[CLI] Add --model-type override and keep launch_server supported (#19523)

This commit is contained in:
Liangsheng Yin
2026-02-27 18:16:31 -08:00
committed by GitHub
parent e08ef06758
commit ac400cb7bb
3 changed files with 93 additions and 145 deletions

View File

@@ -10,6 +10,39 @@ from sglang.srt.utils import kill_process_tree
logger = logging.getLogger(__name__)
def _extract_model_type_override(extra_argv):
"""Extract and remove --model-type override from argv."""
model_type = "auto"
filtered_argv = []
i = 0
while i < len(extra_argv):
arg = extra_argv[i]
if arg == "--model-type":
if i + 1 >= len(extra_argv):
raise Exception(
"Error: --model-type requires a value. "
"Valid values are: auto, llm, diffusion."
)
model_type = extra_argv[i + 1]
i += 2
continue
if arg.startswith("--model-type="):
model_type = arg.split("=", 1)[1]
i += 1
continue
filtered_argv.append(arg)
i += 1
if model_type not in ("auto", "llm", "diffusion"):
raise Exception(
f"Error: invalid --model-type '{model_type}'. "
"Valid values are: auto, llm, diffusion."
)
return model_type, filtered_argv
def serve(args, extra_argv):
if any(h in extra_argv for h in ("-h", "--help")):
# Since the server type is determined by the model, and we don't have a model path,
@@ -22,6 +55,10 @@ def serve(args, extra_argv):
"This command can launch either a standard language model server or a diffusion model server."
)
print("The server type is determined by the model path.\n")
print(
"Optional override: --model-type {auto,llm,diffusion} "
"(default: auto, fallback to LLM on detection failure).\n"
)
print("For specific arguments, please provide a model_path.")
print("\n--- Help for Standard Language Model Server ---")
from sglang.srt.server_args import prepare_server_args
@@ -41,11 +78,19 @@ def serve(args, extra_argv):
parser.print_help()
return
model_path = get_model_path(extra_argv)
model_type, dispatch_argv = _extract_model_type_override(extra_argv)
model_path = get_model_path(dispatch_argv)
try:
is_diffusion_model = get_is_diffusion_model(model_path)
if is_diffusion_model:
logger.info("Diffusion model detected")
if model_type == "auto":
is_diffusion_model = get_is_diffusion_model(model_path)
if is_diffusion_model:
logger.info("Diffusion model detected")
else:
is_diffusion_model = model_type == "diffusion"
logger.info(
"Dispatch override enabled: --model-type=%s " "(skip auto detection)",
model_type,
)
if is_diffusion_model:
# Logic for Diffusion Models
@@ -58,7 +103,7 @@ def serve(args, extra_argv):
description="SGLang Diffusion Model Serving"
)
add_multimodal_gen_serve_args(parser)
parsed_args, remaining_argv = parser.parse_known_args(extra_argv)
parsed_args, remaining_argv = parser.parse_known_args(dispatch_argv)
execute_serve_cmd(parsed_args, remaining_argv)
else:
@@ -68,7 +113,7 @@ def serve(args, extra_argv):
# Add a dummy argument for the program name, expected by prepare_server_args
# as it typically processes sys.argv
server_args = prepare_server_args(extra_argv)
server_args = prepare_server_args(dispatch_argv)
run_server(server_args)
finally:

