Django uv docker setup

[blossomsg]

Question

Hello All,
I am exploring uv with docker, but facing some challenges setting up Dockerfile

for the sake of upload i have added an extension .txt
Dockerfile.txt

I am referring django for professionals book
in which they are setting pipenv with docker, but i wanted to explore with uv
I keep getting the below error

 => ERROR [stage-0 8/8] RUN --mount=type=cache,target=/root/.cache/uv     uv sync --locked --no-dev                                                                                                                                                                         0.2s 
------
 > [stage-0 8/8] RUN --mount=type=cache,target=/root/.cache/uv     uv sync --locked --no-dev:
0.220 error: failed to create directory `/nonexistent/.cache/uv`: Permission denied (os error 13)
------
Dockerfile:61
--------------------
  60 |     COPY . /app
  61 | >>> RUN --mount=type=cache,target=/root/.cache/uv \
  62 | >>>     uv sync --locked --no-dev
  63 |
--------------------
ERROR: failed to build: failed to solve: process "/bin/sh -c uv sync --locked --no-dev" did not complete successfully: exit code: 2

here is the docker file snippet from the book.

I referred these links
https://docs.astral.sh/uv/guides/integration/docker/#using-uv-in-docker
https://github.com/astral-sh/uv-docker-example/blob/main/Dockerfile

Did the necessary tweaks, but still facing permissions issue.
Do let me know what needs to be refactored, it would be really helpful
Thank You.

Platform

Microsoft Windows 11 Pro x64

Version

uv 0.8.2 (21fadbc 2025-07-22)

[zanieb]

Copying this inline for readability

# syntax=docker/dockerfile:1

# Comments are provided throughout this file to help you get started.
# If you need more help, visit the Dockerfile reference guide at
# https://docs.docker.com/go/dockerfile-reference/

# Want to help us make this template better? Share your feedback here: https://forms.gle/ybq9Krt8jtBL3iCk7

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


# Setup a non-root user
RUN groupadd --system --gid 999 nonroot \
 && useradd --system --gid 999 --uid 999 --create-home nonroot

# Prevents Python from writing pyc files.
ENV PYTHONDONTWRITEBYTECODE=1

# Keeps Python from buffering stdout and stderr to avoid situations where
# the application crashes without emitting any logs due to buffering.
ENV PYTHONUNBUFFERED=1

WORKDIR /app

# Enable bytecode compilation
ENV UV_COMPILE_BYTECODE=1

# Copy from the cache instead of linking since it's a mounted volume
ENV UV_LINK_MODE=copy

# Ensure installed tools can be executed out of the box
ENV UV_TOOL_BIN_DIR=/usr/local/bin

# Create a non-privileged user that the app will run under.
# See https://docs.docker.com/go/dockerfile-user-best-practices/
ARG UID=10001
RUN adduser \
    --disabled-password \
    --gecos "" \
    --home "/nonexistent" \
    --shell "/sbin/nologin" \
    --no-create-home \
    --uid "${UID}" \
    appuser

# Download dependencies as a separate step to take advantage of Docker's caching.
# Leverage a cache mount to /root/.cache/pip to speed up subsequent builds.
# Leverage a bind mount to requirements.txt to avoid having to copy them into
# into this layer.
RUN --mount=type=cache,target=/root/.cache/uv \
    --mount=type=bind,source=uv.lock,target=uv.lock \
    --mount=type=bind,source=pyproject.toml,target=pyproject.toml \
    uv sync --locked --no-install-project --no-dev

# Switch to the non-privileged user to run the application.
USER appuser

# Copy the source code into the container.
COPY . /app
RUN --mount=type=cache,target=/root/.cache/uv \
    uv sync --locked --no-dev

# Place executables in the environment at the front of the path
ENV PATH="/app/.venv/bin:$PATH"

# Reset the entrypoint, don't invoke `uv`
ENTRYPOINT []

# Use the non-root user to run our application
USER nonroot


# Expose the port that the application listens on.
EXPOSE 8000

# Run the application.
CMD ["uv", "run", "python", "manage.py", "runserver", "0.0.0.0:8000"]

[zanieb]

You change the home directory to --home "/nonexistent" so uv attempts to store the cache there. You have some mounts for the uv cache --mount=type=cache,target=/root/.cache/uv but note that uses /root instead of /nonexistent

[blossomsg]

Hello @zanieb ,
thanks for the revert.

