Setting up a Docker environment for a FastAPI application with uv | Containerizing with uv

In this tutorial, we will go through the steps to set up uv with a FastAPI application in a Docker container. uv is a high-performance, event-driven web server for Unix and Python. FastAPI is a modern web framework for building APIs with Python. By combining the two, we can create powerful and efficient web applications.

To get started, you will need the following tools installed on your system:

1. Docker
2. Python
3. FastAPI
4. uv

Here are the steps to set up uv with a FastAPI application in a Docker container:

Step 1: Create a FastAPI application

First, create a new directory for your FastAPI application:

$ mkdir fastapi-app
$ cd fastapi-app

Next, install FastAPI and uv using pip:

$ pip install fastapi uvicorn

Now, create a file named main.py in the fastapi-app directory and add the following code:

from fastapi import FastAPI

app = FastAPI()

@app.get('/')
def read_root():
    return {"Hello": "World"}

This code creates a simple FastAPI application with a single endpoint that returns a JSON response with the message "Hello World".

Step 2: Create a Dockerfile

Next, create a Dockerfile in the fastapi-app directory to build a Docker image for your application:

FROM python:3.9

WORKDIR /app

COPY requirements.txt .

RUN pip install -r requirements.txt

COPY . .

CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"]

This Dockerfile specifies a Python 3.9 base image, sets the working directory to /app, copies the requirements.txt file, installs the dependencies, copies the FastAPI application code, and runs uvicorn to start the server on port 8000.

Step 3: Create a requirements.txt file

Create a file named requirements.txt in the fastapi-app directory and add the following dependencies:

fastapi
uvicorn

This file lists the Python packages required for your FastAPI application.

Step 4: Build the Docker image

Now, build the Docker image for your FastAPI application by running the following command in the fastapi-app directory:

$ docker build -t fastapi-app .

This command will build a Docker image with the tag fastapi-app.

Step 5: Run the Docker container

Finally, run the Docker container for your FastAPI application using the following command:

$ docker run -d -p 8000:8000 fastapi-app

This command will start the Docker container in detached mode, mapping port 8000 on the host to port 8000 in the container.

That’s it! You now have a FastAPI application running in a Docker container with uv as the web server. You can access your application by visiting http://localhost:8000 in your web browser.

In summary, uv is a powerful web server that can be easily integrated with FastAPI applications in Docker containers. By following the steps outlined in this tutorial, you can create efficient and scalable web applications with ease.