92230ba679
<!-- Thank you for contributing to uv! To help us out with reviewing, please consider the following: - Does this pull request include a summary of the change? (See below.) - Does this pull request include a descriptive title? - Does this pull request include references to any relevant issues? --> ## Summary Fix suggestion for uv when used with FastAPI and Docker. ## Test Plan The Dockerfile sets `/app` as workdir, later the CMD command points again to `app/main.py` instead of only `main.py`, causing the following error: ``` Path does not exist app/main.py ```
3.2 KiB
| title | description |
|---|---|
| Using uv with FastAPI | A guide to using uv with FastAPI to manage Python dependencies, run applications, and deploy with Docker. |
Using uv with FastAPI
FastAPI is a modern, high-performance Python web framework. You can use uv to manage your FastAPI project, including installing dependencies, managing environments, running FastAPI applications, and more.
!!! note
You can view the source code for this guide in the [uv-fastapi-example](https://github.com/astral-sh/uv-fastapi-example) repository.
Migrating an existing FastAPI project
As an example, consider the sample application defined in the FastAPI documentation, structured as follows:
project
└── app
├── __init__.py
├── main.py
├── dependencies.py
├── routers
│ ├── __init__.py
│ ├── items.py
│ └── users.py
└── internal
├── __init__.py
└── admin.py
To use uv with this application, inside the project directory run:
$ uv init --app
This creates a project with an application layout
and a pyproject.toml file.
Then, add a dependency on FastAPI:
$ uv add fastapi --extra standard
You should now have the following structure:
project
├── pyproject.toml
└── app
├── __init__.py
├── main.py
├── dependencies.py
├── routers
│ ├── __init__.py
│ ├── items.py
│ └── users.py
└── internal
├── __init__.py
└── admin.py
And the contents of the pyproject.toml file should look something like this:
[project]
name = "uv-fastapi-example"
version = "0.1.0"
description = "FastAPI project"
readme = "README.md"
requires-python = ">=3.12"
dependencies = [
"fastapi[standard]",
]
From there, you can run the FastAPI application with:
$ uv run fastapi dev
uv run will automatically resolve and lock the project dependencies (i.e., create a uv.lock
alongside the pyproject.toml), create a virtual environment, and run the command in that
environment.
Test the app by opening http://127.0.0.1:8000/?token=jessica in a web browser.
Deployment
To deploy the FastAPI application with Docker, you can use the following Dockerfile:
FROM python:3.12-slim
# Install uv.
COPY --from=ghcr.io/astral-sh/uv:latest /uv /uvx /bin/
# Copy the application into the container.
COPY . /app
# Install the application dependencies.
WORKDIR /app
RUN uv sync --frozen --no-cache
# Run the application.
CMD ["/app/.venv/bin/fastapi", "run", "main.py", "--port", "80", "--host", "0.0.0.0"]
Build the Docker image with:
$ docker build -t fastapi-app .
Run the Docker container locally with:
$ docker run -p 8000:80 fastapi-app
Navigate to http://127.0.0.1:8000/?token=jessica in your browser to verify that the app is running correctly.
!!! tip
For more on using uv with Docker, see the [Docker guide](./docker.md).