chore: Updating how default embedding model is set in stack (#3818)

# What does this PR do?

Refactor setting default vector store provider and embedding model to
use an optional `vector_stores` config in the `StackRunConfig` and clean
up code to do so (had to add back in some pieces of VectorDB). Also
added remote Qdrant and Weaviate to starter distro (based on other PR
where inference providers were added for UX).

New config is simply (default for Starter distro):

```yaml
vector_stores:
  default_provider_id: faiss
  default_embedding_model:
    provider_id: sentence-transformers
    model_id: nomic-ai/nomic-embed-text-v1.5
```

## Test Plan
CI and Unit tests.

---------

Signed-off-by: Francisco Javier Arceo <farceo@redhat.com>
Co-authored-by: Ashwin Bharambe <ashwin.bharambe@gmail.com>

llama_stack/providers/inline/vector_io/faiss/__init__.py

@@ -16,11 +16,6 @@ async def get_provider_impl(config: FaissVectorIOConfig, deps: dict[Api, Any]):
 
     assert isinstance(config, FaissVectorIOConfig), f"Unexpected config type: {type(config)}"
 
-    impl = FaissVectorIOAdapter(
-        config,
-        deps[Api.inference],
-        deps[Api.models],
-        deps.get(Api.files),
-    )
+    impl = FaissVectorIOAdapter(config, deps[Api.inference], deps.get(Api.files))
     await impl.initialize()
     return impl

llama_stack/providers/inline/vector_io/faiss/faiss.py

@@ -17,27 +17,14 @@ from numpy.typing import NDArray
 from llama_stack.apis.common.errors import VectorStoreNotFoundError
 from llama_stack.apis.files import Files
 from llama_stack.apis.inference import Inference, InterleavedContent
-from llama_stack.apis.models import Models
 from llama_stack.apis.vector_dbs import VectorDB
-from llama_stack.apis.vector_io import (
-    Chunk,
-    QueryChunksResponse,
-    VectorIO,
-)
+from llama_stack.apis.vector_io import Chunk, QueryChunksResponse, VectorIO
 from llama_stack.log import get_logger
-from llama_stack.providers.datatypes import (
-    HealthResponse,
-    HealthStatus,
-    VectorDBsProtocolPrivate,
-)
+from llama_stack.providers.datatypes import HealthResponse, HealthStatus, VectorDBsProtocolPrivate
 from llama_stack.providers.utils.kvstore import kvstore_impl
 from llama_stack.providers.utils.kvstore.api import KVStore
 from llama_stack.providers.utils.memory.openai_vector_store_mixin import OpenAIVectorStoreMixin
-from llama_stack.providers.utils.memory.vector_store import (
-    ChunkForDeletion,
-    EmbeddingIndex,
-    VectorDBWithIndex,
-)
+from llama_stack.providers.utils.memory.vector_store import ChunkForDeletion, EmbeddingIndex, VectorDBWithIndex
 
 from .config import FaissVectorIOConfig
 
@@ -155,12 +142,7 @@ class FaissIndex(EmbeddingIndex):
 
         await self._save_index()
 
-    async def query_vector(
-        self,
-        embedding: NDArray,
-        k: int,
-        score_threshold: float,
-    ) -> QueryChunksResponse:
+    async def query_vector(self, embedding: NDArray, k: int, score_threshold: float) -> QueryChunksResponse:
         distances, indices = await asyncio.to_thread(self.index.search, embedding.reshape(1, -1).astype(np.float32), k)
         chunks = []
         scores = []
@@ -175,12 +157,7 @@ class FaissIndex(EmbeddingIndex):
 
         return QueryChunksResponse(chunks=chunks, scores=scores)
 
-    async def query_keyword(
-        self,
-        query_string: str,
-        k: int,
-        score_threshold: float,
-    ) -> QueryChunksResponse:
+    async def query_keyword(self, query_string: str, k: int, score_threshold: float) -> QueryChunksResponse:
         raise NotImplementedError(
             "Keyword search is not supported - underlying DB FAISS does not support this search mode"
         )
@@ -200,17 +177,10 @@ class FaissIndex(EmbeddingIndex):
 
 
 class FaissVectorIOAdapter(OpenAIVectorStoreMixin, VectorIO, VectorDBsProtocolPrivate):
-    def __init__(
-        self,
-        config: FaissVectorIOConfig,
-        inference_api: Inference,
-        models_api: Models,
-        files_api: Files | None,
-    ) -> None:
+    def __init__(self, config: FaissVectorIOConfig, inference_api: Inference, files_api: Files | None) -> None:
         super().__init__(files_api=files_api, kvstore=None)
         self.config = config
         self.inference_api = inference_api
-        self.models_api = models_api
         self.cache: dict[str, VectorDBWithIndex] = {}
 
     async def initialize(self) -> None:
@@ -252,17 +222,11 @@ class FaissVectorIOAdapter(OpenAIVectorStoreMixin, VectorIO, VectorDBsProtocolPr
         except Exception as e:
             return HealthResponse(status=HealthStatus.ERROR, message=f"Health check failed: {str(e)}")
 
-    async def register_vector_db(
-        self,
-        vector_db: VectorDB,
-    ) -> None:
+    async def register_vector_db(self, vector_db: VectorDB) -> None:
         assert self.kvstore is not None
 
         key = f"{VECTOR_DBS_PREFIX}{vector_db.identifier}"
-        await self.kvstore.set(
-            key=key,
-            value=vector_db.model_dump_json(),
-        )
+        await self.kvstore.set(key=key, value=vector_db.model_dump_json())
 
         # Store in cache
         self.cache[vector_db.identifier] = VectorDBWithIndex(
@@ -285,12 +249,7 @@ class FaissVectorIOAdapter(OpenAIVectorStoreMixin, VectorIO, VectorDBsProtocolPr
         del self.cache[vector_db_id]
         await self.kvstore.delete(f"{VECTOR_DBS_PREFIX}{vector_db_id}")
 
-    async def insert_chunks(
-        self,
-        vector_db_id: str,
-        chunks: list[Chunk],
-        ttl_seconds: int | None = None,
-    ) -> None:
+    async def insert_chunks(self, vector_db_id: str, chunks: list[Chunk], ttl_seconds: int | None = None) -> None:
         index = self.cache.get(vector_db_id)
         if index is None:
             raise ValueError(f"Vector DB {vector_db_id} not found. found: {self.cache.keys()}")
@@ -298,10 +257,7 @@ class FaissVectorIOAdapter(OpenAIVectorStoreMixin, VectorIO, VectorDBsProtocolPr
         await index.insert_chunks(chunks)
 
     async def query_chunks(
-        self,
-        vector_db_id: str,
-        query: InterleavedContent,
-        params: dict[str, Any] | None = None,
+        self, vector_db_id: str, query: InterleavedContent, params: dict[str, Any] | None = None
     ) -> QueryChunksResponse:
         index = self.cache.get(vector_db_id)
         if index is None: