Deploying a FastAPI Project on a Linux Server with Nginx and Systemd Service: A Simplified Guide with Uvicorn and Hot Reload

Introduction

FastAPI is a modern, fast (high-performance) web framework for building APIs with Python based on standard Python type hints. Deploying a FastAPI project on a Linux server can be a bit tricky, but with the help of Nginx and Systemd service, you can easily serve your FastAPI application to the world. In this blog, we will walk you through the process of setting up a FastAPI project on a Linux server using Nginx as the reverse proxy and Uvicorn as the ASGI server for managing the FastAPI application. We will also cover hot reloading of your Python project and how to restart the service when changes are made.

Prerequisites

1. A Linux server with Python 3.6 or higher installed.
2. A working FastAPI project.
3. A domain name and SSL certificate (optional but recommended).

Step 1: Install Required Packages

First, let’s install the required packages for our FastAPI project:

pip install fastapi uvicorn

Step 2: Configure Your FastAPI Application

In your FastAPI project, create a file named main.py and set up your FastAPI application:

from fastapi import FastAPI

app = FastAPI()

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

Step 3: Create a Systemd Service for Your FastAPI Application

Create a new file in /etc/systemd/system/fastapi-project.service with the following content:

[Unit]
Description=FastAPI Project

[Service]
User=www-data
Group=www-data
WorkingDirectory=/path/to/your/fastapi-project
ExecStart=/usr/local/bin/uvicorn main:app --host 0.0.0.0 --port 8000 --reload

[Install]
WantedBy=multi-user.target

Replace /path/to/your/fastapi-project with the actual path to your FastAPI project. The --reload flag is used for hot reloading.

Step 4: Start and Enable the Systemd Service

Start the systemd service:

sudo systemctl start fastapi-project.service

Enable the service to start on boot:

sudo systemctl enable fastapi-project.service

Step 5: Install and Configure Nginx

Install Nginx:

sudo apt-get update
sudo apt-get install nginx

Step 6: Test Your FastAPI Application

Test your FastAPI application by visiting http://your_domain_or_server_ip:8000 in your web browser or using a tool like curl:

curl http://your_domain_or_server_ip:8000

You should see the JSON response {"Hello": "World"} if everything is set up correctly.

Step 7: How to Restart the Service

To restart the FastAPI service, use the following commands:

1. Restart the service:

sudo systemctl restart fastapi-project.service

1. Check the status of the service:

sudo systemctl status fastapi-project.service

With these commands, you can restart the FastAPI service when changes are made to the Python project.

In conclusion, deploying a FastAPI project on a Linux server with Nginx and Systemd service, along with Uvicorn for hot reloading, simplifies the process of serving your application to the world. With this setup, you can easily manage and update your FastAPI application while ensuring a smooth experience for your users.