View File

@@ -1,160 +1,53 @@
import hashlib
import json
import logging
import os
import subprocess
import tempfile
from functools import lru_cache
from typing import Optional
import filelock
from sglang.srt.environ import envs
logger = logging.getLogger(__name__)
temp_dir = tempfile.gettempdir()
def _get_lock(model_name_or_path: str, cache_dir: Optional[str] = None):
lock_dir = cache_dir or temp_dir
os.makedirs(os.path.dirname(lock_dir), exist_ok=True)
model_name = model_name_or_path.replace("/", "-")
hash_name = hashlib.sha256(model_name.encode()).hexdigest()
lock_file_name = hash_name + model_name + ".lock"
lock = filelock.FileLock(os.path.join(lock_dir, lock_file_name), mode=0o666)
return lock
def _hf_hub_download(
repo_id: str,
filename: str,
local_dir: Optional[str] = None,
**kwargs,
) -> str:
"""Unified hf_hub_download supporting both Hugging Face Hub and ModelScope."""
if envs.SGLANG_USE_MODELSCOPE.get():
from modelscope import model_file_download
return model_file_download(
model_id=repo_id,
file_path=filename,
cache_dir=local_dir,
**kwargs,
)
else:
from huggingface_hub import hf_hub_download as _hf_hub_download_impl
return _hf_hub_download_impl(
repo_id=repo_id,
filename=filename,
local_dir=local_dir,
**kwargs,
)
# Copied and adapted from hf_diffusers_utils.py
def _maybe_download_model(
model_name_or_path: str, local_dir: str | None = None, download: bool = True
) -> str:
"""
Resolve a model path. If it's a local directory, return it.
If it's a Hugging Face Hub ID, download only the config file
(`model_index.json` or `config.json`) and return its directory.
Args:
model_name_or_path: Local path or Hugging Face Hub model ID
local_dir: Local directory to save the downloaded file (if any)
download: Whether to download from Hugging Face Hub when needed
Returns:
Local directory path that contains the downloaded config file, or the original local directory.
"""
if os.path.exists(model_name_or_path):
logger.debug("Model already exists locally")
return model_name_or_path
if not download:
return model_name_or_path
with _get_lock(model_name_or_path):
# Try `model_index.json` first (diffusers models)
source_hub = "MS Hub" if envs.SGLANG_USE_MODELSCOPE.get() else "HF Hub"
try:
logger.debug(
"Downloading model_index.json from %s for %s...",
source_hub,
model_name_or_path,
)
file_path = _hf_hub_download(
repo_id=model_name_or_path,
filename="model_index.json",
local_dir=local_dir,
)
logger.debug("Downloaded to %s", file_path)
return os.path.dirname(file_path)
except Exception as e_index:
logger.debug("model_index.json not found or failed: %s", e_index)
# Fallback to `config.json`
try:
logger.debug(
"Downloading config.json from %s for %s...",
source_hub,
model_name_or_path,
)
file_path = _hf_hub_download(
repo_id=model_name_or_path,
filename="config.json",
local_dir=local_dir,
)
logger.debug("Downloaded to %s", file_path)
return os.path.dirname(file_path)
except Exception as e_config:
raise ValueError(
(
"Could not find model locally at %s and failed to download "
"model_index.json/config.json from %s: %s"
)
% (model_name_or_path, source_hub, e_config)
) from e_config
# Copied and adapted from hf_diffusers_utils.py
def is_diffusers_model_path(model_path: str) -> True:
"""
Verify if the model directory contains a valid diffusers configuration.
Args:
model_path: Path to the model directory
Returns:
The loaded model configuration as a dictionary if the model is a diffusers model
None if the model is not a diffusers model
"""
# Prefer model_index.json which indicates a diffusers pipeline
config_path = os.path.join(model_path, "model_index.json")
def _is_diffusers_model_dir(model_dir: str) -> bool:
"""Check if a local directory contains a valid diffusers model_index.json."""
config_path = os.path.join(model_dir, "model_index.json")
if not os.path.exists(config_path):
return False
# Load the config
with open(config_path) as f:
config = json.load(f)
# Verify diffusers version exists
if "_diffusers_version" not in config:
return "_diffusers_version" in config
def get_is_diffusion_model(model_path: str) -> bool:
"""Detect whether model_path points to a diffusion model.
For local directories, checks the filesystem directly.
For HF/ModelScope model IDs, attempts to fetch only model_index.json.
Returns False on any failure (network error, 404, offline mode, etc.)
so that the caller falls through to the standard LLM server path.
"""
if os.path.isdir(model_path):
return _is_diffusers_model_dir(model_path)
try:
if envs.SGLANG_USE_MODELSCOPE.get():
from modelscope import model_file_download
file_path = model_file_download(
model_id=model_path, file_path="model_index.json"
)
else:
from huggingface_hub import hf_hub_download
file_path = hf_hub_download(repo_id=model_path, filename="model_index.json")
return _is_diffusers_model_dir(os.path.dirname(file_path))
except Exception as e:
logger.debug("Failed to auto-detect diffusion model for %s: %s", model_path, e)
return False
return True
def get_is_diffusion_model(model_path: str):
model_path = _maybe_download_model(model_path)
is_diffusion_model = is_diffusers_model_path(model_path)
if is_diffusion_model:
logger.info("Diffusion model detected")
return is_diffusion_model
def get_model_path(extra_argv):

View File

@@ -29,6 +29,16 @@ def run_server(server_args):
if __name__ == "__main__":
import warnings
warnings.warn(
"'python -m sglang.launch_server' is still supported, but "
"'sglang serve' is the recommended entrypoint.\n"
" Example: sglang serve --model-path <model> [options]",
UserWarning,
stacklevel=1,
)
server_args = prepare_server_args(sys.argv[1:])
try: