feat: support config file for vllm runtime (#780)

**Reason for Change**:

support to load config from file and overwrite runtime args.

**Requirements**

- [x] added unit tests and e2e tests (if applicable).

---------

Signed-off-by: jerryzhuang <zhuangqhc@gmail.com>

charts/kaito/workspace/templates/inference-params.yaml

@@ -0,0 +1,19 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: inference-params-template
+  namespace: {{ .Release.Namespace }}
+data:
+  inference_config.yaml: |
+    # Maximum number of steps to find the max available seq len fitting in the GPU memory.
+    max_probe_steps: 6
+
+    vllm:
+      cpu-offload-gb: 0
+      gpu-memory-utilization: 0.95
+      swap-space: 4
+
+      # max-seq-len-to-capture: 8192
+      # num-scheduler-steps: 1
+      # enable-chunked-prefill: false
+      # see https://docs.vllm.ai/en/stable/models/engine_args.html for more options.

presets/workspace/inference/vllm/inference_api.py

@@ -3,7 +3,10 @@
 import logging
 import gc
 import os
-from typing import Callable, Optional, List
+import argparse
+from typing import Callable, Optional, List, Any
+import yaml
+from dataclasses import dataclass
 
 import uvloop
 import torch
@@ -21,33 +24,88 @@
     format='%(levelname)s %(asctime)s %(filename)s:%(lineno)d] %(message)s',
     datefmt='%m-%d %H:%M:%S')
 
-def make_arg_parser(parser: FlexibleArgumentParser) -> FlexibleArgumentParser:
-    local_rank = int(os.environ.get("LOCAL_RANK",
-                                    0))  # Default to 0 if not set
-    port = 5000 + local_rank  # Adjust port based on local rank
-
-    server_default_args = {
-        "disable_frontend_multiprocessing": False,
-        "port": port,
-    }
-    parser.set_defaults(**server_default_args)
-
-    # See https://docs.vllm.ai/en/stable/models/engine_args.html for more args
-    engine_default_args = {
-        "model": "/workspace/vllm/weights",
-        "cpu_offload_gb": 0,
-        "gpu_memory_utilization": 0.95,
-        "swap_space": 4,
-        "disable_log_stats": False,
-        "uvicorn_log_level": "error"
-    }
-    parser.set_defaults(**engine_default_args)
-
-    # KAITO only args
-    # They should start with "kaito-" prefix to avoid conflict with vllm args
-    parser.add_argument("--kaito-adapters-dir", type=str, default="/mnt/adapter", help="Directory where adapters are stored in KAITO preset.")
-
-    return parser
+class KAITOArgumentParser(argparse.ArgumentParser):
+    vllm_parser = FlexibleArgumentParser(description="vLLM serving server")
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        # Initialize vllm parser
+        self.vllm_parser = api_server.make_arg_parser(self.vllm_parser)
+        self._reset_vllm_defaults()
+
+        # KAITO only args
+        # They should start with "kaito-" prefix to avoid conflict with vllm args
+        self.add_argument("--kaito-adapters-dir", type=str, default="/mnt/adapter", help="Directory where adapters are stored in KAITO preset.")
+        self.add_argument("--kaito-config-file", type=str, default="", help="Additional args for KAITO preset.")
+        self.add_argument("--kaito-max-probe-steps", type=int, default=6, help="Maximum number of steps to find the max available seq len fitting in the GPU memory.")
+
+    def _reset_vllm_defaults(self):
+        local_rank = int(os.environ.get("LOCAL_RANK",
+                                        0))  # Default to 0 if not set
+        port = 5000 + local_rank  # Adjust port based on local rank
+
+        server_default_args = {
+            "disable_frontend_multiprocessing": False,
+            "port": port,
+        }
+        self.vllm_parser.set_defaults(**server_default_args)
+
+        # See https://docs.vllm.ai/en/stable/models/engine_args.html for more args
+        engine_default_args = {
+            "model": "/workspace/vllm/weights",
+            "cpu_offload_gb": 0,
+            "gpu_memory_utilization": 0.95,
+            "swap_space": 4,
+            "disable_log_stats": False,
+            "uvicorn_log_level": "error"
+        }
+        self.vllm_parser.set_defaults(**engine_default_args)
+
+    def parse_args(self, *args, **kwargs):
+        args = super().parse_known_args(*args, **kwargs)
+        kaito_args = args[0]
+        runtime_args = args[1] # Remaining args
+
+        # Load KAITO config
+        if kaito_args.kaito_config_file:
+            file_config = KaitoConfig.from_yaml(kaito_args.kaito_config_file)
+            if kaito_args.kaito_max_probe_steps is None:
+                kaito_args.kaito_max_probe_steps = file_config.max_probe_steps
+
+            for key, value in file_config.vllm.items():
+                runtime_args.append(f"--{key}")
+                runtime_args.append(str(value))
+
+        vllm_args = self.vllm_parser.parse_args(runtime_args, **kwargs)
+        # Merge KAITO and vLLM args
+        return argparse.Namespace(**vars(kaito_args), **vars(vllm_args))
+
+    def print_help(self, file=None):
+        super().print_help(file)
+        print("\norignal vLLM server arguments:\n")
+        self.vllm_parser.print_help(file)
+
+@dataclass
+class KaitoConfig:
+    # Extra arguments for the vllm serving server, will be forwarded to the vllm server.
+    # This should be in key-value format.
+    vllm: dict[str, Any]
+
+    # Maximum number of steps to find the max available seq len fitting in the GPU memory.
+    max_probe_steps: int
+
+    @staticmethod
+    def from_yaml(yaml_file: str) -> 'KaitoConfig':
+        with open(yaml_file, 'r') as file:
+            config_data = yaml.safe_load(file)
+        return KaitoConfig(
+            vllm=config_data.get('vllm', {}),
+            max_probe_steps=config_data.get('max_probe_steps', 6)
+        )
+
+    def to_yaml(self) -> str:
+        return yaml.dump(self.__dict__)
 
