Run FastAPI with Gunicorn (as a service) through Nginx

gunicorn_config.py

from multiprocessing import cpu_count

import subprocess
import atexit


bind = "127.0.0.1:8000"

workers = 2 # cpu_count() * 2 + 1
worker_class = "sync"
worker_connections = 1024


# NOTE: next lines are optional
# used to run background script
background_process = subprocess.Popen(["python", "background.py"])

def shutdown_background_process() -> None:
    background_process.terminate()
    background_process.wait()

atexit.register(shutdown_background_process)

guvicorn.service

[Unit]
Description=Project Gunicorn
After=network.target

[Service]
Group=www-data
WorkingDirectory=/project/directory
Environment="PATH=/project/directory/.venv/bin"
ExecStart=/project/directory/.venv/bin/gunicorn -c gunicorn_config.py -k uvicorn.workers.UvicornWorker --bind unix:/tmp/project.sock src:web_app

[Install]
WantedBy=multi-user.target

nginx_example.conf

upstream app_server {
    server unix:/tmp/project.sock fail_timeout=0;
}

server {
    listen 80;
    server_name project.example.com;

    return 301 https://$host$request_uri;
}

server {
    listen 443 ssl;
    client_max_body_size 4G;

    server_name project.example.com;

    ssl_certificate /etc/ssl/self.pem;
    ssl_certificate_key /etc/ssl/self.key;

    keepalive_timeout 5;

    location / {
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header Host $http_host;
        proxy_redirect off;
        proxy_pass http://app_server;
    }

    error_log /var/log/nginx/project.example.com-error.log;
}

note.txt

- nginx.conf's `user` value must be set to `www-data` (set by default)