Split model http handler vs model manager (#459)

* refactor: introduce service layer for model management and separate business logic from HTTP handling

* refactor: replace model manager with service layer for improved model handling

* Continue migrating services

* Renaming

* swap names to reduce the changeset

* sanitize log output for model packaging error

* refactor: update comments to improve clarity in handler and manager

Author: ilopezluna

main.go

@@ -84,17 +84,18 @@ func main() {
 	}
 	baseTransport.Proxy = http.ProxyFromEnvironment
 
-	modelManager := models.NewManager(
+	clientConfig := models.ClientConfig{
+		StoreRootPath: modelPath,
+		Logger:        log.WithFields(logrus.Fields{"component": "model-manager"}),
+		Transport:     baseTransport,
+	}
+	modelHandler := models.NewHandler(
 		log,
-		models.ClientConfig{
-			StoreRootPath: modelPath,
-			Logger:        log.WithFields(logrus.Fields{"component": "model-manager"}),
-			Transport:     baseTransport,
-		},
+		clientConfig,
 		nil,
 		memEstimator,
 	)
-
+	modelManager := models.NewManager(log.WithFields(logrus.Fields{"component": "model-manager"}), clientConfig)
 	log.Infof("LLAMA_SERVER_PATH: %s", llamaServerPath)
 
 	// Create llama.cpp configuration from environment variables
@@ -151,6 +152,7 @@ func main() {
 			mlx.Name:      mlxBackend,
 		},
 		llamaCppBackend,
+		modelHandler,
 		modelManager,
 		http.DefaultClient,
 		nil,
@@ -168,8 +170,8 @@ func main() {
 	// Register path prefixes to forward all HTTP methods (including OPTIONS) to components
 	// Components handle method routing internally
 	// Register both with and without trailing slash to avoid redirects
-	router.Handle(inference.ModelsPrefix, modelManager)
-	router.Handle(inference.ModelsPrefix+"/", modelManager)
+	router.Handle(inference.ModelsPrefix, modelHandler)
+	router.Handle(inference.ModelsPrefix+"/", modelHandler)
 	router.Handle(inference.InferencePrefix+"/", scheduler)
 	// Add path aliases: /v1 -> /engines/v1, /rerank -> /engines/rerank, /score -> /engines/score.
 	aliasHandler := &middleware.AliasHandler{Handler: scheduler}
@@ -178,7 +180,7 @@ func main() {
 	router.Handle("/score", aliasHandler)
 
 	// Add Ollama API compatibility layer (only register with trailing slash to catch sub-paths)
-	ollamaHandler := ollama.NewHandler(log, modelManager, scheduler, nil)
+	ollamaHandler := ollama.NewHandler(log, scheduler, nil, modelManager)
 	router.Handle(ollama.APIPrefix+"/", ollamaHandler)
 
 	// Register root handler LAST - it will only catch exact "/" requests that don't match other patterns

pkg/inference/backends/llamacpp/llamacpp.go

@@ -229,7 +229,7 @@ func (l *llamaCpp) GetRequiredMemoryForModel(ctx context.Context, model string,
 
 // parseModel parses a model (local or remote) and returns the GGUF file and config.
 func (l *llamaCpp) parseModel(ctx context.Context, model string) (*parser.GGUFFile, types.Config, error) {
-	inStore, err := l.modelManager.IsModelInStore(model)
+	inStore, err := l.modelManager.InStore(model)
 	if err != nil {
 		return nil, types.Config{}, fmt.Errorf("checking if model is in local store: %w", err)
 	}
@@ -271,7 +271,7 @@ func (l *llamaCpp) parseLocalModel(model string) (*parser.GGUFFile, types.Config
 }
 
 func (l *llamaCpp) parseRemoteModel(ctx context.Context, model string) (*parser.GGUFFile, types.Config, error) {
-	mdl, err := l.modelManager.GetRemoteModel(ctx, model)
+	mdl, err := l.modelManager.GetRemote(ctx, model)
 	if err != nil {
 		return nil, types.Config{}, fmt.Errorf("getting remote model(%s): %w", model, err)
 	}
@@ -292,7 +292,7 @@ func (l *llamaCpp) parseRemoteModel(ctx context.Context, model string) (*parser.
 	if ggufDigest.String() == "" {
 		return nil, types.Config{}, fmt.Errorf("model(%s) has no GGUF layer", model)
 	}
-	blobURL, err := l.modelManager.GetRemoteModelBlobURL(model, ggufDigest)
+	blobURL, err := l.modelManager.GetRemoteBlobURL(model, ggufDigest)
 	if err != nil {
 		return nil, types.Config{}, fmt.Errorf("getting GGUF blob URL for model(%s): %w", model, err)
 	}

pkg/inference/models/adapter.go

@@ -0,0 +1,67 @@
+package models
+
+import (
+	"fmt"
+
+	"github.com/docker/model-runner/pkg/distribution/types"
+)
+
+func ToModel(m types.Model) (*Model, error) {
+	desc, err := m.Descriptor()
+	if err != nil {
+		return nil, fmt.Errorf("get descriptor: %w", err)
+	}
+
+	id, err := m.ID()
+	if err != nil {
+		return nil, fmt.Errorf("get id: %w", err)
+	}
+
+	cfg, err := m.Config()
+	if err != nil {
+		return nil, fmt.Errorf("get config: %w", err)
+	}
+
+	created := int64(0)
+	if desc.Created != nil {
+		created = desc.Created.Unix()
+	}
+
+	return &Model{
+		ID:      id,
+		Tags:    m.Tags(),
+		Created: created,
+		Config:  cfg,
+	}, nil
+}
+
+// ToModelFromArtifact converts a types.ModelArtifact (typically from remote registry)
+// to the API Model representation. Remote models don't have tags.
+func ToModelFromArtifact(artifact types.ModelArtifact) (*Model, error) {
+	desc, err := artifact.Descriptor()
+	if err != nil {
+		return nil, fmt.Errorf("get descriptor: %w", err)
+	}
+
+	id, err := artifact.ID()
+	if err != nil {
+		return nil, fmt.Errorf("get id: %w", err)
+	}
+
+	cfg, err := artifact.Config()
+	if err != nil {
+		return nil, fmt.Errorf("get config: %w", err)
+	}
+
+	created := int64(0)
+	if desc.Created != nil {
+		created = desc.Created.Unix()
+	}
+
+	return &Model{
+		ID:      id,
+		Tags:    nil, // Remote models don't have local tags
+		Created: created,
+		Config:  cfg,
+	}, nil
+}

pkg/inference/models/api.go

@@ -125,32 +125,3 @@ type Model struct {
 	// Config describes the model.
 	Config types.Config `json:"config"`
 }
-
-func ToModel(m types.Model) (*Model, error) {
-	desc, err := m.Descriptor()
-	if err != nil {
-		return nil, fmt.Errorf("get descriptor: %w", err)
-	}
-
-	id, err := m.ID()
-	if err != nil {
-		return nil, fmt.Errorf("get id: %w", err)
-	}
-
-	cfg, err := m.Config()
-	if err != nil {
-		return nil, fmt.Errorf("get config: %w", err)
-	}
-
-	created := int64(0)
-	if desc.Created != nil {
-		created = desc.Created.Unix()
-	}
-
-	return &Model{
-		ID:      id,
-		Tags:    m.Tags(),
-		Created: created,
-		Config:  cfg,
-	}, nil
-}