test_offline_mode.py

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""Tests for HF_HUB_OFFLINE mode"""

import dataclasses
import importlib
import sys

import pytest
import urllib3

from vllm import LLM
from vllm.distributed import cleanup_dist_env_and_memory
from vllm.engine.arg_utils import EngineArgs

MODEL_CONFIGS = [
    {
        "model": "facebook/opt-125m",
        "enforce_eager": True,
        "gpu_memory_utilization": 0.20,
        "max_model_len": 64,
        "max_num_batched_tokens": 64,
        "max_num_seqs": 64,
        "tensor_parallel_size": 1,
    },
    {
        "model": "Qwen/Qwen3-0.6B",
        "enforce_eager": True,
        "gpu_memory_utilization": 0.50,
        "max_model_len": 64,
        "max_num_batched_tokens": 64,
        "max_num_seqs": 64,
        "tensor_parallel_size": 1,
        "tokenizer": "Qwen/Qwen3-4B",
    },
    {
        "model": "mistralai/Mistral-7B-Instruct-v0.1",
        "enforce_eager": True,
        "gpu_memory_utilization": 0.95,
        "max_model_len": 64,
        "max_num_batched_tokens": 64,
        "max_num_seqs": 64,
        "tensor_parallel_size": 1,
        "tokenizer_mode": "mistral",
    },
    # TODO: re-enable once these tests are run with V1
    # {
    #     "model": "sentence-transformers/all-MiniLM-L12-v2",
    #     "enforce_eager": True,
    #     "gpu_memory_utilization": 0.20,
    #     "max_model_len": 64,
    #     "max_num_batched_tokens": 64,
    #     "max_num_seqs": 64,
    #     "tensor_parallel_size": 1,
    # },
]


@pytest.fixture(scope="module")
def cache_models():
    # Cache model files first
    for model_config in MODEL_CONFIGS:
        LLM(**model_config)
        cleanup_dist_env_and_memory()

    yield


@pytest.mark.skip_global_cleanup
@pytest.mark.usefixtures("cache_models")
def test_offline_mode(monkeypatch: pytest.MonkeyPatch):
    # Set HF to offline mode and ensure we can still construct an LLM
    with monkeypatch.context() as m:
        try:
            m.setenv("HF_HUB_OFFLINE", "1")
            m.setenv("VLLM_NO_USAGE_STATS", "1")

            def disable_connect(*args, **kwargs):
                raise RuntimeError("No http calls allowed")

            m.setattr(
                urllib3.connection.HTTPConnection,
                "connect",
                disable_connect,
            )
            m.setattr(
                urllib3.connection.HTTPSConnection,
                "connect",
                disable_connect,
            )

            # Need to re-import huggingface_hub
            # and friends to set up offline mode
            _re_import_modules()
            # Cached model files should be used in offline mode
            for model_config in MODEL_CONFIGS:
                LLM(**model_config)
        finally:
            # Reset the environment after the test
            # NB: Assuming tests are run in online mode
            _re_import_modules()


def _re_import_modules():
    hf_hub_module_names = [k for k in sys.modules if k.startswith("huggingface_hub")]
    transformers_module_names = [
        k
        for k in sys.modules
        if k.startswith("transformers") and not k.startswith("transformers_modules")
    ]

    # These modules are aliased in Transformers v5 and so cannot be reloaded directly
    aliased_modules = ["tokenization_utils", "tokenization_utils_fast"]

    reload_exception = None
    for module_name in hf_hub_module_names + transformers_module_names:
        if any(module_name.endswith(f".{alias}") for alias in aliased_modules):
            # Remove from sys.modules so they are re-aliased on next import
            del sys.modules[module_name]
            continue
        try:
            importlib.reload(sys.modules[module_name])
        except Exception as e:
            reload_exception = e
            # Try to continue clean up so that other tests are less likely to
            # be affected

    # Error this test if reloading a module failed
    if reload_exception is not None:
        raise reload_exception


@pytest.mark.skip_global_cleanup
@pytest.mark.usefixtures("cache_models")
def test_model_from_huggingface_offline(monkeypatch: pytest.MonkeyPatch):
    # Set HF to offline mode and ensure we can still construct an LLM
    with monkeypatch.context() as m:
        try:
            m.setenv("HF_HUB_OFFLINE", "1")
            m.setenv("VLLM_NO_USAGE_STATS", "1")

            def disable_connect(*args, **kwargs):
                raise RuntimeError("No http calls allowed")

            m.setattr(
                urllib3.connection.HTTPConnection,
                "connect",
                disable_connect,
            )
            m.setattr(
                urllib3.connection.HTTPSConnection,
                "connect",
                disable_connect,
            )
            # Need to re-import huggingface_hub
            # and friends to set up offline mode
            _re_import_modules()
            engine_args = EngineArgs(model="facebook/opt-125m")
            LLM(**dataclasses.asdict(engine_args))
        finally:
            # Reset the environment after the test
            # NB: Assuming tests are run in online mode
            _re_import_modules()