fix: Ensure model provided in vLLM inference (#820)

**Reason for Change**:
Update to include model name in requests made to VLLM (has a /v1/models
endpoint)

presets/ragengine/config.py

@@ -38,7 +38,7 @@
 """
 
 # LLM (Large Language Model) configuration
-LLM_INFERENCE_URL = os.getenv("LLM_INFERENCE_URL", "http://localhost:5000/chat")
+LLM_INFERENCE_URL = os.getenv("LLM_INFERENCE_URL", "http://localhost:5000/v1/completions")
 LLM_ACCESS_SECRET = os.getenv("LLM_ACCESS_SECRET", "default-access-secret")
 # LLM_RESPONSE_FIELD = os.getenv("LLM_RESPONSE_FIELD", "result")  # Uncomment if needed in the future
 

presets/ragengine/inference/inference.py

@@ -1,18 +1,32 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT license.
 
+import logging
 from typing import Any
+from dataclasses import field
 from llama_index.core.llms import CustomLLM, CompletionResponse, LLMMetadata, CompletionResponseGen
 from llama_index.llms.openai import OpenAI
 from llama_index.core.llms.callbacks import llm_completion_callback
 import requests
+from requests.exceptions import HTTPError
+from urllib.parse import urlparse, urljoin
 from ragengine.config import LLM_INFERENCE_URL, LLM_ACCESS_SECRET #, LLM_RESPONSE_FIELD
 
+# Configure logging
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
+
 OPENAI_URL_PREFIX = "https://api.openai.com"
 HUGGINGFACE_URL_PREFIX = "https://api-inference.huggingface.co"
+DEFAULT_HEADERS = {
+    "Authorization": f"Bearer {LLM_ACCESS_SECRET}",
+    "Content-Type": "application/json"
+}
 
 class Inference(CustomLLM):
     params: dict = {}
+    _default_model: str = None
+    _model_retrieval_attempted: bool = False
 
     def set_params(self, params: dict) -> None:
         self.params = params
@@ -25,7 +39,7 @@ def stream_complete(self, prompt: str, **kwargs: Any) -> CompletionResponseGen:
         pass
 
     @llm_completion_callback()
-    def complete(self, prompt: str, **kwargs) -> CompletionResponse:
+    def complete(self, prompt: str, formatted: bool, **kwargs) -> CompletionResponse:
         try:
             if LLM_INFERENCE_URL.startswith(OPENAI_URL_PREFIX):
                 return self._openai_complete(prompt, **kwargs, **self.params)
@@ -38,29 +52,99 @@ def complete(self, prompt: str, **kwargs) -> CompletionResponse:
             self.params = {}
 
     def _openai_complete(self, prompt: str, **kwargs: Any) -> CompletionResponse:
-        llm = OpenAI(
-            api_key=LLM_ACCESS_SECRET,
-            **kwargs  # Pass all kwargs directly; kwargs may include model, temperature, max_tokens, etc.
-        )
-        return llm.complete(prompt)
+        return OpenAI(api_key=LLM_ACCESS_SECRET, **kwargs).complete(prompt)
 
     def _huggingface_remote_complete(self, prompt: str, **kwargs: Any) -> CompletionResponse:
-        headers = {"Authorization": f"Bearer {LLM_ACCESS_SECRET}"}
-        data = {"messages": [{"role": "user", "content": prompt}]}
-        response = requests.post(LLM_INFERENCE_URL, json=data, headers=headers)
-        response_data = response.json()
-        return CompletionResponse(text=str(response_data))
+        return self._post_request(
+            {"messages": [{"role": "user", "content": prompt}]},
+            headers={"Authorization": f"Bearer {LLM_ACCESS_SECRET}"}
+        )
 