 def load_lora_adapters(adapters_dir: str) -> Optional[LoRAModulePath]:
     lora_list: List[LoRAModulePath] = []
@@ -130,53 +188,60 @@ def is_context_length_safe(executor: ExecutorBase, num_gpu_blocks: int) -> bool:
     executor.scheduler_config.max_num_batched_tokens = context_length
 
     try:
+        logger.info(f"Try to determine available gpu blocks for context length {context_length}")
         # see https://github.com/vllm-project/vllm/blob/v0.6.3/vllm/engine/llm_engine.py#L477
         available_gpu_blocks, _ = executor.determine_num_available_blocks()
     except torch.OutOfMemoryError as e:
         return False    
 
     return available_gpu_blocks >= num_gpu_blocks
 
+def try_set_max_available_seq_len(args: argparse.Namespace):
+    if args.max_model_len is not None:
+        logger.info(f"max_model_len is set to {args.max_model_len}, skip probing.")
+        return
+
+    max_probe_steps = 0
+    if args.kaito_max_probe_steps is not None:
+        try:
+            max_probe_steps = int(args.kaito_max_probe_steps)
+        except ValueError:
+            raise ValueError("kaito_max_probe_steps must be an integer.")
+
+    if max_probe_steps <= 0:
+        return
+
+    engine_args = EngineArgs.from_cli_args(args)
+    # read the model config from hf weights path.
+    # vllm will perform different parser for different model architectures
+    # and read it into a unified EngineConfig.
+    engine_config = engine_args.create_engine_config()
+
+    max_model_len = engine_config.model_config.max_model_len
+    available_seq_len = max_model_len
+    logger.info("Try run profiler to find max available seq len")
+    available_seq_len = find_max_available_seq_len(engine_config, max_probe_steps)
+    # see https://github.com/vllm-project/vllm/blob/v0.6.3/vllm/worker/worker.py#L262
+    if available_seq_len <= 0:
+        raise ValueError("No available memory for the cache blocks. "
+                        "Try increasing `gpu_memory_utilization` when "
+                        "initializing the engine.")
+
+    if available_seq_len != max_model_len:
+        logger.info(f"Set max_model_len from {max_model_len} to {available_seq_len}")
+        args.max_model_len = available_seq_len
+    else:
+        logger.info(f"Using model default max_model_len {max_model_len}")
+
 if __name__ == "__main__":
-    parser = FlexibleArgumentParser(description='vLLM serving server')
-    parser = api_server.make_arg_parser(parser)
-    parser = make_arg_parser(parser)
+    parser = KAITOArgumentParser(description='KAITO wrapper of vLLM serving server')
     args = parser.parse_args()
 
     # set LoRA adapters
     if args.lora_modules is None:
         args.lora_modules = load_lora_adapters(args.kaito_adapters_dir)
 
-    if args.max_model_len is None:
-        max_probe_steps = 6
-        if os.getenv("MAX_PROBE_STEPS") is not None:
-            try:
-                max_probe_steps = int(os.getenv("MAX_PROBE_STEPS"))
-            except ValueError:
-                raise ValueError("MAX_PROBE_STEPS must be an integer.")
-
-        engine_args = EngineArgs.from_cli_args(args)
-        # read the model config from hf weights path.
-        # vllm will perform different parser for different model architectures
-        # and read it into a unified EngineConfig.
-        engine_config = engine_args.create_engine_config()
-
-        max_model_len = engine_config.model_config.max_model_len
-        available_seq_len = max_model_len
-        if max_probe_steps > 0:
-            logger.info("Try run profiler to find max available seq len")
-            available_seq_len = find_max_available_seq_len(engine_config, max_probe_steps)
-        # see https://github.com/vllm-project/vllm/blob/v0.6.3/vllm/worker/worker.py#L262
-        if available_seq_len <= 0:
-            raise ValueError("No available memory for the cache blocks. "
-                         "Try increasing `gpu_memory_utilization` when "
-                         "initializing the engine.")
-
-        if available_seq_len != max_model_len:
-            logger.info(f"Set max_model_len from {max_model_len} to {available_seq_len}")
-            args.max_model_len = available_seq_len
-        else:
-            logger.info(f"Using model default max_model_len {max_model_len}")
+    try_set_max_available_seq_len(args)
 