I tried both ways
--home "/nonexistent"

    --gecos "" \
    --home "/nonexistent" \
    --shell "/sbin/nologin" \

RUN --mount=type=cache,target=/nonexistent/.cache/uv \
    uv sync --locked --no-dev

and same with --home "/root"

    --gecos "" \
    --home "/root" \
    --shell "/sbin/nologin" \

RUN --mount=type=cache,target=/root/.cache/uv \
    uv sync --locked --no-dev

But unfortunately i am still getting same error, my last attempt was with "/root", that is why the path of cache is with root.

 => ERROR [stage-0 8/8] RUN --mount=type=cache,target=/root/.cache/uv     uv sync --locked --no-dev                                                                                                                                                                         0.2s 
------
 > [stage-0 8/8] RUN --mount=type=cache,target=/root/.cache/uv     uv sync --locked --no-dev:
0.178 error: failed to create directory `/root/.cache/uv`: Permission denied (os error 13)
------
Dockerfile:60
--------------------
  59 |     COPY . /app
  60 | >>> RUN --mount=type=cache,target=/root/.cache/uv \
  61 | >>>     uv sync --locked --no-dev
  62 |
--------------------
ERROR: failed to build: failed to solve: process "/bin/sh -c uv sync --locked --no-dev" did not complete successfully: exit code: 2

[zanieb]

You're switching to the unprivileged user early

# Switch to the non-privileged user to run the application.
USER appuser

# Copy the source code into the container.
COPY . /app
RUN --mount=type=cache,target=/root/.cache/uv \
    uv sync --locked --no-dev

Do that later?

[blossomsg]

Amazing @zanieb , thanks alot for the help.
Just worked in one go😁.
attaching the new formatted dockerfile.

# syntax=docker/dockerfile:1

# Comments are provided throughout this file to help you get started.
# If you need more help, visit the Dockerfile reference guide at
# https://docs.docker.com/go/dockerfile-reference/

# Want to help us make this template better? Share your feedback here: https://forms.gle/ybq9Krt8jtBL3iCk7

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


# Setup a non-root user
RUN groupadd --system --gid 999 nonroot \
 && useradd --system --gid 999 --uid 999 --create-home nonroot

# Prevents Python from writing pyc files.
ENV PYTHONDONTWRITEBYTECODE=1

# Keeps Python from buffering stdout and stderr to avoid situations where
# the application crashes without emitting any logs due to buffering.
ENV PYTHONUNBUFFERED=1

WORKDIR /app

# Enable bytecode compilation
ENV UV_COMPILE_BYTECODE=1

# Copy from the cache instead of linking since it's a mounted volume
ENV UV_LINK_MODE=copy

# Ensure installed tools can be executed out of the box
ENV UV_TOOL_BIN_DIR=/usr/local/bin

# Create a non-privileged user that the app will run under.
# See https://docs.docker.com/go/dockerfile-user-best-practices/
ARG UID=10001
RUN adduser \
    --disabled-password \
    --gecos "" \
    --home "/root" \
    --shell "/sbin/nologin" \
    --no-create-home \
    --uid "${UID}" \
    appuser

# Download dependencies as a separate step to take advantage of Docker's caching.
# Leverage a cache mount to /root/.cache/pip to speed up subsequent builds.
# Leverage a bind mount to requirements.txt to avoid having to copy them into
# into this layer.
RUN --mount=type=bind,source=uv.lock,target=uv.lock \
    --mount=type=bind,source=pyproject.toml,target=pyproject.toml \
    uv sync --locked --no-install-project --no-dev


# Copy the source code into the container.
COPY . /app
RUN --mount=type=cache,target=/root/.cache/uv \
    uv sync --locked --no-dev

# Switch to the non-privileged user to run the application.
USER appuser

# Place executables in the environment at the front of the path
ENV PATH="/app/.venv/bin:$PATH"

# Reset the entrypoint, don't invoke `uv`
ENTRYPOINT []

# Use the non-root user to run our application
USER nonroot

# Expose the port that the application listens on.
EXPOSE 8000

# Run the application.
CMD ["uv", "run", "python", "manage.py", "runserver", "0.0.0.0:8000"]