uv cache populate / export cache

[adriangb]

It would be nice to have the ability to pre-cache dependencies. In particular I would find this useful in a monorepo context to:

1. Have a docker layer where I populate the cache with all dependencies.
2. In another service specific layer I do a --cache-from or similar from this cache layer and tell uv to use the cache that was built in that layer.

This is important because if I have services with the following deps:

tensorflow
some-small-package

And

tensorflow
some-other-small-package

If I don't have a "common" step where I download tensorflow I'd end up downloading it twice (once for each service) which is wasteful. Yes you can parallelize it but IMO efficient serial >> inefficient parallel.

Alternatively something like python-poetry/poetry#5983 and functionality in uv to populate that folder of wheels could do the trick.

[charliermarsh]

What's the typical mechanism that you'd use to ensure that those two layers use the same TensorFlow version?

[adriangb]

Currently it's a PITA with all package managers that I know of that support monorepos.

Hence why I think something like:

FROM python:3.12-slim-bullseye AS deps
COPY --from=ghcr.io/astral-sh/uv:latest /uv /bin/uv
COPY uv.lock .
RUN --mount=type=cache,target=/root/.cache/uv \
  uv cache populate

FROM python:3.12-slim-bullseye AS service
COPY --from=ghcr.io/astral-sh/uv:latest /uv /bin/uv
COPY . /app
RUN --mount=from=deps,source=/root/.cache/uv,target=/root/.cache/uv \
  uv install --package service

Would be nice.

[samypr100]

I'd say this is similar in the venue/spirit of #1681 / #3163 as populating the cache will involve downloading and possibly a build step which is a common workflow achieved with pip wheel or download.