Files
DocsGPT/application/scripts/prefetch_models.py
T
Alex 4707c45b93 fix(parser,vectorstore): stop the first-request downloads in a warmed install
Three things still reached the network from a container whose models were
baked in:

- tiktoken fetched cl100k_base from openaipublic.blob.core.windows.net on
  every fresh container (its cache defaulted to /tmp), and token accounting
  calls it on every chat. prefetch_models now warms it too; the image sets
  TIKTOKEN_CACHE_DIR.
- The chunker loaded its tokenizer with Tokenizer.from_pretrained, which
  revalidates the revision with a HEAD request per process start and stalls
  for the etag timeout (10 s) when huggingface.co is unreachable. It now reads
  tokenizer.json from the hub cache first and only downloads on a miss; the
  repo-metadata read for models outside the registry does the same.
- tldextract fetched the public suffix list on the first web crawl; the
  bundled snapshot is used instead.

application/scripts/verify_offline.py exercises these paths (and docling's
conversion when the extra is installed) so an image can be checked with
docker run --network none.
2026-09-05 15:50:20 +01:00

114 lines
3.7 KiB
Python

"""Download the model artifacts a fresh container would otherwise fetch.
Run at image build time so a fresh container does not download on its first
request, and an air-gapped install works at all. Two things are warmed:
* Embedding models, into FastEmbed's cache. Both the legacy and the current
default are baked: an upgraded deployment keeps using mpnet until it runs
``reembed``, while a new one starts on granite.
* tiktoken's ``cl100k_base`` encoding, which token accounting uses on every
chat. tiktoken caches it under ``TIKTOKEN_CACHE_DIR`` (a temp dir when
unset), so the image sets that variable and this warms it.
Usage::
python -m application.scripts.prefetch_models # the defaults
python -m application.scripts.prefetch_models granite-311m # a subset
"""
from __future__ import annotations
import logging
import sys
from typing import List, Optional, Sequence
from application.vectorstore.model_registry import (
DEFAULT_LEGACY,
DEFAULT_NEW_INSTALL,
known_names,
resolve,
)
logger = logging.getLogger("prefetch_models")
#: Fetched when no names are given.
DEFAULT_MODELS = (DEFAULT_LEGACY, DEFAULT_NEW_INSTALL)
#: tiktoken encodings the application loads (``application.utils.get_encoding``).
TIKTOKEN_ENCODINGS = ("cl100k_base",)
def prefetch_tiktoken(names: Sequence[str] = TIKTOKEN_ENCODINGS) -> List[str]:
"""Warm tiktoken's cache for each encoding in ``names``.
Returns:
The encodings fetched.
"""
import tiktoken
for name in names:
logger.info("Fetching tiktoken encoding %s", name)
tiktoken.get_encoding(name)
return list(names)
def prefetch(names: Sequence[str], cache_dir: Optional[str] = None) -> List[str]:
"""Fetch each named model's artifacts.
Args:
names: Registry names or aliases.
cache_dir: FastEmbed cache directory; its default when omitted.
Returns:
The repositories actually fetched.
Raises:
SystemExit: If a name is not in the registry, since a silent skip at
build time becomes a download at run time on an offline host.
"""
from fastembed import TextEmbedding
from fastembed.common.model_description import ModelSource, PoolingType
pooling_types = {"cls": PoolingType.CLS, "mean": PoolingType.MEAN}
fetched: List[str] = []
for name in names:
spec = resolve(name)
if spec is None:
raise SystemExit(
f"Unknown embedding model {name!r}. Known: {', '.join(known_names())}"
)
if spec.provider != "fastembed":
logger.info("Skipping %s: served remotely, nothing to cache.", spec.name)
continue
logger.info("Fetching %s", spec.repo)
TextEmbedding.add_custom_model(
model=spec.repo,
pooling=pooling_types[spec.pooling],
normalization=spec.normalize,
sources=ModelSource(hf=spec.repo),
dim=spec.dimension,
model_file=spec.onnx_file,
)
kwargs = {"model_name": spec.repo}
if cache_dir:
kwargs["cache_dir"] = cache_dir
TextEmbedding(**kwargs)
fetched.append(spec.repo)
return fetched
def main(argv: Optional[Sequence[str]] = None) -> int:
logging.basicConfig(level=logging.INFO, format="%(levelname)s %(message)s")
import os
names = list(argv) if argv else list(DEFAULT_MODELS)
fetched = prefetch(names, os.environ.get("EMBEDDINGS_CACHE_DIR"))
logger.info("Cached %d model(s): %s", len(fetched), ", ".join(fetched))
encodings = prefetch_tiktoken()
logger.info("Cached tiktoken encoding(s): %s", ", ".join(encodings))
return 0
if __name__ == "__main__":
sys.exit(main(sys.argv[1:]))