Enable loading of lora-adapter parts in dev mode

Signed-off-by: Rishi Jat <rishijat098@gmail.com>

Author: rishi-jat

pkg/cmd/dev/dev.go

@@ -85,6 +85,25 @@ func runDev(ctx context.Context, options *DevStartOptions) error {
 		return err
 	}
 
+	// Detect and collect lora-adapter parts
+	var loraPaths []string
+	for _, part := range kitfile.Model.Parts {
+		if strings.EqualFold(part.Type, "lora-adapter") {
+			partAbsPath, _, err := filesystem.VerifySubpath(options.contextDir, part.Path)
+			if err != nil {
+				output.Debugf("Failed to verify lora-adapter path %s: %v", part.Path, err)
+				continue
+			}
+			loraPath, err := findLoraAdapterFile(partAbsPath)
+			if err != nil {
+				output.Debugf("Failed to find lora-adapter file in %s: %v", partAbsPath, err)
+				continue
+			}
+			output.Infof("Found lora-adapter: %s", loraPath)
+			loraPaths = append(loraPaths, loraPath)
+		}
+	}
+
 	llmHarness := &harness.LLMHarness{}
 	llmHarness.Host = options.host
 	llmHarness.Port = options.port
@@ -93,7 +112,7 @@ func runDev(ctx context.Context, options *DevStartOptions) error {
 		return err
 	}
 
-	if err := llmHarness.Start(modelPath); err != nil {
+	if err := llmHarness.Start(modelPath, loraPaths); err != nil {
 		return err
 	}
 
@@ -170,6 +189,43 @@ func findModelFile(absPath string) (string, error) {
 	return modelPath, nil
 }
 
+// findLoraAdapterFile finds a lora adapter file (.gguf) within a path.
+// If the path is a regular file, it returns that file.
+// If the path is a directory, it searches for .gguf files within it.
+func findLoraAdapterFile(absPath string) (string, error) {
+	stat, err := os.Lstat(absPath)
+	if err != nil {
+		return "", err
+	}
+	if stat.Mode().IsRegular() {
+		// lora adapter path refers to a regular file; assume it's fine to use
+		return absPath, nil
+	} else if !stat.IsDir() {
+		return "", fmt.Errorf("could not find lora adapter file in %s: path is not regular file or directory", absPath)
+	}
+
+	loraPath := ""
+	if err := filepath.WalkDir(absPath, func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		if strings.HasSuffix(path, ".gguf") && d.Type().IsRegular() {
+			if loraPath == "" {
+				loraPath = path
+			} else {
+				return fmt.Errorf("multiple lora adapter files found: %s and %s", loraPath, path)
+			}
+		}
+		return nil
+	}); err != nil {
+		return "", fmt.Errorf("error searching for lora adapter file in %s: %w", absPath, err)
+	} else if loraPath == "" {
+		return "", fmt.Errorf("could not find lora adapter file in %s", absPath)
+	}
+	output.Debugf("Found lora adapter path in directory %s at %s", absPath, loraPath)
+	return loraPath, nil
+}
+
 // extractModelKitToCache extracts a ModelKit reference to a cache directory
 // using the unpack library with model filter
 func extractModelKitToCache(ctx context.Context, options *DevStartOptions) error {

pkg/lib/harness/llm-harness.go

@@ -63,7 +63,7 @@ func (harness *LLMHarness) Init() error {
 	return nil
 }
 
-func (harness *LLMHarness) Start(modelPath string) (err error) {
+func (harness *LLMHarness) Start(modelPath string, loraPaths []string) (err error) {
 
 	harnessPath := constants.HarnessPath(harness.ConfigHome)
 	pidFile := filepath.Join(harnessPath, constants.HarnessProcessFile)
@@ -85,10 +85,12 @@ func (harness *LLMHarness) Start(modelPath string) (err error) {
 
 	uiHome := filepath.Join(harnessPath, "ui")
 	output.Debugf("model path is %s", modelPath)
+	for _, loraPath := range loraPaths {
+		output.Debugf("lora adapter path is %s", loraPath)
+	}
 	var cmd *exec.Cmd
 	if runtime.GOOS == "windows" {
-		cmd = exec.Command(
-			"./llamafile.exe",
+		args := []string{
 			"--server",
 			"--model", modelPath,
 			"--host", harness.Host,
@@ -97,11 +99,19 @@ func (harness *LLMHarness) Start(modelPath string) (err error) {
 			"--gpu", "AUTO",
 			"--nobrowser",
 			"--unsecure",
-		)
+		}
+		for _, loraPath := range loraPaths {
+			args = append(args, "--lora", loraPath)
+		}
+		cmd = exec.Command("./llamafile.exe", args...)
 	} else {
+		loraArgs := ""
+		for _, loraPath := range loraPaths {
+			loraArgs += fmt.Sprintf(" --lora %s", loraPath)
+		}
 		cmd = exec.Command("sh", "-c",
-			fmt.Sprintf("./llamafile --server --model %s --host %s --port %d --path %s --gpu AUTO --nobrowser --unsecure",
-				modelPath, harness.Host, harness.Port, uiHome),
+			fmt.Sprintf("./llamafile --server --model %s --host %s --port %d --path %s --gpu AUTO --nobrowser --unsecure%s",
+				modelPath, harness.Host, harness.Port, uiHome, loraArgs),
 		)
 	}