(feat) Allow using include to include external YAML files in a config.yaml (#6922)

* add helper to process inlcudes directive on yaml

* add doc on config management

* unit tests for `include` on config.yaml

tests/proxy_unit_tests/example_config_yaml/config_with_include.yaml

@@ -0,0 +1,5 @@
+include:
+  - included_models.yaml
+
+litellm_settings:
+  callbacks: ["prometheus"]

tests/proxy_unit_tests/example_config_yaml/config_with_missing_include.yaml

@@ -0,0 +1,5 @@
+include:
+  - non-existent-file.yaml
+
+litellm_settings:
+  callbacks: ["prometheus"]

tests/proxy_unit_tests/example_config_yaml/config_with_multiple_includes.yaml

@@ -0,0 +1,6 @@
+include:
+  - models_file_1.yaml
+  - models_file_2.yaml
+
+litellm_settings:
+  callbacks: ["prometheus"]

tests/proxy_unit_tests/example_config_yaml/included_models.yaml

@@ -0,0 +1,4 @@
+model_list:
+  - model_name: included-model
+    litellm_params:
+      model: gpt-4

tests/proxy_unit_tests/example_config_yaml/models_file_1.yaml

@@ -0,0 +1,4 @@
+model_list:
+  - model_name: included-model-1
+    litellm_params:
+      model: gpt-4

tests/proxy_unit_tests/example_config_yaml/models_file_2.yaml

@@ -0,0 +1,4 @@
+model_list:
+  - model_name: included-model-2
+    litellm_params:
+      model: gpt-3.5-turbo

tests/proxy_unit_tests/test_proxy_config_unit_test.py

@@ -23,6 +23,8 @@ import logging
 
 from litellm.proxy.proxy_server import ProxyConfig
 
+INVALID_FILES = ["config_with_missing_include.yaml"]
+
 
 @pytest.mark.asyncio
 async def test_basic_reading_configs_from_files():
@@ -38,6 +40,9 @@ async def test_basic_reading_configs_from_files():
     print(files)
 
     for file in files:
+        if file in INVALID_FILES:  # these are intentionally invalid files
+            continue
+        print("reading file=", file)
         config_path = os.path.join(example_config_yaml_path, file)
         config = await proxy_config_instance.get_config(config_file_path=config_path)
         print(config)
@@ -115,3 +120,67 @@ async def test_read_config_file_with_os_environ_vars():
             os.environ[key] = _old_env_vars[key]
         else:
             del os.environ[key]
+
+
+@pytest.mark.asyncio
+async def test_basic_include_directive():
+    """
+    Test that the include directive correctly loads and merges configs
+    """
+    proxy_config_instance = ProxyConfig()
+    current_path = os.path.dirname(os.path.abspath(__file__))
+    config_path = os.path.join(
+        current_path, "example_config_yaml", "config_with_include.yaml"
+    )
+
+    config = await proxy_config_instance.get_config(config_file_path=config_path)
+
+    # Verify the included model list was merged
+    assert len(config["model_list"]) > 0
+    assert any(
+        model["model_name"] == "included-model" for model in config["model_list"]
+    )
+
+    # Verify original config settings remain
+    assert config["litellm_settings"]["callbacks"] == ["prometheus"]
+
+
+@pytest.mark.asyncio
+async def test_missing_include_file():
+    """
+    Test that a missing included file raises FileNotFoundError
+    """
+    proxy_config_instance = ProxyConfig()
+    current_path = os.path.dirname(os.path.abspath(__file__))
+    config_path = os.path.join(
+        current_path, "example_config_yaml", "config_with_missing_include.yaml"
+    )
+
+    with pytest.raises(FileNotFoundError):
+        await proxy_config_instance.get_config(config_file_path=config_path)
+
+
+@pytest.mark.asyncio
+async def test_multiple_includes():
+    """
+    Test that multiple files in the include list are all processed correctly
+    """
+    proxy_config_instance = ProxyConfig()
+    current_path = os.path.dirname(os.path.abspath(__file__))
+    config_path = os.path.join(
+        current_path, "example_config_yaml", "config_with_multiple_includes.yaml"
+    )
+
+    config = await proxy_config_instance.get_config(config_file_path=config_path)
+
+    # Verify models from both included files are present
+    assert len(config["model_list"]) == 2
+    assert any(
+        model["model_name"] == "included-model-1" for model in config["model_list"]
+    )
+    assert any(
+        model["model_name"] == "included-model-2" for model in config["model_list"]
+    )
+
+    # Verify original config settings remain
+    assert config["litellm_settings"]["callbacks"] == ["prometheus"]