LCORE-217: Additional checks in /models endpoint

docs/openapi.json

@@ -96,6 +96,9 @@
                                 "model_type": "llm"
                             }
                         ]
+                    },
+                    "503": {
+                        "description": "Connection to Llama Stack is broken"
                     }
                 }
             }

src/app/endpoints/models.py

@@ -3,11 +3,13 @@
 import logging
 from typing import Any
 
-from fastapi import APIRouter, Request
+from llama_stack_client import APIConnectionError
+from fastapi import APIRouter, HTTPException, Request, status
 
 from client import get_llama_stack_client
 from configuration import configuration
 from models.responses import ModelsResponse
+from utils.endpoints import check_configuration_loaded
 
 logger = logging.getLogger(__name__)
 router = APIRouter(tags=["models"])
@@ -36,16 +38,42 @@
             },
         ]
     },
+    503: {"description": "Connection to Llama Stack is broken"},
 }
 
 
 @router.get("/models", responses=models_responses)
 def models_endpoint_handler(_request: Request) -> ModelsResponse:
     """Handle requests to the /models endpoint."""
-    llama_stack_config = configuration.llama_stack_configuration
-    logger.info("LLama stack config: %s", llama_stack_config)
+    check_configuration_loaded(configuration)
 
-    client = get_llama_stack_client(llama_stack_config)
-    models = client.models.list()
-    m = [dict(m) for m in models]
-    return ModelsResponse(models=m)
+    llama_stack_configuration = configuration.llama_stack_configuration
+    logger.info("LLama stack config: %s", llama_stack_configuration)
+
+    try:
+        # try to get Llama Stack client
+        client = get_llama_stack_client(llama_stack_configuration)
+        # retrieve models
+        models = client.models.list()
+        m = [dict(m) for m in models]
+        return ModelsResponse(models=m)
+    # connection to Llama Stack server
+    except APIConnectionError as e:
+        logger.error("Unable to connect to Llama Stack: %s", e)
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail={
+                "response": "Unable to connect to Llama Stack",
+                "cause": str(e),
+            },
+        ) from e
+    # any other exception that can occur during model listing
+    except Exception as e:
+        logger.error("Unable to retrieve list of models: %s", e)
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail={
+                "response": "Unable to retrieve list of models",
+                "cause": str(e),
+            },
+        ) from e

tests/unit/app/endpoints/test_models.py

@@ -0,0 +1,132 @@
+import pytest
+
+from unittest.mock import Mock
+from fastapi import HTTPException, status
+
+from app.endpoints.models import models_endpoint_handler
+from configuration import AppConfig
+
+
+def test_models_endpoint_handler_configuration_not_loaded(mocker):
+    """Test the models endpoint handler if configuration is not loaded."""
+    # simulate state when no configuration is loaded
+    mocker.patch(
+        "app.endpoints.models.configuration",
+        return_value=mocker.Mock(),
+    )
+    mocker.patch("app.endpoints.models.configuration", None)
+
+    request = None
+    with pytest.raises(HTTPException) as e:
+        models_endpoint_handler(request)
+        assert e.status_code == status.HTTP_500_INTERNAL_SERVER_ERROR
+        assert e.detail["response"] == "Configuration is not loaded"
+
+
+def test_models_endpoint_handler_improper_llama_stack_configuration(mocker):
+    """Test the models endpoint handler if Llama Stack configuration is not proper."""
+    # configuration for tests
+    config_dict = {
+        "name": "test",
+        "service": {
+            "host": "localhost",
+            "port": 8080,
+            "auth_enabled": False,
+            "workers": 1,
+            "color_log": True,
+            "access_log": True,
+        },
+        "llama_stack": {
+            "api_key": "test-key",
+            "url": "http://test.com:1234",
+            "use_as_library_client": False,
+        },
+        "user_data_collection": {
+            "transcripts_disabled": True,
+        },
+        "mcp_servers": [],
+    }
+    cfg = AppConfig()
+    cfg.init_from_dict(config_dict)
+
+    mocker.patch(
+        "app.endpoints.models.configuration",
+        return_value=None,
+    )
+
+    request = None
+    with pytest.raises(HTTPException) as e:
+        models_endpoint_handler(request)
+        assert e.status_code == status.HTTP_500_INTERNAL_SERVER_ERROR
+        assert e.detail["response"] == "LLama stack is not configured"
+
+
+def test_models_endpoint_handler_configuration_loaded(mocker):
+    """Test the models endpoint handler if configuration is loaded."""
+    # configuration for tests
+    config_dict = {
+        "name": "foo",
+        "service": {
+            "host": "localhost",
+            "port": 8080,
+            "auth_enabled": False,
+            "workers": 1,
+            "color_log": True,
+            "access_log": True,
+        },
+        "llama_stack": {
+            "api_key": "xyzzy",
+            "url": "http://x.y.com:1234",
+            "use_as_library_client": False,
+        },
+        "user_data_collection": {
+            "feedback_disabled": True,
+        },
+    }
+    cfg = AppConfig()
+    cfg.init_from_dict(config_dict)
+
+    with pytest.raises(HTTPException) as e:
+        request = None
+        models_endpoint_handler(request)
+        assert e.status_code == status.HTTP_500_INTERNAL_SERVER_ERROR
+        assert e.detail["response"] == "Unable to connect to Llama Stack"
+
+
+def test_models_endpoint_handler_unable_to_retrieve_models_list(mocker):
+    """Test the models endpoint handler if configuration is loaded."""
+    # configuration for tests
+    config_dict = {
+        "name": "foo",
+        "service": {
+            "host": "localhost",
+            "port": 8080,
+            "auth_enabled": False,
+            "workers": 1,
+            "color_log": True,
+            "access_log": True,
+        },
+        "llama_stack": {
+            "api_key": "xyzzy",
+            "url": "http://x.y.com:1234",
+            "use_as_library_client": False,
+        },
+        "user_data_collection": {
+            "feedback_disabled": True,
+        },
+    }
+    cfg = AppConfig()
+    cfg.init_from_dict(config_dict)
+
+    # Mock the LlamaStack client
+    mock_client = Mock()
+    mock_client.models.list.return_value = []
+
+    # Mock the LlamaStack client (shouldn't be called directly)
+    mocker.patch(
+        "app.endpoints.models.get_llama_stack_client", return_value=mock_client
+    )
+
+    request = None
+    response = models_endpoint_handler(request)
+    assert response is not None