fix(proxy_server.py): fix _delete_deployment to handle base case where db_model list is empty

don't delete all router models  b/c of empty list

Fixes https://github.com/BerriAI/litellm/issues/7196

litellm/proxy/proxy_server.py

@@ -2088,7 +2088,10 @@ class ProxyConfig:
         """
         global user_config_file_path, llm_router
         combined_id_list = []
-        if llm_router is None:
+
+        ## BASE CASES ##
+        # if llm_router is None or db_models is empty, return 0
+        if llm_router is None or len(db_models) == 0:
             return 0
 
         ## DB MODELS ##
@@ -2418,6 +2421,19 @@ class ProxyConfig:
 
         return config
 
+    async def _get_models_from_db(self, prisma_client: PrismaClient) -> list:
+        try:
+            new_models = await prisma_client.db.litellm_proxymodeltable.find_many()
+        except Exception as e:
+            verbose_proxy_logger.exception(
+                "litellm.proxy_server.py::add_deployment() - Error getting new models from DB - {}".format(
+                    str(e)
+                )
+            )
+            new_models = []
+
+        return new_models
+
     async def add_deployment(
         self,
         prisma_client: PrismaClient,
@@ -2435,15 +2451,9 @@ class ProxyConfig:
                 raise ValueError(
                     f"Master key is not initialized or formatted. master_key={master_key}"
                 )
-            try:
-                new_models = await prisma_client.db.litellm_proxymodeltable.find_many()
-            except Exception as e:
-                verbose_proxy_logger.exception(
-                    "litellm.proxy_server.py::add_deployment() - Error getting new models from DB - {}".format(
-                        str(e)
-                    )
-                )
-                new_models = []
+
+            new_models = await self._get_models_from_db(prisma_client=prisma_client)
+
             # update llm router
             await self._update_llm_router(
                 new_models=new_models, proxy_logging_obj=proxy_logging_obj

tests/local_testing/test_config.py

@@ -175,6 +175,62 @@ async def test_add_existing_deployment():
     assert init_len_list == len(llm_router.model_list)
 
 
+@pytest.mark.asyncio
+async def test_db_error_new_model_check():
+    """
+    - if error in db, don't delete existing models
+
+    Relevant issue: https://github.com/BerriAI/litellm/blob/ddfe687b13e9f31db2fb2322887804e3d01dd467/litellm/proxy/proxy_server.py#L2461
+    """
+    import base64
+
+    litellm_params = LiteLLM_Params(
+        model="gpt-3.5-turbo",
+        api_key=os.getenv("AZURE_API_KEY"),
+        api_base=os.getenv("AZURE_API_BASE"),
+        api_version=os.getenv("AZURE_API_VERSION"),
+    )
+    deployment = Deployment(model_name="gpt-3.5-turbo", litellm_params=litellm_params)
+    deployment_2 = Deployment(
+        model_name="gpt-3.5-turbo-2", litellm_params=litellm_params
+    )
+
+    llm_router = litellm.Router(
+        model_list=[
+            deployment.to_json(exclude_none=True),
+            deployment_2.to_json(exclude_none=True),
+        ]
+    )
+
+    init_len_list = len(llm_router.model_list)
+    print(f"llm_router: {llm_router}")
+    master_key = "sk-1234"
+    setattr(litellm.proxy.proxy_server, "llm_router", llm_router)
+    setattr(litellm.proxy.proxy_server, "master_key", master_key)
+    pc = ProxyConfig()
+
+    encrypted_litellm_params = litellm_params.dict(exclude_none=True)
+
+    for k, v in encrypted_litellm_params.items():
+        if isinstance(v, str):
+            encrypted_value = encrypt_value(v, master_key)
+            encrypted_litellm_params[k] = base64.b64encode(encrypted_value).decode(
+                "utf-8"
+            )
+    db_model = DBModel(
+        model_id=deployment.model_info.id,
+        model_name="gpt-3.5-turbo",
+        litellm_params=encrypted_litellm_params,
+        model_info={"id": deployment.model_info.id},
+    )
+
+    db_models = []
+    deleted_deployments = await pc._delete_deployment(db_models=db_models)
+    assert deleted_deployments == 0
+
+    assert init_len_list == len(llm_router.model_list)
+
+
 litellm_params = LiteLLM_Params(
     model="azure/chatgpt-v-2",
     api_key=os.getenv("AZURE_API_KEY"),