uv/docs/guides/docker.md

Using uv in Docker

Running in Docker

A Docker image is published with a built version of uv available. To run a uv command in a container:

docker run ghcr.io/astral-sh/uv --help

Installing uv

uv can be installed by copying from the official Docker image:

FROM ghcr.io/astral-sh/uv:latest as uv
FROM python:3.12-slim-bullseye
COPY --from=uv /uv /bin/uv

Or with the standalone installer:

FROM python:3.12-slim-bullseye
RUN apt-get update && apt-get install -y curl --no-install-recommends
RUN curl -LsSf https://astral.sh/uv/install.sh | sh
ENV PATH="/root/.cargo/bin/:
$PATH"

Note this requires curl to be available.

In either case, it is best practice to pin to a specific uv version.

Installing a package

Once uv is installed in an image, it can be used to install some packages.

The system Python environment is safe to use this context, since a container is already isolated. The --system flag can be used to install in the system environment:

RUN uv pip install --system ruff

To use the system Python environment by default, set the UV_SYSTEM_PYTHON variable:

ENV UV_SYSTEM_PYTHON=1

Alternatively, a virtual environment can be created and activated:

RUN uv venv /opt/venv
# Use the virtual environment automatically
ENV VIRTUAL_ENV=/opt/venv
# Place entry points in the environment at the front of the path
ENV PATH="/opt/venv/bin:$PATH"

When using a virtual environment, the --system flag should be omitted from uv invocations:

RUN uv pip install ruff

Installing requirements

To install requirements files, copy them into the container:

COPY requirements.txt .
RUN uv pip install -r requirements.txt

Installing a project

When installing a project alongside requirements, it is prudent to separate copying the requirements from the rest of the source code. This allows the dependencies of the project (which do not change often) to be cached separately from the project itself (which changes very frequently).

COPY pyproject.toml .
RUN uv pip install -r pyproject.toml
COPY . .
RUN uv pip install -e .

Optimizations

Using uv temporarily

If uv isn't needed in the final image, the binary can be mounted in each invocation:

RUN --mount=from=uv,source=/uv,target=/bin/uv \
    uv pip install --system ruff

Caching

A cache mount can be used to improve performance across builds:

RUN --mount=type=cache,target=/root/.cache/uv \
 ./uv pip install -r requirements.txt -->

Note the cache directory's location can be determined with the uv cache dir command. Alternatively, the cache can be set to a constant location:

ENV UV_CACHE_DIR=/opt/uv-cache/

If not mounting the cache, image size can be reduced with --no-cache flag.