     def _custom_api_complete(self, prompt: str, **kwargs: Any) -> CompletionResponse:
-        headers = {"Authorization": f"Bearer {LLM_ACCESS_SECRET}"}
+        model = kwargs.pop("model", self._get_default_model())
         data = {"prompt": prompt, **kwargs}
+        if model:
+            data["model"] = model # Include the model only if it is not None
+
+        # DEBUG: Call the debugging function
+        # self._debug_curl_command(data)
+        try:
+            return self._post_request(data, headers=DEFAULT_HEADERS)
+        except HTTPError as e:
+            if e.response.status_code == 400:
+                logger.warning(
+                    f"Potential issue with 'model' parameter in API response. "
+                    f"Response: {str(e)}. Attempting to update the model name as a mitigation..."
+                )
+                self._default_model = self._fetch_default_model()  # Fetch default model dynamically
+                if self._default_model:
+                    logger.info(f"Default model '{self._default_model}' fetched successfully. Retrying request...")
+                    data["model"] = self._default_model
+                    return self._post_request(data, headers=DEFAULT_HEADERS)
+                else:
+                    logger.error("Failed to fetch a default model. Aborting retry.")
+            raise  # Re-raise the exception if not recoverable
+        except Exception as e:
+            logger.error(f"An unexpected error occurred: {e}")
+            raise
+
+    def _get_models_endpoint(self) -> str:
+        """
+        Constructs the URL for the /v1/models endpoint based on LLM_INFERENCE_URL.
+        """
+        parsed = urlparse(LLM_INFERENCE_URL)
+        return urljoin(f"{parsed.scheme}://{parsed.netloc}", "/v1/models")
 
-        response = requests.post(LLM_INFERENCE_URL, json=data, headers=headers)
-        response_data = response.json()
+    def _fetch_default_model(self) -> str:
+        """
+        Fetch the default model from the /v1/models endpoint.
+        """
+        try:
+            models_url = self._get_models_endpoint()
+            response = requests.get(models_url, headers=DEFAULT_HEADERS)
+            response.raise_for_status()  # Raise an exception for HTTP errors (includes 404)
+
+            models = response.json().get("data", [])
+            return models[0].get("id") if models else None
+        except Exception as e:
+            logger.error(f"Error fetching models from {models_url}: {e}. \"model\" parameter will not be included with inference call.")
+            return None
+
+    def _get_default_model(self) -> str:
+        """
+        Returns the cached default model if available, otherwise fetches and caches it.
+        """
+        if not self._default_model and not self._model_retrieval_attempted:
+            self._model_retrieval_attempted = True
+            self._default_model = self._fetch_default_model()
+        return self._default_model
 
-        # Dynamically extract the field from the response based on the specified response_field
-        # completion_text = response_data.get(RESPONSE_FIELD, "No response field found") # not necessary for now
-        return CompletionResponse(text=str(response_data))
+    def _post_request(self, data: dict, headers: dict) -> CompletionResponse:
+        try:
+            response = requests.post(LLM_INFERENCE_URL, json=data, headers=headers)
+            response.raise_for_status()  # Raise exception for HTTP errors
+            response_data = response.json()
+            return CompletionResponse(text=str(response_data))
+        except requests.RequestException as e:
+            logger.error(f"Error during POST request to {LLM_INFERENCE_URL}: {e}")
+            raise
+
+    def _debug_curl_command(self, data: dict) -> None:
+        """
+        Constructs and prints the equivalent curl command for debugging purposes.
+        """
+        import json
+        # Construct curl command
+        curl_command = (
+                f"curl -X POST {LLM_INFERENCE_URL} "
+                + " ".join([f'-H "{key}: {value}"' for key, value in {
+            "Authorization": f"Bearer {LLM_ACCESS_SECRET}",
+            "Content-Type": "application/json"
+        }.items()])
+                + f" -d '{json.dumps(data)}'"
+        )
+        logger.info("Equivalent curl command:")
+        logger.info(curl_command)
 
