server: replace blob prefix separator from ':' to '-' (#3146)

This fixes issues with blob file names that contain ':' characters to be rejected by file systems that do not support them.

server/fixblobs.go

+package server
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// fixBlobs walks the provided dir and replaces (":") to ("-") in the file
+// prefix. (e.g. sha256:1234 -> sha256-1234)
+func fixBlobs(dir string) error {
+	return filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		baseName := filepath.Base(path)
+		typ, sha, ok := strings.Cut(baseName, ":")
+		if ok && typ == "sha256" {
+			newPath := filepath.Join(filepath.Dir(path), typ+"-"+sha)
+			if err := os.Rename(path, newPath); err != nil {
+				return err
+			}
+		}
+		return nil
+	})
+}

server/fixblobs_test.go

+package server
+
+import (
+	"io/fs"
+	"os"
+	"path/filepath"
+	"runtime"
+	"slices"
+	"strings"
+	"testing"
+)
+
+func TestFixBlobs(t *testing.T) {
+	cases := []struct {
+		path []string
+		want []string
+	}{
+		{path: []string{"sha256-1234"}, want: []string{"sha256-1234"}},
+		{path: []string{"sha256:1234"}, want: []string{"sha256-1234"}},
+		{path: []string{"sha259:5678"}, want: []string{"sha259:5678"}},
+		{path: []string{"sha256:abcd"}, want: []string{"sha256-abcd"}},
+		{path: []string{"x/y/sha256:abcd"}, want: []string{"x/y/sha256-abcd"}},
+		{path: []string{"x:y/sha256:abcd"}, want: []string{"x:y/sha256-abcd"}},
+		{path: []string{"x:y/sha256:abcd"}, want: []string{"x:y/sha256-abcd"}},
+		{path: []string{"x:y/sha256:abcd", "sha256:1234"}, want: []string{"x:y/sha256-abcd", "sha256-1234"}},
+		{path: []string{"x:y/sha256:abcd", "sha256-1234"}, want: []string{"x:y/sha256-abcd", "sha256-1234"}},
+	}
+
+	for _, tt := range cases {
+		t.Run(strings.Join(tt.path, "|"), func(t *testing.T) {
+			hasColon := slices.ContainsFunc(tt.path, func(s string) bool { return strings.Contains(s, ":") })
+			if hasColon && runtime.GOOS == "windows" {
+				t.Skip("skipping test on windows")
+			}
+
+			rootDir := t.TempDir()
+			for _, path := range tt.path {
+				fullPath := filepath.Join(rootDir, path)
+				fullDir, _ := filepath.Split(fullPath)
+
+				t.Logf("creating dir %s", fullDir)
+				if err := os.MkdirAll(fullDir, 0o755); err != nil {
+					t.Fatal(err)
+				}
+
+				t.Logf("writing file %s", fullPath)
+				if err := os.WriteFile(fullPath, nil, 0o644); err != nil {
+					t.Fatal(err)
+				}
+			}
+
+			if err := fixBlobs(rootDir); err != nil {
+				t.Fatal(err)
+			}
+
+			got := slurpFiles(os.DirFS(rootDir))
+
+			slices.Sort(tt.want)
+			slices.Sort(got)
+			if !slices.Equal(got, tt.want) {
+				t.Fatalf("got = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func slurpFiles(fsys fs.FS) []string {
+	var sfs []string
+	fn := func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		if d.IsDir() {
+			return nil
+		}
+		sfs = append(sfs, path)
+		return nil
+	}
+	if err := fs.WalkDir(fsys, ".", fn); err != nil {
+		panic(err)
+	}
+	return sfs
+}

server/images.go

@@ -795,9 +795,7 @@ func PruneLayers() error {
 
 	for _, blob := range blobs {
 		name := blob.Name()
-		if runtime.GOOS == "windows" {
 		name = strings.ReplaceAll(name, "-", ":")
-		}
 		if strings.HasPrefix(name, "sha256:") {
 			deleteMap[name] = struct{}{}
 		}

server/layers.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"io"
 	"os"
-	"runtime"
 	"strings"
 
 	"golang.org/x/exp/slices"
@@ -47,10 +46,7 @@ func NewLayer(r io.Reader, mediatype string) (*Layer, error) {
 		return nil, err
 	}
 
-	delimiter := ":"
-	if runtime.GOOS == "windows" {
-		delimiter = "-"
-	}
+	const delimiter = "-"
 
 	pattern := strings.Join([]string{"sha256", "*-partial"}, delimiter)
 	temp, err := os.CreateTemp(blobs, pattern)

server/modelpath.go

@@ -6,7 +6,6 @@ import (
 	"net/url"
 	"os"
 	"path/filepath"
-	"runtime"
 	"strings"
 )
 
@@ -150,10 +149,7 @@ func GetBlobsPath(digest string) (string, error) {
 		return "", err
 	}
 
-	if runtime.GOOS == "windows" {
 	digest = strings.ReplaceAll(digest, ":", "-")
-	}
-
 	path := filepath.Join(dir, "blobs", digest)
 	dirPath := filepath.Dir(path)
 	if digest == "" {

server/routes.go

@@ -1088,6 +1088,14 @@ func Serve(ln net.Listener) error {
 
 	slog.SetDefault(slog.New(handler))
 
+	blobsDir, err := GetBlobsPath("")
+	if err != nil {
+		return err
+	}
+	if err := fixBlobs(blobsDir); err != nil {
+		return err
+	}
+
 	if noprune := os.Getenv("OLLAMA_NOPRUNE"); noprune == "" {
 		// clean up unused layers and manifests
 		if err := PruneLayers(); err != nil {