +66,13 @@ type indexCache struct {
 }
 
 func (i *indexCache) get(ctx context.Context, u string, keys map[string][]byte, arch string, opts *indexOpts) (*APKIndex, error) {
-	if strings.HasPrefix(u, "https://") {
+	asURL, err := url.Parse(u)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse key as URI: %w", err)
+	}
+
+	switch asURL.Scheme {
+	case "https":
 		// We don't want remote indexes to change while we're running.
 		once, _ := i.onces.LoadOrStore(u, &sync.Once{})
 		once.(*sync.Once).Do(func() {
@@ -76,7 +82,7 @@ func (i *indexCache) get(ctx context.Context, u string, keys map[string][]byte,
 				err: err,
 			})
 		})
-	} else {
+	case "", "file":
 		i.Lock()
 		defer i.Unlock()
 
@@ -97,6 +103,8 @@ func (i *indexCache) get(ctx context.Context, u string, keys map[string][]byte,
 			})
 			i.modtimes[u] = mod
 		}
+	default:
+		return nil, fmt.Errorf("scheme %s not supported", asURL.Scheme)
 	}
 
 	v, ok := i.indexes.Load(u)