     @property
     def metadata(self) -> LLMMetadata:

presets/ragengine/main.py

@@ -60,11 +60,17 @@ async def index_documents(request: IndexRequest): # TODO: Research async/sync wh
 @app.post("/query", response_model=QueryResponse)
 async def query_index(request: QueryRequest):
     try:
-        llm_params = request.llm_params or {} # Default to empty dict if no params provided
-        rerank_params = request.rerank_params or {} # Default to empty dict if no params provided
-        return rag_ops.query(request.index_name, request.query, request.top_k, llm_params, rerank_params)
+        llm_params = request.llm_params or {}  # Default to empty dict if no params provided
+        rerank_params = request.rerank_params or {}  # Default to empty dict if no params provided
+        return rag_ops.query(
+            request.index_name, request.query, request.top_k, llm_params, rerank_params
+        )
+    except ValueError as ve:
+        raise HTTPException(status_code=400, detail=str(ve))  # Validation issue
     except Exception as e:
-        raise HTTPException(status_code=500, detail=str(e))
+        raise HTTPException(
+            status_code=500, detail=f"An unexpected error occurred: {str(e)}"
+        )
 
 @app.get("/indexed-documents", response_model=ListDocumentsResponse)
 async def list_all_indexed_documents():

presets/ragengine/models.py

@@ -1,9 +1,10 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT license.
 
-from typing import Dict, List, Optional
+from typing import Any, Dict, List, Optional
+
+from pydantic import BaseModel, Field, model_validator
 
-from pydantic import BaseModel
 
 class Document(BaseModel):
     text: str
@@ -22,8 +23,32 @@ class QueryRequest(BaseModel):
     index_name: str
     query: str
     top_k: int = 10
-    llm_params: Optional[Dict] = None  # Accept a dictionary for parameters
-    rerank_params: Optional[Dict] = None # Accept a dictionary for parameters
+    # Accept a dictionary for our LLM parameters
+    llm_params: Optional[Dict[str, Any]] = Field(
+        default_factory=dict,
+        description="Optional parameters for the language model, e.g., temperature, top_p",
+    )
+    # Accept a dictionary for rerank parameters
+    rerank_params: Optional[Dict[str, Any]] = Field(
+        default_factory=dict,
+        description="Optional parameters for reranking, e.g., top_n, batch_size",
+    )
+
+    @model_validator(mode="before")
+    def validate_params(cls, values: Dict[str, Any]) -> Dict[str, Any]:
+        llm_params = values.get("llm_params", {})
+        rerank_params = values.get("rerank_params", {})
+
+        # Validate LLM parameters
+        if "temperature" in llm_params and not (0.0 <= llm_params["temperature"] <= 1.0):
+            raise ValueError("Temperature must be between 0.0 and 1.0.")
+        # TODO: More LLM Param Validations here
+        # Validate rerank parameters
+        top_k = values.get("top_k")
+        if "top_n" in rerank_params and rerank_params["top_n"] > top_k:
+            raise ValueError("Invalid configuration: 'top_n' for reranking cannot exceed 'top_k' from the RAG query.")
+
+        return values
 
 class ListDocumentsResponse(BaseModel):
     documents: Dict[str, Dict[str, Dict[str, str]]]

presets/ragengine/tests/api/test_main.py

@@ -175,7 +175,7 @@ def test_query_index_failure():
     }
 
     response = client.post("/query", json=request_data)
-    assert response.status_code == 500
+    assert response.status_code == 400
     assert response.json()["detail"] == "No such index: 'non_existent_index' exists."
 
 

presets/ragengine/tests/vector_store/test_base_store.py

@@ -89,8 +89,8 @@ def test_query_documents(self, mock_post, vector_store_manager):
 
         mock_post.assert_called_once_with(
             LLM_INFERENCE_URL,
-            json={"prompt": "Context information is below.\n---------------------\ntype: text\n\nFirst document\n---------------------\nGiven the context information and not prior knowledge, answer the query.\nQuery: First\nAnswer: ", "formatted": True, 'temperature': 0.7},
-            headers={"Authorization": f"Bearer {LLM_ACCESS_SECRET}"}
+            json={"prompt": "Context information is below.\n---------------------\ntype: text\n\nFirst document\n---------------------\nGiven the context information and not prior knowledge, answer the query.\nQuery: First\nAnswer: ", 'temperature': 0.7},
+            headers={"Authorization": f"Bearer {LLM_ACCESS_SECRET}", 'Content-Type': 'application/json'}
         )
 
     def test_add_document(self, vector_store_manager):