Don't download files that are already cached

The nerdctl archive has already been downloaded
to the cache, so don't log downloading it again.

Signed-off-by: Anders F Björklund <[email protected]>

Author: afbjorklund

cmd/limactl/start.go

@@ -468,7 +468,7 @@ func createAction(cmd *cobra.Command, args []string) error {
 	if len(inst.Errors) > 0 {
 		return fmt.Errorf("errors inspecting instance: %+v", inst.Errors)
 	}
-	if _, err = start.Prepare(cmd.Context(), inst); err != nil {
+	if _, err = start.Prepare(cmd.Context(), inst, false); err != nil {
 		return err
 	}
 	logrus.Infof("Run `limactl start %s` to start the instance.", inst.Name)

pkg/fileutils/download.go

@@ -41,6 +41,17 @@ func DownloadFile(dest string, f limayaml.File, decompress bool, description str
 	return res.CachePath, nil
 }
 
+// CachedFile returns path in cache.
+func CachedFile(f limayaml.File) (string, error) {
+	path, err := downloader.Cached(f.Location,
+		downloader.WithCache(),
+		downloader.WithExpectedDigest(f.Digest))
+	if err != nil {
+		return "", fmt.Errorf("cache did not contain %q: %w", f.Location, err)
+	}
+	return path, nil
+}
+
 // Errors compose multiple into a single error.
 // Errors filters out ErrSkipped.
 func Errors(errs []error) error {

pkg/start/start.go

@@ -34,14 +34,21 @@ const DefaultWatchHostAgentEventsTimeout = 10 * time.Minute
 // ensureNerdctlArchiveCache prefetches the nerdctl-full-VERSION-GOOS-GOARCH.tar.gz archive
 // into the cache before launching the hostagent process, so that we can show the progress in tty.
 // https://github.com/lima-vm/lima/issues/326
-func ensureNerdctlArchiveCache(y *limayaml.LimaYAML) (string, error) {
+func ensureNerdctlArchiveCache(y *limayaml.LimaYAML, start bool) (string, error) {
 	if !*y.Containerd.System && !*y.Containerd.User {
 		// nerdctl archive is not needed
 		return "", nil
 	}
 
 	errs := make([]error, len(y.Containerd.Archives))
 	for i, f := range y.Containerd.Archives {
+		// Skip downloading again if the file is already in the cache
+		if start && f.Arch == *y.Arch && !downloader.IsLocal(f.Location) {
+			path, err := fileutils.CachedFile(f)
+			if err == nil {
+				return path, nil
+			}
+		}
 		path, err := fileutils.DownloadFile("", f, false, "the nerdctl archive", *y.Arch)
 		if err != nil {
 			errs[i] = err
@@ -65,7 +72,7 @@ type Prepared struct {
 }
 
 // Prepare ensures the disk, the nerdctl archive, etc.
-func Prepare(_ context.Context, inst *store.Instance) (*Prepared, error) {
+func Prepare(_ context.Context, inst *store.Instance, start bool) (*Prepared, error) {
 	y, err := inst.LoadYAML()
 	if err != nil {
 		return nil, err
@@ -83,7 +90,7 @@ func Prepare(_ context.Context, inst *store.Instance) (*Prepared, error) {
 	if err := limaDriver.CreateDisk(); err != nil {
 		return nil, err
 	}
-	nerdctlArchiveCache, err := ensureNerdctlArchiveCache(y)
+	nerdctlArchiveCache, err := ensureNerdctlArchiveCache(y, start)
 	if err != nil {
 		return nil, err
 	}
@@ -116,7 +123,7 @@ func Start(ctx context.Context, inst *store.Instance) error {
 		}
 	}
 
-	prepared, err := Prepare(ctx, inst)
+	prepared, err := Prepare(ctx, inst, true)
 	if err != nil {
 		return err
 	}