     # Run the serving server
     logger.info(f"Starting server on port {args.port}")

presets/workspace/inference/vllm/tests/test_vllm_inference_api.py

@@ -13,13 +13,15 @@
 # Add the parent directory to sys.path
 sys.path.append(parent_dir)
 
-from inference_api import binary_search_with_limited_steps
+from inference_api import binary_search_with_limited_steps, KaitoConfig
 from huggingface_hub import snapshot_download
 import shutil
 
 TEST_MODEL = "facebook/opt-125m"
 TEST_ADAPTER_NAME1 = "mylora1"
 TEST_ADAPTER_NAME2 = "mylora2"
+TEST_MODEL_NAME = "mymodel"
+TEST_MODEL_LEN = 1024
 CHAT_TEMPLATE = ("{{ bos_token }}{% for message in messages %}{% if (message['role'] == 'user') %}"
     "{{'<|user|>' + '\n' + message['content'] + '<|end|>' + '\n' + '<|assistant|>' + '\n'}}"
     "{% elif (message['role'] == 'assistant') %}{{message['content'] + '<|end|>' + '\n'}}{% endif %}{% endfor %}")
@@ -33,18 +35,33 @@ def setup_server(request, tmp_path_factory, autouse=True):
     global TEST_PORT
     TEST_PORT = port
 
+    # prepare testing adapter images
     tmp_file_dir = tmp_path_factory.mktemp("adapter")
     print(f"Downloading adapter image to {tmp_file_dir}")
     snapshot_download(repo_id="slall/facebook-opt-125M-imdb-lora", local_dir=str(tmp_file_dir / TEST_ADAPTER_NAME1))
     snapshot_download(repo_id="slall/facebook-opt-125M-imdb-lora", local_dir=str(tmp_file_dir / TEST_ADAPTER_NAME2))
 
+    # prepare testing config file
+    config_file = tmp_file_dir / "config.yaml"
+    kaito_config = KaitoConfig(
+        vllm={
+            "max-model-len": TEST_MODEL_LEN,
+            "served-model-name": TEST_MODEL_NAME
+        },
+        max_probe_steps=0,
+    )
+    with open(config_file, "w") as f:
+        f.write(kaito_config.to_yaml())
+
     args = [
         "python3",
         os.path.join(parent_dir, "inference_api.py"),
         "--model", TEST_MODEL,
         "--chat-template", CHAT_TEMPLATE,
+        "--max-model-len", "2048", # expected to be overridden by config file
         "--port", str(TEST_PORT),
         "--kaito-adapters-dir", tmp_file_dir,
+        "--kaito-config-file", config_file,
     ]
     print(f">>> Starting server on port {TEST_PORT}")
     env = os.environ.copy()
@@ -90,7 +107,7 @@ def find_available_port(start_port=5000, end_port=8000):
 
 def test_completions_api(setup_server):
     request_data = {
-        "model": TEST_MODEL,
+        "model": TEST_MODEL_NAME,
         "prompt": "Say this is a test",
         "max_tokens": 7,
         "temperature": 0.5,
@@ -108,7 +125,7 @@ def test_completions_api(setup_server):
 
 def test_chat_completions_api(setup_server):
     request_data = {
-        "model": TEST_MODEL,
+        "model": TEST_MODEL_NAME,
         "messages": [
             {"role": "user", "content": "Hello!"},
             {"role": "assistant", "content": "Hi there! How can I help you today?"}
@@ -135,11 +152,12 @@ def test_model_list(setup_server):
 
     assert "data" in data, f"The response should contain a 'data' key, but got {data}"
     assert len(data["data"]) == 3, f"The response should contain three models, but got {data['data']}"
-    assert data["data"][0]["id"] == TEST_MODEL, f"The first model should be the test model, but got {data['data'][0]['id']}"
+    assert data["data"][0]["id"] == TEST_MODEL_NAME, f"The first model should be the test model, but got {data['data'][0]['id']}"
+    assert data["data"][0]["max_model_len"] == TEST_MODEL_LEN, f"The first model should have the test model length, but got {data['data'][0]['max_model_len']}"
     assert data["data"][1]["id"] == TEST_ADAPTER_NAME2, f"The second model should be the test adapter, but got {data['data'][1]['id']}"
-    assert data["data"][1]["parent"] == TEST_MODEL, f"The second model should have the test model as parent, but got {data['data'][1]['parent']}"
+    assert data["data"][1]["parent"] == TEST_MODEL_NAME, f"The second model should have the test model as parent, but got {data['data'][1]['parent']}"
     assert data["data"][2]["id"] == TEST_ADAPTER_NAME1, f"The third model should be the test adapter, but got {data['data'][2]['id']}"
-    assert data["data"][2]["parent"] == TEST_MODEL, f"The third model should have the test model as parent, but got {data['data'][2]['parent']}"
+    assert data["data"][2]["parent"] == TEST_MODEL_NAME, f"The third model should have the test model as parent, but got {data['data'][2]['parent']}"
 
 def test_binary_search_with_limited_steps():